fix(rpm): explicitly Provides user(name) to satisfy systemd unit Requires

Diagnosing the persistent "Nothing to do" on v0.1.10 surfaced that
removing %attr(,,name) from %files wasn't enough. systemd-rpm-macros
ships its own rpm dep generator (/usr/lib/rpm/systemd.req) that parses
User=/Group= directives from every .service file the package ships
and emits Requires: user(NAME)/group(NAME) accordingly.

Rpmbuild log from v0.1.10 shows these Requires are still emitted even
after the %attr removal. Meanwhile the sysusers provides-generator
emits group(NAME) in both unversioned and versioned forms, but only
a versioned user(NAME) = <base64> when the u-line has GECOS/home/shell
fields. The asymmetry leaves Requires: user(NAME) unresolvable.

Add explicit Provides: user(NAME) back to both specs, with a comment
documenting the actual cause (systemd unit parsing, not file attrs)
so the next person touching these specs doesn't repeat the mistake.

Why monsoon didn't hit this: it creates its user in %pre via
groupadd/useradd (not sysusers.d), so no Provides are generated at
all — matching the Requires: user(monsoon) by luck of the rpm solver
treating unknown symbols as soft-fails for that path. Ours went through
the sysusers Provides code path and hit the asymmetry instead.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-prerelease.yml

@@ -1,342 +0,0 @@
-name: build-prerelease
-
-# Manually-dispatched workflow that builds CUDA-flavoured neuron binaries
-# (and a single cortex binary), packages each as a Fedora RPM, signs
-# them, and publishes to the `unstable` channel at rpm.lair.cafe.
-#
-# Trigger from the Gitea UI: Actions → build-prerelease → Run workflow.
-# Optionally provide a `ref` to build from a non-default branch.
-#
-# The published packages are versioned as e.g.
-#   helexa-neuron-blackwell-0.1.16-0.1.20260518T140530.gitabcdef0.fc43.x86_64
-#                                       ^^^^^^^^^^^^^^^^^^ ^^^^^^^^
-#                                       commit time (s)    commit sha
-# so they sort BELOW the eventual 0.1.16-1 stable release, and so two
-# commits on the same day are still strictly ordered by their commit
-# timestamps (rather than by RPM-vercmp's alpha-vs-digit precedence
-# on the SHA fragment).
-
-on:
-  # Auto-build on every push to main so the unstable channel tracks
-  # head without a manual dispatch step.
-  push:
-    branches: [main]
-  # Manual dispatch still available to build from a non-main ref.
-  workflow_dispatch:
-    inputs:
-      ref:
-        description: "Git ref to build (branch / tag / commit). Defaults to the workflow's branch."
-        required: false
-        default: ""
-
-concurrency:
-  # Share the group with ci.yml so the two workflows can't run
-  # concurrently on the same `rust` runner (act reuses the workspace
-  # cache and races destroy each other's build files mid-compile).
-  # cancel-in-progress=false → workflows queue; if a newer push lands,
-  # the older run is still picked up by ci.yml's own ref-keyed
-  # concurrency (same group, queued).
-  group: cortex-runner-pool-${{ github.ref }}
-  cancel-in-progress: false
-
-env:
-  CARGO_INCREMENTAL: "0"
-
-jobs:
-  prepare:
-    name: Resolve version stamps
-    runs-on: rust
-    outputs:
-      version: ${{ steps.info.outputs.version }}
-      release: ${{ steps.info.outputs.release }}
-      short_sha: ${{ steps.info.outputs.short_sha }}
-      commit_timestamp: ${{ steps.info.outputs.commit_timestamp }}
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-          fetch-depth: 0
-
-      - id: info
-        run: |
-          set -eux
-          VERSION=$(awk -F\" '/^version[[:space:]]*=/ { print $2; exit }' Cargo.toml)
-          SHORT_SHA=$(git rev-parse --short=7 HEAD)
-          # Second-precise commit timestamp gives the release stamp a
-          # strictly monotonic numeric prefix. The earlier %Y%m%d-only
-          # form let same-day builds be ordered by RPM's rpmvercmp
-          # rules over the SHA, which is non-chronological — e.g.
-          # "git602e8e1" sorts newer than "gitf9f5fa4" purely because
-          # rpmvercmp ranks digit-prefixed segments above alpha ones.
-          # The SHA stays only as a debug identifier; sort order is
-          # decided entirely by the timestamp.
-          COMMIT_TIMESTAMP=$(git log -1 --format=%cd --date=format:%Y%m%d%H%M%S HEAD)
-          RELEASE="0.1.${COMMIT_TIMESTAMP}.git${SHORT_SHA}"
-          echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
-          echo "release=${RELEASE}" >> "$GITHUB_OUTPUT"
-          echo "short_sha=${SHORT_SHA}" >> "$GITHUB_OUTPUT"
-          echo "commit_timestamp=${COMMIT_TIMESTAMP}" >> "$GITHUB_OUTPUT"
-
-  build-cortex:
-    name: Build cortex binary
-    needs: prepare
-    # runner-rust image already provides rust/cargo/clippy/rustfmt via
-    # dnf — no rustup install step needed.
-    runs-on: rust
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-
-      - name: Build cortex (release)
-        run: cargo build --release -p cortex-cli
-
-      - name: Stage binary
-        run: |
-          mkdir --parents artifacts
-          cp target/release/cortex artifacts/cortex
-          ./artifacts/cortex --version || true
-
-      - uses: actions/upload-artifact@v3
-        with:
-          name: cortex-fc43
-          path: artifacts/cortex
-          retention-days: 1
-
-  build-neuron:
-    name: Build neuron-${{ matrix.flavour }}
-    needs: prepare
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - flavour: ampere
-            compute_cap: "86"
-            runner: cuda-13.0
-            cuda_home: /usr/local/cuda-13.0
-            build_jobs: 8
-            nvcc_threads: 4
-            cargo_features: "cuda cudnn flash-attn"
-          - flavour: ada
-            compute_cap: "89"
-            runner: cuda-13.0
-            cuda_home: /usr/local/cuda-13.0
-            build_jobs: 8
-            nvcc_threads: 4
-            cargo_features: "cuda cudnn flash-attn"
-          - flavour: blackwell
-            compute_cap: "120"
-            runner: cuda-13.0
-            cuda_home: /usr/local/cuda-13.0
-            build_jobs: 8
-            nvcc_threads: 4
-            cargo_features: "cuda cudnn flash-attn"
-    runs-on: ${{ matrix.runner }}
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-
-      - name: Build neuron with CUDA (${{ matrix.flavour }})
-        run: |
-          set -eux
-          export PATH="${{ matrix.cuda_home }}/bin:${PATH}"
-          export LD_LIBRARY_PATH="${{ matrix.cuda_home }}/targets/x86_64-linux/lib:${{ matrix.cuda_home }}/lib64:${LD_LIBRARY_PATH:-}"
-          export LIBRARY_PATH="${{ matrix.cuda_home }}/targets/x86_64-linux/lib:${{ matrix.cuda_home }}/lib64:${LIBRARY_PATH:-}"
-          cargo build --release -p neuron --features "${{ matrix.cargo_features }}"
-        env:
-          CUDA_COMPUTE_CAP: ${{ matrix.compute_cap }}
-          CARGO_BUILD_JOBS: ${{ matrix.build_jobs }}
-          NVCC_THREADS: ${{ matrix.nvcc_threads }}
-
-      - name: Stage binary
-        run: |
-          mkdir --parents artifacts
-          cp target/release/neuron artifacts/neuron-${{ matrix.flavour }}
-          file "artifacts/neuron-${{ matrix.flavour }}"
-
-      - uses: actions/upload-artifact@v3
-        with:
-          name: neuron-${{ matrix.flavour }}-fc43
-          path: artifacts/neuron-${{ matrix.flavour }}
-          retention-days: 1
-
-  package-cortex:
-    name: Package cortex RPM
-    needs: [prepare, build-cortex]
-    runs-on: rpm
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-
-      - uses: actions/download-artifact@v3
-        with:
-          name: cortex-fc43
-          path: artifacts/
-
-      - name: Build RPM
-        run: |
-          set -eux
-          rm -f ~/.rpmmacros
-          rpmdev-setuptree
-          cp artifacts/cortex ~/rpmbuild/SOURCES/
-          cp data/cortex.service ~/rpmbuild/SOURCES/
-          cp data/cortex-sysusers.conf ~/rpmbuild/SOURCES/
-          cp data/cortex-firewalld.xml ~/rpmbuild/SOURCES/
-          cp cortex.example.toml ~/rpmbuild/SOURCES/
-          cp models.example.toml ~/rpmbuild/SOURCES/
-          cp LICENSE ~/rpmbuild/SOURCES/
-          rpmbuild -bb rpm/cortex-prerelease.spec \
-            --define "cortex_version ${{ needs.prepare.outputs.version }}" \
-            --define "cortex_prerelease ${{ needs.prepare.outputs.release }}" \
-            --undefine dist \
-            --define "dist .fc43"
-
-      - uses: actions/upload-artifact@v3
-        with:
-          name: rpm-cortex-fc43
-          path: ~/rpmbuild/RPMS/x86_64/*.rpm
-          retention-days: 7
-
-  package-neuron:
-    name: Package helexa-neuron-${{ matrix.flavour }} RPM
-    needs: [prepare, build-neuron]
-    runs-on: rpm
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - flavour: ampere
-          - flavour: ada
-          - flavour: blackwell
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-
-      - uses: actions/download-artifact@v3
-        with:
-          name: neuron-${{ matrix.flavour }}-fc43
-          path: artifacts/
-
-      - name: Build RPM
-        run: |
-          set -eux
-          rm -f ~/.rpmmacros
-          rpmdev-setuptree
-          cp artifacts/neuron-${{ matrix.flavour }} ~/rpmbuild/SOURCES/
-          cp data/neuron.service ~/rpmbuild/SOURCES/
-          cp data/neuron-sysusers.conf ~/rpmbuild/SOURCES/
-          cp data/neuron-firewalld.xml ~/rpmbuild/SOURCES/
-          cp neuron.example.toml ~/rpmbuild/SOURCES/
-          cp LICENSE ~/rpmbuild/SOURCES/
-          rpmbuild -bb rpm/helexa-neuron-prerelease.spec \
-            --define "neuron_version ${{ needs.prepare.outputs.version }}" \
-            --define "neuron_flavour ${{ matrix.flavour }}" \
-            --define "neuron_prerelease ${{ needs.prepare.outputs.release }}" \
-            --undefine dist \
-            --define "dist .fc43"
-
-      - uses: actions/upload-artifact@v3
-        with:
-          name: rpm-neuron-${{ matrix.flavour }}-fc43
-          path: ~/rpmbuild/RPMS/x86_64/*.rpm
-          retention-days: 7
-
-  publish:
-    name: Publish to rpm.lair.cafe (unstable)
-    needs: [package-cortex, package-neuron]
-    runs-on: rpm
-    concurrency:
-      group: rpm-publish
-      cancel-in-progress: false
-    env:
-      RPM_REPO_HOST: oolon.kosherinata.internal
-      FEDORA_VERSION: "43"
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-
-      - name: Download all built RPMs
-        uses: actions/download-artifact@v3
-        with:
-          path: rpms/
-          pattern: rpm-*-fc43
-
-      - name: Flatten RPM artifacts
-        run: |
-          set -eux
-          find rpms/ -name '*.rpm' -exec mv --target-directory=rpms/ {} +
-          find rpms/ -mindepth 1 -type d -empty -delete
-          ls -la rpms/
-
-      - name: Check for sequoia-sq
-        run: |
-          if ! command -v sq &> /dev/null; then
-            echo "ERROR: sequoia-sq is not installed. Install with: sudo dnf install sequoia-sq"
-            exit 1
-          fi
-
-      - name: Import signing key
-        env:
-          # Pass secrets via env so values stay out of the rendered shell
-          # script (which Gitea includes in step logs). Template
-          # expansion of ${{ secrets.X }} inside `run:` writes the literal
-          # value into the script and depends on Gitea's log masker to
-          # scrub it — fragile for multi-line keys.
-          RPM_SIGNING_KEY: ${{ secrets.RPM_SIGNING_KEY }}
-          RPM_SIGNING_KEY_ID: ${{ secrets.RPM_SIGNING_KEY_ID }}
-        run: |
-          echo "$RPM_SIGNING_KEY" | gpg --batch --import
-          fpr=$(gpg --batch --with-colons --list-keys "$RPM_SIGNING_KEY_ID" | awk -F: '/^fpr:/ { print $10; exit }')
-          echo "${fpr}:6:" | gpg --batch --import-ownertrust
-          sed "s/@GPG_NAME@/$RPM_SIGNING_KEY_ID/" rpm/rpmmacros > ~/.rpmmacros
-
-      - name: Sign RPMs
-        run: |
-          set -eux
-          for rpm in rpms/*.rpm; do
-            echo "signing ${rpm}..."
-            rpm --addsign "${rpm}"
-          done
-
-      - name: Set up SSH for rsync
-        run: |
-          install --directory --mode 700 ~/.ssh
-          echo "${RSYNC_SSH_KEY}" | install --mode 600 /dev/stdin ~/.ssh/id_ed25519
-        env:
-          RSYNC_SSH_KEY: ${{ secrets.RSYNC_SSH_KEY }}
-
-      - name: Test SSH connectivity
-        run: |
-          ssh -o StrictHostKeyChecking=accept-new "gitea_ci@${RPM_REPO_HOST}" exit
-
-      - name: Ensure unstable repo directory exists
-        run: |
-          ssh "gitea_ci@${RPM_REPO_HOST}" \
-            "mkdir --parents /var/www/rpm/fedora/${FEDORA_VERSION}/x86_64/unstable"
-
-      - name: Sync RPMs to unstable repo
-        run: |
-          rsync \
-            --archive \
-            --verbose \
-            --chmod D755,F644 \
-            rpms/*.rpm \
-            "gitea_ci@${RPM_REPO_HOST}:/var/www/rpm/fedora/${FEDORA_VERSION}/x86_64/unstable/"
-
-      - name: Update unstable repo metadata
-        run: |
-          ssh "gitea_ci@${RPM_REPO_HOST}" \
-            "cd /var/www/rpm/fedora/${FEDORA_VERSION}/x86_64/unstable && createrepo_c --update ."
-
-      - name: Generate packages.json manifest
-        run: |
-          scp script/generate-packages-json.py "gitea_ci@${RPM_REPO_HOST}:/tmp/"
-          ssh "gitea_ci@${RPM_REPO_HOST}" \
-            "python3 /tmp/generate-packages-json.py \
-              --repodata-dir /var/www/rpm/fedora/${FEDORA_VERSION}/x86_64/unstable/repodata \
-              --output /var/www/rpm/fedora/${FEDORA_VERSION}/x86_64/unstable/packages.json \
-              --base-url https://rpm.lair.cafe/fedora/${FEDORA_VERSION}/x86_64/unstable"

.gitea/workflows/ci.yml

@@ -7,16 +7,6 @@ on:
   pull_request:
     branches: [main]
 
-# Share a concurrency group with build-prerelease.yml so the two
-# workflows don't race on the same `rust` runner workspace (act's
-# /root/.cache/act/<hash>/hostexecutor/ is shared across concurrent
-# jobs and one job's checkout step nukes another's in-flight build
-# files). cancel-in-progress=false → they queue; same-ref pushes
-# coalesce per workflow via cancel-in-progress on each.
-concurrency:
-  group: cortex-runner-pool-${{ github.ref }}
-  cancel-in-progress: false
-
 env:
   CARGO_INCREMENTAL: "0"
   RUSTC_WRAPPER: sccache
@@ -26,42 +16,53 @@ env:
   SCCACHE_S3_USE_SSL: "false"
   AWS_ACCESS_KEY_ID: ${{ secrets.SCCACHE_S3_ACCESS_KEY }}
   AWS_SECRET_ACCESS_KEY: ${{ secrets.SCCACHE_S3_SECRET_KEY }}
-  # fmt, clippy, and test all run in parallel on the same `rust` runner
-  # and would otherwise share /root/.cache/act/<hash>/hostexecutor/target/,
-  # racing each other's cargo temp files (.tmpXXXXXX) and failing builds
-  # mid-compile. Give each job its own target directory so the invocations
-  # don't collide. sccache still backs the actual rustc cache, so the
-  # rebuild penalty is small.
-  CARGO_TARGET_DIR: target-${{ github.job }}
 
 jobs:
-  fmt:
-    name: Format
-    runs-on: rust
+  check:
+    name: Format, lint, build, test
+    runs-on: fedora
     steps:
       - uses: actions/checkout@v4
-      - run: cargo fmt --check --all
 
-  clippy:
-    name: Clippy
-    runs-on: rust
-    steps:
-      - uses: actions/checkout@v4
-      - run: cargo clippy --workspace -- -D warnings
-      - run: sccache --show-stats
+      - name: Cache cargo registry and target
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-
 
-  test:
-    name: Test
-    runs-on: rust
-    steps:
-      - uses: actions/checkout@v4
-      - run: cargo test --workspace
-      - run: sccache --show-stats
+      - name: Ensure sccache with S3 support
+        env:
+          RUSTC_WRAPPER: ""
+        run: |
+          if sccache --version 2>/dev/null && sccache --show-stats 2>/dev/null; then
+            echo "sccache with S3 support already installed"
+          else
+            cargo install sccache --features s3 --locked
+          fi
+
+      - name: Check formatting
+        run: cargo fmt --check --all
+
+      - name: Clippy
+        run: cargo clippy --workspace -- -D warnings
+
+      - name: Test
+        run: cargo test --workspace
+
+      - name: Show sccache stats
+        run: sccache --show-stats
 
   srpm-cortex:
     name: Build cortex SRPM
-    runs-on: rpm
-    needs: [fmt, clippy, test]
+    runs-on: fedora
+    needs: check
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
       - uses: actions/checkout@v4
@@ -120,8 +121,8 @@ jobs:
 
   srpm-neuron:
     name: Build neuron SRPM
-    runs-on: rpm
-    needs: [fmt, clippy, test]
+    runs-on: fedora
+    needs: check
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
       - uses: actions/checkout@v4
@@ -138,37 +139,37 @@ jobs:
         run: |
           VERSION="${{ steps.version.outputs.VERSION }}"
           sed -i '/\[workspace\.package\]/,/\[/{ s/^version = ".*"/version = "'"${VERSION}"'"/ }' Cargo.toml
-          sed -i "s/^Version:.*/Version:        ${VERSION}/" helexa-neuron.spec
+          sed -i "s/^Version:.*/Version:        ${VERSION}/" neuron.spec
 
       - name: Generate changelog entry
         uses: https://git.lair.cafe/actions/rpm-changelog@v1
         with:
-          spec: helexa-neuron.spec
+          spec: neuron.spec
           version: ${{ steps.version.outputs.VERSION }}
 
       - name: Generate source tarball
         run: |
           set -ex
           VERSION="${{ steps.version.outputs.VERSION }}"
-          tar czf /tmp/helexa-neuron-${VERSION}.tar.gz \
-            --transform "s,^\.,helexa-neuron-${VERSION}," \
+          tar czf /tmp/neuron-${VERSION}.tar.gz \
+            --transform "s,^\.,neuron-${VERSION}," \
             --exclude='./target' \
             --exclude='./.git' \
             --exclude='*.tar.gz' \
             --exclude='*.src.rpm' \
             .
-          mv /tmp/helexa-neuron-${VERSION}.tar.gz .
+          mv /tmp/neuron-${VERSION}.tar.gz .
 
       - name: Vendor Rust dependencies
         run: |
           VERSION="${{ steps.version.outputs.VERSION }}"
           cargo vendor vendor/
-          tar czf helexa-neuron-${VERSION}-vendor.tar.gz vendor/
+          tar czf neuron-${VERSION}-vendor.tar.gz vendor/
           rm -rf vendor/
 
       - name: Build SRPM
         run: |
-          rpmbuild -bs helexa-neuron.spec \
+          rpmbuild -bs neuron.spec \
             --define "_sourcedir $(pwd)" \
             --define "_srcrpmdir $(pwd)"
 
@@ -180,7 +181,7 @@ jobs:
 
   copr-cortex:
     name: Publish cortex to COPR
-    runs-on: fedora-43
+    runs-on: fedora
     needs: srpm-cortex
     steps:
       - name: Download SRPM
@@ -191,13 +192,13 @@ jobs:
       - name: Publish to COPR
         uses: https://git.lair.cafe/actions/copr-publish@v1
         with:
-          project: helexa/helexa
+          project: helexa/cortex
           srpm: "*.src.rpm"
           copr-config: ${{ secrets.COPR_CONFIG }}
 
   copr-neuron:
     name: Publish neuron to COPR
-    runs-on: fedora-43
+    runs-on: fedora
     needs: srpm-neuron
     steps:
       - name: Download SRPM
@@ -208,53 +209,31 @@ jobs:
       - name: Publish to COPR
         uses: https://git.lair.cafe/actions/copr-publish@v1
         with:
-          project: helexa/helexa
+          project: helexa/neuron
           srpm: "*.src.rpm"
           copr-config: ${{ secrets.COPR_CONFIG }}
 
   bump-version:
     name: Bump version in source
-    runs-on: rust
+    runs-on: fedora
     needs: [copr-cortex, copr-neuron]
     steps:
       - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
 
-      - name: Determine version
-        id: version
-        run: echo "VERSION=${GITHUB_REF#refs/tags/v}" >> "$GITHUB_OUTPUT"
-
-      - name: Stamp version
-        run: |
-          VERSION="${{ steps.version.outputs.VERSION }}"
-          sed -i '/\[workspace\.package\]/,/\[/{ s/^version = ".*"/version = "'"${VERSION}"'"/ }' Cargo.toml
-          sed -i "s/^Version:.*/Version:        ${VERSION}/" cortex.spec
-          sed -i "s/^Version:.*/Version:        ${VERSION}/" helexa-neuron.spec
-          cargo check --workspace 2>/dev/null || true
-
-      - name: Generate cortex changelog entry
-        uses: https://git.lair.cafe/actions/rpm-changelog@v1
-        with:
-          spec: cortex.spec
-          version: ${{ steps.version.outputs.VERSION }}
-
-      - name: Generate helexa-neuron changelog entry
-        uses: https://git.lair.cafe/actions/rpm-changelog@v1
-        with:
-          spec: helexa-neuron.spec
-          version: ${{ steps.version.outputs.VERSION }}
-
-      - name: Commit and push
+      - name: Stamp version and push
         env:
           GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
-          VERSION="${{ steps.version.outputs.VERSION }}"
+          VERSION="${GITHUB_REF#refs/tags/v}"
+          sed -i '/\[workspace\.package\]/,/\[/{ s/^version = ".*"/version = "'"${VERSION}"'"/ }' Cargo.toml
+          sed -i "s/^Version:.*/Version:        ${VERSION}/" cortex.spec
+          sed -i "s/^Version:.*/Version:        ${VERSION}/" neuron.spec
+          cargo check --workspace 2>/dev/null || true
           git config user.name "Gitea Actions"
           git config user.email "actions@git.lair.cafe"
-          git add Cargo.toml Cargo.lock cortex.spec helexa-neuron.spec
+          git add Cargo.toml Cargo.lock cortex.spec neuron.spec
           if git diff --cached --quiet; then
-            echo "Nothing to commit for ${VERSION}"
+            echo "Version already at ${VERSION}"
           else
             git commit -m "chore: bump version to ${VERSION}"
             git remote set-url origin "https://gitea-actions:${GITEA_TOKEN}@git.lair.cafe/helexa/cortex.git"

.gitignore

@@ -4,6 +4,4 @@
 .idea/
 .vscode/
 cortex.toml
-models.toml
 doc/plan/*
-/target-cuda/

CLAUDE.md

@@ -125,8 +125,7 @@ automatically. Clippy warnings must be resolved, not suppressed with
   - One or more GPU nodes running mistral.rs on port 8080
   - Optionally a metrics-only node (no GPU) for Prometheus/Grafana
 - Each node runs `mistralrs serve` on port 8080
-- Gateway listens on port 31313 (API) and 31314 (metrics)
-- neuron listens on port 13131 on each GPU host
+- Gateway listens on port 8000 (API) and 9100 (metrics)
 - TLS terminated at gateway or via nginx; internal traffic is plaintext over WireGuard
 
 ## Conventions
@@ -381,7 +380,7 @@ processes (one process per loaded model, each on its own port).
 
 ## neuron API
 
-neuron exposes an HTTP API on port 13131 that cortex polls and calls.
+neuron exposes an HTTP API on port 9090 that cortex polls and calls.
 
 ```
 GET  /discovery
@@ -425,8 +424,8 @@ endpoint. cortex.toml shrinks to:
 
 ```toml
 [gateway]
-listen = "0.0.0.0:31313"
-metrics_listen = "0.0.0.0:31314"
+listen = "0.0.0.0:8000"
+metrics_listen = "0.0.0.0:9100"
 
 [eviction]
 strategy = "lru"
@@ -434,15 +433,15 @@ defrag_after_cycles = 50
 
 [[neurons]]
 name = "beast"
-endpoint = "http://beast.hanzalova.internal:13131"
+endpoint = "http://beast.hanzalova.internal:9090"
 
 [[neurons]]
 name = "benjy"
-endpoint = "http://benjy.hanzalova.internal:13131"
+endpoint = "http://benjy.kosherinata.internal:9090"
 
 [[neurons]]
 name = "quadbrat"
-endpoint = "http://quadbrat.hanzalova.internal:13131"
+endpoint = "http://quadbrat.hanzalova.internal:9090"
 ```
 
 On startup and periodically, cortex calls `GET /discovery` and
@@ -522,7 +521,7 @@ cortex/
 │   │       └── metrics.rs      # prometheus exporter (unchanged)
 │   ├── neuron/                 # node plane (replaces cortex-agent)
 │   │   └── src/
-│   │       ├── main.rs         # binary entrypoint, axum server on :13131
+│   │       ├── main.rs         # binary entrypoint, axum server on :9090
 │   │       ├── discovery.rs    # nvidia-smi, device enumeration
 │   │       ├── health.rs       # runtime GPU polling
 │   │       ├── api.rs          # HTTP handlers for /discovery, /models, etc.
@@ -596,65 +595,70 @@ placement matching can be added incrementally.
 Completed. Both packages have RPM specs, systemd units, and example configs.
 CI builds parallel SRPMs on tag push and publishes to separate COPR repos.
 
-- `cortex.spec` — installs the `cortex` binary. Package name keeps the
-  short `cortex` because no Fedora package collides with it.
-- `helexa-neuron.spec` — installs the `neuron` binary under package name
-  `helexa-neuron`. Renamed from bare `neuron` to avoid collision with
-  Fedora's NEURON neural-simulation package
-  (https://src.fedoraproject.org/rpms/neuron); binary, systemd unit,
-  system user, and config dir all stay named `neuron` since those are
-  project-local contexts.
+- `cortex.spec` → `helexa/cortex` COPR: binary, systemd unit, config files
+- `neuron.spec` → `helexa/neuron` COPR: binary, systemd unit, config
 - `data/cortex.service`, `data/neuron.service` — systemd units
 - `cortex.example.toml`, `neuron.example.toml`, `models.example.toml`
-- CI: parallel `srpm-cortex` + `srpm-neuron` jobs, then parallel COPR
-  publish to a single project `helexa/helexa` hosting both packages.
+- CI: parallel `srpm-cortex` + `srpm-neuron` jobs, then parallel COPR publish
 
 Install:
 ```sh
-dnf copr enable helexa/helexa
-dnf install cortex                # gateway host
-dnf install helexa-neuron         # GPU nodes
+dnf copr enable helexa/cortex && dnf install cortex    # gateway host
+dnf copr enable helexa/neuron && dnf install neuron    # GPU nodes
 ```
 
-## 2026-05-18 addendum: candle-native pivot
+### Phase 11: llama.cpp harness stub
 
-Phases 11 (llama.cpp harness) and 12 (mistral.rs COPR) below are
-**superseded**. The project no longer treats mistral.rs or llama.cpp as
-dependencies — both are conceptually out of scope. neuron becomes a
-candle-native inference daemon, with `Harness` retained as an
-internal seam for adding future engines (vision/audio/diffusion) but
-its only implementation being in-process candle.
+**Goal:** Prove the harness abstraction works with a second engine.
 
-The full staged plan for this pivot lives at
-`~/.claude/plans/create-a-more-aggressive-calm-naur.md`. Summary:
+**Steps:**
+1. `crates/neuron/src/harness/llamacpp.rs` — implement the `Harness`
+   trait for llama.cpp's `llama-server`.
+   - `start()` — launch `llama-server` with the correct model path,
+     `--port`, `--n-gpu-layers`, `--tensor-split` args. Track the
+     child process.
+   - `stop()` — send SIGTERM to the child process.
+   - `list_models()` — llama-server serves one model per process, so
+     return a single-element list.
+   - `load_model()` — start a new llama-server process for this model.
+   - `unload_model()` — stop the process.
+   - `inference_endpoint()` — return `http://localhost:{assigned_port}`.
+2. Port allocation: neuron assigns ports from a range (e.g. 8100-8199)
+   to llama-server instances.
+3. Register in `HarnessRegistry` when configured:
+   ```toml
+   [[harnesses]]
+   name = "llamacpp"
+   binary = "/usr/local/bin/llama-server"
+   port_range = [8100, 8199]
+   ```
+4. Tests: mock llama-server (simple HTTP server returning canned
+   responses), test load/unload/endpoint lifecycle.
 
-- **Stage 1 (this commit):** delete `mistralrs.rs` and `llamacpp.rs`,
-  scaffold inert `CandleHarness`, drop `endpoint`/`systemd_unit` from
-  `HarnessConfig`, default no-op `start`/`stop` on the `Harness` trait.
-- **Stages 2–4:** wire up candle model load/unload (quantized Qwen3
-  first), add OpenAI-compatible inference endpoint in neuron, then SSE
-  streaming.
-- **Stages 5–6:** load-on-activation (default models in config) and
-  unload-on-deactivation (graceful shutdown).
-- **Stages 7–8:** multi-GPU tensor parallelism and broader model/quant
-  coverage.
+**Done when:** A model with `harness = "llamacpp"` in `models.toml` can
+be loaded and served through cortex. Tests pass with mock llama-server.
 
-Sections of this document that describe mistral.rs HTTP behaviour
-("mistral.rs API gotchas") are retained as historical context for
-Phases 1–10 — they document what was true while the project depended
-on mistral.rs. They do not describe current behaviour.
+### Phase 12 (lower priority): mistral.rs COPR packaging
 
----
+**Goal:** Fedora RPMs for mistral.rs built against specific CUDA versions.
 
-### Phase 11 (superseded): llama.cpp harness stub
+**Steps:**
+1. `mistralrs-cuda.spec` — RPM spec that clones a pinned mistral.rs git
+   tag, builds with `--features cuda`, links against the system CUDA
+   toolkit. Produces `mistralrs-cuda13-server` (CUDA 13.x / sm_120) and
+   `mistralrs-cuda12-server` (CUDA 12.x / sm_89). Install binary to
+   `/usr/local/bin/mistralrs`.
+2. COPR build config: enable the NVIDIA CUDA repo as a build dependency.
+   Pin the CUDA toolkit version in `BuildRequires`.
+3. Gitea Actions or manual workflow: bump the mistral.rs tag in the spec,
+   trigger COPR rebuild.
+4. neuron's mistralrs harness config references which binary/package
+   provides the mistral.rs binary. neuron could warn at startup if the
+   installed mistral.rs CUDA version doesn't match the discovered driver.
 
-~~Originally planned as a second engine to prove the harness
-abstraction.~~ Replaced by the candle harness work in the 2026-05-18
-addendum above. llama.cpp's any-model/any-hardware breadth is no
-longer in scope for helexa.
+**Done when:** `dnf install mistralrs-cuda13-server` on beast provides a
+working `mistralrs` binary built for Blackwell GPUs. `dnf install
+mistralrs-cuda12-server` on benjy provides one built for Ada GPUs.
 
-### Phase 12 (superseded): mistral.rs COPR packaging
-
-~~Originally planned to ship CUDA-versioned mistral.rs RPMs.~~ Replaced
-by the candle harness work in the 2026-05-18 addendum above. With
-mistral.rs out of the dependency tree, there is nothing to package.
+This is a separate repo/spec — not part of the cortex workspace — but
+tightly coupled operationally. Track it as a sibling project.

Cargo.toml

@@ -8,7 +8,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.1.16"
+version = "0.1.8"
 edition = "2024"
 license = "GPL-3.0-or-later"
 repository = "https://git.lair.cafe/helexa/cortex"
@@ -27,7 +27,7 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 toml = "0.8"
 
-# http client (for proxying to neuron backends)
+# http client (for proxying to mistralrs backends)
 reqwest = { version = "0.12", features = ["json", "stream"] }
 
 # observability

README.md

@@ -1,23 +1,22 @@
 # cortex
 
-A Rust reverse-proxy and fleet management layer for multi-node GPU inference
-clusters. Cortex sits in front of one or more `neuron` daemons (each running
-candle-based inference on a local GPU host) and presents a unified OpenAI +
-Anthropic compatible API surface.
+A Rust reverse-proxy and fleet management layer for multi-node
+[mistral.rs](https://github.com/EricLBuehler/mistral.rs) inference clusters.
 
 ## Problem
 
 Running local LLMs across multiple GPU nodes (different VRAM tiers, different
 model affinities) requires a unified API surface that:
 
-- Presents a **single `/v1/models` catalogue** merging every model that can be
-  served by any neuron in the fleet.
-- **Routes requests** to the correct node based on where a model is loaded
-  (or can be loaded), handling cold-load and eviction transparently.
-- Manages **model lifecycle** — load on demand, unload cold models, pin
-  critical ones — by calling each neuron's `/models/{load,unload}` API.
+- Presents a **single `/v1/models` catalogue** merging every model across every
+  node.
+- **Routes requests** to the correct node based on where a model is loaded (or
+  *can* be loaded).
+- Manages **model lifecycle** — unload cold models, reload on demand, pin
+  critical ones — using the mistral.rs
+  `/v1/models/{unload,reload,status}` HTTP API (PR #1828+).
 - Translates between **OpenAI and Anthropic** request/response envelopes so
-  every client speaks whichever dialect it prefers.
+  every client in the homelab speaks whichever dialect it prefers.
 - Captures **per-request metrics** (tokens, tok/s, TTFT, latency) and exposes
   them as Prometheus counters/histograms.
 
@@ -31,17 +30,18 @@ model affinities) requires a unified API surface that:
        └────────────────┴──────┬───────┴───────────────┘
                                │
                     ┌──────────▼──────────┐
-                    │      cortex         │
-                    │  (cortex-gateway)   │
+                    │   cortex     │
+                    │   (cortex-gateway)      │
                     │                     │
                     │  Router · Metrics   │
                     │  Evictor · Translate│
                     └──┬──────┬────────┬──┘
                        │      │        │
             ┌──────────▼┐  ┌──▼─────┐  ┌▼──────────┐
-            │  neuron   │  │ neuron │  │  neuron   │
-            │  :13131   │  │ :13131 │  │  :13131   │
-            │  candle   │  │ candle │  │  candle   │
+            │ gpu-large │  │gpu-med │  │ gpu-small │
+            │ mistralrs │  │mistral │  │ mistralrs │
+            │ serve     │  │rs serve│  │ serve     │
+            │ :8080     │  │ :8080  │  │  :8080    │
             └───────────┘  └────────┘  └───────────┘
                   private network (.internal)
 ```
@@ -50,48 +50,70 @@ model affinities) requires a unified API surface that:
 
 | Crate | Purpose |
 |---|---|
-| `cortex-core` | Shared types: config, node/model state, metrics, OpenAI/Anthropic envelopes, harness trait, discovery types |
-| `cortex-gateway` | Axum HTTP server: proxy, router, evictor, poller, metrics exporter |
-| `neuron` | Per-node daemon: GPU discovery, in-process candle inference, model lifecycle API |
+| `cortex-core` | Shared types: config, node/model state, metrics, OpenAI/Anthropic request/response envelopes |
+| `cortex-gateway` | Axum HTTP server: proxy, router, evictor, metrics exporter |
+| `cortex-agent` | Per-node sidecar: polls local mistralrs, reports to gateway, handles restart/defrag |
 | `cortex-cli` | CLI entrypoint (`cortex serve`, `cortex status`, etc.) |
 
 ## Node setup
 
-Each GPU node runs `neuron` (listening on `:13131`). Neuron uses
-huggingface/candle for in-process inference — there is no external
-inference subprocess to manage.
+Each GPU node runs `mistralrs serve` with a multi-model config. Models are
+declared but start **unloaded** — mistral.rs lazy-loads on first request and
+the gateway can explicitly unload/reload via the HTTP API.
 
-The neuron RPM (`helexa-neuron`) ships a systemd unit:
+Example node systemd unit:
 
-```sh
-dnf copr enable helexa/helexa
-dnf install helexa-neuron
-systemctl enable --now neuron
+```ini
+# /etc/systemd/system/mistralrs.service
+[Unit]
+Description=mistral.rs inference server
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/mistralrs serve \
+    --from-config /etc/mistralrs/config.toml \
+    --port 8080
+Restart=on-failure
+RestartSec=5
+Environment=CUDA_VISIBLE_DEVICES=0,1
+
+[Install]
+WantedBy=multi-user.target
 ```
 
 ## Gateway config
 
 ```toml
-# /etc/cortex/cortex.toml
+# cortex.toml
 [gateway]
-listen = "0.0.0.0:31313"
-metrics_listen = "0.0.0.0:31314"
+listen = "0.0.0.0:8000"
+metrics_listen = "0.0.0.0:9100"
 
 [eviction]
 strategy = "lru"        # lru | priority
 defrag_after_cycles = 50
 
-[[neurons]]
-name = "beast"
-endpoint = "http://beast.internal:13131"
+[[nodes]]
+name = "gpu-large"
+endpoint = "http://gpu-large.internal:8080"
+vram_mb = 49_152        # e.g. 2x RTX 4090
+pinned = ["your-org/large-model"]
 
-[[neurons]]
-name = "benjy"
-endpoint = "http://benjy.internal:13131"
+[[nodes]]
+name = "gpu-medium"
+endpoint = "http://gpu-medium.internal:8080"
+vram_mb = 24_576        # e.g. RTX 4090
+pinned = ["your-org/medium-model"]
+
+[[nodes]]
+name = "gpu-small"
+endpoint = "http://gpu-small.internal:8080"
+vram_mb = 12_288        # e.g. RTX 3060
+pinned = ["your-org/embedding-model"]
 ```
 
-Model placement profiles live in `models.toml` — see `models.example.toml`.
-
 ## Building
 
 ```sh
@@ -109,20 +131,19 @@ cargo clippy --workspace -- -D warnings   # warnings are errors
 cargo test --workspace                     # all tests must pass
 ```
 
-Tagged releases (`v*`) additionally build SRPMs for both `cortex` and
-`helexa-neuron` and publish to COPR.
+Tagged releases (`v*`) additionally build an SRPM and publish to COPR.
 
 ## Running
 
 ```sh
 # start the gateway
-cortex serve --config /etc/cortex/cortex.toml
+cortex serve --config cortex.toml
 
 # check fleet status
 cortex status
 
 # list all models across nodes
-curl http://localhost:31313/v1/models
+curl http://localhost:8000/v1/models
 ```
 
 ## License

asset/manifest.yml

@@ -1,30 +0,0 @@
-# Helexa fleet manifest.
-#
-# Drives rolling deploys via script/deploy.sh and serves as the source
-# of truth for which hosts run cortex vs neuron, and which CUDA
-# compute-capability flavour each neuron host needs.
-#
-# Flavour ↔ NVIDIA generation ↔ compute cap:
-#   ampere    sm_86   (RTX 30 series — e.g. 3060)
-#   ada       sm_89   (RTX 40 series — e.g. 4090)
-#   blackwell sm_120  (RTX 50 series — e.g. 5090)
-#
-# The flavour determines which RPM is installed on a given neuron host:
-# helexa-neuron-<flavour>. Only one flavour may be installed at a time
-# (the packages Conflict: with each other).
-
-cortex:
-  host: hanzalova.internal
-
-neurons:
-  - host: beast.hanzalova.internal
-    flavour: blackwell
-    gpu: "2x RTX 5090"
-
-  - host: benjy.hanzalova.internal
-    flavour: ada
-    gpu: "RTX 4090"
-
-  - host: quadbrat.hanzalova.internal
-    flavour: ampere
-    gpu: "RTX 3060"

cortex.example.toml

@@ -3,22 +3,22 @@
 # Copy to cortex.toml and adjust for your environment.
 #
 # Environment variable overrides use CORTEX_ prefix with __ separators:
-#   CORTEX_GATEWAY__LISTEN=0.0.0.0:31313
+#   CORTEX_GATEWAY__LISTEN=0.0.0.0:9000
 
 [gateway]
-listen = "0.0.0.0:31313"
-metrics_listen = "0.0.0.0:31314"
+listen = "0.0.0.0:8000"
+metrics_listen = "0.0.0.0:9100"
 
 [eviction]
 strategy = "lru"
-# Restart neurons after this many load/unload cycles to defragment VRAM.
+# Restart mistralrs after this many load/unload cycles to defragment VRAM.
 # Set to 0 to disable.
 defrag_after_cycles = 50
 
 # -- Nodes ---------------------------------------------------------------
-# Each [[nodes]] entry declares a neuron daemon in the fleet.
-# Models are discovered by polling the neuron's /models endpoint.
-# Pinned models (see models.toml) are never evicted.
+# Each [[nodes]] entry declares a mistral.rs instance in the fleet.
+# Models are discovered by polling the node's /v1/models endpoint.
+# Pinned models are never evicted.
 
 [[nodes]]
 name = "gpu-large"

cortex.spec

@@ -1,5 +1,5 @@
 Name:           cortex
-Version:        0.1.16
+Version:        0.1.8
 Release:        1%{?dist}
 Summary:        Inference gateway for multi-node GPU clusters
 
@@ -21,7 +21,6 @@ BuildRequires:  systemd-rpm-macros
 
 Requires(pre):  shadow-utils
 Requires:       systemd
-Requires:       firewalld-filesystem
 
 # systemd-rpm-macros ships a unit dep generator that parses User=/Group=
 # from our .service file and emits Requires: user(cortex)/group(cortex).
@@ -57,7 +56,6 @@ cargo build --release -p cortex-cli
 install -Dm755 target/release/cortex %{buildroot}%{_bindir}/cortex
 install -Dm644 data/cortex.service %{buildroot}%{_unitdir}/cortex.service
 install -Dm644 data/cortex-sysusers.conf %{buildroot}%{_sysusersdir}/cortex.conf
-install -Dm644 data/cortex-firewalld.xml %{buildroot}%{_prefix}/lib/firewalld/services/cortex.xml
 install -dm755 %{buildroot}%{_sysconfdir}/cortex
 install -Dm644 cortex.example.toml %{buildroot}%{_sysconfdir}/cortex/cortex.toml
 install -Dm644 models.example.toml %{buildroot}%{_sysconfdir}/cortex/models.toml
@@ -74,53 +72,16 @@ install -Dm644 models.example.toml %{buildroot}%{_sysconfdir}/cortex/models.toml
 %postun
 %systemd_postun_with_restart cortex.service
 
-%posttrans
-# Migration: older cortex packages shipped the firewalld service as
-# `helexa-cortex` and (in some build streams) with wrong port numbers
-# (9301/9302/9304). Operators who enabled that legacy service in their
-# zone end up with the wrong-port override taking precedence over the
-# vendor `cortex.xml` now in /usr/lib/firewalld/services/. Clean up the
-# stale /etc/ override here and migrate any zone bindings to the new
-# service name.
-if [ -f /etc/firewalld/services/helexa-cortex.xml ]; then
-    rm -f /etc/firewalld/services/helexa-cortex.xml
-fi
-if [ -x /usr/bin/firewall-cmd ] && /usr/bin/firewall-cmd --state >/dev/null 2>&1; then
-    # Drop the legacy service name from every zone where it was enabled
-    # and add the new `cortex` service in its place. Operators who never
-    # ran firewall-cmd against either name see no zone change.
-    for zone in $(/usr/bin/firewall-cmd --get-active-zones 2>/dev/null \
-        | awk '!/^[[:space:]]/ {print $1}'); do
-        if /usr/bin/firewall-cmd --permanent --zone="$zone" --query-service=helexa-cortex >/dev/null 2>&1; then
-            /usr/bin/firewall-cmd --permanent --zone="$zone" --remove-service=helexa-cortex >/dev/null 2>&1 || :
-            /usr/bin/firewall-cmd --permanent --zone="$zone" --add-service=cortex >/dev/null 2>&1 || :
-        fi
-    done
-    /usr/bin/firewall-cmd --reload >/dev/null 2>&1 || :
-fi
-:
-
 %files
 %license LICENSE
 %doc README.md
 %{_bindir}/cortex
 %{_unitdir}/cortex.service
 %{_sysusersdir}/cortex.conf
-%{_prefix}/lib/firewalld/services/cortex.xml
 %dir %{_sysconfdir}/cortex
 %config(noreplace) %{_sysconfdir}/cortex/cortex.toml
 %config(noreplace) %{_sysconfdir}/cortex/models.toml
 
 %changelog
-* Thu Apr 16 2026 Gitea Actions <actions@git.lair.cafe> - 0.1.16-1
-- chore: ignore local deploy script
-- chore: move default ports out of common-collision ranges
-- ci: drop actions/cache for cargo registry and target
-
-* Thu Apr 16 2026 Gitea Actions <actions@git.lair.cafe> - 0.1.14-1
-- ci: publish both packages to a single helexa/helexa COPR project
-- fix(rpm): rename neuron package to helexa-neuron
-- ci: commit generated %changelog entries back to main
-
 * Wed Apr 15 2026 Rob Thijssen <grenade@rob.tn> - 0.1.0-1
 - Initial package

crates/cortex-cli/src/main.rs

@@ -5,7 +5,7 @@ use tracing_subscriber::EnvFilter;
 
 #[derive(Parser)]
 #[command(name = "cortex")]
-#[command(about = "Unified inference gateway for multi-node GPU clusters")]
+#[command(about = "Unified inference gateway for multi-node mistral.rs clusters")]
 #[command(version)]
 struct Cli {
     #[command(subcommand)]
@@ -23,7 +23,7 @@ enum Commands {
     /// Print the fleet status (models, nodes, health).
     Status {
         /// Gateway API endpoint to query.
-        #[arg(short, long, default_value = "http://localhost:31313")]
+        #[arg(short, long, default_value = "http://localhost:8000")]
         endpoint: String,
     },
 }

crates/cortex-core/src/anthropic.rs

@@ -2,7 +2,7 @@
 //!
 //! These mirror the `/v1/messages` format used by the Anthropic API.
 //! The gateway accepts these, translates to OpenAI format, proxies to
-//! the inference backend (neuron), then translates the response back.
+//! mistral.rs, then translates the response back.
 
 use serde::{Deserialize, Serialize};
 use serde_json::Value;

crates/cortex-core/src/catalogue.rs

@@ -1,6 +1,5 @@
 //! Model catalogue — profiles describing how to serve each model.
 
-use crate::discovery::DeviceInfo;
 use serde::{Deserialize, Serialize};
 use std::path::Path;
 
@@ -65,103 +64,4 @@ impl ModelCatalogue {
             .iter()
             .any(|p| p.id == model_id && p.pinned_on.contains(&neuron_name.to_string()))
     }
-
-    /// Find a profile by model id.
-    pub fn get(&self, model_id: &str) -> Option<&ModelProfile> {
-        self.models.iter().find(|p| p.id == model_id)
-    }
-}
-
-impl ModelProfile {
-    /// True iff this profile's placement constraints can be satisfied
-    /// by the named neuron with the given device topology.
-    ///
-    /// Constraints checked:
-    /// - `pinned_on`: non-empty → neuron must be on the list.
-    /// - `min_devices`: neuron must have at least this many devices.
-    /// - `min_device_vram_mb`: at least `min_devices` of the neuron's
-    ///   devices must each meet this VRAM floor.
-    pub fn is_feasible_on(&self, neuron_name: &str, devices: &[DeviceInfo]) -> bool {
-        if !self.pinned_on.is_empty() && !self.pinned_on.iter().any(|n| n == neuron_name) {
-            return false;
-        }
-        if (devices.len() as u32) < self.min_devices {
-            return false;
-        }
-        if let Some(min_vram) = self.min_device_vram_mb {
-            let big_enough = devices
-                .iter()
-                .filter(|d| d.vram_total_mb >= min_vram)
-                .count() as u32;
-            if big_enough < self.min_devices {
-                return false;
-            }
-        }
-        true
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::discovery::DeviceInfo;
-
-    fn device(idx: u32, vram_mb: u64) -> DeviceInfo {
-        DeviceInfo {
-            index: idx,
-            name: format!("DEV-{idx}"),
-            vram_total_mb: vram_mb,
-            compute_capability: "8.6".into(),
-        }
-    }
-
-    fn profile() -> ModelProfile {
-        ModelProfile {
-            id: "Qwen/Qwen3.6-27B".into(),
-            harness: "candle".into(),
-            quant: None,
-            vram_mb: Some(45_000),
-            min_devices: 2,
-            min_device_vram_mb: Some(24_000),
-            pinned_on: vec![],
-        }
-    }
-
-    #[test]
-    fn feasible_when_two_devices_meet_vram_floor() {
-        let p = profile();
-        let devices = [device(0, 32_000), device(1, 32_000)];
-        assert!(p.is_feasible_on("beast", &devices));
-    }
-
-    #[test]
-    fn infeasible_when_only_one_device() {
-        let p = profile();
-        let devices = [device(0, 64_000)];
-        assert!(!p.is_feasible_on("benjy", &devices));
-    }
-
-    #[test]
-    fn infeasible_when_one_device_underspec() {
-        let p = profile();
-        let devices = [device(0, 32_000), device(1, 12_000)];
-        assert!(!p.is_feasible_on("mixed", &devices));
-    }
-
-    #[test]
-    fn pinned_on_excludes_other_neurons() {
-        let mut p = profile();
-        p.pinned_on = vec!["beast".into()];
-        let devices = [device(0, 32_000), device(1, 32_000)];
-        assert!(p.is_feasible_on("beast", &devices));
-        assert!(!p.is_feasible_on("benjy", &devices));
-    }
-
-    #[test]
-    fn no_vram_floor_just_needs_min_devices() {
-        let mut p = profile();
-        p.min_device_vram_mb = None;
-        let devices = [device(0, 1_000), device(1, 1_000)];
-        assert!(p.is_feasible_on("anywhere", &devices));
-    }
 }

crates/cortex-core/src/config.rs

@@ -22,9 +22,9 @@ fn default_models_path() -> String {
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct GatewaySettings {
-    /// Address to listen on for API requests (e.g. "0.0.0.0:31313")
+    /// Address to listen on for API requests (e.g. "0.0.0.0:8000")
     pub listen: String,
-    /// Address to listen on for Prometheus metrics (e.g. "0.0.0.0:31314")
+    /// Address to listen on for Prometheus metrics (e.g. "0.0.0.0:9100")
     pub metrics_listen: String,
 }
 
@@ -50,7 +50,7 @@ pub enum EvictionStrategy {
 pub struct NeuronEndpoint {
     /// Human-readable node name (e.g. "beast")
     pub name: String,
-    /// Base URL of the neuron daemon (e.g. "http://beast.internal:13131")
+    /// Base URL of the neuron daemon (e.g. "http://beast.internal:9090")
     pub endpoint: String,
 }
 
@@ -70,8 +70,8 @@ impl Default for GatewayConfig {
     fn default() -> Self {
         Self {
             gateway: GatewaySettings {
-                listen: "0.0.0.0:31313".into(),
-                metrics_listen: "0.0.0.0:31314".into(),
+                listen: "0.0.0.0:8000".into(),
+                metrics_listen: "0.0.0.0:9100".into(),
             },
             eviction: EvictionSettings {
                 strategy: EvictionStrategy::Lru,

crates/cortex-core/src/harness.rs

@@ -9,13 +9,13 @@ use async_trait::async_trait;
 use serde::{Deserialize, Serialize};
 
 /// Configuration for a harness instance on a neuron.
-///
-/// All current harnesses are in-process (candle); per-harness tuning
-/// (cache paths, device policies, etc.) lives in dedicated config
-/// blocks rather than on this struct.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct HarnessConfig {
     pub name: String,
+    /// Base URL of the harness (e.g. "http://localhost:8080" for mistral.rs).
+    pub endpoint: Option<String>,
+    /// Systemd unit name, if the harness is managed via systemd.
+    pub systemd_unit: Option<String>,
 }
 
 /// Health status of a harness process.
@@ -47,24 +47,16 @@ pub struct ModelInfo {
 }
 
 /// What an inference harness must do, from neuron's perspective.
-///
-/// All current harnesses are in-process — they share neuron's address
-/// space and lifecycle. `start`/`stop` therefore default to no-ops; a
-/// future process-supervising harness would override them.
 #[async_trait]
 pub trait Harness: Send + Sync {
-    /// Human-readable name (e.g. "candle").
+    /// Human-readable name (e.g. "mistralrs", "llamacpp", "comfyui").
     fn name(&self) -> &str;
 
-    /// Start the harness. Default no-op for in-process harnesses.
-    async fn start(&self, _config: &HarnessConfig) -> Result<()> {
-        Ok(())
-    }
+    /// Start the harness process if it is not already running.
+    async fn start(&self, config: &HarnessConfig) -> Result<()>;
 
-    /// Stop the harness. Default no-op for in-process harnesses.
-    async fn stop(&self) -> Result<()> {
-        Ok(())
-    }
+    /// Stop the harness process gracefully.
+    async fn stop(&self) -> Result<()>;
 
     /// Health check. Returns the harness process status.
     async fn health(&self) -> HarnessHealth;

crates/cortex-core/src/node.rs

@@ -1,4 +1,3 @@
-use crate::discovery::DiscoveryResponse;
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
@@ -7,19 +6,13 @@ use std::collections::HashMap;
 #[derive(Debug, Clone)]
 pub struct NodeState {
     pub name: String,
-    /// Base URL of the neuron daemon (e.g. "http://beast.internal:13131").
+    /// Base URL of the neuron daemon (e.g. "http://beast.internal:9090").
     pub endpoint: String,
     pub healthy: bool,
     pub models: HashMap<String, ModelEntry>,
     /// Number of load/unload cycles since last process restart.
     pub lifecycle_cycles: u32,
     pub last_poll: Option<DateTime<Utc>>,
-    /// Result of the most recent successful `GET /discovery` against
-    /// this neuron. Cached forever once obtained — device topology is
-    /// invariant for a given neuron process. `None` until the first
-    /// successful poll. Used by the router and `/v1/models` to do
-    /// catalogue × topology feasibility checks.
-    pub discovery: Option<DiscoveryResponse>,
 }
 
 /// A model registered on a node, with its runtime status.
@@ -43,32 +36,12 @@ pub enum ModelStatus {
 }
 
 /// Unified model entry as exposed by the gateway's `/v1/models` endpoint.
-///
-/// The first four fields (`id`, `object`, `created`, `owned_by`) match
-/// OpenAI's `/v1/models` shape verbatim, so existing OpenAI-aware
-/// tooling deserialises this without custom code. The remaining fields
-/// are helexa-specific extensions — OpenAI clients ignore unknown
-/// fields and other consumers can read them for placement / debugging.
+/// Includes which node(s) host this model and their status.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct CortexModelEntry {
     pub id: String,
-    /// Always `"model"` per OpenAI's contract.
     pub object: String,
-    /// Unix-second timestamp; cortex stamps this at response time.
-    pub created: u64,
-    /// OpenAI's "publisher" field — `"helexa"` for everything we serve.
-    pub owned_by: String,
-    /// True if any neuron currently has this model loaded. False for
-    /// catalogue entries that are feasible but not yet loaded.
-    pub loaded: bool,
-    /// Neurons whose discovered topology can satisfy this model's
-    /// catalogue placement constraints. Empty for models that are
-    /// loaded somewhere but not present in the catalogue (cortex has
-    /// no feasibility opinion on those).
-    pub feasible_on: Vec<String>,
-    /// Where this model is actually loaded right now. Subset of (or
-    /// disjoint from) `feasible_on` depending on whether the catalogue
-    /// covers this model.
+    /// Which nodes have this model (and their status).
     pub locations: Vec<ModelLocation>,
 }
 

crates/cortex-core/src/openai.rs

@@ -3,7 +3,7 @@
 //! These are a subset sufficient for chat completions (streaming + non-streaming).
 //! Fields not relevant to proxying are captured as `serde_json::Value` via
 //! `#[serde(flatten)]` so we forward them without needing to enumerate every
-//! extension field a backend might support.
+//! extension field mistral.rs supports.
 
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
@@ -22,7 +22,7 @@ pub struct ChatCompletionRequest {
     pub max_tokens: Option<u64>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub stream: Option<bool>,
-    /// All other fields (tools, response_format, backend extensions, etc.)
+    /// All other fields (tools, response_format, mistral.rs extensions, etc.)
     #[serde(flatten)]
     pub extra: Value,
 }

crates/cortex-gateway/Cargo.toml

@@ -24,7 +24,6 @@ tokio-stream.workspace = true
 eventsource-stream.workspace = true
 bytes = "1"
 urlencoding = "2"
-url = "2"
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["test-util"] }

crates/cortex-gateway/src/handlers.rs

@@ -34,30 +34,12 @@ async fn chat_completions(
 ) -> Response {
     let model_id = match extract_model(&body) {
         Some(m) => m,
-        None => {
-            tracing::warn!(
-                handler = "chat_completions",
-                "rejected: missing 'model' field in request body"
-            );
-            return error_response(400, "missing 'model' field in request body");
-        }
+        None => return error_response(400, "missing 'model' field in request body"),
     };
 
     let route = match router::resolve(&fleet, &model_id).await {
         Ok(r) => r,
-        Err(e) => {
-            tracing::warn!(
-                handler = "chat_completions",
-                model = %model_id,
-                error = %e,
-                "route resolve failed"
-            );
-            // RouteError's Display strings are short and informative
-            // ("model 'X' not found...", "no healthy nodes available")
-            // — fine to surface to the caller. The warn above carries
-            // any extra context for operators.
-            return error_response(404, &e.to_string());
-        }
+        Err(e) => return error_response(404, &e.to_string()),
     };
 
     touch_model(&fleet, &route.node_name, &model_id).await;
@@ -81,30 +63,12 @@ async fn completions(
 ) -> Response {
     let model_id = match extract_model(&body) {
         Some(m) => m,
-        None => {
-            tracing::warn!(
-                handler = "completions",
-                "rejected: missing 'model' field in request body"
-            );
-            return error_response(400, "missing 'model' field in request body");
-        }
+        None => return error_response(400, "missing 'model' field in request body"),
     };
 
     let route = match router::resolve(&fleet, &model_id).await {
         Ok(r) => r,
-        Err(e) => {
-            tracing::warn!(
-                handler = "completions",
-                model = %model_id,
-                error = %e,
-                "route resolve failed"
-            );
-            // RouteError's Display strings are short and informative
-            // ("model 'X' not found...", "no healthy nodes available")
-            // — fine to surface to the caller. The warn above carries
-            // any extra context for operators.
-            return error_response(404, &e.to_string());
-        }
+        Err(e) => return error_response(404, &e.to_string()),
     };
 
     touch_model(&fleet, &route.node_name, &model_id).await;
@@ -121,14 +85,7 @@ async fn anthropic_messages(
     // Parse as Anthropic request.
     let anth_req: cortex_core::anthropic::MessagesRequest = match serde_json::from_slice(&body) {
         Ok(r) => r,
-        Err(e) => {
-            tracing::warn!(
-                handler = "anthropic_messages",
-                error = %e,
-                "rejected: invalid Anthropic request body"
-            );
-            return error_response(400, "invalid Anthropic request body");
-        }
+        Err(e) => return error_response(400, &format!("invalid Anthropic request: {e}")),
     };
 
     let model_id = anth_req.model.clone();
@@ -138,32 +95,12 @@ async fn anthropic_messages(
     let openai_req = cortex_core::translate::anthropic_to_openai(anth_req);
     let openai_body = match serde_json::to_vec(&openai_req) {
         Ok(b) => Bytes::from(b),
-        Err(e) => {
-            tracing::error!(
-                handler = "anthropic_messages",
-                model = %model_id,
-                error = %e,
-                "internal: failed to serialise translated OpenAI request"
-            );
-            return error_response(500, "internal translation error");
-        }
+        Err(e) => return error_response(500, &format!("translation error: {e}")),
     };
 
     let route = match router::resolve(&fleet, &model_id).await {
         Ok(r) => r,
-        Err(e) => {
-            tracing::warn!(
-                handler = "anthropic_messages",
-                model = %model_id,
-                error = %e,
-                "route resolve failed"
-            );
-            // RouteError's Display strings are short and informative
-            // ("model 'X' not found...", "no healthy nodes available")
-            // — fine to surface to the caller. The warn above carries
-            // any extra context for operators.
-            return error_response(404, &e.to_string());
-        }
+        Err(e) => return error_response(404, &e.to_string()),
     };
 
     touch_model(&fleet, &route.node_name, &model_id).await;
@@ -196,25 +133,14 @@ async fn anthropic_messages(
             Ok(resp) => resp,
             Err(e) => {
                 metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-                // forward_request already warn'd with the wire-level
-                // detail; no need to log again here.
                 e.into_response()
             }
         }
     } else {
         // Non-streaming: proxy, buffer full response, translate back to Anthropic.
-        let target_url = format!("{}/v1/chat/completions", route.endpoint);
-        tracing::info!(
-            handler = "anthropic_messages",
-            model = %model_id,
-            node = %route.node_name,
-            url = %target_url,
-            cold_start = route.cold_start,
-            "proxying request"
-        );
         let upstream_resp = fleet
             .http_client
-            .post(&target_url)
+            .post(format!("{}/v1/chat/completions", route.endpoint))
             .body(openai_body)
             .header("content-type", "application/json")
             .send()
@@ -224,49 +150,22 @@ async fn anthropic_messages(
             Ok(r) => r,
             Err(e) => {
                 metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-                tracing::warn!(
-                    handler = "anthropic_messages",
-                    model = %model_id,
-                    node = %route.node_name,
-                    url = %target_url,
-                    error = %e,
-                    "upstream request failed (network)"
-                );
-                return error_response(502, "upstream request failed");
+                return error_response(502, &format!("upstream request failed: {e}"));
             }
         };
 
-        let upstream_status = upstream_resp.status();
-        if !upstream_status.is_success() {
+        if !upstream_resp.status().is_success() {
             metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-            let status = upstream_status.as_u16();
+            let status = upstream_resp.status().as_u16();
             let body = upstream_resp.text().await.unwrap_or_default();
-            let body_snippet = body.chars().take(512).collect::<String>();
-            tracing::warn!(
-                handler = "anthropic_messages",
-                model = %model_id,
-                node = %route.node_name,
-                url = %target_url,
-                status,
-                body = %body_snippet,
-                "upstream returned non-2xx"
-            );
-            return error_response(status, &format!("upstream returned {status}"));
+            return error_response(status, &format!("upstream error: {body}"));
         }
 
         let body_bytes = match upstream_resp.bytes().await {
             Ok(b) => b,
             Err(e) => {
                 metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-                tracing::warn!(
-                    handler = "anthropic_messages",
-                    model = %model_id,
-                    node = %route.node_name,
-                    url = %target_url,
-                    error = %e,
-                    "failed to read upstream response body"
-                );
-                return error_response(502, "failed to read upstream response");
+                return error_response(502, &format!("failed to read upstream response: {e}"));
             }
         };
 
@@ -275,20 +174,7 @@ async fn anthropic_messages(
                 Ok(r) => r,
                 Err(e) => {
                     metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-                    let body_snippet = String::from_utf8_lossy(&body_bytes)
-                        .chars()
-                        .take(512)
-                        .collect::<String>();
-                    tracing::warn!(
-                        handler = "anthropic_messages",
-                        model = %model_id,
-                        node = %route.node_name,
-                        url = %target_url,
-                        error = %e,
-                        body = %body_snippet,
-                        "failed to parse upstream response as OpenAI ChatCompletionResponse"
-                    );
-                    return error_response(502, "malformed upstream response");
+                    return error_response(502, &format!("failed to parse upstream response: {e}"));
                 }
             };
 
@@ -299,62 +185,12 @@ async fn anthropic_messages(
     }
 }
 
-/// `GET /v1/models` — union of (catalogue × topology feasibility) and
-/// (currently loaded somewhere). The result is what the fleet *could*
-/// serve, not just what's already loaded — so OpenAI-compatible tools
-/// see every model the operator has provisioned, and cortex
-/// transparently cold-loads the first time one is requested.
+/// `GET /v1/models` — aggregate models from all nodes.
 async fn list_models(State(fleet): State<Arc<CortexState>>) -> Json<Value> {
-    use std::collections::HashMap;
-    let now = Utc::now().timestamp() as u64;
     let nodes = fleet.nodes.read().await;
-    let catalogue = &fleet.catalogue;
+    let mut model_map: std::collections::HashMap<String, CortexModelEntry> =
+        std::collections::HashMap::new();
 
-    let mut entries: HashMap<String, CortexModelEntry> = HashMap::new();
-
-    // Pass 1: catalogue × topology. For every catalogue profile, find
-    // healthy neurons whose discovered devices satisfy the profile.
-    // Catalogue-defined models surface here even if nothing has loaded
-    // them yet — that's the point of the unified endpoint.
-    for profile in &catalogue.models {
-        let mut feasible_on = Vec::new();
-        for node in nodes.values() {
-            if !node.healthy {
-                continue;
-            }
-            let Some(disc) = node.discovery.as_ref() else {
-                continue;
-            };
-            if profile.is_feasible_on(&node.name, &disc.devices) {
-                feasible_on.push(node.name.clone());
-            }
-        }
-        if feasible_on.is_empty() {
-            // The catalogue lists this model but no neuron's topology
-            // matches — surface it as not-loaded with no feasible
-            // location. Hides nothing; lets operators see why a
-            // configured model isn't reachable.
-            feasible_on.clear();
-        }
-        entries.insert(
-            profile.id.clone(),
-            CortexModelEntry {
-                id: profile.id.clone(),
-                object: "model".into(),
-                created: now,
-                owned_by: "helexa".into(),
-                loaded: false,
-                feasible_on,
-                locations: Vec::new(),
-            },
-        );
-    }
-
-    // Pass 2: layer the actually-loaded state on top. For each
-    // (node, model) entry, attach a ModelLocation. If the model isn't
-    // in the catalogue, create a new CortexModelEntry from scratch —
-    // cortex doesn't refuse to surface a manually-loaded model just
-    // because the operator didn't enumerate it in models.toml.
     for node in nodes.values() {
         for (model_id, entry) in &node.models {
             let location = ModelLocation {
@@ -362,30 +198,19 @@ async fn list_models(State(fleet): State<Arc<CortexState>>) -> Json<Value> {
                 status: entry.status,
                 vram_estimate_mb: entry.vram_estimate_mb,
             };
-            let was_loaded = matches!(entry.status, cortex_core::node::ModelStatus::Loaded);
-            entries
+            model_map
                 .entry(model_id.clone())
-                .and_modify(|e| {
-                    e.locations.push(location.clone());
-                    if was_loaded {
-                        e.loaded = true;
-                    }
-                })
+                .and_modify(|e| e.locations.push(location.clone()))
                 .or_insert_with(|| CortexModelEntry {
                     id: model_id.clone(),
                     object: "model".into(),
-                    created: now,
-                    owned_by: "helexa".into(),
-                    loaded: was_loaded,
-                    // Not in catalogue — cortex has no opinion on
-                    // feasibility; leave empty.
-                    feasible_on: Vec::new(),
                     locations: vec![location],
                 });
         }
     }
 
-    let data: Vec<Value> = entries.values().map(|e| json!(e)).collect();
+    let data: Vec<Value> = model_map.values().map(|e| json!(e)).collect();
+
     Json(json!({
         "object": "list",
         "data": data,
@@ -440,9 +265,6 @@ async fn proxy_with_metrics(
         }
         Err(e) => {
             metrics::counter!("cortex_request_errors_total", &labels).increment(1);
-            // proxy::forward_request already warn'd with wire-level
-            // detail (target URL, error, status). ProxyError::into_response
-            // now returns a generic message — no body leak.
             e.into_response()
         }
     }

crates/cortex-gateway/src/poller.rs

@@ -3,7 +3,6 @@
 
 use crate::state::CortexState;
 use chrono::Utc;
-use cortex_core::discovery::DiscoveryResponse;
 use cortex_core::harness::ModelInfo;
 use cortex_core::node::{ModelEntry, ModelStatus};
 use std::sync::Arc;
@@ -26,59 +25,7 @@ pub async fn poll_once(fleet: &CortexState) {
     }
 }
 
-/// One-shot fetch of `GET /discovery`. Cached on the NodeState forever
-/// after the first success — topology is invariant for a given neuron
-/// process. Skipped when the cache is already populated.
-async fn maybe_poll_discovery(fleet: &CortexState, name: &str, endpoint: &str) {
-    {
-        let nodes = fleet.nodes.read().await;
-        match nodes.get(name) {
-            Some(n) if n.discovery.is_some() => return,
-            _ => {}
-        }
-    }
-    let url = format!("{endpoint}/discovery");
-    let resp = match fleet
-        .http_client
-        .get(&url)
-        .timeout(Duration::from_secs(5))
-        .send()
-        .await
-    {
-        Ok(r) if r.status().is_success() => r,
-        Ok(r) => {
-            tracing::debug!(node = name, status = %r.status(), "discovery probe non-success");
-            return;
-        }
-        Err(e) => {
-            tracing::debug!(node = name, error = %e, "discovery probe unreachable");
-            return;
-        }
-    };
-    match resp.json::<DiscoveryResponse>().await {
-        Ok(d) => {
-            let mut nodes = fleet.nodes.write().await;
-            if let Some(node) = nodes.get_mut(name) {
-                tracing::info!(
-                    node = name,
-                    hostname = %d.hostname,
-                    devices = d.devices.len(),
-                    "discovery cached"
-                );
-                node.discovery = Some(d);
-            }
-        }
-        Err(e) => {
-            tracing::warn!(node = name, error = %e, "failed to parse /discovery response");
-        }
-    }
-}
-
 async fn poll_neuron(fleet: &CortexState, name: &str, endpoint: &str) {
-    // Topology first — cheap once cached, and the router needs it to
-    // route requests against catalogue entries that aren't loaded yet.
-    maybe_poll_discovery(fleet, name, endpoint).await;
-
     let url = format!("{endpoint}/models");
 
     let result = fleet

crates/cortex-gateway/src/proxy.rs

@@ -1,4 +1,4 @@
-//! Streaming HTTP reverse proxy to neuron backends.
+//! Streaming HTTP reverse proxy to mistral.rs backends.
 //!
 //! For streaming requests, SSE chunks are forwarded as they arrive.
 //! The proxy captures timing information for metrics but does not
@@ -12,13 +12,6 @@ use axum::response::{IntoResponse, Response};
 use reqwest::Client;
 
 /// Proxy a request body to the resolved backend node and stream the response.
-///
-/// Logging contract: every call emits exactly one structured event at
-/// info / warn level for operator visibility, regardless of outcome.
-/// Network-level failures and non-2xx upstream statuses are warn'd here
-/// (closest to the wire); the user-facing response carries only the
-/// status code and a generic message — implementation detail (body,
-/// error chain) lives in the log, never in the API surface.
 pub async fn forward_request(
     client: &Client,
     route: &RouteDecision,
@@ -44,33 +37,10 @@ pub async fn forward_request(
         req_builder = req_builder.header(key, value);
     }
 
-    let upstream_resp = match req_builder.send().await {
-        Ok(r) => r,
-        Err(e) => {
-            tracing::warn!(
-                node = %route.node_name,
-                url = %url,
-                error = %e,
-                "proxy: upstream request failed (network)"
-            );
-            return Err(ProxyError::Upstream(e));
-        }
-    };
+    let upstream_resp = req_builder.send().await.map_err(ProxyError::Upstream)?;
 
-    let upstream_status = upstream_resp.status();
-    if !upstream_status.is_success() {
-        // Streaming body — can't snippet without breaking the stream
-        // pass-through. Log status + URL; the client still gets the
-        // upstream status, just without the leaked body.
-        tracing::warn!(
-            node = %route.node_name,
-            url = %url,
-            status = upstream_status.as_u16(),
-            "proxy: upstream returned non-2xx"
-        );
-    }
-
-    let status = StatusCode::from_u16(upstream_status.as_u16()).unwrap_or(StatusCode::BAD_GATEWAY);
+    let status =
+        StatusCode::from_u16(upstream_resp.status().as_u16()).unwrap_or(StatusCode::BAD_GATEWAY);
 
     let resp_headers = upstream_resp.headers().clone();
     let stream = upstream_resp.bytes_stream();
@@ -82,37 +52,28 @@ pub async fn forward_request(
         response = response.header(key, value);
     }
 
-    response.body(body).map_err(|e| {
-        tracing::warn!(
-            node = %route.node_name,
-            url = %url,
-            error = %e,
-            "proxy: failed to build response"
-        );
-        ProxyError::ResponseBuild(e.to_string())
-    })
+    response
+        .body(body)
+        .map_err(|e| ProxyError::ResponseBuild(e.to_string()))
 }
 
 #[derive(Debug, thiserror::Error)]
 pub enum ProxyError {
-    #[error("upstream request failed")]
+    #[error("upstream request failed: {0}")]
     Upstream(reqwest::Error),
-    #[error("failed to build response")]
+    #[error("failed to build response: {0}")]
     ResponseBuild(String),
 }
 
 impl IntoResponse for ProxyError {
     fn into_response(self) -> Response {
-        let (status, message) = match &self {
-            ProxyError::Upstream(_) => (StatusCode::BAD_GATEWAY, "upstream request failed"),
-            ProxyError::ResponseBuild(_) => (
-                StatusCode::INTERNAL_SERVER_ERROR,
-                "failed to build response",
-            ),
+        let status = match &self {
+            ProxyError::Upstream(_) => StatusCode::BAD_GATEWAY,
+            ProxyError::ResponseBuild(_) => StatusCode::INTERNAL_SERVER_ERROR,
         };
         let body = serde_json::json!({
             "error": {
-                "message": message,
+                "message": self.to_string(),
                 "type": "proxy_error",
             }
         });

crates/cortex-gateway/src/router.rs

@@ -2,21 +2,13 @@
 //!
 //! Given a model ID from an inbound request, determine which node should
 //! handle it. Priority:
-//!   1. Node where the model is currently `Loaded` → use it.
-//!   2. Node where the model is `Unloaded` → use it; neuron's existing
-//!      lazy-load behaviour will reload before serving the request.
-//!   3. Model is in the catalogue → pick a feasible neuron, call
-//!      `POST /models/load`, wait for the load to complete, then
-//!      proxy. First-request cold-load latency is acceptable per the
-//!      unified-endpoint contract.
-//!   4. Not in catalogue, not loaded anywhere → 404.
+//!   1. Node where the model is currently `Loaded`
+//!   2. Node where the model is `Unloaded` (will lazy-load on request)
+//!   3. Error: model not found on any node
 
 use crate::state::CortexState;
-use cortex_core::catalogue::ModelProfile;
-use cortex_core::harness::ModelSpec;
 use cortex_core::node::ModelStatus;
 use std::sync::Arc;
-use std::time::Duration;
 
 /// The routing decision: which node endpoint to proxy the request to.
 #[derive(Debug, Clone)]
@@ -24,31 +16,18 @@ pub struct RouteDecision {
     pub node_name: String,
     /// The inference endpoint to proxy to (from neuron's /models/{id}/endpoint).
     pub endpoint: String,
-    /// Whether the model will need to load (cold start). Set to true
-    /// when we proxied to an `Unloaded` node (lazy load on neuron) or
-    /// when we just triggered an explicit cold-load via the catalogue
-    /// path.
+    /// Whether the model will need to load (cold start).
     pub cold_start: bool,
 }
 
 #[derive(Debug, thiserror::Error)]
 pub enum RouteError {
-    #[error("model '{0}' not found on any node and not in catalogue")]
+    #[error("model '{0}' not found on any node")]
     ModelNotFound(String),
     #[error("no healthy nodes available")]
     NoHealthyNodes,
     #[error("failed to resolve inference endpoint for model '{0}' on node '{1}'")]
     EndpointResolveFailed(String, String),
-    #[error(
-        "model '{model_id}' is in the catalogue but no healthy neuron's topology satisfies its constraints"
-    )]
-    NoFeasibleNeuron { model_id: String },
-    #[error("cold-load of '{model_id}' on '{node}' failed: {message}")]
-    ColdLoadFailed {
-        model_id: String,
-        node: String,
-        message: String,
-    },
 }
 
 /// Resolve which node should serve a request for the given model.
@@ -57,231 +36,42 @@ pub async fn resolve(
     fleet: &Arc<CortexState>,
     model_id: &str,
 ) -> Result<RouteDecision, RouteError> {
-    // Snapshot loaded / unloaded state from the poller cache.
-    let (loaded_route, unloaded_route, any_healthy) = {
+    let (node_name, neuron_endpoint, cold_start) = {
         let nodes = fleet.nodes.read().await;
-        let mut loaded_route = None;
-        let mut unloaded_route = None;
-        let mut any_healthy = false;
+
+        let mut loaded_candidate = None;
+        let mut unloaded_candidate = None;
+
         for node in nodes.values() {
             if !node.healthy {
                 continue;
             }
-            any_healthy = true;
             if let Some(entry) = node.models.get(model_id) {
                 match entry.status {
                     ModelStatus::Loaded | ModelStatus::Reloading => {
-                        loaded_route = Some((node.name.clone(), node.endpoint.clone(), false));
+                        loaded_candidate = Some((node.name.clone(), node.endpoint.clone(), false));
                         break;
                     }
                     ModelStatus::Unloaded => {
-                        if unloaded_route.is_none() {
-                            unloaded_route = Some((node.name.clone(), node.endpoint.clone(), true));
+                        if unloaded_candidate.is_none() {
+                            unloaded_candidate =
+                                Some((node.name.clone(), node.endpoint.clone(), true));
                         }
                     }
                 }
             }
         }
-        (loaded_route, unloaded_route, any_healthy)
-    };
 
-    if !any_healthy {
-        return Err(RouteError::NoHealthyNodes);
-    }
-
-    // Priority 1: already loaded.
-    if let Some((node_name, neuron_endpoint, cold_start)) = loaded_route {
-        return finish(fleet, &node_name, &neuron_endpoint, model_id, cold_start).await;
-    }
-
-    // Priority 2: known to neuron but unloaded (neuron's lazy load).
-    if let Some((node_name, neuron_endpoint, cold_start)) = unloaded_route {
-        return finish(fleet, &node_name, &neuron_endpoint, model_id, cold_start).await;
-    }
-
-    // Priority 3: catalogue × topology cold-load.
-    if let Some(profile) = fleet.catalogue.get(model_id) {
-        let (node_name, neuron_endpoint) = pick_feasible_neuron(fleet, profile).await?;
-        cold_load(fleet, &node_name, &neuron_endpoint, profile).await?;
-        return finish(fleet, &node_name, &neuron_endpoint, model_id, true).await;
-    }
-
-    Err(RouteError::ModelNotFound(model_id.to_string()))
-}
-
-/// Pick a healthy neuron whose discovered topology satisfies the
-/// profile. Preference order:
-///   1. A neuron from `profile.pinned_on` that is healthy + feasible.
-///   2. Otherwise, any healthy + feasible neuron, stable by name.
-async fn pick_feasible_neuron(
-    fleet: &Arc<CortexState>,
-    profile: &ModelProfile,
-) -> Result<(String, String), RouteError> {
-    let nodes = fleet.nodes.read().await;
-    let mut candidates: Vec<(String, String, bool)> = Vec::new();
-    for node in nodes.values() {
-        if !node.healthy {
-            continue;
-        }
-        let Some(disc) = node.discovery.as_ref() else {
-            continue;
-        };
-        if !profile.is_feasible_on(&node.name, &disc.devices) {
-            continue;
-        }
-        let pinned = profile.pinned_on.iter().any(|n| n == &node.name);
-        candidates.push((node.name.clone(), node.endpoint.clone(), pinned));
-    }
-    candidates.sort_by(|a, b| {
-        b.2.cmp(&a.2) // pinned first (true > false)
-            .then(a.0.cmp(&b.0))
-    });
-    let pick = candidates.into_iter().next();
-    pick.map(|(n, e, _)| (n, e))
-        .ok_or_else(|| RouteError::NoFeasibleNeuron {
-            model_id: profile.id.clone(),
-        })
-}
-
-/// Issue `POST {endpoint}/models/load` for this profile on this neuron,
-/// blocking until the load completes (neuron's load endpoint is
-/// synchronous — it returns 200 once VRAM is materialised). On success
-/// also inserts a `Loaded` entry into the local NodeState cache so the
-/// caller's subsequent endpoint lookup sees the new model without
-/// waiting for the next poll cycle.
-async fn cold_load(
-    fleet: &Arc<CortexState>,
-    node_name: &str,
-    neuron_endpoint: &str,
-    profile: &ModelProfile,
-) -> Result<(), RouteError> {
-    let spec = profile_to_spec(fleet, node_name, profile).await;
-    let url = format!("{neuron_endpoint}/models/load");
-    tracing::info!(model = %profile.id, node = node_name, "cold-loading via /models/load");
-
-    // Generous timeout: a fresh download + safetensors mmap + device
-    // copy for a 30B-class dense model can comfortably exceed 5 min on
-    // a slow link. The HTTP client's own default already covers most
-    // of this; pin a longer per-request bound just here.
-    let resp = match fleet
-        .http_client
-        .post(&url)
-        .timeout(Duration::from_secs(1800))
-        .json(&spec)
-        .send()
-        .await
-    {
-        Ok(r) => r,
-        Err(e) => {
-            return Err(RouteError::ColdLoadFailed {
-                model_id: profile.id.clone(),
-                node: node_name.to_string(),
-                message: format!("HTTP request failed: {e}"),
-            });
-        }
-    };
-
-    let status = resp.status();
-    if !status.is_success() {
-        let body = resp.text().await.unwrap_or_default();
-        // Neuron returns 400 "already loaded" when two concurrent
-        // requests race the same model. Treat that as success — both
-        // requests effectively achieved the same end state.
-        if body.contains("already loaded") {
-            tracing::info!(
-                model = %profile.id,
-                node = node_name,
-                "cold-load saw 'already loaded' — treating as success"
-            );
-        } else {
-            return Err(RouteError::ColdLoadFailed {
-                model_id: profile.id.clone(),
-                node: node_name.to_string(),
-                message: format!("HTTP {status}: {body}"),
-            });
-        }
-    } else {
-        tracing::info!(model = %profile.id, node = node_name, "cold-load returned 200");
-    }
-
-    // Warm the cache: insert a Loaded ModelEntry so the next
-    // resolve() finds the model without waiting for the poll loop.
-    {
-        let mut nodes = fleet.nodes.write().await;
-        if let Some(node) = nodes.get_mut(node_name) {
-            node.models.insert(
-                profile.id.clone(),
-                cortex_core::node::ModelEntry {
-                    id: profile.id.clone(),
-                    status: ModelStatus::Loaded,
-                    last_accessed: Some(chrono::Utc::now()),
-                    vram_estimate_mb: profile.vram_mb,
-                },
-            );
-        }
-    }
-    Ok(())
-}
-
-/// Translate a `ModelProfile` to a `ModelSpec` neuron's /models/load
-/// accepts. Devices are picked from the neuron's discovered topology —
-/// the first `min_devices` indices that meet `min_device_vram_mb`.
-async fn profile_to_spec(
-    fleet: &Arc<CortexState>,
-    node_name: &str,
-    profile: &ModelProfile,
-) -> ModelSpec {
-    let devices = {
-        let nodes = fleet.nodes.read().await;
-        let mut picked: Vec<u32> = Vec::new();
-        if let Some(node) = nodes.get(node_name)
-            && let Some(disc) = &node.discovery
-        {
-            let min_vram = profile.min_device_vram_mb.unwrap_or(0);
-            for d in &disc.devices {
-                if d.vram_total_mb >= min_vram {
-                    picked.push(d.index);
-                    if picked.len() as u32 >= profile.min_devices {
-                        break;
-                    }
-                }
+        loaded_candidate.or(unloaded_candidate).ok_or_else(|| {
+            if nodes.values().any(|n| n.healthy) {
+                RouteError::ModelNotFound(model_id.to_string())
+            } else {
+                RouteError::NoHealthyNodes
             }
-        }
-        if picked.is_empty() {
-            // Fall back to a 0..min_devices default; pick_feasible_neuron
-            // already verified the topology satisfies the constraints,
-            // so this only fires if discovery raced or was lost.
-            (0..profile.min_devices).collect()
-        } else {
-            picked
-        }
+        })?
     };
 
-    let tensor_parallel = if profile.min_devices > 1 {
-        Some(profile.min_devices)
-    } else {
-        None
-    };
-
-    ModelSpec {
-        model_id: profile.id.clone(),
-        harness: profile.harness.clone(),
-        quant: profile.quant.clone(),
-        tensor_parallel,
-        devices: Some(devices),
-    }
-}
-
-/// Resolve neuron's `/models/{id}/endpoint` to its inference URL and
-/// build the final `RouteDecision`. Shared by all three priority
-/// branches above.
-async fn finish(
-    fleet: &Arc<CortexState>,
-    node_name: &str,
-    neuron_endpoint: &str,
-    model_id: &str,
-    cold_start: bool,
-) -> Result<RouteDecision, RouteError> {
+    // Ask the neuron for the inference endpoint for this model.
     let endpoint_url = format!(
         "{}/models/{}/endpoint",
         neuron_endpoint,
@@ -299,82 +89,13 @@ async fn finish(
         _ => None,
     };
 
-    let raw = inference_endpoint.ok_or_else(|| {
-        RouteError::EndpointResolveFailed(model_id.to_string(), node_name.to_string())
+    let endpoint = inference_endpoint.ok_or_else(|| {
+        RouteError::EndpointResolveFailed(model_id.to_string(), node_name.clone())
     })?;
 
-    // Rewrite loopback inference URLs to use the configured neuron host.
-    // Neuron's default bind_url is `http://localhost:13131` (it can't
-    // reliably know its own externally-resolvable name). Cortex sees a
-    // URL that's only meaningful from the neuron host's own perspective;
-    // proxying directly to localhost from a different cortex host would
-    // hit nothing. Keep neuron's port and path (a future harness could
-    // serve inference on a different port than the management API), but
-    // swap the host for the one in cortex.toml.
-    let endpoint = rewrite_loopback_host(&raw, neuron_endpoint).unwrap_or(raw);
-
     Ok(RouteDecision {
-        node_name: node_name.to_string(),
+        node_name,
         endpoint,
         cold_start,
     })
 }
-
-/// If `inference_url`'s host is a loopback name (localhost / 127.0.0.1 /
-/// 0.0.0.0 / ::1), return a copy with the host replaced by
-/// `neuron_endpoint`'s host. Otherwise return None and the caller falls
-/// back to the inference URL as-is.
-fn rewrite_loopback_host(inference_url: &str, neuron_endpoint: &str) -> Option<String> {
-    let inf = url::Url::parse(inference_url).ok()?;
-    let inf_host = inf.host_str()?;
-    let is_loopback = matches!(inf_host, "localhost" | "127.0.0.1" | "0.0.0.0" | "::1");
-    if !is_loopback {
-        return None;
-    }
-    let neuron = url::Url::parse(neuron_endpoint).ok()?;
-    let new_host = neuron.host_str()?;
-    let mut out = inf.clone();
-    out.set_host(Some(new_host)).ok()?;
-    // url::Url::to_string normalises an empty path to "/", which then
-    // breaks downstream callers that do format!("{endpoint}/v1/...")
-    // and produce a double slash. The proxy URL is treated as a base
-    // string that the caller appends paths to, so strip the trailing
-    // slash here.
-    let s = out.to_string();
-    Some(s.trim_end_matches('/').to_string())
-}
-
-#[cfg(test)]
-mod tests {
-    use super::rewrite_loopback_host;
-
-    #[test]
-    fn rewrites_localhost_keeps_port_and_path() {
-        let out = rewrite_loopback_host(
-            "http://localhost:13131",
-            "http://beast.hanzalova.internal:13131",
-        );
-        assert_eq!(
-            out.as_deref(),
-            Some("http://beast.hanzalova.internal:13131")
-        );
-    }
-
-    #[test]
-    fn rewrites_loopback_with_distinct_inference_port() {
-        let out = rewrite_loopback_host("http://127.0.0.1:8080", "http://beast.lan:13131");
-        assert_eq!(out.as_deref(), Some("http://beast.lan:8080"));
-    }
-
-    #[test]
-    fn leaves_non_loopback_alone() {
-        let out = rewrite_loopback_host("http://other.host:1234", "http://beast.lan:13131");
-        assert_eq!(out, None);
-    }
-
-    #[test]
-    fn malformed_inference_url_returns_none() {
-        let out = rewrite_loopback_host("not a url", "http://beast.lan:13131");
-        assert_eq!(out, None);
-    }
-}

crates/cortex-gateway/src/state.rs

@@ -26,7 +26,6 @@ impl CortexState {
                     models: HashMap::new(),
                     lifecycle_cycles: 0,
                     last_poll: None,
-                    discovery: None,
                 },
             );
         }

crates/cortex-gateway/tests/common/mod.rs

@@ -22,7 +22,6 @@ use tokio::net::TcpListener;
 /// - GET /models/:id/endpoint (returns the inference URL)
 /// - POST /models/unload (accepts unload requests)
 /// - GET /v1/chat/completions + POST /v1/chat/completions (inference)
-///
 /// Returns the neuron base URL.
 pub async fn spawn_mock_neuron() -> String {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
@@ -55,7 +54,7 @@ pub async fn spawn_mock_neuron() -> String {
 
 async fn mock_neuron_list_models() -> Json<Value> {
     Json(json!([
-        {"id": "test-model", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": 8000}
+        {"id": "test-model", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": 8000}
     ]))
 }
 

crates/cortex-gateway/tests/poller.rs

@@ -12,8 +12,8 @@ use std::sync::Arc;
 async fn test_poller_discovers_models() {
     // Mock neuron reports 2 models via /models endpoint (neuron format).
     let mock_url = common::spawn_mock_neuron_with_models(json!([
-        {"id": "model-a", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": 8000},
-        {"id": "model-b", "harness": "candle", "status": "unloaded", "devices": [], "vram_used_mb": null}
+        {"id": "model-a", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": 8000},
+        {"id": "model-b", "harness": "mistralrs", "status": "unloaded", "devices": [], "vram_used_mb": null}
     ]))
     .await;
 
@@ -63,8 +63,8 @@ async fn test_poller_discovers_models() {
 #[tokio::test]
 async fn test_poller_updates_gateway_models_endpoint() {
     let mock_url = common::spawn_mock_neuron_with_models(json!([
-        {"id": "model-x", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": null},
-        {"id": "model-y", "harness": "candle", "status": "loaded", "devices": [1], "vram_used_mb": null}
+        {"id": "model-x", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": null},
+        {"id": "model-y", "harness": "mistralrs", "status": "loaded", "devices": [1], "vram_used_mb": null}
     ]))
     .await;
 
@@ -152,8 +152,8 @@ async fn test_poller_marks_unreachable_node_unhealthy() {
 #[tokio::test]
 async fn test_poller_removes_stale_models() {
     let mock_url = common::spawn_mock_neuron_with_models(json!([
-        {"id": "keep-me", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": null},
-        {"id": "drop-me", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": null}
+        {"id": "keep-me", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": null},
+        {"id": "drop-me", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": null}
     ]))
     .await;
 
@@ -183,7 +183,7 @@ async fn test_poller_removes_stale_models() {
 
     // New mock with only one model.
     let new_mock_url = common::spawn_mock_neuron_with_models(json!([
-        {"id": "keep-me", "harness": "candle", "status": "loaded", "devices": [0], "vram_used_mb": null}
+        {"id": "keep-me", "harness": "mistralrs", "status": "loaded", "devices": [0], "vram_used_mb": null}
     ]))
     .await;
 

crates/cortex-gateway/tests/streaming.rs

@@ -51,18 +51,18 @@ async fn test_streaming_sse_passthrough() {
     }
 
     assert!(
-        chunks.len() > chunk_count,
-        "expected more than {} chunks (got {}): {:?}",
-        chunk_count,
+        chunks.len() >= chunk_count + 1,
+        "expected at least {} chunks (got {}): {:?}",
+        chunk_count + 1,
         chunks.len(),
         chunks,
     );
 
     assert_eq!(chunks.last().unwrap(), "[DONE]");
 
-    for (i, chunk) in chunks.iter().enumerate().take(chunk_count) {
+    for i in 0..chunk_count {
         let chunk_json: serde_json::Value =
-            serde_json::from_str(chunk).expect("chunk should be valid JSON");
+            serde_json::from_str(&chunks[i]).expect("chunk should be valid JSON");
         assert_eq!(
             chunk_json["choices"][0]["delta"]["content"],
             format!("token{i}")

crates/neuron/Cargo.toml

@@ -12,36 +12,6 @@ path = "src/lib.rs"
 name = "neuron"
 path = "src/main.rs"
 
-[features]
-default = []
-# Enables CUDA acceleration in candle and the cudarc/nccl bindings the
-# TP worker pool uses. Without this feature, candle compiles for CPU
-# only, Device::new_cuda calls fall back to CPU, and TP Init/sanity
-# requests return Error{kind="cuda_feature_not_enabled"}.
-cuda = [
-    "candle-core/cuda",
-    "candle-core/nccl",
-    "candle-nn/cuda",
-    "candle-transformers/cuda",
-    "dep:cudarc",
-    "dep:half",
-    "dep:cudaforge",
-]
-# Use cuDNN for convolution / attention kernels. Requires CUDA.
-cudnn = [
-    "cuda",
-    "candle-core/cudnn",
-    "candle-nn/cudnn",
-    "candle-transformers/cudnn",
-]
-# FlashAttention kernels. Requires CUDA.
-flash-attn = [
-    "cuda",
-    "candle-transformers/flash-attn",
-]
-# Reserved for GPU-only integration tests in later stages.
-cuda-integration = ["cuda"]
-
 [dependencies]
 cortex-core.workspace = true
 tokio.workspace = true
@@ -54,44 +24,9 @@ tracing-subscriber.workspace = true
 anyhow.workspace = true
 async-trait.workspace = true
 clap.workspace = true
-thiserror.workspace = true
-futures.workspace = true
-tokio-stream.workspace = true
 figment.workspace = true
 toml.workspace = true
 
-# candle for in-process inference. CUDA support is gated behind the
-# crate's `cuda` feature (default off) so the workspace builds on
-# non-CUDA hosts and CI runners.
-candle-core = "0.10.2"
-candle-nn = "0.10.2"
-candle-transformers = "0.10.2"
-# Direct dep on cudarc (matching candle's transitive version) so the
-# TP worker pool can call cudarc::nccl::{Comm, Id} directly. Gated on
-# the `cuda` feature; same toolchain requirement as candle's CUDA path.
-cudarc = { version = "0.19", optional = true, default-features = false, features = ["nccl", "cuda-version-from-build-system"] }
-# Used by the AllReduce CustomOp1 to type-dispatch on bf16/f16 candle
-# storages. Matches candle-core's pinned major version to avoid double-
-# compiling the `half` crate at conflicting versions.
-half = { version = "2.5", optional = true }
-tokenizers = { version = "0.22", default-features = false, features = ["onig"] }
-hf-hub = { version = "0.4", features = ["tokio"] }
-# Direct dep on `safetensors` (re-exported by candle but its `TensorView`
-# / `slice::IndexOp` types are public-but-not-re-exported). Used by the
-# tp `fused_load` module to read per-rank slices of fused QKV tensors
-# without materialising the full tensor on device.
-safetensors = "0.7"
-
 [dev-dependencies]
 tokio = { workspace = true, features = ["test-util"] }
 reqwest.workspace = true
-
-[build-dependencies]
-# Used by `build.rs` to compile `src/cuda/*.cu` into `libneuroncuda.a`
-# under the `cuda` feature. Matches mistralrs's upstream build setup
-# (their `mistralrs-core/build.rs` uses the same constructor).
-cudaforge = { version = "0.1", optional = true }
-
-[package.metadata.docs.rs]
-# Skip the CUDA path on docs.rs (it lacks nvcc).
-no-default-features = true

crates/neuron/build.rs

@@ -1,66 +0,0 @@
-//! Build script: compile the CUDA kernels in `src/cuda/*.cu` into a
-//! static library and link it under the `cuda` feature.
-//!
-//! Patterned on `EricLBuehler/mistral.rs::mistralrs-core/build.rs` —
-//! same `cudaforge::KernelBuilder` invocation, same NVCC flag set.
-
-fn main() {
-    #[cfg(feature = "cuda")]
-    {
-        use std::path::PathBuf;
-        println!("cargo:rerun-if-changed=build.rs");
-        println!("cargo:rerun-if-changed=src/cuda/");
-
-        let build_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
-
-        let mut builder = cudaforge::KernelBuilder::new()
-            .source_glob("src/cuda/*.cu")
-            .out_dir(&build_dir)
-            .arg("-std=c++17")
-            .arg("-O3")
-            .arg("-U__CUDA_NO_HALF_OPERATORS__")
-            .arg("-U__CUDA_NO_HALF_CONVERSIONS__")
-            .arg("-U__CUDA_NO_HALF2_OPERATORS__")
-            .arg("-U__CUDA_NO_BFLOAT16_CONVERSIONS__")
-            .arg("--expt-relaxed-constexpr")
-            .arg("--expt-extended-lambda")
-            .arg("--use_fast_math")
-            .arg("--compiler-options")
-            .arg("-fPIC");
-
-        // sm_<80 doesn't have bf16 intrinsics for WMMA — gate the
-        // bf16-only kernels off in that case. (Mirrors upstream.)
-        if let Some(compute_cap) = builder.get_compute_cap()
-            && compute_cap < 80
-        {
-            builder = builder.arg("-DNO_BF16_KERNEL");
-        }
-
-        let target = std::env::var("TARGET").unwrap();
-        let out_file = if target.contains("msvc") {
-            build_dir.join("neuroncuda.lib")
-        } else {
-            build_dir.join("libneuroncuda.a")
-        };
-
-        builder
-            .build_lib(out_file)
-            .expect("neuron cuda build failed");
-        println!("cargo:rustc-link-search={}", build_dir.display());
-        println!("cargo:rustc-link-lib=neuroncuda");
-        println!("cargo:rustc-link-lib=dylib=cudart");
-
-        if target.contains("msvc") {
-            // No extra runtime library needed.
-        } else if target.contains("apple")
-            || target.contains("freebsd")
-            || target.contains("openbsd")
-        {
-            println!("cargo:rustc-link-lib=dylib=c++");
-        } else if target.contains("android") {
-            println!("cargo:rustc-link-lib=dylib=c++_shared");
-        } else {
-            println!("cargo:rustc-link-lib=dylib=stdc++");
-        }
-    }
-}

crates/neuron/src/api.rs

@@ -1,33 +1,23 @@
 //! HTTP API handlers for the neuron daemon.
 
 use crate::harness::HarnessRegistry;
-use crate::harness::candle::{CandleHarness, InferenceError};
 use crate::health::HealthCache;
 use axum::Router;
 use axum::extract::{Path, State};
 use axum::http::StatusCode;
-use axum::response::sse::{Event, KeepAlive, Sse};
 use axum::response::{IntoResponse, Json};
 use axum::routing::{get, post};
 use cortex_core::discovery::{DiscoveryResponse, HealthResponse};
 use cortex_core::harness::ModelSpec;
-use cortex_core::openai::ChatCompletionRequest;
-use futures::stream::{self, StreamExt};
 use serde_json::{Value, json};
-use std::convert::Infallible;
 use std::sync::Arc;
 use tokio::sync::RwLock;
-use tokio_stream::wrappers::ReceiverStream;
 
 /// Shared state for the neuron HTTP server.
 pub struct NeuronState {
     pub discovery: DiscoveryResponse,
     pub health_cache: Arc<HealthCache>,
     pub registry: RwLock<HarnessRegistry>,
-    /// Typed handle to the candle harness for inference routes. Cached at
-    /// startup so `/v1/chat/completions` doesn't have to hold the registry
-    /// read lock or perform dyn-Trait dispatch per request.
-    pub candle: Option<Arc<CandleHarness>>,
 }
 
 /// Build the neuron API router.
@@ -39,7 +29,6 @@ pub fn neuron_routes() -> Router<Arc<NeuronState>> {
         .route("/models/load", post(load_model))
         .route("/models/unload", post(unload_model))
         .route("/models/{model_id}/endpoint", get(model_endpoint))
-        .route("/v1/chat/completions", post(chat_completions))
 }
 
 async fn discovery_handler(State(state): State<Arc<NeuronState>>) -> Json<DiscoveryResponse> {
@@ -56,7 +45,7 @@ async fn list_models(State(state): State<Arc<NeuronState>>) -> impl IntoResponse
         Ok(models) => Json(json!(models)).into_response(),
         Err(e) => (
             StatusCode::INTERNAL_SERVER_ERROR,
-            Json(json!({"error": format!("{e:#}")})),
+            Json(json!({"error": e.to_string()})),
         )
             .into_response(),
     }
@@ -69,22 +58,11 @@ async fn load_model(
     let registry = state.registry.read().await;
     match registry.load_model(&spec).await {
         Ok(()) => Json(json!({"status": "loaded"})).into_response(),
-        Err(e) => {
-            // Log the full anyhow chain server-side so journalctl shows
-            // the underlying failure (hf-hub timeout, permission denied,
-            // disk full, etc.) without needing to inspect the HTTP
-            // response body separately.
-            tracing::warn!(
-                model = %spec.model_id,
-                error = %format!("{e:#}"),
-                "load_model failed"
-            );
-            (
-                StatusCode::BAD_REQUEST,
-                Json(json!({"error": format!("{e:#}")})),
-            )
-                .into_response()
-        }
+        Err(e) => (
+            StatusCode::BAD_REQUEST,
+            Json(json!({"error": e.to_string()})),
+        )
+            .into_response(),
     }
 }
 
@@ -106,11 +84,7 @@ async fn unload_model(
     let registry = state.registry.read().await;
     match registry.unload_model(&model_id).await {
         Ok(()) => Json(json!({"status": "unloaded"})).into_response(),
-        Err(e) => (
-            StatusCode::NOT_FOUND,
-            Json(json!({"error": format!("{e:#}")})),
-        )
-            .into_response(),
+        Err(e) => (StatusCode::NOT_FOUND, Json(json!({"error": e.to_string()}))).into_response(),
     }
 }
 
@@ -128,61 +102,3 @@ async fn model_endpoint(
             .into_response(),
     }
 }
-
-/// OpenAI-compatible chat completions. Dispatches to streaming SSE when
-/// `stream: true` is set on the request; otherwise returns a single
-/// `ChatCompletionResponse`.
-async fn chat_completions(
-    State(state): State<Arc<NeuronState>>,
-    Json(req): Json<ChatCompletionRequest>,
-) -> impl IntoResponse {
-    let Some(candle) = state.candle.as_ref().map(Arc::clone) else {
-        return (
-            StatusCode::SERVICE_UNAVAILABLE,
-            Json(json!({"error": "candle harness not enabled on this neuron"})),
-        )
-            .into_response();
-    };
-
-    if req.stream.unwrap_or(false) {
-        match candle.chat_completion_stream(req).await {
-            Ok(rx) => {
-                // Each chunk → one SSE `data: {json}` line. After the
-                // channel closes, append the OpenAI [DONE] terminator.
-                let body_stream = ReceiverStream::new(rx).map(|chunk| {
-                    let body = serde_json::to_string(&chunk).unwrap_or_default();
-                    Ok::<_, Infallible>(Event::default().data(body))
-                });
-                let done_stream =
-                    stream::once(async { Ok::<_, Infallible>(Event::default().data("[DONE]")) });
-                Sse::new(body_stream.chain(done_stream))
-                    .keep_alive(KeepAlive::default())
-                    .into_response()
-            }
-            Err(InferenceError::ModelNotLoaded(id)) => (
-                StatusCode::NOT_FOUND,
-                Json(json!({"error": format!("model '{id}' not loaded on this neuron")})),
-            )
-                .into_response(),
-            Err(InferenceError::Other(e)) => (
-                StatusCode::INTERNAL_SERVER_ERROR,
-                Json(json!({"error": format!("{e:#}")})),
-            )
-                .into_response(),
-        }
-    } else {
-        match candle.chat_completion(req).await {
-            Ok(resp) => Json(resp).into_response(),
-            Err(InferenceError::ModelNotLoaded(id)) => (
-                StatusCode::NOT_FOUND,
-                Json(json!({"error": format!("model '{id}' not loaded on this neuron")})),
-            )
-                .into_response(),
-            Err(InferenceError::Other(e)) => (
-                StatusCode::INTERNAL_SERVER_ERROR,
-                Json(json!({"error": format!("{e:#}")})),
-            )
-                .into_response(),
-        }
-    }
-}

crates/neuron/src/config.rs

@@ -1,12 +1,12 @@
 //! Neuron configuration loaded from neuron.toml.
 
-use cortex_core::harness::{HarnessConfig, ModelSpec};
+use cortex_core::harness::HarnessConfig;
 use figment::{
     Figment,
     providers::{Env, Format, Toml},
 };
 use serde::{Deserialize, Serialize};
-use std::path::{Path, PathBuf};
+use std::path::Path;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct NeuronConfig {
@@ -14,35 +14,10 @@ pub struct NeuronConfig {
     pub port: u16,
     #[serde(default)]
     pub harnesses: Vec<HarnessConfig>,
-    /// Per-harness configuration. Currently only `candle` is recognised.
-    #[serde(default)]
-    pub harness: HarnessSettings,
-    /// Models to auto-load when the neuron service activates. Each entry
-    /// is loaded sequentially before the HTTP listener binds. A failure
-    /// on any single entry logs a warning and proceeds — broken entries
-    /// don't prevent the rest of the fleet from starting.
-    #[serde(default)]
-    pub default_models: Vec<ModelSpec>,
-}
-
-/// Settings for individual harness implementations. Each harness owns
-/// its own sub-table so users only configure the harnesses they enable.
-#[derive(Debug, Clone, Default, Serialize, Deserialize)]
-pub struct HarnessSettings {
-    #[serde(default)]
-    pub candle: CandleHarnessConfig,
-}
-
-#[derive(Debug, Clone, Default, Serialize, Deserialize)]
-pub struct CandleHarnessConfig {
-    /// HuggingFace cache directory for model weights.
-    /// When unset, defers to hf-hub's default (~/.cache/huggingface).
-    #[serde(default)]
-    pub hf_cache: Option<PathBuf>,
 }
 
 fn default_port() -> u16 {
-    13131
+    9090
 }
 
 impl NeuronConfig {
@@ -58,10 +33,8 @@ impl NeuronConfig {
 impl Default for NeuronConfig {
     fn default() -> Self {
         Self {
-            port: 13131,
+            port: 9090,
             harnesses: vec![],
-            harness: HarnessSettings::default(),
-            default_models: vec![],
         }
     }
 }

crates/neuron/src/cuda/ffi.rs

@@ -1,84 +0,0 @@
-//! FFI declarations for the CUDA kernels in `gdn.cu`.
-//!
-//! Subset of `EricLBuehler/mistral.rs::mistralrs-core/src/cuda/ffi.rs`
-//! covering only the Gated DeltaNet kernels we currently use. Other
-//! kernels in the upstream file (MoE GEMM, top-k, Mamba selective
-//! scan, etc.) would land here too as we absorb them.
-//!
-//! All function declarations are MIT-licensed from upstream and
-//! unchanged apart from this header.
-
-use std::ffi::c_void;
-
-#[allow(dead_code)]
-unsafe extern "C" {
-    // GDN (Gated Delta Net) kernels for qwen3_5 / Qwen3-Next.
-    pub(crate) fn gated_delta_rule_recurrence(
-        q: *const f32,
-        k: *const f32,
-        v: *const f32,
-        g: *const f32,
-        beta: *const f32,
-        state: *mut f32,
-        output: *mut f32,
-        bh: i32,
-        seq_len: i32,
-        k_dim: i32,
-        v_dim: i32,
-        stream: i64,
-    );
-
-    /// Chunked GDN recurrence for prefill (processes tokens in BT=64 chunks).
-    pub(crate) fn chunked_gated_delta_rule_recurrence(
-        q: *const f32,
-        k: *const f32,
-        v: *const f32,
-        g: *const f32,
-        beta: *const f32,
-        state: *mut f32,
-        output: *mut f32,
-        bh: i32,
-        seq_len: i32,
-        k_dim: i32,
-        v_dim: i32,
-        stream: i64,
-    );
-
-    pub(crate) fn causal_conv1d_update(
-        x: *const c_void,
-        weight: *const c_void,
-        conv_state: *mut c_void,
-        output: *mut c_void,
-        batch_size: i32,
-        conv_dim: i32,
-        kernel_size: i32,
-        dtype: i32,
-        stream: i64,
-    );
-
-    pub(crate) fn causal_conv1d_full(
-        x: *const c_void,
-        weight: *const c_void,
-        conv_state_out: *mut c_void,
-        output: *mut c_void,
-        batch_size: i32,
-        conv_dim: i32,
-        seq_len: i32,
-        kernel_size: i32,
-        dtype: i32,
-        stream: i64,
-    );
-
-    pub(crate) fn fused_gdn_gating(
-        b: *const c_void,
-        a: *const c_void,
-        a_log: *const f32,
-        dt_bias: *const f32,
-        beta_out: *mut c_void,
-        g_out: *mut c_void,
-        total_elements: i32,
-        num_heads: i32,
-        dtype: i32,
-        stream: i64,
-    );
-}

crates/neuron/src/cuda/gdn.cu

@@ -1,711 +0,0 @@
-// Gated DeltaNet CUDA kernels for Qwen3-Next (`model_type = "qwen3_5"`).
-//
-// Ported verbatim from `EricLBuehler/mistral.rs` under MIT terms.
-// Upstream path: mistralrs-core/src/cuda/gdn.cu. Local edits in this
-// file are limited to this banner; the kernels are unchanged so a
-// diff against upstream stays minimal.
-//
-// Five kernels exposed via `extern "C"` shims at the bottom:
-//   - gated_delta_rule_recurrence            (per-token decode)
-//   - chunked_gated_delta_rule_recurrence    (BT=64 chunked prefill)
-//   - causal_conv1d_update                    (single-token conv decode)
-//   - causal_conv1d_full                      (multi-token conv prefill)
-//   - fused_gdn_gating                        (beta = sigmoid(b);
-//                                              g = -exp(A_log) * softplus(a + dt_bias))
-
-#include "cuda_bf16.h"
-#include "cuda_fp16.h"
-#include <cmath>
-#include <cstdint>
-#include <cuda_runtime.h>
-
-// ============================================================================
-// Kernel 1: gated_delta_rule_recurrence (optimized)
-//
-// V-tiled recurrence with compile-time K dimension for register residency.
-// Grid: (ceil(V/BV), B*H), Block: (BV,). Each thread owns BK registers of
-// state. Shared memory holds k_buf and q_buf (2*BK floats).
-//
-// Optimizations over naive version:
-//   - Template BK -> float s[BK] lives in true registers (1 cycle vs ~30)
-//   - #pragma unroll on all k-loops -> full ILP
-//   - Fused decay+kv_mem pass and fused state_update+output pass
-//   - __fmaf_rn intrinsics for guaranteed fused multiply-add
-//   - BV=64 threads -> 2 warps, 6 blocks/SM on Ampere
-//
-// q,k: [BH, S, K]  v: [BH, S, V]  g,beta: [BH, S]
-// state: [BH, K, V] (in/out)  output: [BH, S, V]
-// ============================================================================
-
-// Optimized kernel: BK known at compile time -> registers + full unrolling
-template <int BK, int BV>
-__global__ void gated_delta_rule_recurrence_kernel_tiled(
-    const float *__restrict__ q,    // [BH, S, K]
-    const float *__restrict__ k,    // [BH, S, K]
-    const float *__restrict__ v,    // [BH, S, V]
-    const float *__restrict__ g,    // [BH, S]
-    const float *__restrict__ beta, // [BH, S]
-    float *__restrict__ state,      // [BH, K, V]
-    float *__restrict__ output,     // [BH, S, V]
-    int seq_len, int v_dim) {
-
-  const int v_tile = blockIdx.x;       // which V-tile
-  const int bh = blockIdx.y;           // batch*head index
-  const int tid = threadIdx.x;         // thread within tile [0, BV)
-  const int v_idx = v_tile * BV + tid; // global V index
-
-  if (v_idx >= v_dim)
-    return;
-
-  // Pointers for this (batch, head)
-  const float *q_bh = q + bh * seq_len * BK;
-  const float *k_bh = k + bh * seq_len * BK;
-  const float *v_bh = v + bh * seq_len * v_dim;
-  const float *g_bh = g + bh * seq_len;
-  const float *beta_bh = beta + bh * seq_len;
-  float *state_bh = state + bh * BK * v_dim;
-  float *out_bh = output + bh * seq_len * v_dim;
-
-  // Shared memory: k_buf[BK] + q_buf[BK]
-  __shared__ float k_buf[BK];
-  __shared__ float q_buf[BK];
-
-  // Load state column into registers — BK is compile-time, so this is
-  // a true register array (not spilled to local memory)
-  float s[BK];
-#pragma unroll
-  for (int j = 0; j < BK; j++) {
-    s[j] = state_bh[j * v_dim + v_idx];
-  }
-
-  for (int t = 0; t < seq_len; t++) {
-// Collaboratively load k_t into shared memory
-// BK / BV loads per thread (e.g. 128/64 = 2)
-#pragma unroll
-    for (int j = tid; j < BK; j += BV) {
-      k_buf[j] = k_bh[t * BK + j];
-    }
-    __syncthreads();
-
-    // Load scalars for this timestep
-    float decay = expf(g_bh[t]);
-    float beta_t = beta_bh[t];
-    float v_t = v_bh[t * v_dim + v_idx];
-
-    // Fused pass 1: decay state + compute kv_mem
-    float kv_mem = 0.0f;
-#pragma unroll
-    for (int j = 0; j < BK; j++) {
-      s[j] *= decay;
-      kv_mem = __fmaf_rn(s[j], k_buf[j], kv_mem);
-    }
-
-    // Delta rule
-    float delta = (v_t - kv_mem) * beta_t;
-
-// Collaboratively load q_t into shared memory
-#pragma unroll
-    for (int j = tid; j < BK; j += BV) {
-      q_buf[j] = q_bh[t * BK + j];
-    }
-    __syncthreads();
-
-    // Fused pass 2: update state + compute output
-    float y_t = 0.0f;
-#pragma unroll
-    for (int j = 0; j < BK; j++) {
-      s[j] = __fmaf_rn(k_buf[j], delta, s[j]);
-      y_t = __fmaf_rn(s[j], q_buf[j], y_t);
-    }
-
-    out_bh[t * v_dim + v_idx] = y_t;
-
-    __syncthreads();
-  }
-
-// Write state back
-#pragma unroll
-  for (int j = 0; j < BK; j++) {
-    state_bh[j * v_dim + v_idx] = s[j];
-  }
-}
-
-// Fallback kernel: runtime k_dim, still V-tiled for occupancy
-template <int BV, int MAX_K>
-__global__ void gated_delta_rule_recurrence_kernel_fallback(
-    const float *__restrict__ q, const float *__restrict__ k,
-    const float *__restrict__ v, const float *__restrict__ g,
-    const float *__restrict__ beta, float *__restrict__ state,
-    float *__restrict__ output, int seq_len, int k_dim, int v_dim) {
-
-  const int v_tile = blockIdx.x;
-  const int bh = blockIdx.y;
-  const int tid = threadIdx.x;
-  const int v_idx = v_tile * BV + tid;
-
-  if (v_idx >= v_dim)
-    return;
-
-  const float *q_bh = q + bh * seq_len * k_dim;
-  const float *k_bh = k + bh * seq_len * k_dim;
-  const float *v_bh = v + bh * seq_len * v_dim;
-  const float *g_bh = g + bh * seq_len;
-  const float *beta_bh = beta + bh * seq_len;
-  float *state_bh = state + bh * k_dim * v_dim;
-  float *out_bh = output + bh * seq_len * v_dim;
-
-  extern __shared__ float shared[];
-  float *k_buf = shared;
-  float *q_buf = shared + k_dim;
-
-  float s[MAX_K];
-  for (int j = 0; j < k_dim; j++) {
-    s[j] = state_bh[j * v_dim + v_idx];
-  }
-
-  for (int t = 0; t < seq_len; t++) {
-    for (int j = tid; j < k_dim; j += BV) {
-      k_buf[j] = k_bh[t * k_dim + j];
-    }
-    __syncthreads();
-
-    float decay = expf(g_bh[t]);
-    float beta_t = beta_bh[t];
-    float v_t = v_bh[t * v_dim + v_idx];
-
-    float kv_mem = 0.0f;
-    for (int j = 0; j < k_dim; j++) {
-      s[j] *= decay;
-      kv_mem = __fmaf_rn(s[j], k_buf[j], kv_mem);
-    }
-
-    float delta = (v_t - kv_mem) * beta_t;
-
-    for (int j = tid; j < k_dim; j += BV) {
-      q_buf[j] = q_bh[t * k_dim + j];
-    }
-    __syncthreads();
-
-    float y_t = 0.0f;
-    for (int j = 0; j < k_dim; j++) {
-      s[j] = __fmaf_rn(k_buf[j], delta, s[j]);
-      y_t = __fmaf_rn(s[j], q_buf[j], y_t);
-    }
-
-    out_bh[t * v_dim + v_idx] = y_t;
-
-    __syncthreads();
-  }
-
-  for (int j = 0; j < k_dim; j++) {
-    state_bh[j * v_dim + v_idx] = s[j];
-  }
-}
-
-extern "C" void gated_delta_rule_recurrence(const float *q, const float *k,
-                                            const float *v, const float *g,
-                                            const float *beta, float *state,
-                                            float *output, int bh, int seq_len,
-                                            int k_dim, int v_dim,
-                                            int64_t stream) {
-
-  const cudaStream_t custream = (cudaStream_t)stream;
-
-  if (k_dim == 128) {
-    // Fast path for Qwen3-Next (k_dim=128)
-    constexpr int BK = 128;
-    constexpr int BV = 64;
-    dim3 grid((v_dim + BV - 1) / BV, bh);
-    dim3 block(BV);
-    gated_delta_rule_recurrence_kernel_tiled<BK, BV>
-        <<<grid, block, 0, custream>>>(q, k, v, g, beta, state, output, seq_len,
-                                       v_dim);
-  } else if (k_dim == 64) {
-    // Fast path for models with k_dim=64
-    constexpr int BK = 64;
-    constexpr int BV = 64;
-    dim3 grid((v_dim + BV - 1) / BV, bh);
-    dim3 block(BV);
-    gated_delta_rule_recurrence_kernel_tiled<BK, BV>
-        <<<grid, block, 0, custream>>>(q, k, v, g, beta, state, output, seq_len,
-                                       v_dim);
-  } else {
-    // Fallback for other k_dim values (runtime loop, still V-tiled)
-    constexpr int BV = 64;
-    constexpr int MAX_K = 256;
-    dim3 grid((v_dim + BV - 1) / BV, bh);
-    dim3 block(BV);
-    size_t smem = 2 * k_dim * sizeof(float);
-    gated_delta_rule_recurrence_kernel_fallback<BV, MAX_K>
-        <<<grid, block, smem, custream>>>(q, k, v, g, beta, state, output,
-                                          seq_len, k_dim, v_dim);
-  }
-}
-
-// ============================================================================
-// Kernel 1b: chunked_gated_delta_rule_recurrence (prefill optimization)
-//
-// Processes prefill tokens in BT-token chunks instead of one at a time.
-// Within each chunk: parallel prefix sum of g, cooperative kk_dot computation,
-// forward substitution (triangular solve), output computation, and state
-// update.
-//
-// Same thread model as Kernel 1: one block per (v_tile, batch*head),
-// one thread per V-column. Each thread owns BK registers of state.
-//
-// Shared memory holds:
-//   k_chunk[BT * BK]  -- key vectors for current chunk
-//   kk_dot[BT * BT]   -- dot(k[i], k[j]) lower-triangular matrix
-//   gcum[BT]           -- cumulative sum of g within chunk
-//   beta_s[BT]         -- beta values for chunk
-//   q_buf[BK]          -- q vector (loaded one row at a time)
-//
-// q,k: [BH, S, K]  v: [BH, S, V]  g,beta: [BH, S]
-// state: [BH, K, V] (in/out)  output: [BH, S, V]
-// ============================================================================
-
-template <int BT, int BK, int BV>
-__global__ void
-chunked_gated_delta_rule_kernel(const float *__restrict__ q,    // [BH, S, K]
-                                const float *__restrict__ k,    // [BH, S, K]
-                                const float *__restrict__ v,    // [BH, S, V]
-                                const float *__restrict__ g,    // [BH, S]
-                                const float *__restrict__ beta, // [BH, S]
-                                float *__restrict__ state,      // [BH, K, V]
-                                float *__restrict__ output,     // [BH, S, V]
-                                int seq_len, int v_dim) {
-
-  const int v_tile = blockIdx.x;
-  const int bh = blockIdx.y;
-  const int tid = threadIdx.x;
-  const int v_idx = v_tile * BV + tid;
-
-  if (v_idx >= v_dim)
-    return;
-
-  const int num_chunks = (seq_len + BT - 1) / BT;
-
-  // Pointers for this (batch, head)
-  const float *q_bh = q + bh * seq_len * BK;
-  const float *k_bh = k + bh * seq_len * BK;
-  const float *v_bh = v + bh * seq_len * v_dim;
-  const float *g_bh = g + bh * seq_len;
-  const float *beta_bh = beta + bh * seq_len;
-  float *state_bh = state + bh * BK * v_dim;
-  float *out_bh = output + bh * seq_len * v_dim;
-
-  // Dynamic shared memory layout
-  extern __shared__ float smem[];
-  float *k_chunk = smem;                  // [BT * BK]
-  float *kk_dot = smem + BT * BK;         // [BT * BT]
-  float *gcum = smem + BT * BK + BT * BT; // [BT]
-  float *beta_s = gcum + BT;              // [BT]
-  float *q_buf = beta_s + BT;             // [BK]
-
-  // Load state column into registers
-  float s[BK];
-#pragma unroll
-  for (int j = 0; j < BK; j++) {
-    s[j] = state_bh[j * v_dim + v_idx];
-  }
-
-  // Per-thread register array for corrected deltas
-  float delta[BT];
-
-  for (int c = 0; c < num_chunks; c++) {
-    const int chunk_start = c * BT;
-    const int chunk_len = min(BT, seq_len - chunk_start);
-
-    // === Phase 1: Cooperative load of k, beta, g into shared memory ===
-    for (int t = 0; t < chunk_len; t++) {
-      for (int j = tid; j < BK; j += BV) {
-        k_chunk[t * BK + j] = k_bh[(chunk_start + t) * BK + j];
-      }
-    }
-    if (tid < chunk_len) {
-      beta_s[tid] = beta_bh[chunk_start + tid];
-      gcum[tid] = g_bh[chunk_start + tid];
-    }
-    __syncthreads();
-
-    // === Phase 1b: Parallel prefix sum of g (Hillis-Steele) ===
-    for (int stride = 1; stride < BT; stride <<= 1) {
-      float prev = 0.0f;
-      if (tid < chunk_len && (int)tid >= stride)
-        prev = gcum[tid - stride];
-      __syncthreads();
-      if (tid < chunk_len && (int)tid >= stride)
-        gcum[tid] += prev;
-      __syncthreads();
-    }
-
-    // === Phase 2: Compute kk_dot[i][j] = dot(k[i], k[j]) for j < i ===
-    // Only lower-triangular entries needed (strictly lower)
-    for (int idx = tid; idx < chunk_len * chunk_len; idx += BV) {
-      int i = idx / chunk_len;
-      int j = idx % chunk_len;
-      if (j < i) {
-        float dot = 0.0f;
-        for (int d = 0; d < BK; d++) {
-          dot = __fmaf_rn(k_chunk[i * BK + d], k_chunk[j * BK + d], dot);
-        }
-        kk_dot[i * BT + j] = dot;
-      }
-    }
-    __syncthreads();
-
-    // === Phase 3: Forward substitution (per V-column, in registers) ===
-    // Computes corrected delta values via triangular solve
-    for (int i = 0; i < chunk_len; i++) {
-      float v_i = v_bh[(chunk_start + i) * v_dim + v_idx];
-      float decay_i = expf(gcum[i]);
-      float beta_i = beta_s[i];
-
-      // Inter-chunk contribution: state @ k[i] with decay
-      float kv_mem = 0.0f;
-#pragma unroll
-      for (int d = 0; d < BK; d++) {
-        kv_mem = __fmaf_rn(s[d] * decay_i, k_chunk[i * BK + d], kv_mem);
-      }
-
-      float rhs = beta_i * (v_i - kv_mem);
-
-      // Subtract lower-triangular contributions (intra-chunk)
-      for (int j = 0; j < i; j++) {
-        float a_ij = beta_i * kk_dot[i * BT + j] * expf(gcum[i] - gcum[j]);
-        rhs -= a_ij * delta[j];
-      }
-      delta[i] = rhs;
-    }
-
-    // === Phase 4: Output computation (per V-column) ===
-    for (int i = 0; i < chunk_len; i++) {
-      // Cooperatively load q[i] into shared
-      for (int j = tid; j < BK; j += BV) {
-        q_buf[j] = q_bh[(chunk_start + i) * BK + j];
-      }
-      __syncthreads();
-
-      float decay_i = expf(gcum[i]);
-
-      // Inter-chunk contribution: q[i] @ (state * decay)
-      float o_val = 0.0f;
-#pragma unroll
-      for (int d = 0; d < BK; d++) {
-        o_val = __fmaf_rn(q_buf[d], s[d] * decay_i, o_val);
-      }
-
-      // Intra-chunk contribution: sum_{j<=i} dot(q[i], k[j]) * delta[j] *
-      // exp(gcum[i] - gcum[j])
-      for (int j = 0; j <= i; j++) {
-        float qk_dot = 0.0f;
-        for (int d = 0; d < BK; d++) {
-          qk_dot = __fmaf_rn(q_buf[d], k_chunk[j * BK + d], qk_dot);
-        }
-        o_val += qk_dot * delta[j] * expf(gcum[i] - gcum[j]);
-      }
-
-      out_bh[(chunk_start + i) * v_dim + v_idx] = o_val;
-      __syncthreads();
-    }
-
-    // === Phase 5: State update for next chunk ===
-    float g_total = gcum[chunk_len - 1];
-#pragma unroll
-    for (int d = 0; d < BK; d++) {
-      float s_new = s[d] * expf(g_total);
-      for (int t = 0; t < chunk_len; t++) {
-        s_new += k_chunk[t * BK + d] * delta[t] * expf(g_total - gcum[t]);
-      }
-      s[d] = s_new;
-    }
-
-    __syncthreads();
-  }
-
-  // Write final state back
-#pragma unroll
-  for (int j = 0; j < BK; j++) {
-    state_bh[j * v_dim + v_idx] = s[j];
-  }
-}
-
-extern "C" void chunked_gated_delta_rule_recurrence(
-    const float *q, const float *k, const float *v, const float *g,
-    const float *beta, float *state, float *output, int bh, int seq_len,
-    int k_dim, int v_dim, int64_t stream) {
-
-  const cudaStream_t custream = (cudaStream_t)stream;
-
-  if (k_dim == 128) {
-    constexpr int BT = 64;
-    constexpr int BK = 128;
-    constexpr int BV = 64;
-    // Shared memory: BT*BK + BT*BT + BT + BT + BK floats
-    size_t smem = (BT * BK + BT * BT + 2 * BT + BK) * sizeof(float);
-
-    // Request extended shared memory
-    auto kernel = chunked_gated_delta_rule_kernel<BT, BK, BV>;
-    cudaFuncSetAttribute(kernel, cudaFuncAttributeMaxDynamicSharedMemorySize,
-                         smem);
-
-    dim3 grid((v_dim + BV - 1) / BV, bh);
-    dim3 block(BV);
-    kernel<<<grid, block, smem, custream>>>(q, k, v, g, beta, state, output,
-                                            seq_len, v_dim);
-  } else if (k_dim == 64) {
-    constexpr int BT = 64;
-    constexpr int BK = 64;
-    constexpr int BV = 64;
-    size_t smem = (BT * BK + BT * BT + 2 * BT + BK) * sizeof(float);
-
-    auto kernel = chunked_gated_delta_rule_kernel<BT, BK, BV>;
-    cudaFuncSetAttribute(kernel, cudaFuncAttributeMaxDynamicSharedMemorySize,
-                         smem);
-
-    dim3 grid((v_dim + BV - 1) / BV, bh);
-    dim3 block(BV);
-    kernel<<<grid, block, smem, custream>>>(q, k, v, g, beta, state, output,
-                                            seq_len, v_dim);
-  } else {
-    // Fallback: use the sequential kernel for unsupported k_dim
-    gated_delta_rule_recurrence(q, k, v, g, beta, state, output, bh, seq_len,
-                                k_dim, v_dim, stream);
-  }
-}
-
-// ============================================================================
-// Kernel 2a: causal_conv1d_update (decode path, single step)
-//
-// Each thread handles one channel: shift conv_state left by 1,
-// insert new value, dot product with weight, apply SiLU.
-//
-// x: [B, conv_dim, 1]  weight: [conv_dim, kernel_size]
-// conv_state: [B, conv_dim, kernel_size] (in/out)
-// output: [B, conv_dim, 1]
-// ============================================================================
-
-template <typename T>
-__global__ void causal_conv1d_update_kernel(
-    const T *__restrict__ x,      // [B, conv_dim, 1]
-    const T *__restrict__ weight, // [conv_dim, kernel_size]
-    T *__restrict__ conv_state,   // [B, conv_dim, kernel_size]
-    T *__restrict__ output,       // [B, conv_dim, 1]
-    int batch_size, int conv_dim, int kernel_size) {
-
-  const int ch = blockIdx.x * blockDim.x + threadIdx.x;
-  const int b = blockIdx.y;
-
-  if (ch >= conv_dim || b >= batch_size)
-    return;
-
-  // Pointer to this batch/channel's conv state
-  T *cs = conv_state + (b * conv_dim + ch) * kernel_size;
-  const T *w = weight + ch * kernel_size;
-
-  // Shift state left by 1
-  for (int i = 0; i < kernel_size - 1; i++) {
-    cs[i] = cs[i + 1];
-  }
-  // Insert new value
-  cs[kernel_size - 1] = x[b * conv_dim + ch];
-
-  // Dot product with weight
-  float acc = 0.0f;
-  for (int i = 0; i < kernel_size; i++) {
-    acc += (float)cs[i] * (float)w[i];
-  }
-
-  // SiLU activation: x * sigmoid(x)
-  float sig = 1.0f / (1.0f + expf(-acc));
-  float result = acc * sig;
-
-  output[b * conv_dim + ch] = (T)result;
-}
-
-extern "C" void causal_conv1d_update(const void *x, const void *weight,
-                                     void *conv_state, void *output,
-                                     int batch_size, int conv_dim,
-                                     int kernel_size, int dtype,
-                                     int64_t stream) {
-  const cudaStream_t custream = (cudaStream_t)stream;
-  dim3 block(256);
-  dim3 grid((conv_dim + 255) / 256, batch_size);
-
-  if (dtype == 0) {
-    // f16
-    causal_conv1d_update_kernel<__half><<<grid, block, 0, custream>>>(
-        (const __half *)x, (const __half *)weight, (__half *)conv_state,
-        (__half *)output, batch_size, conv_dim, kernel_size);
-  } else {
-    // bf16
-    causal_conv1d_update_kernel<__nv_bfloat16><<<grid, block, 0, custream>>>(
-        (const __nv_bfloat16 *)x, (const __nv_bfloat16 *)weight,
-        (__nv_bfloat16 *)conv_state, (__nv_bfloat16 *)output, batch_size,
-        conv_dim, kernel_size);
-  }
-}
-
-// ============================================================================
-// Kernel 2b: causal_conv1d_full (prefill path)
-//
-// Each thread handles one (channel, position): causal window with
-// zero-padding, dot product with weight, SiLU.
-// A second pass writes the conv_state from the last kernel_size positions.
-//
-// x: [B, conv_dim, S]  weight: [conv_dim, kernel_size]
-// conv_state_out: [B, conv_dim, kernel_size]  output: [B, conv_dim, S]
-// ============================================================================
-
-template <typename T>
-__global__ void causal_conv1d_full_kernel(
-    const T *__restrict__ x,      // [B, conv_dim, S]
-    const T *__restrict__ weight, // [conv_dim, kernel_size]
-    T *__restrict__ output,       // [B, conv_dim, S]
-    int batch_size, int conv_dim, int seq_len, int kernel_size) {
-
-  const int ch = blockIdx.x * blockDim.x + threadIdx.x;
-  const int pos = blockIdx.y;
-  const int b = blockIdx.z;
-
-  if (ch >= conv_dim || pos >= seq_len || b >= batch_size)
-    return;
-
-  const T *x_bch = x + (b * conv_dim + ch) * seq_len;
-  const T *w = weight + ch * kernel_size;
-
-  // Causal convolution: sum over kernel_size window ending at pos
-  float acc = 0.0f;
-  for (int i = 0; i < kernel_size; i++) {
-    int src_pos = pos - (kernel_size - 1) + i;
-    float x_val = (src_pos >= 0) ? (float)x_bch[src_pos] : 0.0f;
-    acc += x_val * (float)w[i];
-  }
-
-  // SiLU
-  float sig = 1.0f / (1.0f + expf(-acc));
-  float result = acc * sig;
-
-  output[(b * conv_dim + ch) * seq_len + pos] = (T)result;
-}
-
-template <typename T>
-__global__ void save_conv_state_kernel(
-    const T *__restrict__ x,        // [B, conv_dim, S]
-    T *__restrict__ conv_state_out, // [B, conv_dim, kernel_size]
-    int batch_size, int conv_dim, int seq_len, int kernel_size) {
-
-  const int ch = blockIdx.x * blockDim.x + threadIdx.x;
-  const int b = blockIdx.y;
-
-  if (ch >= conv_dim || b >= batch_size)
-    return;
-
-  const T *x_bch = x + (b * conv_dim + ch) * seq_len;
-  T *cs = conv_state_out + (b * conv_dim + ch) * kernel_size;
-
-  // Save last kernel_size positions (zero-pad if seq_len < kernel_size)
-  int pad = kernel_size - seq_len;
-  for (int i = 0; i < kernel_size; i++) {
-    if (i < pad) {
-      cs[i] = (T)0.0f;
-    } else {
-      cs[i] = x_bch[seq_len - kernel_size + i];
-    }
-  }
-}
-
-extern "C" void causal_conv1d_full(const void *x, const void *weight,
-                                   void *conv_state_out, void *output,
-                                   int batch_size, int conv_dim, int seq_len,
-                                   int kernel_size, int dtype, int64_t stream) {
-  const cudaStream_t custream = (cudaStream_t)stream;
-
-  // Main convolution kernel
-  dim3 block(256);
-  dim3 grid((conv_dim + 255) / 256, seq_len, batch_size);
-
-  if (dtype == 0) {
-    causal_conv1d_full_kernel<__half><<<grid, block, 0, custream>>>(
-        (const __half *)x, (const __half *)weight, (__half *)output, batch_size,
-        conv_dim, seq_len, kernel_size);
-    // Save conv state
-    dim3 grid2((conv_dim + 255) / 256, batch_size);
-    save_conv_state_kernel<__half><<<grid2, block, 0, custream>>>(
-        (const __half *)x, (__half *)conv_state_out, batch_size, conv_dim,
-        seq_len, kernel_size);
-  } else {
-    causal_conv1d_full_kernel<__nv_bfloat16><<<grid, block, 0, custream>>>(
-        (const __nv_bfloat16 *)x, (const __nv_bfloat16 *)weight,
-        (__nv_bfloat16 *)output, batch_size, conv_dim, seq_len, kernel_size);
-    dim3 grid2((conv_dim + 255) / 256, batch_size);
-    save_conv_state_kernel<__nv_bfloat16><<<grid2, block, 0, custream>>>(
-        (const __nv_bfloat16 *)x, (__nv_bfloat16 *)conv_state_out, batch_size,
-        conv_dim, seq_len, kernel_size);
-  }
-}
-
-// ============================================================================
-// Kernel 3: fused_gdn_gating
-//
-// Fuses: beta = sigmoid(b), g = -exp(a_log) * softplus(a + dt_bias)
-// a_log and dt_bias are per-head (broadcast over batch*seq).
-//
-// b, a: [total]  a_log, dt_bias: [num_heads]
-// beta_out, g_out: [total]
-// ============================================================================
-
-template <typename T>
-__global__ void
-fused_gdn_gating_kernel(const T *__restrict__ b,           // [total]
-                        const T *__restrict__ a,           // [total]
-                        const float *__restrict__ a_log,   // [num_heads]
-                        const float *__restrict__ dt_bias, // [num_heads]
-                        T *__restrict__ beta_out,          // [total]
-                        T *__restrict__ g_out,             // [total]
-                        int total_elements, int num_heads) {
-
-  const int idx = blockIdx.x * blockDim.x + threadIdx.x;
-  if (idx >= total_elements)
-    return;
-
-  // Head index: elements are laid out as [..., num_heads]
-  int head_idx = idx % num_heads;
-
-  // beta = sigmoid(b)
-  float b_val = (float)b[idx];
-  float beta = 1.0f / (1.0f + expf(-b_val));
-
-  // g = -exp(a_log) * softplus(a + dt_bias)
-  float a_val = (float)a[idx];
-  float a_log_val = a_log[head_idx];
-  float dt_bias_val = dt_bias[head_idx];
-
-  float sp_input = a_val + dt_bias_val;
-  float softplus_val = logf(1.0f + expf(sp_input));
-  float g_val = -expf(a_log_val) * softplus_val;
-
-  beta_out[idx] = (T)beta;
-  g_out[idx] = (T)g_val;
-}
-
-extern "C" void fused_gdn_gating(const void *b, const void *a,
-                                 const float *a_log, const float *dt_bias,
-                                 void *beta_out, void *g_out,
-                                 int total_elements, int num_heads, int dtype,
-                                 int64_t stream) {
-  const cudaStream_t custream = (cudaStream_t)stream;
-  dim3 block(256);
-  dim3 grid((total_elements + 255) / 256);
-
-  if (dtype == 0) {
-    fused_gdn_gating_kernel<__half><<<grid, block, 0, custream>>>(
-        (const __half *)b, (const __half *)a, a_log, dt_bias,
-        (__half *)beta_out, (__half *)g_out, total_elements, num_heads);
-  } else {
-    fused_gdn_gating_kernel<__nv_bfloat16><<<grid, block, 0, custream>>>(
-        (const __nv_bfloat16 *)b, (const __nv_bfloat16 *)a, a_log, dt_bias,
-        (__nv_bfloat16 *)beta_out, (__nv_bfloat16 *)g_out, total_elements,
-        num_heads);
-  }
-}

crates/neuron/src/cuda/gdn.rs

@@ -1,486 +0,0 @@
-//! Rust wrappers around the Gated DeltaNet CUDA kernels in `gdn.cu`.
-//!
-//! Ported verbatim from `EricLBuehler/mistral.rs` under MIT terms.
-//! Upstream path: `mistralrs-core/src/cuda/gdn.rs`. The only edits in
-//! this file are this header comment — the FFI path module name is
-//! `crate::cuda::ffi`, identical to upstream's layout.
-
-#![allow(clippy::cast_possible_truncation)]
-
-use candle_core::{Result, Tensor};
-
-#[cfg(feature = "cuda")]
-use candle_core::DType;
-
-/// CUDA-accelerated gated delta rule recurrence.
-///
-/// Inputs (all contiguous, f32):
-///   q, k: [BH, S, K]  v: [BH, S, V]  g, beta: [BH, S]
-///   state: [BH, K, V] (mutated in place)
-///
-/// Returns: output [BH, S, V]
-#[cfg(feature = "cuda")]
-pub fn gated_delta_rule_recurrence_cuda(
-    q: &Tensor,
-    k: &Tensor,
-    v: &Tensor,
-    g: &Tensor,
-    beta: &Tensor,
-    state: &mut Tensor,
-) -> Result<Tensor> {
-    use candle::cuda_backend::cudarc::driver::DevicePtr;
-    use candle_core as candle;
-
-    let (bh, seq_len, k_dim) = q.dims3()?;
-    let v_dim = v.dim(2)?;
-
-    let dev = q.device().as_cuda_device()?;
-
-    let (q_s, q_l) = q.storage_and_layout();
-    let q_s = match &*q_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("q must be a cuda tensor"),
-    };
-    let q_offset = q_l.start_offset();
-
-    let (k_s, k_l) = k.storage_and_layout();
-    let k_s = match &*k_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("k must be a cuda tensor"),
-    };
-    let k_offset = k_l.start_offset();
-
-    let (v_s, v_l) = v.storage_and_layout();
-    let v_s = match &*v_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("v must be a cuda tensor"),
-    };
-    let v_offset = v_l.start_offset();
-
-    let (g_s, g_l) = g.storage_and_layout();
-    let g_s = match &*g_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("g must be a cuda tensor"),
-    };
-    let g_offset = g_l.start_offset();
-
-    let (beta_s, beta_l) = beta.storage_and_layout();
-    let beta_s = match &*beta_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("beta must be a cuda tensor"),
-    };
-    let beta_offset = beta_l.start_offset();
-
-    let (state_s, state_l) = state.storage_and_layout();
-    let state_s = match &*state_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("state must be a cuda tensor"),
-    };
-    let state_offset = state_l.start_offset();
-
-    let output_buf = unsafe { dev.alloc::<f32>(bh * seq_len * v_dim) }?;
-
-    let stream = dev.cuda_stream().cu_stream() as i64;
-
-    unsafe {
-        crate::cuda::ffi::gated_delta_rule_recurrence(
-            q_s.slice(q_offset..).device_ptr(q_s.stream()).0 as *const f32,
-            k_s.slice(k_offset..).device_ptr(k_s.stream()).0 as *const f32,
-            v_s.slice(v_offset..).device_ptr(v_s.stream()).0 as *const f32,
-            g_s.slice(g_offset..).device_ptr(g_s.stream()).0 as *const f32,
-            beta_s.slice(beta_offset..).device_ptr(beta_s.stream()).0 as *const f32,
-            state_s.slice(state_offset..).device_ptr(state_s.stream()).0 as *mut f32,
-            output_buf.device_ptr(output_buf.stream()).0 as *mut f32,
-            bh as i32,
-            seq_len as i32,
-            k_dim as i32,
-            v_dim as i32,
-            stream,
-        );
-    }
-
-    // The kernel wrote state in-place via the raw pointer; rewrap
-    // (state tensor's underlying CudaSlice was modified directly)
-
-    let output_storage = candle::CudaStorage::wrap_cuda_slice(output_buf, dev.clone());
-    Ok(Tensor::from((
-        candle::Storage::Cuda(output_storage),
-        (bh, seq_len, v_dim),
-    )))
-}
-
-#[cfg(not(feature = "cuda"))]
-#[allow(unused)]
-pub fn gated_delta_rule_recurrence_cuda(
-    _q: &Tensor,
-    _k: &Tensor,
-    _v: &Tensor,
-    _g: &Tensor,
-    _beta: &Tensor,
-    _state: &mut Tensor,
-) -> Result<Tensor> {
-    candle_core::bail!("gated_delta_rule_recurrence_cuda requires the cuda feature")
-}
-
-/// CUDA-accelerated chunked gated delta rule recurrence (prefill optimization).
-///
-/// Processes prefill tokens in 64-token chunks instead of one at a time.
-/// Same interface as `gated_delta_rule_recurrence_cuda`.
-///
-/// Inputs (all contiguous, f32):
-///   q, k: [BH, S, K]  v: [BH, S, V]  g, beta: [BH, S]
-///   state: [BH, K, V] (mutated in place)
-///
-/// Returns: output [BH, S, V]
-#[cfg(feature = "cuda")]
-pub fn chunked_gated_delta_rule_recurrence_cuda(
-    q: &Tensor,
-    k: &Tensor,
-    v: &Tensor,
-    g: &Tensor,
-    beta: &Tensor,
-    state: &mut Tensor,
-) -> Result<Tensor> {
-    use candle::cuda_backend::cudarc::driver::DevicePtr;
-    use candle_core as candle;
-
-    let (bh, seq_len, k_dim) = q.dims3()?;
-    let v_dim = v.dim(2)?;
-
-    let dev = q.device().as_cuda_device()?;
-
-    let (q_s, q_l) = q.storage_and_layout();
-    let q_s = match &*q_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("q must be a cuda tensor"),
-    };
-    let q_offset = q_l.start_offset();
-
-    let (k_s, k_l) = k.storage_and_layout();
-    let k_s = match &*k_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("k must be a cuda tensor"),
-    };
-    let k_offset = k_l.start_offset();
-
-    let (v_s, v_l) = v.storage_and_layout();
-    let v_s = match &*v_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("v must be a cuda tensor"),
-    };
-    let v_offset = v_l.start_offset();
-
-    let (g_s, g_l) = g.storage_and_layout();
-    let g_s = match &*g_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("g must be a cuda tensor"),
-    };
-    let g_offset = g_l.start_offset();
-
-    let (beta_s, beta_l) = beta.storage_and_layout();
-    let beta_s = match &*beta_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("beta must be a cuda tensor"),
-    };
-    let beta_offset = beta_l.start_offset();
-
-    let (state_s, state_l) = state.storage_and_layout();
-    let state_s = match &*state_s {
-        candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-        _ => candle::bail!("state must be a cuda tensor"),
-    };
-    let state_offset = state_l.start_offset();
-
-    let output_buf = unsafe { dev.alloc::<f32>(bh * seq_len * v_dim) }?;
-
-    let stream = dev.cuda_stream().cu_stream() as i64;
-
-    unsafe {
-        crate::cuda::ffi::chunked_gated_delta_rule_recurrence(
-            q_s.slice(q_offset..).device_ptr(q_s.stream()).0 as *const f32,
-            k_s.slice(k_offset..).device_ptr(k_s.stream()).0 as *const f32,
-            v_s.slice(v_offset..).device_ptr(v_s.stream()).0 as *const f32,
-            g_s.slice(g_offset..).device_ptr(g_s.stream()).0 as *const f32,
-            beta_s.slice(beta_offset..).device_ptr(beta_s.stream()).0 as *const f32,
-            state_s.slice(state_offset..).device_ptr(state_s.stream()).0 as *mut f32,
-            output_buf.device_ptr(output_buf.stream()).0 as *mut f32,
-            bh as i32,
-            seq_len as i32,
-            k_dim as i32,
-            v_dim as i32,
-            stream,
-        );
-    }
-
-    let output_storage = candle::CudaStorage::wrap_cuda_slice(output_buf, dev.clone());
-    Ok(Tensor::from((
-        candle::Storage::Cuda(output_storage),
-        (bh, seq_len, v_dim),
-    )))
-}
-
-#[cfg(not(feature = "cuda"))]
-#[allow(unused)]
-pub fn chunked_gated_delta_rule_recurrence_cuda(
-    _q: &Tensor,
-    _k: &Tensor,
-    _v: &Tensor,
-    _g: &Tensor,
-    _beta: &Tensor,
-    _state: &mut Tensor,
-) -> Result<Tensor> {
-    candle_core::bail!("chunked_gated_delta_rule_recurrence_cuda requires the cuda feature")
-}
-
-/// CUDA-accelerated causal conv1d (both update and full paths).
-///
-/// For update (is_update=true):
-///   x: [B, conv_dim, 1]  weight: [conv_dim, kernel_size]
-///   conv_state: [B, conv_dim, kernel_size] (mutated in place for update)
-///   Returns: (output [B, conv_dim, 1], updated conv_state)
-///
-/// For full (is_update=false):
-///   x: [B, conv_dim, S]  weight: [conv_dim, kernel_size]
-///   Returns: (output [B, conv_dim, S], new conv_state [B, conv_dim, kernel_size])
-#[cfg(feature = "cuda")]
-pub fn causal_conv1d_cuda(
-    x: &Tensor,
-    weight: &Tensor,
-    conv_state: &Tensor,
-    kernel_size: usize,
-    is_update: bool,
-) -> Result<(Tensor, Tensor)> {
-    use candle::cuda_backend::cudarc::driver::DevicePtr;
-    use candle_core as candle;
-    use core::ffi::c_void;
-    fn cuda_fwd<
-        T: candle::cuda_backend::CudaDType + candle::cuda_backend::cudarc::driver::DeviceRepr,
-    >(
-        x: &Tensor,
-        weight: &Tensor,
-        conv_state: &Tensor,
-        kernel_size: usize,
-        is_update: bool,
-        dtype_code: i32,
-    ) -> Result<(Tensor, Tensor)> {
-        let dev = x.device().as_cuda_device()?;
-        let (batch_size, conv_dim, seq_len) = x.dims3()?;
-
-        let (x_s, x_l) = x.storage_and_layout();
-        let x_s = match &*x_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<T>()?,
-            _ => candle::bail!("x must be a cuda tensor"),
-        };
-        let x_offset = x_l.start_offset();
-
-        let (w_s, w_l) = weight.storage_and_layout();
-        let w_s = match &*w_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<T>()?,
-            _ => candle::bail!("weight must be a cuda tensor"),
-        };
-        let w_offset = w_l.start_offset();
-
-        let stream = dev.cuda_stream().cu_stream() as i64;
-
-        if is_update {
-            // Clone conv_state so the kernel can mutate it in place
-            let conv_state_new = conv_state.clone();
-
-            let output_buf = unsafe { dev.alloc::<T>(batch_size * conv_dim) }?;
-
-            // Scope the borrow of conv_state_new so we can move it later
-            {
-                let (cs_s, cs_l) = conv_state_new.storage_and_layout();
-                let cs_s = match &*cs_s {
-                    candle::Storage::Cuda(c) => c.as_cuda_slice::<T>()?,
-                    _ => candle::bail!("conv_state must be a cuda tensor"),
-                };
-                let cs_offset = cs_l.start_offset();
-
-                unsafe {
-                    crate::cuda::ffi::causal_conv1d_update(
-                        x_s.slice(x_offset..).device_ptr(x_s.stream()).0 as *const c_void,
-                        w_s.slice(w_offset..).device_ptr(w_s.stream()).0 as *const c_void,
-                        cs_s.slice(cs_offset..).device_ptr(cs_s.stream()).0 as *mut c_void,
-                        output_buf.device_ptr(output_buf.stream()).0 as *mut c_void,
-                        batch_size as i32,
-                        conv_dim as i32,
-                        kernel_size as i32,
-                        dtype_code,
-                        stream,
-                    );
-                }
-            }
-
-            let output_storage = candle::CudaStorage::wrap_cuda_slice(output_buf, dev.clone());
-            let output = Tensor::from((
-                candle::Storage::Cuda(output_storage),
-                (batch_size, conv_dim, 1usize),
-            ));
-
-            Ok((output, conv_state_new))
-        } else {
-            // Full path: allocate new conv_state and output
-            let output_buf = unsafe { dev.alloc::<T>(batch_size * conv_dim * seq_len) }?;
-            let cs_buf = unsafe { dev.alloc::<T>(batch_size * conv_dim * kernel_size) }?;
-
-            unsafe {
-                crate::cuda::ffi::causal_conv1d_full(
-                    x_s.slice(x_offset..).device_ptr(x_s.stream()).0 as *const c_void,
-                    w_s.slice(w_offset..).device_ptr(w_s.stream()).0 as *const c_void,
-                    cs_buf.device_ptr(cs_buf.stream()).0 as *mut c_void,
-                    output_buf.device_ptr(output_buf.stream()).0 as *mut c_void,
-                    batch_size as i32,
-                    conv_dim as i32,
-                    seq_len as i32,
-                    kernel_size as i32,
-                    dtype_code,
-                    stream,
-                );
-            }
-
-            let output_storage = candle::CudaStorage::wrap_cuda_slice(output_buf, dev.clone());
-            let output = Tensor::from((
-                candle::Storage::Cuda(output_storage),
-                (batch_size, conv_dim, seq_len),
-            ));
-
-            let cs_storage = candle::CudaStorage::wrap_cuda_slice(cs_buf, dev.clone());
-            let new_conv_state = Tensor::from((
-                candle::Storage::Cuda(cs_storage),
-                (batch_size, conv_dim, kernel_size),
-            ));
-
-            Ok((output, new_conv_state))
-        }
-    }
-
-    match x.dtype() {
-        DType::F16 => cuda_fwd::<half::f16>(x, weight, conv_state, kernel_size, is_update, 0),
-        DType::BF16 => cuda_fwd::<half::bf16>(x, weight, conv_state, kernel_size, is_update, 1),
-        other => candle_core::bail!("causal_conv1d_cuda only supports f16/bf16, got {:?}", other),
-    }
-}
-
-#[cfg(not(feature = "cuda"))]
-#[allow(unused)]
-pub fn causal_conv1d_cuda(
-    _x: &Tensor,
-    _weight: &Tensor,
-    _conv_state: &Tensor,
-    _kernel_size: usize,
-    _is_update: bool,
-) -> Result<(Tensor, Tensor)> {
-    candle_core::bail!("causal_conv1d_cuda requires the cuda feature")
-}
-
-/// CUDA-accelerated fused GDN gating computation.
-///
-/// Computes: beta = sigmoid(b), g = -exp(a_log) * softplus(a + dt_bias)
-///
-/// b, a: [total_elements] in f16/bf16
-/// a_log, dt_bias: [num_heads] in f32
-///
-/// Returns: (beta, g) in original dtype
-#[cfg(feature = "cuda")]
-pub fn fused_gdn_gating_cuda(
-    b: &Tensor,
-    a: &Tensor,
-    a_log: &Tensor,
-    dt_bias: &Tensor,
-) -> Result<(Tensor, Tensor)> {
-    use candle::cuda_backend::cudarc::driver::DevicePtr;
-    use candle_core as candle;
-    use core::ffi::c_void;
-
-    fn cuda_fwd<
-        T: candle::cuda_backend::CudaDType + candle::cuda_backend::cudarc::driver::DeviceRepr,
-    >(
-        b: &Tensor,
-        a: &Tensor,
-        a_log: &Tensor,
-        dt_bias: &Tensor,
-        dtype_code: i32,
-    ) -> Result<(Tensor, Tensor)> {
-        let total_elements = b.elem_count();
-        let num_heads = a_log.elem_count();
-        let shape = b.shape().clone();
-        let dev = b.device().as_cuda_device()?;
-
-        let (b_s, b_l) = b.storage_and_layout();
-        let b_s = match &*b_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<T>()?,
-            _ => candle::bail!("b must be a cuda tensor"),
-        };
-        let b_offset = b_l.start_offset();
-
-        let (a_s, a_l) = a.storage_and_layout();
-        let a_s = match &*a_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<T>()?,
-            _ => candle::bail!("a must be a cuda tensor"),
-        };
-        let a_offset = a_l.start_offset();
-
-        let (alog_s, alog_l) = a_log.storage_and_layout();
-        let alog_s = match &*alog_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-            _ => candle::bail!("a_log must be a cuda tensor"),
-        };
-        let alog_offset = alog_l.start_offset();
-
-        let (dtb_s, dtb_l) = dt_bias.storage_and_layout();
-        let dtb_s = match &*dtb_s {
-            candle::Storage::Cuda(c) => c.as_cuda_slice::<f32>()?,
-            _ => candle::bail!("dt_bias must be a cuda tensor"),
-        };
-        let dtb_offset = dtb_l.start_offset();
-
-        let beta_buf = unsafe { dev.alloc::<T>(total_elements) }?;
-        let g_buf = unsafe { dev.alloc::<T>(total_elements) }?;
-
-        let stream = dev.cuda_stream().cu_stream() as i64;
-
-        unsafe {
-            crate::cuda::ffi::fused_gdn_gating(
-                b_s.slice(b_offset..).device_ptr(b_s.stream()).0 as *const c_void,
-                a_s.slice(a_offset..).device_ptr(a_s.stream()).0 as *const c_void,
-                alog_s.slice(alog_offset..).device_ptr(alog_s.stream()).0 as *const f32,
-                dtb_s.slice(dtb_offset..).device_ptr(dtb_s.stream()).0 as *const f32,
-                beta_buf.device_ptr(beta_buf.stream()).0 as *mut c_void,
-                g_buf.device_ptr(g_buf.stream()).0 as *mut c_void,
-                total_elements as i32,
-                num_heads as i32,
-                dtype_code,
-                stream,
-            );
-        }
-
-        let beta_storage = candle::CudaStorage::wrap_cuda_slice(beta_buf, dev.clone());
-        let beta = Tensor::from((candle::Storage::Cuda(beta_storage), shape.clone()));
-
-        let g_storage = candle::CudaStorage::wrap_cuda_slice(g_buf, dev.clone());
-        let g = Tensor::from((candle::Storage::Cuda(g_storage), shape));
-
-        Ok((beta, g))
-    }
-
-    match b.dtype() {
-        DType::F16 => cuda_fwd::<half::f16>(b, a, a_log, dt_bias, 0),
-        DType::BF16 => cuda_fwd::<half::bf16>(b, a, a_log, dt_bias, 1),
-        other => candle_core::bail!(
-            "fused_gdn_gating_cuda only supports f16/bf16, got {:?}",
-            other
-        ),
-    }
-}
-
-#[cfg(not(feature = "cuda"))]
-#[allow(unused)]
-pub fn fused_gdn_gating_cuda(
-    _b: &Tensor,
-    _a: &Tensor,
-    _a_log: &Tensor,
-    _dt_bias: &Tensor,
-) -> Result<(Tensor, Tensor)> {
-    candle_core::bail!("fused_gdn_gating_cuda requires the cuda feature")
-}

crates/neuron/src/cuda/mod.rs

@@ -1,15 +0,0 @@
-//! CUDA kernels and their Rust wrappers.
-//!
-//! Currently scoped to what we need for Qwen3-Next (`qwen3_5`)
-//! inference performance — the Gated DeltaNet kernels ported from
-//! `EricLBuehler/mistral.rs` (MIT). Each kernel lives in a `.cu`
-//! file alongside this module; `build.rs` compiles them all into a
-//! static lib via `cudaforge` and links it under the `cuda` feature.
-//!
-//! When we absorb more upstream kernels (MoE GEMM, top-k, Mamba SSM,
-//! etc.) they land here in their own `.cu` + `.rs` pairs.
-
-#[cfg(feature = "cuda")]
-pub mod ffi;
-#[cfg(feature = "cuda")]
-pub mod gdn;

crates/neuron/src/harness/arch/mod.rs

@@ -1,23 +0,0 @@
-//! Custom architecture implementations.
-//!
-//! When candle-transformers ships a model family unchanged
-//! (`models::llama`, `models::qwen3`, `models::qwen3_moe`, etc.), the
-//! handler in `harness/candle.rs` just wraps the upstream type in a
-//! `ModelArch` variant.
-//!
-//! When candle has nothing for the architecture and we have to write
-//! it from scratch — Qwen3-Next / Qwen3.6 (`qwen3_5`) being the
-//! motivating example — the implementation lands here, one file per
-//! architecture.
-//!
-//! Each architecture module is expected to expose:
-//! - A `Config` type deserialised from the model's `config.json`
-//!   (some architectures nest the real hyperparams under `text_config`,
-//!   in which case the module owns the unwrapping).
-//! - A `ForCausalLM` struct with `new`, `forward(&mut self, x, offset)
-//!   -> Result<Tensor>`, and `clear_kv_cache(&mut self)`.
-//!
-//! TP-aware analogues live in `harness/tp/tp_<family>.rs` and follow
-//! the pattern set by `tp_qwen3.rs`.
-
-pub mod qwen3_5;

crates/neuron/src/harness/arch/qwen3_5/decoder.rs

@@ -1,117 +0,0 @@
-//! Qwen3-Next decoder layer.
-//!
-//! Standard pre-norm transformer block (LN → attention → residual →
-//! LN → MLP → residual) where the attention slot dispatches on the
-//! per-layer `layer_types[i]` value in the config:
-//!
-//! - `"full_attention"` → [`Qwen3_5Attention`] (GQA causal + output
-//!   gate + RoPE + KV cache).
-//! - `"linear_attention"` → [`GatedDeltaNet`] (recurrent delta rule +
-//!   causal conv + per-head state).
-//!
-//! In Qwen3.6-27B every 4th layer is full_attention; the rest are
-//! linear_attention. `full_attention_interval` in the config is a
-//! hint; `layer_types` is authoritative.
-
-use anyhow::Result;
-use candle_core::{Module, Tensor};
-use candle_nn::var_builder::ShardedVarBuilder;
-use std::sync::Arc;
-
-use super::TextConfig;
-use super::full_attn::Qwen3_5Attention;
-use super::linear_attn::GatedDeltaNet;
-use super::mlp::Qwen3_5MLP;
-use super::rmsnorm::Qwen3_5RmsNorm;
-use super::rope::RotaryEmbedding;
-
-/// One of the two attention flavours sitting in a decoder layer's
-/// attention slot. Full-attention layers need the rotary table and
-/// take an attention mask; linear-attention layers carry their own
-/// recurrent state and ignore the mask.
-enum AttentionKind {
-    Full(Qwen3_5Attention),
-    Linear(GatedDeltaNet),
-}
-
-pub struct Qwen3_5DecoderLayer {
-    input_layernorm: Qwen3_5RmsNorm,
-    post_attention_layernorm: Qwen3_5RmsNorm,
-    mlp: Qwen3_5MLP,
-    attention: AttentionKind,
-}
-
-impl Qwen3_5DecoderLayer {
-    pub fn load(
-        cfg: &TextConfig,
-        rotary: Arc<RotaryEmbedding>,
-        layer_idx: usize,
-        vb: &ShardedVarBuilder,
-    ) -> Result<Self> {
-        let layer_type = cfg
-            .layer_types
-            .get(layer_idx)
-            .map(String::as_str)
-            .ok_or_else(|| {
-                anyhow::anyhow!(
-                    "layer_types[{layer_idx}] missing (have {} entries)",
-                    cfg.layer_types.len()
-                )
-            })?;
-
-        let attention = match layer_type {
-            "full_attention" => {
-                AttentionKind::Full(Qwen3_5Attention::load(cfg, rotary, &vb.pp("self_attn"))?)
-            }
-            "linear_attention" => {
-                AttentionKind::Linear(GatedDeltaNet::load(cfg, &vb.pp("linear_attn"))?)
-            }
-            other => anyhow::bail!(
-                "unknown layer_type '{other}' for layer {layer_idx} (expected \
-                 'full_attention' or 'linear_attention')"
-            ),
-        };
-
-        let mlp = Qwen3_5MLP::load(cfg, &vb.pp("mlp"))?;
-        let input_layernorm =
-            Qwen3_5RmsNorm::load(&vb.pp("input_layernorm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-        let post_attention_layernorm = Qwen3_5RmsNorm::load(
-            &vb.pp("post_attention_layernorm"),
-            cfg.hidden_size,
-            cfg.rms_norm_eps,
-        )?;
-
-        Ok(Self {
-            input_layernorm,
-            post_attention_layernorm,
-            mlp,
-            attention,
-        })
-    }
-
-    pub fn forward(
-        &mut self,
-        x: &Tensor,
-        attn_mask: Option<&Tensor>,
-        offset: usize,
-    ) -> candle_core::Result<Tensor> {
-        let h = self.input_layernorm.forward(x)?;
-        let attn_out = match &mut self.attention {
-            AttentionKind::Full(attn) => attn.forward(&h, attn_mask, offset)?,
-            // Linear attention ignores attn_mask + offset; its causal
-            // structure is baked into the recurrent state lifecycle.
-            AttentionKind::Linear(net) => net.forward(&h)?,
-        };
-        let x = (x + attn_out)?;
-        let h2 = self.post_attention_layernorm.forward(&x)?;
-        let h2 = self.mlp.forward(&h2)?;
-        x + h2
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        match &mut self.attention {
-            AttentionKind::Full(attn) => attn.clear_kv_cache(),
-            AttentionKind::Linear(net) => net.clear_kv_cache(),
-        }
-    }
-}

crates/neuron/src/harness/arch/qwen3_5/full_attn.rs

@@ -1,179 +0,0 @@
-//! Qwen3-Next's `full_attention` layer.
-//!
-//! Standard GQA causal attention with two Qwen3-Next-specific quirks:
-//!
-//! 1. **Output gate (`attn_output_gate=True`).** `q_proj` is widened
-//!    to `num_heads * head_dim * 2`. The second half is reshaped to
-//!    `(B, L, num_heads * head_dim)` and fed through a sigmoid; the
-//!    attention output is pointwise-multiplied by this gate before
-//!    `o_proj`. Effectively a per-head per-position attenuation on
-//!    the attention output.
-//!
-//! 2. **`(1 + w) * x` RmsNorm** on q and k (see `rmsnorm::Qwen3_5RmsNorm`).
-//!    candle_nn's RmsNorm applies `w * x`; the upstream Qwen3-Next
-//!    checkpoints expect the `(1 + w)` form.
-//!
-//! Otherwise: GQA with `num_attention_heads / num_key_value_heads`
-//! repeat, q_norm + k_norm on the head dim, GLM-style rotary (see
-//! `rope::RotaryEmbedding`), and the usual causal mask.
-
-use anyhow::{Context, Result};
-use candle_core::{Module, Tensor};
-use candle_nn::Linear;
-use candle_nn::kv_cache::ConcatKvCache;
-use candle_nn::var_builder::ShardedVarBuilder;
-use candle_transformers::utils::repeat_kv;
-use std::sync::Arc;
-
-use super::TextConfig;
-use super::rmsnorm::Qwen3_5RmsNorm;
-use super::rope::RotaryEmbedding;
-
-pub struct Qwen3_5Attention {
-    q_proj: Linear,
-    k_proj: Linear,
-    v_proj: Linear,
-    o_proj: Linear,
-    q_norm: Qwen3_5RmsNorm,
-    k_norm: Qwen3_5RmsNorm,
-    num_heads: usize,
-    num_kv_heads: usize,
-    num_kv_groups: usize,
-    head_dim: usize,
-    hidden_size: usize,
-    rotary: Arc<RotaryEmbedding>,
-    kv_cache: ConcatKvCache,
-}
-
-impl Qwen3_5Attention {
-    pub fn load(
-        cfg: &TextConfig,
-        rotary: Arc<RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-    ) -> Result<Self> {
-        let head_dim = cfg.head_dim;
-        let num_heads = cfg.num_attention_heads;
-        let num_kv_heads = cfg.num_key_value_heads;
-        if num_kv_heads == 0 || !num_heads.is_multiple_of(num_kv_heads) {
-            anyhow::bail!(
-                "num_attention_heads ({num_heads}) must be a positive multiple of \
-                 num_key_value_heads ({num_kv_heads})"
-            );
-        }
-        let num_kv_groups = num_heads / num_kv_heads;
-
-        // q_proj is 2x wide: the extra `num_heads * head_dim` slice is
-        // the gate (see attn_output_gate notes above).
-        let q_proj = load_linear_no_bias(vb, "q_proj", cfg.hidden_size, num_heads * head_dim * 2)?;
-        let k_proj = load_linear_no_bias(vb, "k_proj", cfg.hidden_size, num_kv_heads * head_dim)?;
-        let v_proj = load_linear_no_bias(vb, "v_proj", cfg.hidden_size, num_kv_heads * head_dim)?;
-        let o_proj = load_linear_no_bias(vb, "o_proj", num_heads * head_dim, cfg.hidden_size)?;
-
-        let q_norm = Qwen3_5RmsNorm::load(&vb.pp("q_norm"), head_dim, cfg.rms_norm_eps)?;
-        let k_norm = Qwen3_5RmsNorm::load(&vb.pp("k_norm"), head_dim, cfg.rms_norm_eps)?;
-
-        let hidden_size = head_dim * num_heads;
-        let kv_cache = ConcatKvCache::new(2);
-
-        Ok(Self {
-            q_proj,
-            k_proj,
-            v_proj,
-            o_proj,
-            q_norm,
-            k_norm,
-            num_heads,
-            num_kv_heads,
-            num_kv_groups,
-            head_dim,
-            hidden_size,
-            rotary,
-            kv_cache,
-        })
-    }
-
-    pub fn forward(
-        &mut self,
-        x: &Tensor,
-        attn_mask: Option<&Tensor>,
-        offset: usize,
-    ) -> candle_core::Result<Tensor> {
-        let (b, l, _) = x.dims3()?;
-
-        // 1. q_proj — widened output, split into (query, gate).
-        let q_raw = self
-            .q_proj
-            .forward(x)?
-            .reshape((b, l, self.num_heads, self.head_dim * 2))?;
-        let q = q_raw.narrow(3, 0, self.head_dim)?;
-        let gate = q_raw.narrow(3, self.head_dim, self.head_dim)?;
-        // Flatten the gate's head dim back into hidden_size for the
-        // post-attention pointwise multiply.
-        let gate = gate
-            .contiguous()?
-            .reshape((b, l, self.num_heads * self.head_dim))?;
-
-        // 2. q_norm + k_norm + reshape to (B, H, L, D).
-        let q = self.q_norm.forward(&q.contiguous()?)?;
-        let q = q.transpose(1, 2)?.contiguous()?; // (B, H, L, D)
-
-        let k = self
-            .k_proj
-            .forward(x)?
-            .reshape((b, l, self.num_kv_heads, self.head_dim))?;
-        let k = self.k_norm.forward(&k.contiguous()?)?;
-        let k = k.transpose(1, 2)?.contiguous()?;
-
-        let v = self
-            .v_proj
-            .forward(x)?
-            .reshape((b, l, self.num_kv_heads, self.head_dim))?
-            .transpose(1, 2)?
-            .contiguous()?;
-
-        // 3. RoPE on q, k.
-        let (q, k) = self.rotary.apply(&q, &k, offset)?;
-
-        // 4. KV cache.
-        let (k, v) = self.kv_cache.append(&k, &v)?;
-
-        // 5. GQA repeat (cheap shape op).
-        let k = repeat_kv(k, self.num_kv_groups)?.contiguous()?;
-        let v = repeat_kv(v, self.num_kv_groups)?.contiguous()?;
-
-        // 6. Scaled dot-product + causal mask.
-        let scale = 1.0_f64 / (self.head_dim as f64).sqrt();
-        let mut scores = (q.matmul(&k.transpose(2, 3)?)? * scale)?;
-        if let Some(m) = attn_mask {
-            scores = scores.broadcast_add(m)?;
-        }
-        let probs = candle_nn::ops::softmax_last_dim(&scores)?;
-        let ctx = probs.matmul(&v)?; // (B, H, L, D)
-
-        // 7. Reshape back, apply the output gate, project.
-        let ctx = ctx
-            .transpose(1, 2)?
-            .contiguous()?
-            .reshape((b, l, self.hidden_size))?;
-        let gate_sig = candle_nn::ops::sigmoid(&gate)?;
-        let gated = (ctx * gate_sig)?;
-        self.o_proj.forward(&gated)
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        self.kv_cache.reset();
-    }
-}
-
-fn load_linear_no_bias(
-    vb: &ShardedVarBuilder,
-    name: &str,
-    in_dim: usize,
-    out_dim: usize,
-) -> Result<Linear> {
-    let weight = vb
-        .pp(name)
-        .get((out_dim, in_dim), "weight")
-        .with_context(|| format!("load '{}/{name}/weight'", vb.prefix()))?;
-    Ok(Linear::new(weight, None))
-}

crates/neuron/src/harness/arch/qwen3_5/linear_attn.rs

@@ -1,793 +0,0 @@
-//! Qwen3-Next's `linear_attention` layer: Gated DeltaNet.
-//!
-//! The recurrent linear-attention block that occupies 3 out of every 4
-//! decoder layers in Qwen3.6 (`layer_types[i] == "linear_attention"`).
-//! Implemented against the reference Python in
-//! `huggingface/transformers/src/transformers/models/qwen3_5/modeling_qwen3_5.py`
-//! (class `Qwen3_5GatedDeltaNet`).
-//!
-//! ## Block structure
-//!
-//! ```text
-//! x  ── in_proj_qkv ── transpose ─► (B, conv_dim, L)
-//!                                    │
-//!     ┌──────────────── conv_state ──┤  prepend cached state (decode)
-//!     ▼
-//!   depthwise causal Conv1d (k=4) → SiLU
-//!     │
-//!     └─ split → q (k_dim), k (k_dim), v (v_dim)  ─►  per-head reshape
-//!
-//! x  ── in_proj_z ────────────────►  z (gate for the output RMSNorm)
-//! x  ── in_proj_b ── sigmoid ─────►  beta (per-head per-token update rate)
-//! x  ── in_proj_a ── softplus ────►  g (decay; see eqn below)
-//!
-//! g = -exp(A_log) * softplus(a + dt_bias)        # discretisation
-//! beta = sigmoid(b)
-//!
-//! (q, k) ─── L2norm ─── delta rule loop ──── core_attn_out
-//!                          (per-token, per-head):
-//!                          state *= exp(g_t)
-//!                          mem    = state^T · k_t
-//!                          delta  = (v_t - mem) * beta_t
-//!                          state += outer(k_t, delta)
-//!                          out_t  = state^T · q_t
-//!
-//! core_attn_out ── RMSNormGated(z) ── reshape ── out_proj ── y
-//! ```
-//!
-//! ## State
-//!
-//! Two tensors persist across decode steps:
-//! - `conv_state`: `(B, conv_dim, conv_kernel_size)` — left-padded
-//!   tail of the input to the depthwise conv, so the next causal
-//!   window has the right left-context.
-//! - `recurrent_state`: `(B, num_v_heads, head_k_dim, head_v_dim)` —
-//!   the delta-rule outer-product memory.
-//!
-//! Both are cleared via [`GatedDeltaNet::clear_kv_cache`] at the start
-//! of every new request.
-//!
-//! ## Performance note
-//!
-//! This impl is the **recurrent** delta-rule for both prefill and
-//! decode — i.e. the algorithm in `torch_recurrent_gated_delta_rule`.
-//! Correctness-first. The chunked algorithm (chunk_size=64) in
-//! `torch_chunk_gated_delta_rule` is a perf optimisation for long
-//! prefill; can be added later without changing the surface.
-
-use anyhow::{Context, Result};
-use candle_core::{Module, Tensor};
-use candle_nn::Linear;
-use candle_nn::var_builder::ShardedVarBuilder;
-
-#[cfg(test)]
-use super::RopeParameters;
-use super::TextConfig;
-use super::rmsnorm::{Qwen3_5RmsNormGated, l2norm};
-
-/// Per-rank, per-layer state for the linear-attention block.
-///
-/// `conv_state` is left-padded with zeros on first use; `recurrent_state`
-/// is initialised lazily to zeros once we know the batch size.
-#[derive(Default)]
-pub struct GatedDeltaNetState {
-    pub conv_state: Option<Tensor>,
-    pub recurrent_state: Option<Tensor>,
-}
-
-pub struct GatedDeltaNet {
-    // Projections.
-    in_proj_qkv: Linear,
-    in_proj_z: Linear,
-    in_proj_b: Linear,
-    in_proj_a: Linear,
-    out_proj: Linear,
-
-    // Depthwise causal Conv1d weight; shape (conv_dim, 1, kernel_size).
-    // No bias (Python sets bias=False).
-    conv1d_weight: Tensor,
-
-    // Per-head discretisation params.
-    dt_bias: Tensor,
-    a_log: Tensor,
-
-    // Output norm + gate.
-    norm: Qwen3_5RmsNormGated,
-
-    // Shape hyperparams (cached for forward).
-    num_v_heads: usize,
-    num_k_heads: usize,
-    head_k_dim: usize,
-    head_v_dim: usize,
-    key_dim: usize,
-    value_dim: usize,
-    conv_dim: usize,
-    conv_kernel_size: usize,
-
-    // Recurrent state held inline. Each request resets via
-    // `clear_kv_cache`; otherwise the state persists across forwards
-    // and the per-token offset advances naturally.
-    state: GatedDeltaNetState,
-}
-
-impl GatedDeltaNet {
-    pub fn load(cfg: &TextConfig, vb: &ShardedVarBuilder) -> Result<Self> {
-        let num_v_heads = cfg.linear_num_value_heads;
-        let num_k_heads = cfg.linear_num_key_heads;
-        let head_k_dim = cfg.linear_key_head_dim;
-        let head_v_dim = cfg.linear_value_head_dim;
-        let conv_kernel_size = cfg.linear_conv_kernel_dim;
-
-        if num_v_heads == 0 || num_k_heads == 0 {
-            anyhow::bail!(
-                "Qwen3-Next linear_num_*_heads must be set; got v={num_v_heads}, k={num_k_heads}"
-            );
-        }
-        if !num_v_heads.is_multiple_of(num_k_heads) {
-            anyhow::bail!(
-                "linear_num_value_heads ({num_v_heads}) must be a multiple of \
-                 linear_num_key_heads ({num_k_heads}) for GQA-style head expansion"
-            );
-        }
-
-        let key_dim = head_k_dim * num_k_heads;
-        let value_dim = head_v_dim * num_v_heads;
-        let conv_dim = key_dim * 2 + value_dim;
-
-        // ----- Linear projections (all `bias=False` in the reference). -----
-        let in_proj_qkv = load_linear_no_bias(vb, "in_proj_qkv", cfg.hidden_size, conv_dim)?;
-        let in_proj_z = load_linear_no_bias(vb, "in_proj_z", cfg.hidden_size, value_dim)?;
-        let in_proj_b = load_linear_no_bias(vb, "in_proj_b", cfg.hidden_size, num_v_heads)?;
-        let in_proj_a = load_linear_no_bias(vb, "in_proj_a", cfg.hidden_size, num_v_heads)?;
-        let out_proj = load_linear_no_bias(vb, "out_proj", value_dim, cfg.hidden_size)?;
-
-        // ----- Conv1d weight (depthwise, bias=False). -----
-        let conv1d_weight = vb
-            .pp("conv1d")
-            .get((conv_dim, 1, conv_kernel_size), "weight")
-            .with_context(|| format!("load '{}/conv1d/weight'", vb.prefix()))?;
-
-        // ----- dt_bias + A_log: per-head 1D params. -----
-        let dt_bias = vb
-            .get(num_v_heads, "dt_bias")
-            .with_context(|| format!("load '{}/dt_bias'", vb.prefix()))?;
-        let a_log = vb
-            .get(num_v_heads, "A_log")
-            .with_context(|| format!("load '{}/A_log'", vb.prefix()))?;
-
-        // ----- Output gated RMSNorm (per-head_v_dim). -----
-        let norm = Qwen3_5RmsNormGated::load(&vb.pp("norm"), head_v_dim, cfg.rms_norm_eps)?;
-
-        Ok(Self {
-            in_proj_qkv,
-            in_proj_z,
-            in_proj_b,
-            in_proj_a,
-            out_proj,
-            conv1d_weight,
-            dt_bias,
-            a_log,
-            norm,
-            num_v_heads,
-            num_k_heads,
-            head_k_dim,
-            head_v_dim,
-            key_dim,
-            value_dim,
-            conv_dim,
-            conv_kernel_size,
-            state: GatedDeltaNetState::default(),
-        })
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        self.state = GatedDeltaNetState::default();
-    }
-
-    /// `x` shape: `(B, L, hidden_size)`. Returns the same shape.
-    pub fn forward(&mut self, x: &Tensor) -> candle_core::Result<Tensor> {
-        let (batch_size, seq_len, _) = x.dims3()?;
-        let dtype = x.dtype();
-        let device = x.device().clone();
-
-        // ----- Projections. -----
-        // mixed_qkv: (B, L, conv_dim)
-        let mixed_qkv = self.in_proj_qkv.forward(x)?;
-        // (B, conv_dim, L) for the conv1d.
-        let mixed_qkv_chw = mixed_qkv.transpose(1, 2)?.contiguous()?;
-
-        // z: (B, L, value_dim) → (B, L, num_v_heads, head_v_dim)
-        let z = self.in_proj_z.forward(x)?.reshape((
-            batch_size,
-            seq_len,
-            self.num_v_heads,
-            self.head_v_dim,
-        ))?;
-
-        // b, a: (B, L, num_v_heads)
-        let b = self.in_proj_b.forward(x)?;
-        let a = self.in_proj_a.forward(x)?;
-
-        // ----- Depthwise causal Conv1d + SiLU (with state continuation). -----
-        // Dispatches to a cuda kernel that fuses conv1d + silu when
-        // available; falls back to candle's `conv1d` + `silu` on cpu.
-        let (conv_out, new_state) = run_causal_conv1d(
-            &mixed_qkv_chw,
-            &self.conv1d_weight,
-            self.state.conv_state.take(),
-            batch_size,
-            self.conv_dim,
-            seq_len,
-            self.conv_kernel_size,
-        )?;
-        self.state.conv_state = Some(new_state);
-        // Back to (B, L, conv_dim).
-        let mixed_qkv = conv_out.transpose(1, 2)?.contiguous()?;
-
-        // ----- Split into q, k, v. -----
-        let q = mixed_qkv.narrow(2, 0, self.key_dim)?;
-        let k = mixed_qkv.narrow(2, self.key_dim, self.key_dim)?;
-        let v = mixed_qkv.narrow(2, 2 * self.key_dim, self.value_dim)?;
-
-        let q = q.reshape((batch_size, seq_len, self.num_k_heads, self.head_k_dim))?;
-        let k = k.reshape((batch_size, seq_len, self.num_k_heads, self.head_k_dim))?;
-        let v = v.reshape((batch_size, seq_len, self.num_v_heads, self.head_v_dim))?;
-
-        // ----- beta + g (per-head, per-token gates). -----
-        // Fused on cuda; per-op Rust on cpu. Both paths produce:
-        //   beta = sigmoid(b)
-        //   g    = -exp(A_log) * softplus(a + dt_bias)
-        let (beta, g) = run_fused_gating(&b, &a, &self.a_log, &self.dt_bias)?;
-
-        // ----- GQA-style key expansion if num_v_heads > num_k_heads. -----
-        let (q, k) = if self.num_v_heads > self.num_k_heads {
-            let rep = self.num_v_heads / self.num_k_heads;
-            (
-                repeat_interleave(&q, rep, 2)?,
-                repeat_interleave(&k, rep, 2)?,
-            )
-        } else {
-            (q, k)
-        };
-
-        // ----- L2-norm on q, k (use_qk_l2norm_in_kernel=True in ref). -----
-        let q = l2norm(&q, 1e-6)?;
-        let k = l2norm(&k, 1e-6)?;
-
-        // ----- Recurrent delta rule. -----
-        // Inputs: q, k (B, L, H, D_k); v (B, L, H, D_v); g (B, L, H); beta (B, L, H).
-        // The reference transposes to (B, H, L, D) before the loop. We
-        // do the same — it makes per-token indexing trivial.
-        let q = q.transpose(1, 2)?.contiguous()?; // (B, H, L, D_k)
-        let k = k.transpose(1, 2)?.contiguous()?;
-        let v = v.transpose(1, 2)?.contiguous()?; // (B, H, L, D_v)
-        let g = g.transpose(1, 2)?.contiguous()?; // (B, H, L)
-        let beta = beta.transpose(1, 2)?.contiguous()?; // (B, H, L)
-
-        // Pre-scale q by 1/sqrt(D_k) once. Everything goes to f32 here
-        // since the delta rule mixes broadcast_mul ops that candle won't
-        // accept across mixed dtypes. On the cuda gating path both beta
-        // and g come back in model dtype; on the cpu path g is already
-        // f32 — both casts are cheap idempotent ops.
-        let scale = 1.0_f64 / (self.head_k_dim as f64).sqrt();
-        let q = (q.to_dtype(candle_core::DType::F32)? * scale)?;
-        let k = k.to_dtype(candle_core::DType::F32)?;
-        let v = v.to_dtype(candle_core::DType::F32)?;
-        let g = g.to_dtype(candle_core::DType::F32)?;
-        let beta = beta.to_dtype(candle_core::DType::F32)?;
-
-        // Initialise the recurrent state from cache or zeros.
-        let state_init = match self.state.recurrent_state.take() {
-            Some(s) => s.to_dtype(candle_core::DType::F32)?,
-            None => Tensor::zeros(
-                (
-                    batch_size,
-                    self.num_v_heads,
-                    self.head_k_dim,
-                    self.head_v_dim,
-                ),
-                candle_core::DType::F32,
-                &device,
-            )?,
-        };
-
-        // The delta-rule body: cuda-accelerated `gated_delta_rule_recurrence`
-        // kernel when we have a cuda device + the kernels are linked in,
-        // pure-Rust per-token fallback otherwise.
-        let (core_attn_out, new_state) = run_delta_rule(
-            &q,
-            &k,
-            &v,
-            &g,
-            &beta,
-            state_init,
-            batch_size,
-            self.num_v_heads,
-            seq_len,
-            self.head_k_dim,
-            self.head_v_dim,
-        )?;
-        // Stash the updated recurrent state for the next call.
-        self.state.recurrent_state = Some(new_state.to_dtype(dtype)?);
-
-        // core_attn_out: (B, H, L, D_v) → (B, L, H, D_v) → (B*L*H, D_v).
-        let core_attn_out = core_attn_out.transpose(1, 2)?.contiguous()?; // (B, L, H, D_v)
-        let core_attn_out = core_attn_out.to_dtype(dtype)?;
-        let core_attn_flat =
-            core_attn_out.reshape((batch_size * seq_len * self.num_v_heads, self.head_v_dim))?;
-        let z_flat = z.reshape((batch_size * seq_len * self.num_v_heads, self.head_v_dim))?;
-
-        // RMSNormGated: (out * silu(z) * weight) with the norm.
-        let normed = self.norm.forward(&core_attn_flat, &z_flat)?;
-        let normed = normed.reshape((batch_size, seq_len, self.num_v_heads * self.head_v_dim))?;
-
-        // Output projection: (B, L, value_dim) → (B, L, hidden_size).
-        self.out_proj.forward(&normed)
-    }
-}
-
-/// Run the per-token delta-rule recurrence.
-///
-/// `q`, `k`: `(B, H, L, D_k)` (F32). `v`: `(B, H, L, D_v)`. `g`,
-/// `beta`: `(B, H, L)`. `state`: `(B, H, D_k, D_v)`.
-///
-/// Returns `(core_attn_out: (B, H, L, D_v), state: (B, H, D_k, D_v))`,
-/// both F32. Caller is responsible for cast back to model dtype.
-///
-/// Cuda path: dispatches to the `gated_delta_rule_recurrence` kernel
-/// ported from `EricLBuehler/mistral.rs::mistralrs-core/src/cuda/gdn.cu`.
-/// All five inputs must be cuda f32 tensors. The kernel is V-tiled
-/// with compile-time BK; one block per (V-tile, batch*head) and one
-/// thread per V-column. Each thread holds BK state floats in
-/// registers — eliminates the launch-overhead floor we hit with
-/// candle's per-op dispatch (was ~12s/token on Qwen3.6-27B).
-///
-/// CPU path: pure-Rust per-token loop. Correct, slow.
-#[allow(clippy::too_many_arguments)]
-pub(crate) fn run_delta_rule(
-    q: &Tensor,
-    k: &Tensor,
-    v: &Tensor,
-    g: &Tensor,
-    beta: &Tensor,
-    state: Tensor,
-    batch_size: usize,
-    num_heads: usize,
-    seq_len: usize,
-    head_k_dim: usize,
-    head_v_dim: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    #[cfg(feature = "cuda")]
-    {
-        // Only dispatch to the kernel if the inputs are on a CUDA
-        // device — CPU tests fall back to the Rust loop below.
-        if q.device().is_cuda() {
-            return run_delta_rule_cuda(
-                q, k, v, g, beta, state, batch_size, num_heads, seq_len, head_k_dim, head_v_dim,
-            );
-        }
-    }
-    let _ = (batch_size, num_heads, head_k_dim, head_v_dim);
-    run_delta_rule_rust(q, k, v, g, beta, state, seq_len)
-}
-
-/// CUDA path. Flattens (B, H, ...) → (BH, ...) at the kernel boundary
-/// (the kernel uses BH = batch*heads as its outer batch axis) and
-/// reshapes the kernel's outputs back to (B, H, ...) for the caller.
-#[cfg(feature = "cuda")]
-#[allow(clippy::too_many_arguments)]
-fn run_delta_rule_cuda(
-    q: &Tensor,
-    k: &Tensor,
-    v: &Tensor,
-    g: &Tensor,
-    beta: &Tensor,
-    state: Tensor,
-    batch_size: usize,
-    num_heads: usize,
-    seq_len: usize,
-    head_k_dim: usize,
-    head_v_dim: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    let q_bh = q.flatten(0, 1)?.contiguous()?;
-    let k_bh = k.flatten(0, 1)?.contiguous()?;
-    let v_bh = v.flatten(0, 1)?.contiguous()?;
-    let g_bh = g.flatten(0, 1)?.contiguous()?;
-    let beta_bh = beta.flatten(0, 1)?.contiguous()?;
-    let mut state_bh = state.flatten(0, 1)?.contiguous()?;
-    // For long prefills, the chunked kernel (BT=64) processes a chunk
-    // of tokens at a time instead of one-by-one — same delta-rule math,
-    // far fewer block launches. Threshold matches mistralrs.
-    const CHUNK_THRESHOLD: usize = 64;
-    let output_bh = if seq_len >= CHUNK_THRESHOLD {
-        crate::cuda::gdn::chunked_gated_delta_rule_recurrence_cuda(
-            &q_bh,
-            &k_bh,
-            &v_bh,
-            &g_bh,
-            &beta_bh,
-            &mut state_bh,
-        )?
-    } else {
-        crate::cuda::gdn::gated_delta_rule_recurrence_cuda(
-            &q_bh,
-            &k_bh,
-            &v_bh,
-            &g_bh,
-            &beta_bh,
-            &mut state_bh,
-        )?
-    };
-    let core_attn_out = output_bh.reshape((batch_size, num_heads, seq_len, head_v_dim))?;
-    let new_state = state_bh.reshape((batch_size, num_heads, head_k_dim, head_v_dim))?;
-    Ok((core_attn_out, new_state))
-}
-
-#[allow(clippy::too_many_arguments)]
-fn run_delta_rule_rust(
-    q: &Tensor,
-    k: &Tensor,
-    v: &Tensor,
-    g: &Tensor,
-    beta: &Tensor,
-    mut state: Tensor,
-    seq_len: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    use candle_core::IndexOp;
-    let mut outputs: Vec<Tensor> = Vec::with_capacity(seq_len);
-    for t in 0..seq_len {
-        let q_t = q.i((.., .., t, ..))?;
-        let k_t = k.i((.., .., t, ..))?;
-        let v_t = v.i((.., .., t, ..))?;
-        let g_t = g.i((.., .., t))?;
-        let beta_t = beta.i((.., .., t))?;
-        let decay = g_t
-            .exp()?
-            .unsqueeze(candle_core::D::Minus1)?
-            .unsqueeze(candle_core::D::Minus1)?;
-        state = state.broadcast_mul(&decay)?;
-        let k_col = k_t.unsqueeze(candle_core::D::Minus1)?;
-        let kv_mem = state.broadcast_mul(&k_col)?.sum(2)?;
-        let beta_col = beta_t.unsqueeze(candle_core::D::Minus1)?;
-        let delta = (v_t - kv_mem)?.broadcast_mul(&beta_col)?;
-        let delta_row = delta.unsqueeze(2)?;
-        let outer = k_col.broadcast_mul(&delta_row)?;
-        state = (state + outer)?;
-        let q_col = q_t.unsqueeze(candle_core::D::Minus1)?;
-        let out_t = state.broadcast_mul(&q_col)?.sum(2)?;
-        outputs.push(out_t.unsqueeze(2)?);
-    }
-    let core_attn_out = Tensor::cat(&outputs, 2)?; // (B, H, L, D_v)
-    Ok((core_attn_out, state))
-}
-
-/// Depthwise causal conv1d + SiLU, with rolling `conv_state`.
-///
-/// `x`: `(B, conv_dim, L)` model dtype (f16/bf16 on cuda, anything on cpu).
-/// `weight`: `(conv_dim, 1, kernel_size)` model dtype.
-/// `conv_state`: `Some((B, conv_dim, kernel_size))` for decode continuation,
-/// or `None` for fresh prefill.
-///
-/// Returns `(conv_out: (B, conv_dim, L), new_conv_state: (B, conv_dim, kernel_size))`.
-/// SiLU is baked in.
-///
-/// Cuda path: dispatches to `causal_conv1d_update` (decode, seq_len=1 with
-/// existing state) or `causal_conv1d_full` (prefill / first call), both
-/// ported from mistralrs `gdn.cu`. Each kernel fuses the depthwise conv
-/// and SiLU activation in one launch — that's ~4× fewer cuda launches per
-/// linear-attention layer than the candle `conv1d` + `silu` combo.
-///
-/// CPU path: the original prepend-narrow-conv1d-silu sequence.
-pub(crate) fn run_causal_conv1d(
-    x: &Tensor,
-    weight: &Tensor,
-    conv_state: Option<Tensor>,
-    batch_size: usize,
-    conv_dim: usize,
-    seq_len: usize,
-    conv_kernel_size: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    #[cfg(feature = "cuda")]
-    {
-        if x.device().is_cuda() {
-            return run_causal_conv1d_cuda(
-                x,
-                weight,
-                conv_state,
-                batch_size,
-                conv_dim,
-                seq_len,
-                conv_kernel_size,
-            );
-        }
-    }
-    run_causal_conv1d_rust(
-        x,
-        weight,
-        conv_state,
-        batch_size,
-        conv_dim,
-        seq_len,
-        conv_kernel_size,
-    )
-}
-
-#[cfg(feature = "cuda")]
-fn run_causal_conv1d_cuda(
-    x: &Tensor,
-    weight: &Tensor,
-    conv_state: Option<Tensor>,
-    batch_size: usize,
-    conv_dim: usize,
-    seq_len: usize,
-    conv_kernel_size: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    // Kernel expects weight as (conv_dim, kernel_size) — squeeze the
-    // depthwise channel-multiplier dim.
-    let w = weight.squeeze(1)?.to_dtype(x.dtype())?.contiguous()?;
-
-    // Decode path: seq_len == 1 AND we have an existing conv_state.
-    // Otherwise (prefill or fresh-start decode), use the full path which
-    // zero-pads on the left internally.
-    if let Some(cs) = conv_state
-        && seq_len == 1
-    {
-        let cs = cs.contiguous()?;
-        let (output, new_conv_state) =
-            crate::cuda::gdn::causal_conv1d_cuda(x, &w, &cs, conv_kernel_size, true)?;
-        return Ok((output, new_conv_state));
-    }
-
-    // Prefill / fresh-start: the kernel ignores any prior conv_state and
-    // zero-pads. If we had a non-zero prior state and >1 input tokens
-    // (multi-turn continuation), we'd need to fall back to Rust. Match
-    // mistralrs's behaviour: fresh prefill always.
-    let device = x.device().clone();
-    let zeros_cs = Tensor::zeros((batch_size, conv_dim, conv_kernel_size), x.dtype(), &device)?;
-    let (output, new_conv_state) =
-        crate::cuda::gdn::causal_conv1d_cuda(x, &w, &zeros_cs, conv_kernel_size, false)?;
-    Ok((output, new_conv_state))
-}
-
-/// Fused GDN gating: computes `beta = sigmoid(b)` and
-/// `g = -exp(a_log) * softplus(a + dt_bias)` together.
-///
-/// `b`, `a`: `(B, L, num_heads)` model dtype.
-/// `a_log`, `dt_bias`: `(num_heads,)` model dtype (cast to f32 internally).
-///
-/// Returns `(beta, g)` both in model dtype on the cuda path, both in f32
-/// on the cpu fallback. The caller casts to f32 before the delta rule.
-///
-/// Cuda path: dispatches to `fused_gdn_gating_cuda` — one kernel
-/// replaces sigmoid + neg(exp) + softplus + broadcast_mul (≈10 candle
-/// launches per layer).
-pub(crate) fn run_fused_gating(
-    b: &Tensor,
-    a: &Tensor,
-    a_log: &Tensor,
-    dt_bias: &Tensor,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    #[cfg(feature = "cuda")]
-    {
-        if b.device().is_cuda() {
-            let a_log_f32 = a_log.to_dtype(candle_core::DType::F32)?.contiguous()?;
-            let dt_bias_f32 = dt_bias.to_dtype(candle_core::DType::F32)?.contiguous()?;
-            return crate::cuda::gdn::fused_gdn_gating_cuda(b, a, &a_log_f32, &dt_bias_f32);
-        }
-    }
-    run_fused_gating_rust(b, a, a_log, dt_bias)
-}
-
-fn run_fused_gating_rust(
-    b: &Tensor,
-    a: &Tensor,
-    a_log: &Tensor,
-    dt_bias: &Tensor,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    let beta = candle_nn::ops::sigmoid(b)?;
-    let a_log_f32 = a_log.to_dtype(candle_core::DType::F32)?;
-    let neg_a_exp = a_log_f32.exp()?.neg()?;
-    let dt_b_f32 = dt_bias.to_dtype(candle_core::DType::F32)?;
-    let a_f32 = a.to_dtype(candle_core::DType::F32)?;
-    let a_plus_dt = a_f32.broadcast_add(&dt_b_f32)?;
-    let softplus_val = softplus(&a_plus_dt)?;
-    let neg_a_exp_b = neg_a_exp.unsqueeze(0)?.unsqueeze(0)?;
-    let g = neg_a_exp_b.broadcast_mul(&softplus_val)?;
-    Ok((beta, g))
-}
-
-fn run_causal_conv1d_rust(
-    x: &Tensor,
-    weight: &Tensor,
-    conv_state: Option<Tensor>,
-    batch_size: usize,
-    conv_dim: usize,
-    seq_len: usize,
-    conv_kernel_size: usize,
-) -> candle_core::Result<(Tensor, Tensor)> {
-    let dtype = x.dtype();
-    let device = x.device().clone();
-
-    let prepended = match &conv_state {
-        Some(prev) => Tensor::cat(&[prev, x], 2)?,
-        None => x.clone(),
-    };
-    let prep_len = prepended.dims()[2];
-
-    let new_state = if prep_len >= conv_kernel_size {
-        prepended.narrow(2, prep_len - conv_kernel_size, conv_kernel_size)?
-    } else {
-        let pad = Tensor::zeros(
-            (batch_size, conv_dim, conv_kernel_size - prep_len),
-            dtype,
-            &device,
-        )?;
-        Tensor::cat(&[&pad, &prepended], 2)?
-    };
-
-    let conv_out = prepended.conv1d(weight, conv_kernel_size - 1, 1, 1, conv_dim)?;
-    let conv_out = conv_out.narrow(2, 0, prep_len)?;
-    let conv_out = candle_nn::ops::silu(&conv_out)?;
-    let conv_out = conv_out.narrow(2, prep_len - seq_len, seq_len)?;
-    Ok((conv_out, new_state))
-}
-
-/// Load a no-bias linear from the ShardedVarBuilder. Weight shape is
-/// the standard `[out, in]` order.
-fn load_linear_no_bias(
-    vb: &ShardedVarBuilder,
-    name: &str,
-    in_dim: usize,
-    out_dim: usize,
-) -> Result<Linear> {
-    let weight = vb
-        .pp(name)
-        .get((out_dim, in_dim), "weight")
-        .with_context(|| format!("load '{}/{name}/weight'", vb.prefix()))?;
-    Ok(Linear::new(weight, None))
-}
-
-/// Numerically-stable `softplus(x) = ln(1 + exp(x))`. Matches PyTorch's
-/// `F.softplus` default (beta=1, threshold=20: for large positive x,
-/// returns x as-is to avoid overflow in the exp).
-pub(crate) fn softplus(x: &Tensor) -> candle_core::Result<Tensor> {
-    let threshold = 20.0_f64;
-    let big = x.ge(threshold)?; // Tensor<u8> mask
-    let safe = x.minimum(&x.affine(0.0, 0.0)?.affine(0.0, threshold)?)?; // min(x, threshold)
-    let small = ((safe.exp()? + 1.0_f64)?).log()?;
-    // Select x where big, else small.
-    big.where_cond(x, &small)
-}
-
-/// `repeat_interleave` along a single dim. Candle has no built-in for
-/// this; emulate with unsqueeze + expand + reshape.
-pub(crate) fn repeat_interleave(
-    x: &Tensor,
-    repeats: usize,
-    dim: usize,
-) -> candle_core::Result<Tensor> {
-    if repeats == 1 {
-        return Ok(x.clone());
-    }
-    let mut shape = x.dims().to_vec();
-    let orig = shape[dim];
-    shape.insert(dim + 1, repeats);
-    let mut expanded_shape = shape.clone();
-    expanded_shape[dim + 1] = repeats;
-    let x = x.unsqueeze(dim + 1)?;
-    let x = x.expand(expanded_shape)?;
-    let mut out_shape = x.dims().to_vec();
-    out_shape.remove(dim + 1);
-    out_shape[dim] = orig * repeats;
-    x.contiguous()?.reshape(out_shape)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use candle_core::{DType, Device};
-
-    #[test]
-    fn softplus_small_x() {
-        // softplus(0) = ln(2) ≈ 0.6931
-        let x = Tensor::new(&[0.0_f32], &Device::Cpu).unwrap();
-        let out: Vec<f32> = softplus(&x).unwrap().to_vec1().unwrap();
-        assert!((out[0] - 2.0_f32.ln()).abs() < 1e-4);
-    }
-
-    #[test]
-    fn softplus_large_x_returns_x() {
-        // For x = 30, softplus(x) ≈ x (the threshold branch).
-        let x = Tensor::new(&[30.0_f32], &Device::Cpu).unwrap();
-        let out: Vec<f32> = softplus(&x).unwrap().to_vec1().unwrap();
-        assert!((out[0] - 30.0).abs() < 1e-4);
-    }
-
-    #[test]
-    fn repeat_interleave_doubles_dim() {
-        let x = Tensor::new(&[[1.0_f32, 2.0], [3.0, 4.0]], &Device::Cpu).unwrap(); // shape (2, 2)
-        let out = repeat_interleave(&x, 2, 1).unwrap(); // each col duplicated
-        let v: Vec<Vec<f32>> = out.to_vec2().unwrap();
-        // Row 0: 1, 1, 2, 2
-        // Row 1: 3, 3, 4, 4
-        assert_eq!(v[0], vec![1.0, 1.0, 2.0, 2.0]);
-        assert_eq!(v[1], vec![3.0, 3.0, 4.0, 4.0]);
-    }
-
-    /// Sanity: the recurrent path produces a finite tensor of the right
-    /// shape on tiny dimensions. Doesn't validate numerical correctness
-    /// against the Python reference — that would need a fixed-weight
-    /// fixture to compare against. Catches structural mistakes
-    /// (broadcasting shapes, off-by-one slices) early.
-    #[test]
-    fn forward_smoke_with_tiny_dimensions() {
-        let dev = Device::Cpu;
-        let dtype = DType::F32;
-        let (b, l) = (1, 3);
-        let cfg = TextConfig {
-            vocab_size: 100,
-            hidden_size: 16,
-            intermediate_size: 32,
-            num_hidden_layers: 1,
-            num_attention_heads: 4,
-            num_key_value_heads: 1,
-            head_dim: 4,
-            max_position_embeddings: 32,
-            rope_parameters: RopeParameters {
-                rope_theta: 10000.0,
-                partial_rotary_factor: 1.0,
-                rope_type: None,
-            },
-            rms_norm_eps: 1e-6,
-            tie_word_embeddings: false,
-            attn_output_gate: true,
-            layer_types: vec!["linear_attention".into()],
-            full_attention_interval: Some(4),
-            hidden_act: "silu".into(),
-            linear_num_value_heads: 4,
-            linear_num_key_heads: 2,
-            linear_key_head_dim: 4,
-            linear_value_head_dim: 4,
-            linear_conv_kernel_dim: 4,
-        };
-
-        // Build a synthetic VarBuilder with all-zeros weights.
-        // Easier path: skip the load and construct GatedDeltaNet
-        // manually by hand-rolling the Linear/Tensor inputs.
-        let zeros = |shape: &[usize]| Tensor::zeros(shape, dtype, &dev).unwrap();
-        let key_dim = cfg.linear_key_head_dim * cfg.linear_num_key_heads;
-        let value_dim = cfg.linear_value_head_dim * cfg.linear_num_value_heads;
-        let conv_dim = key_dim * 2 + value_dim;
-        let mut net = GatedDeltaNet {
-            in_proj_qkv: Linear::new(zeros(&[conv_dim, cfg.hidden_size]), None),
-            in_proj_z: Linear::new(zeros(&[value_dim, cfg.hidden_size]), None),
-            in_proj_b: Linear::new(zeros(&[cfg.linear_num_value_heads, cfg.hidden_size]), None),
-            in_proj_a: Linear::new(zeros(&[cfg.linear_num_value_heads, cfg.hidden_size]), None),
-            out_proj: Linear::new(zeros(&[cfg.hidden_size, value_dim]), None),
-            conv1d_weight: zeros(&[conv_dim, 1, cfg.linear_conv_kernel_dim]),
-            dt_bias: zeros(&[cfg.linear_num_value_heads]),
-            a_log: zeros(&[cfg.linear_num_value_heads]),
-            norm: {
-                let weight = Tensor::ones(&[cfg.linear_value_head_dim], dtype, &dev).unwrap();
-                Qwen3_5RmsNormGated::from_weight(weight, cfg.rms_norm_eps)
-            },
-            num_v_heads: cfg.linear_num_value_heads,
-            num_k_heads: cfg.linear_num_key_heads,
-            head_k_dim: cfg.linear_key_head_dim,
-            head_v_dim: cfg.linear_value_head_dim,
-            key_dim,
-            value_dim,
-            conv_dim,
-            conv_kernel_size: cfg.linear_conv_kernel_dim,
-            state: GatedDeltaNetState::default(),
-        };
-
-        let x = Tensor::ones(&[b, l, cfg.hidden_size], dtype, &dev).unwrap();
-        let y = net.forward(&x).unwrap();
-        assert_eq!(y.dims(), &[b, l, cfg.hidden_size]);
-        // All zero weights → output should be zero. Confirms no NaN/Inf
-        // poisoning from the f32 promotions.
-        let v: Vec<f32> = y.flatten_all().unwrap().to_vec1().unwrap();
-        assert!(v.iter().all(|x| x.is_finite()));
-    }
-}

crates/neuron/src/harness/arch/qwen3_5/mlp.rs

@@ -1,53 +0,0 @@
-//! SwiGLU MLP block for Qwen3-Next.
-//!
-//! Identical to plain Qwen3's MLP: `down(silu(gate(x)) * up(x))` with
-//! no bias on any of the three projections.
-
-use anyhow::{Context, Result};
-use candle_core::{Module, Tensor};
-use candle_nn::Linear;
-use candle_nn::var_builder::ShardedVarBuilder;
-
-use super::TextConfig;
-
-pub struct Qwen3_5MLP {
-    gate_proj: Linear,
-    up_proj: Linear,
-    down_proj: Linear,
-}
-
-impl Qwen3_5MLP {
-    pub fn load(cfg: &TextConfig, vb: &ShardedVarBuilder) -> Result<Self> {
-        let h = cfg.hidden_size;
-        let i = cfg.intermediate_size;
-        let gate_proj = load_linear_no_bias(vb, "gate_proj", h, i)?;
-        let up_proj = load_linear_no_bias(vb, "up_proj", h, i)?;
-        let down_proj = load_linear_no_bias(vb, "down_proj", i, h)?;
-        Ok(Self {
-            gate_proj,
-            up_proj,
-            down_proj,
-        })
-    }
-}
-
-impl Module for Qwen3_5MLP {
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        let lhs = candle_nn::ops::silu(&self.gate_proj.forward(x)?)?;
-        let rhs = self.up_proj.forward(x)?;
-        self.down_proj.forward(&(lhs * rhs)?)
-    }
-}
-
-fn load_linear_no_bias(
-    vb: &ShardedVarBuilder,
-    name: &str,
-    in_dim: usize,
-    out_dim: usize,
-) -> Result<Linear> {
-    let weight = vb
-        .pp(name)
-        .get((out_dim, in_dim), "weight")
-        .with_context(|| format!("load '{}/{name}/weight'", vb.prefix()))?;
-    Ok(Linear::new(weight, None))
-}

crates/neuron/src/harness/arch/qwen3_5/mod.rs

@@ -1,397 +0,0 @@
-//! Qwen3-Next (`model_type = "qwen3_5"`) architecture — Qwen3.6's
-//! upstream architecture revision.
-//!
-//! ## Naming
-//!
-//! The model release this targets is `Qwen/Qwen3.6-*` but the
-//! architecture name in HuggingFace's `config.json` is `qwen3_5`.
-//! mistralrs calls the same architecture `qwen3_next`; that label
-//! ages poorly the next time Qwen ship a new arch, so we key on the
-//! canonical `qwen3_5` from the model's own config.
-//!
-//! ## Status
-//!
-//! **Single-GPU dense path is real**. Both attention flavours
-//! (`full_attention` with the output-gated GQA causal attention and
-//! `linear_attention` with the Gated DeltaNet recurrent block) are
-//! implemented. The model loads from upstream safetensors via the
-//! existing `load_arch_dense` dispatch and runs forward end to end.
-//!
-//! Numerical correctness vs the reference Python is **not yet
-//! validated** — the structural code path is right, weight tensor
-//! names match the upstream layout, shapes flow through cleanly, but
-//! the Tbilisi probe (and any other downstream test) is the next
-//! step. Likely places a bug would surface:
-//! - Per-rank vs per-token-position offsets in the recurrent delta
-//!   rule (`linear_attn.rs`).
-//! - Off-by-one in the conv state continuation across decode steps.
-//! - RoPE phase mismatch from MRoPE simplification (we treat the
-//!   three position grids as collapsed, which is correct only for
-//!   text-only inference).
-//!
-//! ## Submodules
-//!
-//! - [`rmsnorm`] — `Qwen3_5RmsNorm` (`(1+w)*x` variant), the
-//!   `Qwen3_5RmsNormGated` used after the delta rule, and the
-//!   `l2norm` helper.
-//! - [`rope`] — text-side rotary embedding (mrope simplified, GLM
-//!   rotate-half).
-//! - [`mlp`] — SwiGLU MLP (gate/up/down, no bias).
-//! - [`full_attn`] — `Qwen3_5Attention` with the output-gate
-//!   widening on `q_proj`.
-//! - [`linear_attn`] — `GatedDeltaNet` recurrent delta-rule block
-//!   (causal depthwise Conv1d → silu → split → L2norm → per-token
-//!   delta rule → RMSNormGated → out_proj).
-//! - [`decoder`] — `Qwen3_5DecoderLayer` dispatching to one of the
-//!   two attention flavours per layer index.
-//!
-//! ## Open work
-//!
-//! - **TP variant.** `harness/tp/tp_qwen3_5.rs` is the next step.
-//!   Sharding strategy diverges by layer type:
-//!   - Full-attention layers: column-parallel q/k/v (including the
-//!     gate half of `q_proj`) + row-parallel `o_proj`, mirroring
-//!     `tp_qwen3.rs`.
-//!   - Linear-attention layers: the recurrent state is per-V-head, so
-//!     V-head-dimension sharding works cleanly — split `num_v_heads`
-//!     across ranks (`num_v_heads / world_size` per rank), shard
-//!     `in_proj_qkv` / `in_proj_z` / `in_proj_b` / `in_proj_a` along
-//!     the V-head dim, and row-parallel `out_proj`. The `A_log` /
-//!     `dt_bias` per-head params shard with the heads.
-//!
-//! - **Chunked delta-rule prefill.** `linear_attn.rs` runs the
-//!   per-token recurrent path for prefill too — correct but O(L).
-//!   Porting `torch_chunk_gated_delta_rule` (chunk_size=64) speeds
-//!   prefill substantially with no surface change.
-
-use anyhow::{Context, Result};
-use candle_core::{DType, Device, IndexOp, Module, Tensor};
-use candle_nn::Embedding;
-use candle_nn::Linear;
-use candle_nn::var_builder::ShardedVarBuilder;
-use serde::Deserialize;
-use std::sync::Arc;
-
-pub mod decoder;
-pub mod full_attn;
-pub mod linear_attn;
-pub mod mlp;
-pub mod rmsnorm;
-pub mod rope;
-
-use decoder::Qwen3_5DecoderLayer;
-use rmsnorm::Qwen3_5RmsNorm;
-use rope::RotaryEmbedding;
-
-/// `model_type` we deserialise from `config.json`. Const so the
-/// dispatch in `candle.rs::load_arch_dense` can pattern-match without
-/// magic strings.
-pub const MODEL_TYPE: &str = "qwen3_5";
-
-/// Top-level shape of Qwen3-Next's `config.json`. The real
-/// hyperparameters live in `text_config`; the rest is multimodal /
-/// tokeniser glue we don't need for the language-model forward.
-#[derive(Debug, Clone, Deserialize)]
-pub struct Config {
-    /// Always `"qwen3_5"` for this architecture. Kept on the struct
-    /// so the (eventual) dispatch / logging code can show it without
-    /// re-parsing the JSON.
-    pub model_type: String,
-    /// The text-side hyperparameters. Everything we actually need.
-    pub text_config: TextConfig,
-}
-
-/// Inner config (the `text_config` block). Mirrors the Qwen3 layout
-/// but with the extras Qwen3-Next adds (`attn_output_gate`,
-/// `layer_types`, `full_attention_interval`, larger `head_dim`).
-#[derive(Debug, Clone, Deserialize)]
-pub struct TextConfig {
-    pub vocab_size: usize,
-    pub hidden_size: usize,
-    pub intermediate_size: usize,
-    pub num_hidden_layers: usize,
-    pub num_attention_heads: usize,
-    pub num_key_value_heads: usize,
-    pub head_dim: usize,
-    pub max_position_embeddings: usize,
-    /// Nested RoPE settings. Qwen3-Next puts `rope_theta` and
-    /// `partial_rotary_factor` inside this block rather than at the
-    /// top level — important because the partial rotary means only
-    /// `head_dim * partial_rotary_factor` dims get RoPE applied (the
-    /// rest pass through unchanged).
-    pub rope_parameters: RopeParameters,
-    pub rms_norm_eps: f64,
-    #[serde(default)]
-    pub tie_word_embeddings: bool,
-
-    /// New in Qwen3-Next: a sigmoid gate multiplied into the attention
-    /// output before the o_proj. The Python reference applies it
-    /// pointwise after softmax+matmul.
-    #[serde(default)]
-    pub attn_output_gate: bool,
-
-    /// One entry per decoder layer; values are `"full_attention"` or
-    /// `"linear_attention"`. Length must equal `num_hidden_layers`.
-    /// `full_attention_interval` is a derived hint (every 4th layer
-    /// by default) — `layer_types` is authoritative.
-    #[serde(default)]
-    pub layer_types: Vec<String>,
-
-    /// Hint for the layer-type pattern (defaults to 4). Kept for
-    /// logging / validation; the forward dispatches on `layer_types`.
-    #[serde(default)]
-    pub full_attention_interval: Option<usize>,
-
-    /// Hidden activation (`"silu"` for Qwen3-Next). Used by the MLP
-    /// and the linear-attention conv1d.
-    #[serde(default = "default_hidden_act")]
-    pub hidden_act: String,
-
-    // --- Gated DeltaNet (linear-attention) hyperparams -----------------
-    /// Per-layer linear-attention V-head count (Qwen3.6-27B: 48).
-    /// More V-heads than K-heads is fine — query/key get
-    /// `repeat_interleave`'d to match before the delta rule.
-    #[serde(default)]
-    pub linear_num_value_heads: usize,
-    /// Per-layer linear-attention K-head count (Qwen3.6-27B: 16).
-    #[serde(default)]
-    pub linear_num_key_heads: usize,
-    /// Per-head key dimension for the linear-attention path
-    /// (Qwen3.6-27B: 128). Separate from `head_dim` which the
-    /// full-attention layers use.
-    #[serde(default)]
-    pub linear_key_head_dim: usize,
-    /// Per-head value dimension for the linear-attention path
-    /// (Qwen3.6-27B: 128).
-    #[serde(default)]
-    pub linear_value_head_dim: usize,
-    /// Causal Conv1d kernel size used before the delta rule
-    /// (Qwen3.6-27B: 4).
-    #[serde(default)]
-    pub linear_conv_kernel_dim: usize,
-}
-
-fn default_hidden_act() -> String {
-    "silu".into()
-}
-
-/// Nested `rope_parameters` block from a Qwen3-Next `config.json`.
-/// `mrope_section` and `mrope_interleaved` are accepted via the
-/// `#[serde(default)]` flatten-tolerance below but ignored — we treat
-/// MRoPE as plain RoPE for text-only inference (the three position
-/// grids carry identical ids when there's no vision input, so the
-/// interleaving is a no-op).
-#[derive(Debug, Clone, Deserialize)]
-pub struct RopeParameters {
-    /// Base for the inverse-frequency computation. Qwen3.6: 10_000_000.
-    #[serde(default = "default_rope_theta")]
-    pub rope_theta: f64,
-    /// Fraction of `head_dim` that gets the rotation applied. The
-    /// remaining `head_dim * (1 - partial_rotary_factor)` dims pass
-    /// through unchanged. Qwen3.6 / Qwen3.5: 0.25.
-    #[serde(default = "default_partial_rotary_factor")]
-    pub partial_rotary_factor: f32,
-    /// `"default"` for the standard inv_freq RoPE; other values (e.g.
-    /// `"linear"`, `"dynamic"`) are upstream-supported but not yet
-    /// implemented here.
-    #[serde(default)]
-    pub rope_type: Option<String>,
-}
-
-fn default_rope_theta() -> f64 {
-    10_000.0
-}
-
-fn default_partial_rotary_factor() -> f32 {
-    1.0
-}
-
-/// Qwen3-Next base transformer (embedding + decoder stack + final
-/// norm). Public so a TP variant in `harness/tp/tp_qwen3_5.rs` can
-/// also build on it later — for now only `Qwen3_5ForCausalLM` is the
-/// loaded handle.
-pub struct Qwen3_5Model {
-    embed_tokens: Embedding,
-    layers: Vec<Qwen3_5DecoderLayer>,
-    norm: Qwen3_5RmsNorm,
-    device: Device,
-    dtype: DType,
-}
-
-impl Qwen3_5Model {
-    pub fn load(cfg: &TextConfig, vb: &ShardedVarBuilder) -> Result<Self> {
-        let dtype = vb.dtype();
-        let device = vb.device().clone();
-
-        // Qwen3-Next is a multimodal architecture whose text core lives
-        // under `model.language_model.*` — sibling to `model.visual.*`
-        // (the vision tower) and to top-level `lm_head` / `mtp.*`.
-        // Every text-side tensor in the safetensors files is under
-        // this prefix; we ignore the vision and MTP weights for
-        // language-model inference.
-        let text_vb = vb.pp("model.language_model");
-
-        let embed_vb = text_vb.pp("embed_tokens");
-        let embed_weight = embed_vb
-            .get((cfg.vocab_size, cfg.hidden_size), "weight")
-            .with_context(|| format!("load '{}/weight'", embed_vb.prefix()))?;
-        let embed_tokens = Embedding::new(embed_weight, cfg.hidden_size);
-
-        let rotary = Arc::new(RotaryEmbedding::new(dtype, cfg, &device)?);
-
-        if cfg.layer_types.len() != cfg.num_hidden_layers {
-            anyhow::bail!(
-                "config.text_config.layer_types must have num_hidden_layers ({}) entries; \
-                 got {}",
-                cfg.num_hidden_layers,
-                cfg.layer_types.len()
-            );
-        }
-
-        let vb_l = text_vb.pp("layers");
-        let mut layers = Vec::with_capacity(cfg.num_hidden_layers);
-        for i in 0..cfg.num_hidden_layers {
-            layers.push(Qwen3_5DecoderLayer::load(
-                cfg,
-                rotary.clone(),
-                i,
-                &vb_l.pp(i),
-            )?);
-        }
-
-        let norm = Qwen3_5RmsNorm::load(&text_vb.pp("norm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-
-        Ok(Self {
-            embed_tokens,
-            layers,
-            norm,
-            device,
-            dtype,
-        })
-    }
-
-    pub fn embed_weight(&self) -> &Tensor {
-        self.embed_tokens.embeddings()
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        for l in &mut self.layers {
-            l.clear_kv_cache();
-        }
-    }
-
-    fn causal_mask(&self, b: usize, tgt: usize, offset: usize) -> candle_core::Result<Tensor> {
-        let minf = f32::NEG_INFINITY;
-        let mask: Vec<_> = (0..tgt)
-            .flat_map(|i| (0..(tgt + offset)).map(move |j| if j <= i + offset { 0. } else { minf }))
-            .collect();
-        Tensor::from_slice(&mask, (b, 1, tgt, tgt + offset), &self.device)?.to_dtype(self.dtype)
-    }
-
-    pub fn forward(&mut self, input: &Tensor, offset: usize) -> candle_core::Result<Tensor> {
-        let (b, l) = input.dims2()?;
-        let mut h = self.embed_tokens.forward(input)?;
-        // Causal mask only needed for L > 1 prefill; full-attention
-        // layers consume it via broadcast_add. Linear-attention layers
-        // ignore the mask.
-        let causal = if l == 1 {
-            None
-        } else {
-            Some(self.causal_mask(b, l, offset)?)
-        };
-        for layer in &mut self.layers {
-            h = layer.forward(&h, causal.as_ref(), offset)?;
-        }
-        self.norm.forward(&h)
-    }
-}
-
-pub struct Qwen3_5ForCausalLM {
-    base: Qwen3_5Model,
-    lm_head: Linear,
-}
-
-impl Qwen3_5ForCausalLM {
-    pub fn new(config: Config, vb: ShardedVarBuilder) -> Result<Self> {
-        let cfg = &config.text_config;
-        let base = Qwen3_5Model::load(cfg, &vb)?;
-        let lm_head = if cfg.tie_word_embeddings {
-            Linear::new(base.embed_weight().clone(), None)
-        } else {
-            let weight = vb
-                .pp("lm_head")
-                .get((cfg.vocab_size, cfg.hidden_size), "weight")
-                .with_context(|| format!("load '{}/lm_head/weight'", vb.prefix()))?;
-            Linear::new(weight, None)
-        };
-        Ok(Self { base, lm_head })
-    }
-
-    /// `input`: token-id tensor of shape `(B, L)`. Returns logits at
-    /// the last position, shape `(B, 1, vocab_size)` — same contract
-    /// as `qwen3::ModelForCausalLM::forward` so the harness's
-    /// `squeeze_to_vocab` helper handles both uniformly.
-    pub fn forward(&mut self, input: &Tensor, offset: usize) -> candle_core::Result<Tensor> {
-        let (_, l) = input.dims2()?;
-        let hidden = self.base.forward(input, offset)?;
-        hidden.i((.., l - 1.., ..))?.apply(&self.lm_head)
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        self.base.clear_kv_cache();
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// Confirms we can deserialise the real upstream config shape.
-    /// Sample taken from `Qwen/Qwen3.6-27B/config.json`, trimmed to
-    /// the fields the architecture cares about. Note `rope_theta` and
-    /// `partial_rotary_factor` are nested under `rope_parameters` —
-    /// Qwen3-Next does NOT have a top-level `rope_theta`.
-    #[test]
-    fn config_deserialises_the_real_qwen3_6_shape() {
-        let raw = r#"{
-            "architectures": ["Qwen3_5ForConditionalGeneration"],
-            "model_type": "qwen3_5",
-            "image_token_id": 248056,
-            "language_model_only": false,
-            "text_config": {
-                "vocab_size": 248064,
-                "hidden_size": 5120,
-                "intermediate_size": 17408,
-                "num_hidden_layers": 64,
-                "num_attention_heads": 64,
-                "num_key_value_heads": 8,
-                "head_dim": 256,
-                "max_position_embeddings": 32768,
-                "rope_parameters": {
-                    "mrope_interleaved": true,
-                    "mrope_section": [11, 11, 10],
-                    "partial_rotary_factor": 0.25,
-                    "rope_theta": 10000000,
-                    "rope_type": "default"
-                },
-                "rms_norm_eps": 1e-6,
-                "tie_word_embeddings": false,
-                "attn_output_gate": true,
-                "full_attention_interval": 4,
-                "layer_types": [
-                    "linear_attention", "linear_attention",
-                    "linear_attention", "full_attention"
-                ]
-            }
-        }"#;
-        let cfg: Config = serde_json::from_str(raw).expect("parse Qwen3.6 config");
-        assert_eq!(cfg.model_type, "qwen3_5");
-        assert_eq!(cfg.text_config.hidden_size, 5120);
-        assert_eq!(cfg.text_config.head_dim, 256);
-        assert!(cfg.text_config.attn_output_gate);
-        assert_eq!(cfg.text_config.full_attention_interval, Some(4));
-        assert_eq!(cfg.text_config.layer_types.len(), 4);
-        assert_eq!(cfg.text_config.rope_parameters.rope_theta, 10_000_000.0);
-        assert!((cfg.text_config.rope_parameters.partial_rotary_factor - 0.25).abs() < 1e-6);
-    }
-}

crates/neuron/src/harness/arch/qwen3_5/rmsnorm.rs

@@ -1,161 +0,0 @@
-//! Norm primitives for Qwen3-Next.
-//!
-//! Two reasons we can't reuse `candle_nn::RmsNorm` directly:
-//!
-//! 1. **`(1.0 + weight)` scaling.** Qwen3-Next's `Qwen3_5RMSNorm`
-//!    initialises `weight` to zeros and applies `(1.0 + weight)` to
-//!    the normalised vector. `candle_nn::RmsNorm` applies `weight`
-//!    directly. The two are equivalent only when the operator has
-//!    pre-shifted the weights — the upstream checkpoints have not. See
-//!    `huggingface/transformers#29402` for the upstream PR that
-//!    introduced the `(1 + w)` form to recover from the zero-init.
-//!
-//! 2. **Gated variant.** The linear-attention layer post-normalises
-//!    its output by an RMSNorm *gated* with a per-element SiLU on
-//!    a sibling `z` projection — fused for numerical reasons (the
-//!    norm's float32 promotion has to happen before the SiLU
-//!    multiply). Not a single existing candle op.
-//!
-//! Both ops accept inputs in any compute dtype; promotion to f32 for
-//! the variance calculation matches the Python reference.
-
-use anyhow::{Context, Result};
-use candle_core::{D, Module, Tensor};
-use candle_nn::var_builder::ShardedVarBuilder;
-
-/// L2-normalise along the last dim with a small epsilon. Matches the
-/// `l2norm` helper in `transformers/models/qwen3_5/modeling_qwen3_5.py`
-/// — `x * rsqrt(sum(x*x) + eps)`. The linear-attention path uses this
-/// on Q and K before the delta rule when
-/// `use_qk_l2norm_in_kernel=True` (which Qwen3-Next always sets).
-pub fn l2norm(x: &Tensor, eps: f32) -> candle_core::Result<Tensor> {
-    let dtype = x.dtype();
-    let x_f32 = x.to_dtype(candle_core::DType::F32)?;
-    let sq = x_f32.sqr()?;
-    let sum = sq.sum_keepdim(D::Minus1)?;
-    let inv = (sum + eps as f64)?.sqrt()?.recip()?;
-    x_f32.broadcast_mul(&inv)?.to_dtype(dtype)
-}
-
-/// Qwen3-Next's RMSNorm. Stores the raw weight tensor; forward applies
-/// `(1.0 + weight) * x_normed`.
-pub struct Qwen3_5RmsNorm {
-    weight: Tensor,
-    eps: f32,
-    size: usize,
-}
-
-impl Qwen3_5RmsNorm {
-    /// Load `weight` from the ShardedVarBuilder. `vb` should already be
-    /// `.pp(...)`-ed to the norm's tensor prefix.
-    pub fn load(vb: &ShardedVarBuilder, size: usize, eps: f64) -> Result<Self> {
-        let weight = vb
-            .get(size, "weight")
-            .with_context(|| format!("load '{}/weight'", vb.prefix()))?;
-        Ok(Self {
-            weight,
-            eps: eps as f32,
-            size,
-        })
-    }
-
-    pub fn size(&self) -> usize {
-        self.size
-    }
-}
-
-impl Module for Qwen3_5RmsNorm {
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        let dtype = x.dtype();
-        let x_f32 = x.to_dtype(candle_core::DType::F32)?;
-        let var = x_f32.sqr()?.mean_keepdim(D::Minus1)?;
-        let normed = x_f32.broadcast_mul(&(var + self.eps as f64)?.sqrt()?.recip()?)?;
-        // Promote weight to f32 and shift by 1.0 *before* multiplying.
-        // Doing the (1 + w) operation in fp16 lands at -inf for the
-        // bottom-of-range weights at load time.
-        let w_f32 = self.weight.to_dtype(candle_core::DType::F32)?;
-        let scale = (w_f32 + 1.0_f64)?;
-        normed.broadcast_mul(&scale)?.to_dtype(dtype)
-    }
-}
-
-/// Gated RMSNorm used at the tail of `Qwen3_5GatedDeltaNet`. Equivalent
-/// to `x_normed * weight * silu(gate)` but with both the norm and the
-/// gate evaluated in float32 to avoid mid-pipeline underflow.
-///
-/// Note: unlike `Qwen3_5RmsNorm`, this variant matches the Python
-/// reference's `Qwen3_5RMSNormGated` which uses `weight` directly (not
-/// `1.0 + weight`).
-pub struct Qwen3_5RmsNormGated {
-    weight: Tensor,
-    eps: f32,
-    size: usize,
-}
-
-impl Qwen3_5RmsNormGated {
-    pub fn load(vb: &ShardedVarBuilder, size: usize, eps: f64) -> Result<Self> {
-        let weight = vb
-            .get(size, "weight")
-            .with_context(|| format!("load '{}/weight'", vb.prefix()))?;
-        Ok(Self {
-            weight,
-            eps: eps as f32,
-            size,
-        })
-    }
-
-    /// Direct constructor — used by unit tests that build a layer
-    /// without going through a VarBuilder.
-    #[cfg(test)]
-    pub(crate) fn from_weight(weight: Tensor, eps: f64) -> Self {
-        let size = weight.dims()[0];
-        Self {
-            weight,
-            eps: eps as f32,
-            size,
-        }
-    }
-
-    pub fn size(&self) -> usize {
-        self.size
-    }
-
-    /// `x` and `gate` share the same last-dim shape (`size`).
-    pub fn forward(&self, x: &Tensor, gate: &Tensor) -> candle_core::Result<Tensor> {
-        let dtype = x.dtype();
-        let x_f32 = x.to_dtype(candle_core::DType::F32)?;
-        let var = x_f32.sqr()?.mean_keepdim(D::Minus1)?;
-        let normed = x_f32.broadcast_mul(&(var + self.eps as f64)?.sqrt()?.recip()?)?;
-        let w = self.weight.to_dtype(candle_core::DType::F32)?;
-        let out = normed.broadcast_mul(&w)?;
-        // SiLU on the float32 gate, multiply back into the normed
-        // tensor, then cast to the model dtype.
-        let g = gate.to_dtype(candle_core::DType::F32)?;
-        let silu_gate = candle_nn::ops::silu(&g)?;
-        (out * silu_gate)?.to_dtype(dtype)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use candle_core::Device;
-
-    #[test]
-    fn l2norm_matches_hand_calc() {
-        let x = Tensor::new(&[3.0_f32, 4.0_f32], &Device::Cpu).unwrap();
-        let out = l2norm(&x, 1e-6).unwrap();
-        let v: Vec<f32> = out.to_vec1().unwrap();
-        // |x| = 5, so x/|x| = [0.6, 0.8] (eps is tiny).
-        assert!((v[0] - 0.6).abs() < 1e-4);
-        assert!((v[1] - 0.8).abs() < 1e-4);
-    }
-
-    #[test]
-    fn l2norm_zero_vector_is_safe_via_epsilon() {
-        let x = Tensor::new(&[0.0_f32, 0.0_f32], &Device::Cpu).unwrap();
-        let out = l2norm(&x, 1e-6).unwrap();
-        let v: Vec<f32> = out.to_vec1().unwrap();
-        assert!(v.iter().all(|x| x.is_finite()));
-    }
-}

crates/neuron/src/harness/arch/qwen3_5/rope.rs

@@ -1,114 +0,0 @@
-//! Rotary position embedding for Qwen3-Next's full-attention layers.
-//!
-//! Qwen3.6 ships with MRoPE (multimodal RoPE) machinery in the
-//! reference Python — three position grids interleaved per
-//! `mrope_section`. For text-only inference all three grids carry the
-//! same position ids and the interleave is a no-op, so this module
-//! implements the plain (non-mrope) flavour: the standard inv_freq
-//! cosine/sine tables driven by `rope_theta` and `head_dim`.
-//!
-//! Rotation flavour: **GLM-style** rotate-half (the second half of the
-//! head dim is negated and swapped into the first). The reference
-//! Python uses `apply_rotary_pos_emb` with `rotate_half`; candle's
-//! `rope_slow` is the matching helper.
-
-use anyhow::Result;
-use candle_core::{DType, Device, Tensor};
-
-use super::TextConfig;
-
-#[derive(Debug, Clone)]
-pub struct RotaryEmbedding {
-    sin: Tensor,
-    cos: Tensor,
-    /// Number of dims at the head's leading edge that the rotation
-    /// covers. The remaining `head_dim - rotary_dim` dims pass through
-    /// unchanged. Qwen3-Next uses `partial_rotary_factor = 0.25`, so
-    /// for `head_dim = 256` only 64 dims rotate.
-    rotary_dim: usize,
-    head_dim: usize,
-}
-
-impl RotaryEmbedding {
-    pub fn new(dtype: DType, cfg: &TextConfig, dev: &Device) -> Result<Self> {
-        let head_dim = cfg.head_dim;
-        let rope = &cfg.rope_parameters;
-        let rotary_dim = (head_dim as f32 * rope.partial_rotary_factor) as usize;
-        if !rotary_dim.is_multiple_of(2) {
-            anyhow::bail!(
-                "rotary_dim = head_dim * partial_rotary_factor = {head_dim} * {} = {rotary_dim} \
-                 must be even (cos/sin are paired)",
-                rope.partial_rotary_factor
-            );
-        }
-        if rotary_dim == 0 {
-            anyhow::bail!(
-                "rotary_dim = 0 (partial_rotary_factor = {} too small)",
-                rope.partial_rotary_factor
-            );
-        }
-        let max_seq_len = cfg.max_position_embeddings;
-        let inv_freq: Vec<f32> = (0..rotary_dim)
-            .step_by(2)
-            .map(|i| 1f32 / rope.rope_theta.powf(i as f64 / rotary_dim as f64) as f32)
-            .collect();
-        let n = inv_freq.len();
-        let inv_freq = Tensor::from_vec(inv_freq, (1, n), dev)?.to_dtype(DType::F32)?;
-        let t = Tensor::arange(0u32, max_seq_len as u32, dev)?
-            .to_dtype(DType::F32)?
-            .reshape((max_seq_len, 1))?;
-        let freqs = t.matmul(&inv_freq)?;
-        Ok(Self {
-            sin: freqs.sin()?.to_dtype(dtype)?,
-            cos: freqs.cos()?.to_dtype(dtype)?,
-            rotary_dim,
-            head_dim,
-        })
-    }
-
-    /// Apply RoPE to q, k.
-    ///
-    /// `q`, `k` shape: `(B, H, L, head_dim)`. `offset` is the index
-    /// into the cached cos/sin table — the position of the first token
-    /// in the current step.
-    ///
-    /// When `rotary_dim < head_dim` the rotation is applied only to the
-    /// first `rotary_dim` dims of each head; the tail passes through
-    /// unchanged (matches the reference Python's
-    /// `apply_rotary_pos_emb` with non-trivial `partial_rotary_factor`).
-    pub fn apply(
-        &self,
-        q: &Tensor,
-        k: &Tensor,
-        offset: usize,
-    ) -> candle_core::Result<(Tensor, Tensor)> {
-        let (_, _, seq_len, head_dim_in) = q.dims4()?;
-        debug_assert_eq!(head_dim_in, self.head_dim, "q head_dim mismatch");
-        let cos = self.cos.narrow(0, offset, seq_len)?;
-        let sin = self.sin.narrow(0, offset, seq_len)?;
-        if self.rotary_dim == self.head_dim {
-            // Full rotation.
-            let q_embed = candle_nn::rotary_emb::rope_slow(&q.contiguous()?, &cos, &sin)?;
-            let k_embed = candle_nn::rotary_emb::rope_slow(&k.contiguous()?, &cos, &sin)?;
-            Ok((q_embed, k_embed))
-        } else {
-            // Partial rotation: narrow → rotate → cat the untouched tail.
-            let tail = self.head_dim - self.rotary_dim;
-            let q_rot = q
-                .narrow(candle_core::D::Minus1, 0, self.rotary_dim)?
-                .contiguous()?;
-            let q_pass = q.narrow(candle_core::D::Minus1, self.rotary_dim, tail)?;
-            let k_rot = k
-                .narrow(candle_core::D::Minus1, 0, self.rotary_dim)?
-                .contiguous()?;
-            let k_pass = k.narrow(candle_core::D::Minus1, self.rotary_dim, tail)?;
-            let q_rotated = candle_nn::rotary_emb::rope_slow(&q_rot, &cos, &sin)?;
-            let k_rotated = candle_nn::rotary_emb::rope_slow(&k_rot, &cos, &sin)?;
-            let q_embed =
-                Tensor::cat(&[&q_rotated, &q_pass.contiguous()?], candle_core::D::Minus1)?;
-            let k_embed =
-                Tensor::cat(&[&k_rotated, &k_pass.contiguous()?], candle_core::D::Minus1)?;
-            Ok((q_embed, k_embed))
-        }
-    }
-}

crates/neuron/src/harness/llamacpp.rs

@@ -0,0 +1 @@
+// llama.cpp harness implementation — Phase 11.

crates/neuron/src/harness/mistralrs.rs

@@ -0,0 +1,163 @@
+//! mistral.rs harness implementation.
+//!
+//! Wraps the mistral.rs HTTP API for model lifecycle management
+//! and optionally manages the process via systemd.
+
+use anyhow::Result;
+use async_trait::async_trait;
+use cortex_core::harness::{Harness, HarnessConfig, HarnessHealth, ModelInfo, ModelSpec};
+use reqwest::Client;
+use serde::Deserialize;
+
+pub struct MistralRsHarness {
+    endpoint: String,
+    systemd_unit: Option<String>,
+    client: Client,
+}
+
+impl MistralRsHarness {
+    pub fn new(endpoint: String, systemd_unit: Option<String>) -> Self {
+        Self {
+            endpoint,
+            systemd_unit,
+            client: Client::builder()
+                .timeout(std::time::Duration::from_secs(30))
+                .build()
+                .expect("failed to build HTTP client"),
+        }
+    }
+}
+
+/// Response from mistral.rs `GET /v1/models`.
+#[derive(Debug, Deserialize)]
+struct ModelsResponse {
+    data: Vec<ModelEntry>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ModelEntry {
+    id: String,
+    #[serde(default)]
+    status: Option<String>,
+}
+
+#[async_trait]
+impl Harness for MistralRsHarness {
+    fn name(&self) -> &str {
+        "mistralrs"
+    }
+
+    async fn start(&self, _config: &HarnessConfig) -> Result<()> {
+        let Some(unit) = &self.systemd_unit else {
+            anyhow::bail!("no systemd unit configured for mistralrs harness");
+        };
+
+        let output = tokio::process::Command::new("systemctl")
+            .args(["start", unit])
+            .output()
+            .await?;
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            anyhow::bail!("systemctl start {unit} failed: {stderr}");
+        }
+
+        // Wait for the health endpoint to respond (up to 30s).
+        let url = format!("{}/health", self.endpoint);
+        for _ in 0..30 {
+            tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+            if self.client.get(&url).send().await.is_ok() {
+                tracing::info!(unit, "mistralrs started and healthy");
+                return Ok(());
+            }
+        }
+        anyhow::bail!("mistralrs started but health endpoint did not respond within 30s");
+    }
+
+    async fn stop(&self) -> Result<()> {
+        let Some(unit) = &self.systemd_unit else {
+            anyhow::bail!("no systemd unit configured for mistralrs harness");
+        };
+
+        let output = tokio::process::Command::new("systemctl")
+            .args(["stop", unit])
+            .output()
+            .await?;
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            anyhow::bail!("systemctl stop {unit} failed: {stderr}");
+        }
+        Ok(())
+    }
+
+    async fn health(&self) -> HarnessHealth {
+        let url = format!("{}/health", self.endpoint);
+        let running = self.client.get(&url).send().await.is_ok();
+        HarnessHealth {
+            name: "mistralrs".into(),
+            running,
+            uptime_secs: None,
+        }
+    }
+
+    async fn list_models(&self) -> Result<Vec<ModelInfo>> {
+        let url = format!("{}/v1/models", self.endpoint);
+        let resp = self.client.get(&url).send().await?;
+
+        if !resp.status().is_success() {
+            anyhow::bail!("GET /v1/models returned {}", resp.status());
+        }
+
+        let models_resp: ModelsResponse = resp.json().await?;
+        Ok(models_resp
+            .data
+            .into_iter()
+            .map(|m| ModelInfo {
+                id: m.id,
+                harness: "mistralrs".into(),
+                status: m.status.unwrap_or_else(|| "loaded".into()),
+                devices: vec![],
+                vram_used_mb: None,
+            })
+            .collect())
+    }
+
+    async fn load_model(&self, spec: &ModelSpec) -> Result<()> {
+        let url = format!("{}/v1/models/reload", self.endpoint);
+        let resp = self
+            .client
+            .post(&url)
+            .json(&serde_json::json!({ "model_id": spec.model_id }))
+            .send()
+            .await?;
+
+        if !resp.status().is_success() {
+            let body = resp.text().await.unwrap_or_default();
+            anyhow::bail!("POST /v1/models/reload failed: {body}");
+        }
+        Ok(())
+    }
+
+    async fn unload_model(&self, model_id: &str) -> Result<()> {
+        let url = format!("{}/v1/models/unload", self.endpoint);
+        let resp = self
+            .client
+            .post(&url)
+            .json(&serde_json::json!({ "model_id": model_id }))
+            .send()
+            .await?;
+
+        if !resp.status().is_success() {
+            let body = resp.text().await.unwrap_or_default();
+            anyhow::bail!("POST /v1/models/unload failed: {body}");
+        }
+        Ok(())
+    }
+
+    async fn inference_endpoint(&self, _model_id: &str) -> Option<String> {
+        // mistral.rs routes internally by model name in the request body,
+        // so the inference endpoint is always the base URL.
+        Some(self.endpoint.clone())
+    }
+}

crates/neuron/src/harness/mod.rs

@@ -1,24 +1,15 @@
 //! Harness registry — maps harness names to trait implementations.
 
-pub mod arch;
-pub mod candle;
-pub mod tp;
+pub mod llamacpp;
+pub mod mistralrs;
 
 use anyhow::Result;
 use cortex_core::harness::{Harness, HarnessConfig, ModelInfo, ModelSpec};
 use std::collections::HashMap;
-use std::sync::Arc;
 
 /// Registry of available harness implementations.
-///
-/// Holds an `Arc<dyn Harness>` per harness for generic lifecycle dispatch
-/// (load/unload/list_models). When a candle harness is registered, a typed
-/// `Arc<CandleHarness>` is also cached so inference routes can bypass the
-/// dyn-Trait dispatch and reach harness-specific methods (chat completion,
-/// streaming, etc.).
 pub struct HarnessRegistry {
-    harnesses: HashMap<String, Arc<dyn Harness>>,
-    candle: Option<Arc<candle::CandleHarness>>,
+    harnesses: HashMap<String, Box<dyn Harness>>,
 }
 
 impl Default for HarnessRegistry {
@@ -31,11 +22,10 @@ impl HarnessRegistry {
     pub fn new() -> Self {
         Self {
             harnesses: HashMap::new(),
-            candle: None,
         }
     }
 
-    pub fn register(&mut self, harness: Arc<dyn Harness>) {
+    pub fn register(&mut self, harness: Box<dyn Harness>) {
         self.harnesses.insert(harness.name().to_string(), harness);
     }
 
@@ -44,12 +34,6 @@ impl HarnessRegistry {
         self.harnesses.keys().cloned().collect()
     }
 
-    /// Typed handle to the candle harness, if registered. Used by inference
-    /// routes that need methods beyond the `Harness` trait surface.
-    pub fn candle(&self) -> Option<Arc<candle::CandleHarness>> {
-        self.candle.clone()
-    }
-
     /// List models from all registered harnesses.
     pub async fn list_all_models(&self) -> Result<Vec<ModelInfo>> {
         let mut all = Vec::new();
@@ -97,25 +81,19 @@ impl HarnessRegistry {
     }
 
     /// Build a registry from harness configs.
-    ///
-    /// `bind_url` is the URL where this neuron serves inference (its own
-    /// listen address). In-process harnesses (currently the only kind)
-    /// return this URL from `inference_endpoint`.
-    pub fn from_configs(
-        configs: &[HarnessConfig],
-        bind_url: &str,
-        settings: &crate::config::HarnessSettings,
-    ) -> Self {
+    pub fn from_configs(configs: &[HarnessConfig]) -> Self {
         let mut registry = Self::new();
         for config in configs {
             match config.name.as_str() {
-                "candle" => {
-                    let harness = Arc::new(candle::CandleHarness::new(
-                        bind_url.to_string(),
-                        settings.candle.hf_cache.clone(),
-                    ));
-                    registry.candle = Some(Arc::clone(&harness));
-                    registry.harnesses.insert("candle".into(), harness);
+                "mistralrs" => {
+                    if let Some(endpoint) = &config.endpoint {
+                        registry.register(Box::new(mistralrs::MistralRsHarness::new(
+                            endpoint.clone(),
+                            config.systemd_unit.clone(),
+                        )));
+                    } else {
+                        tracing::warn!("mistralrs harness missing endpoint, skipping");
+                    }
                 }
                 other => {
                     tracing::warn!(harness = other, "unknown harness type, skipping");

crates/neuron/src/harness/tp/all_reduce.rs

@@ -1,119 +0,0 @@
-//! `AllReduce` as a candle `CustomOp1` — the bridge between candle's
-//! `Tensor` graph and `cudarc::nccl::Comm::all_reduce`.
-//!
-//! Ported from the canonical
-//! `candle-examples/examples/llama_multiprocess/model.rs` pattern.
-//! Row-parallel layers apply this op after their local matmul to sum
-//! partial outputs across NCCL ranks.
-//!
-//! Available only under `--features cuda`; on CPU builds this module
-//! is empty and row-parallel layers degenerate to local matmul only
-//! (useful for compile-checking the model code; correctness requires
-//! cuda).
-//!
-//! Thread-safety caveat: NCCL communicators are technically only
-//! safe to use from a single thread at a time
-//! (https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/usage/threadsafety.html).
-//! We hold the `AllReduce` behind an `Arc<Comm>` and only issue ops
-//! against it from the dedicated `spawn_blocking` thread the inference
-//! pipeline already uses for candle's forward passes.
-
-#![cfg(feature = "cuda")]
-
-use candle_core::backend::BackendStorage;
-use candle_core::{CpuStorage, CudaStorage, CustomOp1, DType, Layout, Result, Shape};
-use cudarc::nccl::{Comm, ReduceOp};
-use half::{bf16, f16};
-use std::sync::Arc;
-
-/// Wraps an NCCL `Comm` so it can be plugged into a candle forward
-/// graph as a custom op. Each row-parallel layer holds one of these.
-pub struct AllReduce {
-    comm: Arc<Comm>,
-}
-
-// SAFETY: `Comm` contains a raw `ncclComm_t` pointer; NCCL's docs note
-// that issuing ops against one comm from multiple threads concurrently
-// is unsafe. We serialise via the single spawn_blocking thread that
-// drives the model's forward pass. The Send/Sync impl is necessary
-// because candle's CustomOp1 trait bounds require it; the correctness
-// invariant is enforced at the call site, not the type level.
-unsafe impl Send for AllReduce {}
-unsafe impl Sync for AllReduce {}
-
-impl AllReduce {
-    pub fn new(comm: Arc<Comm>) -> Self {
-        Self { comm }
-    }
-
-    pub fn comm(&self) -> &Arc<Comm> {
-        &self.comm
-    }
-}
-
-impl CustomOp1 for AllReduce {
-    fn name(&self) -> &'static str {
-        "neuron.tp.all_reduce"
-    }
-
-    fn cpu_fwd(&self, _s: &CpuStorage, _l: &Layout) -> Result<(CpuStorage, Shape)> {
-        candle_core::bail!("AllReduce custom-op invoked on CPU storage; TP requires CUDA")
-    }
-
-    fn cuda_fwd(&self, s: &CudaStorage, l: &Layout) -> Result<(CudaStorage, Shape)> {
-        // Reject non-contiguous inputs explicitly — copying them
-        // server-side would mask shape bugs (a TP layer feeding a
-        // strided activation into all_reduce is almost certainly a
-        // model construction error).
-        fn require_contiguous<T: cudarc::driver::DeviceRepr>(
-            slice: &cudarc::driver::CudaSlice<T>,
-            l: &Layout,
-        ) -> Result<()> {
-            match l.contiguous_offsets() {
-                Some((0, n)) if n == slice.len() => Ok(()),
-                _ => candle_core::bail!(
-                    "AllReduce input is non-contiguous: layout={:?}, slice_len={}",
-                    l,
-                    slice.len()
-                ),
-            }
-        }
-
-        let elem_count = l.shape().elem_count();
-        let dev = s.device().clone();
-
-        let out = match s.dtype() {
-            DType::BF16 => {
-                let src = s.as_cuda_slice::<bf16>()?;
-                require_contiguous(src, l)?;
-                let mut dst = unsafe { dev.alloc::<bf16>(elem_count) }?;
-                self.comm
-                    .all_reduce(src, &mut dst, &ReduceOp::Sum)
-                    .map_err(|e| candle_core::Error::Msg(format!("nccl all_reduce bf16: {e:?}")))?;
-                CudaStorage::wrap_cuda_slice(dst, dev)
-            }
-            DType::F16 => {
-                let src = s.as_cuda_slice::<f16>()?;
-                require_contiguous(src, l)?;
-                let mut dst = unsafe { dev.alloc::<f16>(elem_count) }?;
-                self.comm
-                    .all_reduce(src, &mut dst, &ReduceOp::Sum)
-                    .map_err(|e| candle_core::Error::Msg(format!("nccl all_reduce f16: {e:?}")))?;
-                CudaStorage::wrap_cuda_slice(dst, dev)
-            }
-            DType::F32 => {
-                let src = s.as_cuda_slice::<f32>()?;
-                require_contiguous(src, l)?;
-                let mut dst = unsafe { dev.alloc::<f32>(elem_count) }?;
-                self.comm
-                    .all_reduce(src, &mut dst, &ReduceOp::Sum)
-                    .map_err(|e| candle_core::Error::Msg(format!("nccl all_reduce f32: {e:?}")))?;
-                CudaStorage::wrap_cuda_slice(dst, dev)
-            }
-            dtype => candle_core::bail!(
-                "AllReduce: unsupported dtype {dtype:?}; TP path expects bf16/f16/f32"
-            ),
-        };
-        Ok((out, l.shape().clone()))
-    }
-}

crates/neuron/src/harness/tp/fused_load.rs

@@ -1,213 +0,0 @@
-//! Direct safetensors readers for fused-region weight tensors.
-//!
-//! Qwen3-Next's `in_proj_qkv` and `conv1d` weights are *fused* —
-//! three regions stored sequentially along dim 0 (`[key_q, key_k,
-//! value]`). The per-rank shard for each region has unequal size
-//! (`key_dim/ws` vs `value_dim/ws`), so candle's `ShardedSafeTensors`
-//! built-in `Shard { dim, rank, world_size }` (uniform split) doesn't
-//! map to the right slices.
-//!
-//! The previous approach loaded the full fused tensor onto the device,
-//! `narrow`ed the three regions, and `Tensor::cat(...).contiguous()`'d
-//! the per-rank slice. That left ~100 MB of transient device memory
-//! per linear-attention layer — 48 layers × 100 MB = ~4.8 GB of
-//! allocator pressure during load, enough to trigger fragmentation
-//! OOM on tight-VRAM consumer GPUs.
-//!
-//! This module reads the three per-rank byte ranges *directly from
-//! the safetensors mmap* (host-side), concatenates them into a single
-//! contiguous byte buffer, and uploads as one device allocation. No
-//! full-tensor device materialisation.
-
-use anyhow::{Context, Result, bail};
-use candle_core::safetensors::MmapedSafetensors;
-use candle_core::{DType, Device, Tensor};
-
-/// Read a 2D fused-QKV tensor `[conv_dim, hidden_size]` and return
-/// this rank's per-region slice as a `[per_rank_conv_dim, hidden_size]`
-/// device tensor.
-///
-/// `tensor_name` must be the fully-qualified safetensors key (e.g.
-/// `"model.language_model.layers.5.linear_attn.in_proj_qkv.weight"`).
-#[allow(clippy::too_many_arguments)]
-pub fn load_fused_qkv_2d(
-    mmap: &MmapedSafetensors,
-    tensor_name: &str,
-    hidden_size: usize,
-    key_dim: usize,
-    value_dim: usize,
-    rank: u32,
-    world_size: u32,
-    target_dtype: DType,
-    device: &Device,
-) -> Result<Tensor> {
-    let ws = world_size as usize;
-    let r = rank as usize;
-    if !key_dim.is_multiple_of(ws) || !value_dim.is_multiple_of(ws) {
-        bail!(
-            "fused qkv shard: key_dim ({key_dim}) and value_dim ({value_dim}) \
-             must each be divisible by world_size ({ws})"
-        );
-    }
-    let per_rank_key = key_dim / ws;
-    let per_rank_value = value_dim / ws;
-    let per_rank_conv_dim = per_rank_key * 2 + per_rank_value;
-
-    let view = mmap
-        .get(tensor_name)
-        .with_context(|| format!("mmap.get('{tensor_name}') for fused qkv 2D"))?;
-    let view_dtype: DType = view
-        .dtype()
-        .try_into()
-        .with_context(|| format!("safetensors dtype unsupported for '{tensor_name}'"))?;
-
-    let shape = view.shape();
-    if shape.len() != 2 {
-        bail!(
-            "fused qkv tensor '{tensor_name}' has shape {shape:?}, expected 2D \
-             [conv_dim, hidden_size]"
-        );
-    }
-    let conv_dim = key_dim * 2 + value_dim;
-    if shape[0] != conv_dim || shape[1] != hidden_size {
-        bail!(
-            "fused qkv tensor '{tensor_name}' shape {shape:?} \
-             doesn't match expected [{conv_dim}, {hidden_size}]"
-        );
-    }
-
-    let q_bytes = slice_dim0_bytes(&view, r * per_rank_key, per_rank_key, tensor_name, "q")?;
-    let k_bytes = slice_dim0_bytes(
-        &view,
-        key_dim + r * per_rank_key,
-        per_rank_key,
-        tensor_name,
-        "k",
-    )?;
-    let v_bytes = slice_dim0_bytes(
-        &view,
-        2 * key_dim + r * per_rank_value,
-        per_rank_value,
-        tensor_name,
-        "v",
-    )?;
-
-    let mut bytes = Vec::with_capacity(q_bytes.len() + k_bytes.len() + v_bytes.len());
-    bytes.extend_from_slice(&q_bytes);
-    bytes.extend_from_slice(&k_bytes);
-    bytes.extend_from_slice(&v_bytes);
-
-    let tensor = Tensor::from_raw_buffer(
-        &bytes,
-        view_dtype,
-        &[per_rank_conv_dim, hidden_size],
-        device,
-    )
-    .with_context(|| format!("Tensor::from_raw_buffer for per-rank fused qkv '{tensor_name}'"))?;
-    tensor
-        .to_dtype(target_dtype)
-        .with_context(|| format!("cast '{tensor_name}' to {target_dtype:?}"))
-}
-
-/// Read a 3D fused-QKV tensor `[conv_dim, 1, kernel_size]` (the
-/// depthwise conv1d weight) and return this rank's per-region slice
-/// as a `[per_rank_conv_dim, 1, kernel_size]` device tensor.
-#[allow(clippy::too_many_arguments)]
-pub fn load_fused_qkv_3d(
-    mmap: &MmapedSafetensors,
-    tensor_name: &str,
-    mid: usize,
-    kernel_size: usize,
-    key_dim: usize,
-    value_dim: usize,
-    rank: u32,
-    world_size: u32,
-    target_dtype: DType,
-    device: &Device,
-) -> Result<Tensor> {
-    let ws = world_size as usize;
-    let r = rank as usize;
-    if !key_dim.is_multiple_of(ws) || !value_dim.is_multiple_of(ws) {
-        bail!(
-            "fused conv shard: key_dim ({key_dim}) and value_dim ({value_dim}) \
-             must each be divisible by world_size ({ws})"
-        );
-    }
-    let per_rank_key = key_dim / ws;
-    let per_rank_value = value_dim / ws;
-    let per_rank_conv_dim = per_rank_key * 2 + per_rank_value;
-
-    let view = mmap
-        .get(tensor_name)
-        .with_context(|| format!("mmap.get('{tensor_name}') for fused qkv 3D"))?;
-    let view_dtype: DType = view
-        .dtype()
-        .try_into()
-        .with_context(|| format!("safetensors dtype unsupported for '{tensor_name}'"))?;
-
-    let shape = view.shape();
-    if shape.len() != 3 {
-        bail!(
-            "fused conv tensor '{tensor_name}' has shape {shape:?}, expected 3D \
-             [conv_dim, mid, kernel_size]"
-        );
-    }
-    let conv_dim = key_dim * 2 + value_dim;
-    if shape[0] != conv_dim || shape[1] != mid || shape[2] != kernel_size {
-        bail!(
-            "fused conv tensor '{tensor_name}' shape {shape:?} \
-             doesn't match expected [{conv_dim}, {mid}, {kernel_size}]"
-        );
-    }
-
-    let q_bytes = slice_dim0_bytes(&view, r * per_rank_key, per_rank_key, tensor_name, "q")?;
-    let k_bytes = slice_dim0_bytes(
-        &view,
-        key_dim + r * per_rank_key,
-        per_rank_key,
-        tensor_name,
-        "k",
-    )?;
-    let v_bytes = slice_dim0_bytes(
-        &view,
-        2 * key_dim + r * per_rank_value,
-        per_rank_value,
-        tensor_name,
-        "v",
-    )?;
-
-    let mut bytes = Vec::with_capacity(q_bytes.len() + k_bytes.len() + v_bytes.len());
-    bytes.extend_from_slice(&q_bytes);
-    bytes.extend_from_slice(&k_bytes);
-    bytes.extend_from_slice(&v_bytes);
-
-    let tensor = Tensor::from_raw_buffer(
-        &bytes,
-        view_dtype,
-        &[per_rank_conv_dim, mid, kernel_size],
-        device,
-    )
-    .with_context(|| format!("Tensor::from_raw_buffer for per-rank fused conv '{tensor_name}'"))?;
-    tensor
-        .to_dtype(target_dtype)
-        .with_context(|| format!("cast '{tensor_name}' to {target_dtype:?}"))
-}
-
-/// Read `len` consecutive rows along dim 0 starting at `start` from
-/// the safetensors view, returning the raw bytes. Wraps the same
-/// `view.slice(start..stop)` machinery that candle's
-/// `ShardedSafeTensors::get` uses internally.
-fn slice_dim0_bytes(
-    view: &safetensors::tensor::TensorView<'_>,
-    start: usize,
-    len: usize,
-    tensor_name: &str,
-    region: &str,
-) -> Result<Vec<u8>> {
-    use safetensors::slice::IndexOp;
-    let stop = start + len;
-    let iter = view.slice(start..stop).map_err(|e| {
-        anyhow::anyhow!("slice '{tensor_name}' region {region} ({start}..{stop}): {e:?}")
-    })?;
-    Ok(iter.into_iter().flatten().copied().collect())
-}

crates/neuron/src/harness/tp/mod.rs

@@ -1,791 +0,0 @@
-//! Tensor-parallel inference plumbing.
-//!
-//! The leader process (the neuron daemon proper) drives one
-//! subprocess per non-zero NCCL rank — `tokio::process::Command` on
-//! `/proc/self/exe --worker --rank N --tp-size N --cuda-device N` —
-//! and talks to each over a newline-delimited JSON RPC channel on
-//! the worker's stdin/stdout (see `rpc.rs`).
-//!
-//! Sub-staging:
-//!
-//! - **7a-i (this commit):** process lifecycle. `WorkerPool::spawn`
-//!   forks N workers; `ping` round-trips every worker to confirm
-//!   they're alive; `shutdown` cleanly drains and reaps. `Init` /
-//!   `NcclSanityCheck` are stubbed.
-//! - **7a-ii:** real NCCL `Comm` setup via `Init`, sanity check via
-//!   `NcclSanityCheck`. CUDA-gated.
-//! - **7b:** TP-aware Qwen3 inference dispatched through the pool.
-//! - **7c:** crash detection, streaming SSE, graceful unload.
-
-pub mod all_reduce;
-pub mod fused_load;
-pub mod nccl_state;
-pub mod rpc;
-pub mod tp_linear;
-pub mod tp_qwen3;
-pub mod tp_qwen3_5;
-pub mod worker;
-
-use anyhow::{Context, Result};
-use std::path::{Path, PathBuf};
-use std::process::Stdio;
-use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, Lines};
-use tokio::process::{Child, ChildStdin, ChildStdout, Command};
-
-use rpc::{WorkerRequest, WorkerResponse};
-
-/// Leader-side handle for any TP-loaded model. The pool's
-/// `load_dense_shard` dispatches on `config.json#/model_type` to build
-/// the right variant; downstream callers (the harness's
-/// `chat_completion_tp` path, `generate_step`, `clear_kv_cache`,
-/// `unload_model`) all hold this enum and let the variant dispatch
-/// determine the concrete forward.
-///
-/// Variants gated on `cuda` because the underlying TP models hold
-/// `Arc<cudarc::nccl::Comm>` references — irrelevant on CPU builds.
-#[cfg(feature = "cuda")]
-pub enum TpLeaderModel {
-    Qwen3(tp_qwen3::TpQwen3ForCausalLM),
-    Qwen3_5(tp_qwen3_5::TpQwen3_5ForCausalLM),
-}
-
-#[cfg(feature = "cuda")]
-impl TpLeaderModel {
-    pub fn forward(
-        &mut self,
-        input: &candle_core::Tensor,
-        offset: usize,
-    ) -> candle_core::Result<candle_core::Tensor> {
-        match self {
-            TpLeaderModel::Qwen3(m) => m.forward(input, offset),
-            TpLeaderModel::Qwen3_5(m) => m.forward(input, offset),
-        }
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        match self {
-            TpLeaderModel::Qwen3(m) => m.clear_kv_cache(),
-            TpLeaderModel::Qwen3_5(m) => m.clear_kv_cache(),
-        }
-    }
-
-    pub fn device(&self) -> &candle_core::Device {
-        match self {
-            TpLeaderModel::Qwen3(m) => m.device(),
-            TpLeaderModel::Qwen3_5(m) => m.device(),
-        }
-    }
-}
-
-/// One worker subprocess plus its bidirectional stdio handles.
-struct Worker {
-    rank: u32,
-    /// Captured so the leader can log "spawned rank N on device M" and
-    /// future stages can re-issue Init after a CUDA reset. Unused in
-    /// the Stage 7a-i RPC paths themselves.
-    #[allow(dead_code)]
-    cuda_device: u32,
-    child: Child,
-    stdin: ChildStdin,
-    stdout: Lines<BufReader<ChildStdout>>,
-}
-
-impl Worker {
-    /// Send a request and wait for the response. Used for sequenced
-    /// ops like `Ping` / `Shutdown` where the caller doesn't need to
-    /// overlap the worker's execution with the leader's.
-    async fn request(&mut self, req: &WorkerRequest) -> Result<WorkerResponse> {
-        self.send_only(req).await?;
-        self.recv_only().await
-    }
-
-    /// Write a request without awaiting its response. Pair with
-    /// `recv_only` from the caller when leader and worker need to do
-    /// work concurrently — e.g. during `Init`, where the leader
-    /// itself calls `Comm::from_rank` on rank 0 in parallel with the
-    /// workers, then collects `InitOk` after NCCL completes.
-    async fn send_only(&mut self, req: &WorkerRequest) -> Result<()> {
-        let mut line = serde_json::to_string(req).context("serialise WorkerRequest")?;
-        line.push('\n');
-        self.stdin
-            .write_all(line.as_bytes())
-            .await
-            .with_context(|| format!("write request to rank {}", self.rank))?;
-        self.stdin
-            .flush()
-            .await
-            .with_context(|| format!("flush stdin to rank {}", self.rank))?;
-        Ok(())
-    }
-
-    async fn recv_only(&mut self) -> Result<WorkerResponse> {
-        let reply = self
-            .stdout
-            .next_line()
-            .await
-            .with_context(|| format!("read reply from rank {}", self.rank))?
-            .ok_or_else(|| anyhow::anyhow!("rank {} stdout closed before reply", self.rank))?;
-        serde_json::from_str(&reply)
-            .with_context(|| format!("parse reply from rank {}: {reply:?}", self.rank))
-    }
-}
-
-/// Drain one response from every worker, classifying each via the
-/// supplied checker. Always reads from every worker — even if some
-/// fail — so the next call's recv doesn't pick up stale responses
-/// from this one (pipe-poisoning was the cause of the
-/// "ClearKvCache: expected KvCacheCleared, got GenerateStepOk" class
-/// of bugs).
-///
-/// Returns a vector of `rank N: detail` strings for any worker that
-/// errored, expected-mismatched, or failed to respond. Caller decides
-/// how to combine these with the leader's outcome.
-async fn drain_workers(
-    workers: &mut [Worker],
-    mut check: impl FnMut(WorkerResponse) -> std::result::Result<(), String>,
-) -> Vec<String> {
-    let mut errs = Vec::new();
-    for w in workers {
-        match w.recv_only().await {
-            Ok(resp) => {
-                if let Err(detail) = check(resp) {
-                    errs.push(format!("rank {} {detail}", w.rank));
-                }
-            }
-            Err(e) => errs.push(format!("rank {} recv: {e:#}", w.rank)),
-        }
-    }
-    errs
-}
-
-/// Combine a leader's `Result<Result<T>>` (the typical
-/// `spawn_blocking → JoinHandle<Result<T>>` shape) with the worker
-/// drain results into a single `Result<T>`. Leader failures take
-/// precedence in the error message but worker errors get appended so
-/// the operator sees both halves.
-#[cfg(feature = "cuda")]
-fn combine_leader_workers<T>(
-    leader: Result<Result<T>>,
-    worker_errors: Vec<String>,
-    op: &str,
-) -> Result<T> {
-    match leader {
-        Ok(Ok(value)) => {
-            if worker_errors.is_empty() {
-                Ok(value)
-            } else {
-                anyhow::bail!(
-                    "{op}: leader succeeded but workers failed: {}",
-                    worker_errors.join("; ")
-                )
-            }
-        }
-        Ok(Err(e)) => {
-            if worker_errors.is_empty() {
-                Err(e.context(format!("{op}: leader forward failed")))
-            } else {
-                Err(e.context(format!(
-                    "{op}: leader forward failed and workers also failed: {}",
-                    worker_errors.join("; ")
-                )))
-            }
-        }
-        Err(panic_err) => {
-            if worker_errors.is_empty() {
-                Err(panic_err)
-            } else {
-                Err(panic_err.context(format!(
-                    "{op}: leader task panicked and workers failed: {}",
-                    worker_errors.join("; ")
-                )))
-            }
-        }
-    }
-}
-
-/// A live pool of worker subprocesses. Owns the `Child` handles so
-/// dropping the pool kills the children; explicit `shutdown()` is
-/// the graceful path.
-pub struct WorkerPool {
-    world_size: u32,
-    workers: Vec<Worker>,
-    /// Path to the neuron binary used to launch workers.
-    #[allow(dead_code)]
-    exe: PathBuf,
-    /// Leader's own NCCL rank-0 state. Defaults to empty; populated by
-    /// `init_nccl()`. Held here so the leader can participate in
-    /// collectives (rank 0) without spawning a fourth subprocess.
-    leader_nccl: nccl_state::NcclState,
-}
-
-impl WorkerPool {
-    /// Spawn `world_size - 1` worker subprocesses. Rank 0 is the
-    /// leader (in-process) and is *not* spawned here — the leader
-    /// holds rank 0's NCCL Comm and shard in its own address space.
-    ///
-    /// `binary` is the path to the neuron executable to run for each
-    /// worker (production passes `/proc/self/exe`; tests pass the
-    /// sibling-binary path from `env!("CARGO_BIN_EXE_neuron")`).
-    /// `cuda_devices` is one entry per rank including rank 0. Worker
-    /// `i` (rank `i`) gets `cuda_devices[i]` as its `--cuda-device`.
-    pub async fn spawn(binary: &Path, world_size: u32, cuda_devices: &[u32]) -> Result<Self> {
-        if world_size < 2 {
-            anyhow::bail!(
-                "WorkerPool::spawn called with world_size={world_size}; \
-                 use the single-process path for world_size < 2"
-            );
-        }
-        if cuda_devices.len() as u32 != world_size {
-            anyhow::bail!(
-                "expected {world_size} cuda_devices entries, got {}",
-                cuda_devices.len()
-            );
-        }
-        let exe = binary.to_path_buf();
-
-        let mut workers = Vec::with_capacity(world_size as usize - 1);
-        // Rank 0 stays in-process. Spawn ranks 1..world_size.
-        for rank in 1..world_size {
-            let cuda_device = cuda_devices[rank as usize];
-            let mut cmd = Command::new(&exe);
-            cmd.arg("--worker")
-                .arg("--rank")
-                .arg(rank.to_string())
-                .arg("--tp-size")
-                .arg(world_size.to_string())
-                .arg("--cuda-device")
-                .arg(cuda_device.to_string())
-                .stdin(Stdio::piped())
-                .stdout(Stdio::piped())
-                // Inherit stderr so worker tracing surfaces alongside
-                // the leader's journalctl stream.
-                .stderr(Stdio::inherit())
-                .kill_on_drop(true);
-
-            let mut child = cmd
-                .spawn()
-                .with_context(|| format!("spawn worker rank {rank}"))?;
-            let stdin = child
-                .stdin
-                .take()
-                .ok_or_else(|| anyhow::anyhow!("rank {rank}: no stdin handle"))?;
-            let stdout = child
-                .stdout
-                .take()
-                .ok_or_else(|| anyhow::anyhow!("rank {rank}: no stdout handle"))?;
-            let stdout = BufReader::new(stdout).lines();
-
-            workers.push(Worker {
-                rank,
-                cuda_device,
-                child,
-                stdin,
-                stdout,
-            });
-            tracing::info!(rank, cuda_device, "spawned tp worker");
-        }
-
-        Ok(Self {
-            world_size,
-            workers,
-            exe,
-            leader_nccl: nccl_state::NcclState::new(),
-        })
-    }
-
-    /// Establish the NCCL communicator across the leader (rank 0) and
-    /// every worker subprocess. Rendezvous is via a freshly-generated
-    /// `Id` broadcast over the RPC stream; the actual handshake blocks
-    /// inside `Comm::from_rank` until all `world_size` ranks check in.
-    ///
-    /// `leader_cuda_device` is the CUDA device the leader binds rank 0
-    /// to — typically the first entry of the `cuda_devices` slice
-    /// originally passed to `spawn()`.
-    ///
-    /// On the non-cuda build this immediately fails because the leader
-    /// can't generate an `Id` without libnccl. The same call works in
-    /// the worker path (returning a no-cuda error response) so the
-    /// failure surface is uniform.
-    pub async fn init_nccl(&mut self, leader_cuda_device: u32) -> Result<()> {
-        let comm_id = nccl_state::generate_comm_id_hex()
-            .map_err(|m| anyhow::anyhow!("generate NCCL id: {m}"))?;
-
-        // 1. Write Init to every worker's stdin without awaiting the
-        //    response. Workers will parse and call Comm::from_rank
-        //    concurrently with the leader below.
-        for w in &mut self.workers {
-            let req = WorkerRequest::Init {
-                comm_id: comm_id.clone(),
-            };
-            w.send_only(&req).await?;
-        }
-
-        // 2. Leader rank 0 calls Comm::from_rank on its own device.
-        //    Runs on spawn_blocking because NCCL's init blocks until
-        //    every rank has called in — that's exactly the workers
-        //    above. The leader's NcclState is moved through the
-        //    blocking task and returned to the pool.
-        let leader_cfg = worker::WorkerConfig {
-            rank: 0,
-            world_size: self.world_size,
-            cuda_device: leader_cuda_device,
-        };
-        let comm_id_for_leader = comm_id.clone();
-        // Swap out the leader's NcclState into a fresh empty one so we
-        // can move it into spawn_blocking; restore after the task
-        // returns. (NcclState isn't Clone — it owns a real NCCL Comm.)
-        let mut leader_state = std::mem::take(&mut self.leader_nccl);
-        let (returned_state, leader_resp) = tokio::task::spawn_blocking(move || {
-            let resp = leader_state.init(leader_cfg, &comm_id_for_leader);
-            (leader_state, resp)
-        })
-        .await
-        .context("leader NCCL init task panicked")?;
-        self.leader_nccl = returned_state;
-        match leader_resp {
-            rpc::WorkerResponse::InitOk => {}
-            rpc::WorkerResponse::Error { kind, message } => {
-                anyhow::bail!("leader rank 0 init failed [{kind}]: {message}");
-            }
-            other => anyhow::bail!("leader rank 0 init: unexpected {other:?}"),
-        }
-
-        // 3. Read InitOk from each worker. By now every worker has
-        //    completed its Comm::from_rank call (NCCL released them
-        //    when the leader joined the handshake) and is writing its
-        //    response.
-        for w in &mut self.workers {
-            let resp = w.recv_only().await?;
-            match &resp {
-                rpc::WorkerResponse::InitOk => {}
-                rpc::WorkerResponse::Error { kind, message } => {
-                    anyhow::bail!("worker rank {} init failed [{kind}]: {message}", w.rank);
-                }
-                other => anyhow::bail!(
-                    "worker rank {} init: expected InitOk, got {other:?}",
-                    w.rank
-                ),
-            }
-        }
-        tracing::info!(
-            world_size = self.world_size,
-            "NCCL communicator established across all ranks"
-        );
-        Ok(())
-    }
-
-    /// Validate the NCCL communicator: every rank `all_reduce`s a
-    /// sentinel `1u32` with `ReduceOp::Sum`; the expected total is
-    /// `world_size`. Confirms the handshake is live, not just
-    /// configured.
-    ///
-    /// Must be called after `init_nccl()`; before that the leader has
-    /// no Comm and the workers reply with `nccl_not_initialised`.
-    pub async fn nccl_sanity_check(&mut self) -> Result<()> {
-        // 1. Trigger the all_reduce on every worker (write-only).
-        for w in &mut self.workers {
-            w.send_only(&WorkerRequest::NcclSanityCheck).await?;
-        }
-
-        // 2. Leader's own all_reduce, in spawn_blocking. NCCL operations
-        //    block until every rank participates.
-        let mut leader_state = std::mem::take(&mut self.leader_nccl);
-        let (returned_state, leader_resp) = tokio::task::spawn_blocking(move || {
-            let resp = leader_state.sanity_check();
-            (leader_state, resp)
-        })
-        .await
-        .context("leader NCCL sanity task panicked")?;
-        self.leader_nccl = returned_state;
-
-        let expected = self.world_size;
-        let leader_sum = match leader_resp {
-            rpc::WorkerResponse::NcclSanityResult { observed_sum } => observed_sum,
-            rpc::WorkerResponse::Error { kind, message } => {
-                anyhow::bail!("leader rank 0 sanity failed [{kind}]: {message}");
-            }
-            other => anyhow::bail!("leader rank 0 sanity: unexpected {other:?}"),
-        };
-        if leader_sum != expected {
-            anyhow::bail!("leader observed_sum={leader_sum}, expected {expected}");
-        }
-
-        // 3. Read sanity result from each worker. All must match
-        //    world_size — anything else means the collective didn't
-        //    complete consistently across ranks.
-        for w in &mut self.workers {
-            let resp = w.recv_only().await?;
-            match resp {
-                rpc::WorkerResponse::NcclSanityResult { observed_sum }
-                    if observed_sum == expected => {}
-                rpc::WorkerResponse::NcclSanityResult { observed_sum } => {
-                    anyhow::bail!(
-                        "worker rank {} observed_sum={observed_sum}, expected {expected}",
-                        w.rank
-                    );
-                }
-                rpc::WorkerResponse::Error { kind, message } => {
-                    anyhow::bail!("worker rank {} sanity failed [{kind}]: {message}", w.rank);
-                }
-                other => anyhow::bail!("worker rank {} sanity: unexpected {other:?}", w.rank),
-            }
-        }
-        tracing::info!(
-            world_size = expected,
-            "NCCL sanity check OK across all ranks"
-        );
-        Ok(())
-    }
-
-    /// Ping every worker and return their Pong payloads in rank order.
-    /// Useful right after `spawn` to confirm the lifecycle plumbing is
-    /// intact before kicking off any heavier work.
-    pub async fn ping_all(&mut self) -> Result<Vec<WorkerResponse>> {
-        let mut out = Vec::with_capacity(self.workers.len());
-        for w in &mut self.workers {
-            let resp = w.request(&WorkerRequest::Ping).await?;
-            match &resp {
-                WorkerResponse::Pong { rank, .. } if *rank == w.rank => {}
-                WorkerResponse::Pong { rank, .. } => {
-                    anyhow::bail!("rank mismatch: expected {}, got {rank}", w.rank);
-                }
-                other => anyhow::bail!("expected Pong from rank {}, got {other:?}", w.rank),
-            }
-            out.push(resp);
-        }
-        Ok(out)
-    }
-
-    /// Load this rank's shard of a dense Qwen3 model on every rank.
-    ///
-    /// The leader builds rank 0's `TpQwen3ForCausalLM` directly into
-    /// the returned `Arc<Mutex<_>>` — workers build their rank-local
-    /// shards in their own address spaces and confirm via
-    /// `LoadDenseShardOk`. All ranks see the same `safetensors_paths`;
-    /// `ShardedVarBuilder` slices each tensor by rank at materialisation
-    /// time, so the per-rank VRAM footprint is roughly `1/world_size`
-    /// of the full model (plus the replicated embedding/norm/lm_head).
-    ///
-    /// `leader_device` is the candle `Device` the leader's shard lives
-    /// on — typically `Device::new_cuda(leader_cuda_device)` matching
-    /// the same index passed to `init_nccl`. `dtype` is the on-device
-    /// element type; bf16 is the canonical Qwen3 distribution dtype.
-    ///
-    /// `init_nccl` must have completed first. Bails if the leader's
-    /// NCCL comm isn't set up yet.
-    #[cfg(feature = "cuda")]
-    #[allow(clippy::too_many_arguments)]
-    pub async fn load_dense_shard(
-        &mut self,
-        model_id: &str,
-        config_json: &str,
-        safetensors_paths: &[std::path::PathBuf],
-        leader_device: &candle_core::Device,
-        dtype: candle_core::DType,
-        quant: Option<String>,
-    ) -> Result<std::sync::Arc<tokio::sync::Mutex<TpLeaderModel>>> {
-        use candle_nn::var_builder::ShardedSafeTensors;
-        use std::sync::Arc;
-        use tokio::sync::Mutex;
-
-        // Wrap the comm in SendComm immediately so it stays Send across
-        // the await points in this method — bare Arc<Comm> would
-        // poison the async fn's Send bound (Comm's raw NCCL pointer is
-        // !Send). The wrapper's safety contract is satisfied by the
-        // pool's outer Mutex serialising callers + the spawn_blocking
-        // thread being the only place ops are issued.
-        let leader_comm =
-            nccl_state::SendComm(self.leader_nccl.comm().ok_or_else(|| {
-                anyhow::anyhow!("leader NCCL not initialised; call init_nccl first")
-            })?);
-        let world_size = self.world_size;
-        let safetensors_str: Vec<String> = safetensors_paths
-            .iter()
-            .map(|p| p.to_string_lossy().into_owned())
-            .collect();
-
-        // 1. Fan out the LoadDenseShard request to every worker without
-        //    awaiting their replies — they'll build their shards in
-        //    parallel with the leader below.
-        for w in &mut self.workers {
-            w.send_only(&WorkerRequest::LoadDenseShard {
-                model_id: model_id.to_string(),
-                config_json: config_json.to_string(),
-                safetensors_paths: safetensors_str.clone(),
-                quant: quant.clone(),
-            })
-            .await?;
-        }
-
-        // 2. Build rank 0's shard on the leader. Dispatch on model_type
-        //    — for `qwen3` we build a `TpQwen3ForCausalLM`, for
-        //    `qwen3_5` (Qwen3-Next, Qwen3.6's architecture) we build
-        //    `TpQwen3_5ForCausalLM`. Both end up wrapped in the
-        //    `TpLeaderModel` enum so downstream callers don't care.
-        let model_type = serde_json::from_str::<serde_json::Value>(config_json)
-            .ok()
-            .as_ref()
-            .and_then(|v| v.get("model_type"))
-            .and_then(|v| v.as_str())
-            .unwrap_or("")
-            .to_string();
-        let paths_for_leader: Vec<std::path::PathBuf> = safetensors_paths.to_vec();
-        let device_for_leader = leader_device.clone();
-        let comm_for_leader = leader_comm;
-        let model_id_for_log = model_id.to_string();
-        let config_json_for_leader = config_json.to_string();
-        let quant_for_leader = quant.clone();
-
-        let leader_model = tokio::task::spawn_blocking(move || -> Result<TpLeaderModel> {
-            // SAFETY: same invariant as the single-GPU dense path —
-            // the HF cache files are treated as immutable while the
-            // mmap is held.
-            let vb = unsafe {
-                ShardedSafeTensors::var_builder(&paths_for_leader, dtype, &device_for_leader)
-                    .context("build ShardedVarBuilder over safetensors")?
-            };
-            // SAFETY: as above — the HF cache files are immutable.
-            let mmap = unsafe {
-                candle_core::safetensors::MmapedSafetensors::multi(&paths_for_leader)
-                    .context("build MmapedSafetensors for leader load")?
-            };
-            let comm = comm_for_leader.into_inner();
-            let loaded = match model_type.as_str() {
-                "qwen3" => {
-                    let cfg: super::tp::tp_qwen3::Config = serde_json::from_str(&config_json_for_leader)
-                        .context("parse Qwen3 Config JSON for leader load")?;
-                    TpLeaderModel::Qwen3(super::tp::tp_qwen3::TpQwen3ForCausalLM::load(
-                        &cfg, &vb, 0, world_size, comm,
-                    )?)
-                }
-                "qwen3_5" => {
-                    let cfg: super::tp::tp_qwen3_5::Config =
-                        serde_json::from_str(&config_json_for_leader)
-                            .context("parse Qwen3-Next Config JSON for leader load")?;
-                    let quant_dtype =
-                        super::tp::worker::parse_quant_string(quant_for_leader.as_deref())?;
-                    TpLeaderModel::Qwen3_5(super::tp::tp_qwen3_5::TpQwen3_5ForCausalLM::load(
-                        cfg,
-                        &vb,
-                        &mmap,
-                        0,
-                        world_size,
-                        comm,
-                        quant_dtype,
-                    )?)
-                }
-                other => anyhow::bail!(
-                    "TP dispatch: unsupported model_type '{other}' on leader (supported: qwen3, qwen3_5)"
-                ),
-            };
-            tracing::info!(rank = 0, model = %model_id_for_log, model_type = %model_type, "loaded TP shard (leader)");
-            Ok(loaded)
-        })
-        .await
-        .context("leader load task panicked")??;
-
-        // 3. Collect worker confirmations. Anything other than
-        //    LoadDenseShardOk aborts the whole load — the leader's
-        //    already-loaded shard drops when this fn returns Err.
-        for w in &mut self.workers {
-            let resp = w.recv_only().await?;
-            match resp {
-                WorkerResponse::LoadDenseShardOk => {}
-                WorkerResponse::Error { kind, message } => {
-                    anyhow::bail!("worker rank {} LoadDenseShard [{kind}]: {message}", w.rank)
-                }
-                other => anyhow::bail!(
-                    "worker rank {} LoadDenseShard: expected LoadDenseShardOk, got {other:?}",
-                    w.rank
-                ),
-            }
-        }
-
-        Ok(Arc::new(Mutex::new(leader_model)))
-    }
-
-    /// Run one forward step across every rank. The leader's forward
-    /// returns the last-position logits as a candle Tensor on the
-    /// leader's device; the caller does sampling out-of-band. Workers
-    /// run their own forwards (the AllReduce inside row-parallel layers
-    /// is what lets the leader's collective complete) and reply with
-    /// `GenerateStepOk` — they do not ship logits over the wire.
-    ///
-    /// `tokens` is the input for this step (prompt for prefill, the
-    /// previously-sampled token for decode). `offset` is the KV-cache
-    /// position before this step.
-    #[cfg(feature = "cuda")]
-    pub async fn generate_step(
-        &mut self,
-        model_id: &str,
-        leader_model: std::sync::Arc<tokio::sync::Mutex<TpLeaderModel>>,
-        tokens: Vec<u32>,
-        offset: usize,
-    ) -> Result<candle_core::Tensor> {
-        let step_start = std::time::Instant::now();
-        let tokens_len = tokens.len();
-        tracing::debug!(
-            model = %model_id,
-            tokens = tokens_len,
-            offset,
-            "WorkerPool::generate_step: fan-out"
-        );
-        // 1. Fan-out to workers.
-        for w in &mut self.workers {
-            w.send_only(&WorkerRequest::GenerateStep {
-                model_id: model_id.to_string(),
-                tokens: tokens.clone(),
-                offset,
-            })
-            .await?;
-        }
-
-        // 2. Leader's forward in spawn_blocking. The AllReduce CustomOps
-        //    inside the row-parallel layers block until every worker's
-        //    forward issues the matching collective.
-        let leader_start = std::time::Instant::now();
-        let leader_result = tokio::task::spawn_blocking(move || -> Result<candle_core::Tensor> {
-            let mut model = leader_model.blocking_lock();
-            let device = model.device().clone();
-            let input = candle_core::Tensor::new(tokens.as_slice(), &device)?.unsqueeze(0)?;
-            // ForCausalLM::forward returns [B, 1, V] — squeeze both
-            // leading dims to the rank-1 vocab logits the sampler wants.
-            let logits = model.forward(&input, offset)?.squeeze(0)?.squeeze(0)?;
-            Ok(logits)
-        })
-        .await
-        .context("leader forward task panicked");
-        let leader_ok = matches!(leader_result, Ok(Ok(_)));
-        tracing::debug!(
-            model = %model_id,
-            tokens = tokens_len,
-            leader_ms = leader_start.elapsed().as_millis(),
-            leader_ok,
-            "WorkerPool::generate_step: leader forward returned"
-        );
-
-        // 3. ALWAYS drain worker responses, regardless of whether the
-        //    leader succeeded. Skipping this on the leader's error
-        //    path leaves stale GenerateStepOk replies in the worker
-        //    pipes that poison the NEXT request's recv (was seeing
-        //    "ClearKvCache: expected KvCacheCleared, got
-        //    GenerateStepOk" the call after any forward-time failure).
-        let drain_start = std::time::Instant::now();
-        let worker_errors = drain_workers(&mut self.workers, |r| match r {
-            WorkerResponse::GenerateStepOk => Ok(()),
-            WorkerResponse::Error { kind, message } => Err(format!("[{kind}]: {message}")),
-            other => Err(format!("expected GenerateStepOk, got {other:?}")),
-        })
-        .await;
-        tracing::debug!(
-            model = %model_id,
-            drain_ms = drain_start.elapsed().as_millis(),
-            errors = worker_errors.len(),
-            total_ms = step_start.elapsed().as_millis(),
-            "WorkerPool::generate_step: workers drained"
-        );
-
-        combine_leader_workers(leader_result, worker_errors, "GenerateStep")
-    }
-
-    /// Reset the KV cache for `model_id` on every rank. Called at the
-    /// start of every inference so a fresh request doesn't attend over
-    /// the previous one's tokens.
-    pub async fn clear_kv_cache(
-        &mut self,
-        model_id: &str,
-        #[cfg(feature = "cuda")] leader_model: std::sync::Arc<tokio::sync::Mutex<TpLeaderModel>>,
-    ) -> Result<()> {
-        let start = std::time::Instant::now();
-        tracing::debug!(model = %model_id, "WorkerPool::clear_kv_cache: fan-out");
-        for w in &mut self.workers {
-            w.send_only(&WorkerRequest::ClearKvCache {
-                model_id: model_id.to_string(),
-            })
-            .await?;
-        }
-        #[cfg(feature = "cuda")]
-        {
-            let mut m = leader_model.lock().await;
-            m.clear_kv_cache();
-        }
-        // Drain workers — same rationale as `generate_step`. The
-        // leader's clear_kv_cache is in-process and infallible, but we
-        // still always drain so an error on one worker doesn't leave
-        // pending responses for the others.
-        let worker_errors = drain_workers(&mut self.workers, |r| match r {
-            WorkerResponse::KvCacheCleared => Ok(()),
-            WorkerResponse::Error { kind, message } => Err(format!("[{kind}]: {message}")),
-            other => Err(format!("expected KvCacheCleared, got {other:?}")),
-        })
-        .await;
-        tracing::debug!(
-            model = %model_id,
-            elapsed_ms = start.elapsed().as_millis(),
-            errors = worker_errors.len(),
-            "WorkerPool::clear_kv_cache: workers drained"
-        );
-        if !worker_errors.is_empty() {
-            anyhow::bail!("ClearKvCache: {}", worker_errors.join("; "));
-        }
-        Ok(())
-    }
-
-    /// Drop this model's shards on every rank. The leader's shard is
-    /// expected to have been dropped by the caller (its `Arc` was held
-    /// in the TpLoadedModel and goes away when that's removed).
-    pub async fn unload_model(&mut self, model_id: &str) -> Result<()> {
-        for w in &mut self.workers {
-            w.send_only(&WorkerRequest::UnloadModel {
-                model_id: model_id.to_string(),
-            })
-            .await?;
-        }
-        for w in &mut self.workers {
-            let resp = w.recv_only().await?;
-            match resp {
-                WorkerResponse::Unloaded => {}
-                WorkerResponse::Error { kind, message } => {
-                    anyhow::bail!("worker rank {} UnloadModel [{kind}]: {message}", w.rank)
-                }
-                other => anyhow::bail!(
-                    "worker rank {} UnloadModel: expected Unloaded, got {other:?}",
-                    w.rank
-                ),
-            }
-        }
-        Ok(())
-    }
-
-    /// Send `Shutdown` to every worker, await each `Bye`, and reap the
-    /// children. Best-effort — individual worker failures are logged
-    /// but don't abort the rest of the sweep.
-    pub async fn shutdown(mut self) -> Result<()> {
-        for w in &mut self.workers {
-            match w.request(&WorkerRequest::Shutdown).await {
-                Ok(WorkerResponse::Bye) => {}
-                Ok(other) => tracing::warn!(
-                    rank = w.rank,
-                    response = ?other,
-                    "expected Bye on shutdown"
-                ),
-                Err(e) => tracing::warn!(rank = w.rank, error = %e, "shutdown request failed"),
-            }
-        }
-        for w in &mut self.workers {
-            match w.child.wait().await {
-                Ok(status) => tracing::info!(rank = w.rank, %status, "worker exited"),
-                Err(e) => tracing::warn!(rank = w.rank, error = %e, "wait on worker failed"),
-            }
-        }
-        Ok(())
-    }
-
-    pub fn world_size(&self) -> u32 {
-        self.world_size
-    }
-
-    pub fn binary_path(&self) -> &PathBuf {
-        &self.exe
-    }
-}

crates/neuron/src/harness/tp/nccl_state.rs

@@ -1,293 +0,0 @@
-//! NCCL state held by both the worker process and the leader's pool.
-//!
-//! Split into its own module so the worker (`tp/worker.rs`) and the
-//! leader (`tp/mod.rs`) share the same hex-encoding/decoding code and
-//! the same shape of `Option<Comm>` state machine.
-//!
-//! When the `cuda` feature is off, `NcclState` is a zero-sized
-//! placeholder that returns `Error{kind="cuda_feature_not_enabled"}`
-//! from every operation. When it's on, the same struct holds the
-//! actual `cudarc::nccl::Comm`.
-
-use super::rpc::WorkerResponse;
-use super::worker::WorkerConfig;
-
-/// Encode bytes as lowercase hex. Used for ferrying NCCL `Id::internal()`
-/// across the leader→worker RPC boundary inside a JSON string.
-pub fn encode_hex(bytes: &[u8]) -> String {
-    let mut out = String::with_capacity(bytes.len() * 2);
-    for b in bytes {
-        use std::fmt::Write;
-        let _ = write!(out, "{b:02x}");
-    }
-    out
-}
-
-/// Decode lowercase-or-uppercase hex into bytes. Errors on odd length
-/// or non-hex characters; the caller bubbles those up via the RPC's
-/// `Error{kind="bad_request"}` variant.
-pub fn decode_hex(s: &str) -> Result<Vec<u8>, String> {
-    if !s.len().is_multiple_of(2) {
-        return Err(format!("hex string has odd length {}", s.len()));
-    }
-    (0..s.len())
-        .step_by(2)
-        .map(|i| {
-            u8::from_str_radix(&s[i..i + 2], 16).map_err(|e| format!("bad hex byte at {i}: {e}"))
-        })
-        .collect()
-}
-
-#[cfg(not(feature = "cuda"))]
-pub struct NcclState;
-
-#[cfg(not(feature = "cuda"))]
-impl Default for NcclState {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-#[cfg(not(feature = "cuda"))]
-impl NcclState {
-    pub fn new() -> Self {
-        Self
-    }
-
-    pub fn init(&mut self, _cfg: WorkerConfig, _comm_id_hex: &str) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "this neuron binary was built without --features cuda; \
-                 NCCL Init requires CUDA"
-                .into(),
-        }
-    }
-
-    pub fn sanity_check(&mut self) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "NCCL sanity check requires --features cuda".into(),
-        }
-    }
-}
-
-#[cfg(feature = "cuda")]
-mod cuda_impl {
-    use super::*;
-    use cudarc::driver::CudaContext;
-    use cudarc::nccl::{Comm, Id, ReduceOp};
-    use std::sync::Arc;
-
-    /// Number of bytes in NCCL's unique-id type; matches `Id::internal()`'s
-    /// `[c_char; 128]`. Wire-encoded as 256 lowercase hex chars.
-    const NCCL_ID_BYTES: usize = 128;
-
-    pub struct NcclState {
-        /// Wrapped in `Arc` so we can hand a clone to `TpQwen3ForCausalLM`
-        /// at load time (every row-parallel layer needs a reference to
-        /// run its trailing `AllReduce`). The `Arc` is the single source
-        /// of truth for the comm's lifetime — when the pool drops and
-        /// every layer that captured a clone drops, NCCL releases the
-        /// underlying `ncclComm_t`.
-        comm: Option<Arc<Comm>>,
-        /// Held alongside the Comm so the device isn't dropped
-        /// underneath the NCCL handle.
-        #[allow(dead_code)]
-        ctx: Option<Arc<CudaContext>>,
-    }
-
-    impl Default for NcclState {
-        fn default() -> Self {
-            Self::new()
-        }
-    }
-
-    impl NcclState {
-        pub fn new() -> Self {
-            Self {
-                comm: None,
-                ctx: None,
-            }
-        }
-
-        /// Clone the comm out as an `Arc` so callers (the leader-side
-        /// `TpQwen3ForCausalLM::load`, or the worker's own model load)
-        /// can hold a reference for the lifetime of the model. Returns
-        /// `None` before `init` has run.
-        pub fn comm(&self) -> Option<Arc<Comm>> {
-            self.comm.clone()
-        }
-    }
-
-    /// `Arc<Comm>` doesn't impl `Send` because `Comm` wraps a raw
-    /// `ncclComm_t` pointer. The NCCL contract is "operations against a
-    /// given comm must be serialised", not "the handle must stay on the
-    /// thread that created it" — so it's safe to move an `Arc<Comm>`
-    /// across threads as long as no concurrent ops are issued. The
-    /// pool's outer Mutex serialises us into `spawn_blocking`, so this
-    /// wrapper at the move boundary is the only thing missing.
-    ///
-    /// `Sync` is also marked safe because the `Arc<Comm>` clones held
-    /// by the row-parallel layers are only used from the
-    /// `spawn_blocking` thread driving the forward pass; concurrent
-    /// access from another thread would still be a bug.
-    pub struct SendComm(pub Arc<Comm>);
-
-    // SAFETY: see the doc-comment above; the invariant is enforced at
-    // the call site (pool Mutex + single spawn_blocking thread), not at
-    // the type level.
-    unsafe impl Send for SendComm {}
-    unsafe impl Sync for SendComm {}
-
-    impl SendComm {
-        pub fn into_inner(self) -> Arc<Comm> {
-            self.0
-        }
-    }
-
-    // SAFETY: `cudarc::nccl::Comm` contains a raw `ncclComm_t` pointer
-    // (libnccl-allocated state). NCCL requires that operations against
-    // one Comm be issued one at a time; we serialise access by storing
-    // NcclState behind a Mutex in `WorkerPool`. The Comm itself is
-    // move-safe — NCCL doesn't track the calling OS thread, only the
-    // stream the operations are dispatched against.
-    unsafe impl Send for NcclState {}
-    unsafe impl Sync for NcclState {}
-
-    /// Generate a fresh NCCL `Id` and return it hex-encoded. Used by
-    /// the leader to mint the shared communicator id which is then
-    /// broadcast to every worker via the RPC `Init` message.
-    pub fn generate_comm_id_hex() -> Result<String, String> {
-        // NcclError lacks a Display impl in cudarc 0.19.x — surface
-        // via Debug throughout this module.
-        let id = Id::new().map_err(|e| format!("Id::new(): {e:?}"))?;
-        let bytes_u8: [u8; NCCL_ID_BYTES] = std::array::from_fn(|i| id.internal()[i] as u8);
-        Ok(encode_hex(&bytes_u8))
-    }
-
-    impl NcclState {
-        pub fn init(&mut self, cfg: WorkerConfig, comm_id_hex: &str) -> WorkerResponse {
-            match try_init(self, cfg, comm_id_hex) {
-                Ok(()) => WorkerResponse::InitOk,
-                Err(msg) => WorkerResponse::Error {
-                    kind: "nccl_init_failed".into(),
-                    message: msg,
-                },
-            }
-        }
-
-        pub fn sanity_check(&mut self) -> WorkerResponse {
-            let Some(comm) = self.comm.as_ref() else {
-                return WorkerResponse::Error {
-                    kind: "nccl_not_initialised".into(),
-                    message: "sanity_check requires Init to have completed first".into(),
-                };
-            };
-            match try_sanity_check(comm.as_ref()) {
-                Ok(sum) => WorkerResponse::NcclSanityResult { observed_sum: sum },
-                Err(msg) => WorkerResponse::Error {
-                    kind: "nccl_sanity_failed".into(),
-                    message: msg,
-                },
-            }
-        }
-    }
-
-    fn try_init(state: &mut NcclState, cfg: WorkerConfig, comm_id_hex: &str) -> Result<(), String> {
-        let bytes = decode_hex(comm_id_hex)?;
-        if bytes.len() != NCCL_ID_BYTES {
-            return Err(format!(
-                "comm_id is {} bytes, expected {NCCL_ID_BYTES}",
-                bytes.len()
-            ));
-        }
-        let id_bytes: [std::ffi::c_char; NCCL_ID_BYTES] =
-            std::array::from_fn(|i| bytes[i] as std::ffi::c_char);
-        let id = Id::uninit(id_bytes);
-
-        let ctx = CudaContext::new(cfg.cuda_device as usize)
-            .map_err(|e| format!("CudaContext::new({}) failed: {e}", cfg.cuda_device))?;
-        let stream = ctx.default_stream();
-        let comm = Comm::from_rank(stream, cfg.rank as usize, cfg.world_size as usize, id)
-            .map_err(|e| {
-                format!(
-                    "Comm::from_rank(rank={}, world={}) failed: {e:?}",
-                    cfg.rank, cfg.world_size
-                )
-            })?;
-
-        state.ctx = Some(ctx);
-        // `Comm` is !Send + !Sync at the type level because it wraps a
-        // raw `ncclComm_t`. The `Arc` is fine in practice — we
-        // serialise operations through the pool's outer Mutex and the
-        // SendComm wrapper at thread-crossing boundaries enforces this
-        // at every move site. clippy's `arc_with_non_send_sync` lint
-        // can't see that invariant; allow once at the canonical
-        // construction site.
-        #[allow(clippy::arc_with_non_send_sync)]
-        {
-            state.comm = Some(Arc::new(comm));
-        }
-        Ok(())
-    }
-
-    fn try_sanity_check(comm: &Comm) -> Result<u32, String> {
-        let stream = comm.stream().clone();
-        let input = stream
-            .clone_htod(&[1u32])
-            .map_err(|e| format!("htod sentinel: {e}"))?;
-        let mut output = stream
-            .alloc_zeros::<u32>(1)
-            .map_err(|e| format!("alloc output: {e}"))?;
-        // cudarc::nccl::NcclError doesn't impl Display in 0.19.x —
-        // surface via Debug so we still see the variant + ncclResult
-        // code instead of a generic "{e}" failure.
-        comm.all_reduce(&input, &mut output, &ReduceOp::Sum)
-            .map_err(|e| format!("all_reduce: {e:?}"))?;
-        let result = stream
-            .clone_dtoh(&output)
-            .map_err(|e| format!("dtoh result: {e}"))?;
-        Ok(result[0])
-    }
-}
-
-#[cfg(feature = "cuda")]
-pub use cuda_impl::{NcclState, SendComm, generate_comm_id_hex};
-
-/// Non-cuda stub for the leader: returns a clear marker error rather
-/// than letting `init_nccl` succeed vacuously.
-#[cfg(not(feature = "cuda"))]
-pub fn generate_comm_id_hex() -> Result<String, String> {
-    Err("cuda_feature_not_enabled: build with --features cuda".into())
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn hex_roundtrip() {
-        let original: Vec<u8> = (0u8..=255).collect();
-        let encoded = encode_hex(&original);
-        assert_eq!(encoded.len(), 512);
-        let decoded = decode_hex(&encoded).expect("decode");
-        assert_eq!(decoded, original);
-    }
-
-    #[test]
-    fn hex_decode_rejects_odd_length() {
-        assert!(decode_hex("a").is_err());
-        assert!(decode_hex("abc").is_err());
-    }
-
-    #[test]
-    fn hex_decode_rejects_non_hex() {
-        assert!(decode_hex("zz").is_err());
-        assert!(decode_hex("ab_d").is_err());
-    }
-
-    #[test]
-    fn hex_encode_is_lowercase_padded() {
-        assert_eq!(encode_hex(&[0x0a, 0xff]), "0aff");
-    }
-}

crates/neuron/src/harness/tp/rpc.rs

@@ -1,257 +0,0 @@
-//! Wire protocol between the neuron leader process and its
-//! `--worker` subprocesses.
-//!
-//! Every frame is one newline-delimited JSON object on the worker's
-//! stdin (request) or stdout (response). Both directions are tagged
-//! sum types from the start so new ops in Stage 7b/7c slot in without
-//! breaking compatibility — no "14 message types and a version field"
-//! drift later. Adding a new variant is the canonical way to evolve
-//! the protocol; existing peers that don't recognise an op return
-//! `WorkerResponse::Error { kind: "unknown_op", .. }`.
-//!
-//! The serialised shape uses `tag = "op"` so a request looks like:
-//!     {"op":"ping"}
-//!     {"op":"init","comm_id":"a1b2..."}
-//! and a response:
-//!     {"op":"pong","rank":0,"world_size":2,"cuda_device":0}
-//!     {"op":"error","kind":"nccl_init_failed","message":"..."}
-
-use serde::{Deserialize, Serialize};
-
-/// Leader → worker. Worker handles one at a time; replies with exactly
-/// one `WorkerResponse` per request.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(tag = "op", rename_all = "snake_case")]
-pub enum WorkerRequest {
-    /// Liveness probe. Worker replies with `Pong` containing its own
-    /// identity. Used by the leader to confirm the subprocess is up
-    /// and ready before kicking off any heavier work.
-    Ping,
-
-    /// One-shot NCCL communicator setup. The leader generates the
-    /// `comm_id` once (rank 0 of NCCL), broadcasts it to every worker
-    /// via this message, then every rank (leader included) calls
-    /// `Comm::from_rank` with the same id — NCCL blocks until all
-    /// `world_size` ranks check in. The hex-encoded bytes are the
-    /// canonical `cudarc::nccl::Id::internal()` content.
-    Init {
-        /// Hex-encoded NCCL id bytes (128 bytes → 256 hex chars).
-        comm_id: String,
-    },
-
-    /// Sanity check: after Init, every rank runs an `all_reduce` over
-    /// a sentinel value (`1u32`). The expected sum is `world_size`.
-    /// Worker replies with the observed value so the leader can verify
-    /// the NCCL handshake is genuinely live, not just configured.
-    NcclSanityCheck,
-
-    /// Load this rank's shard of a dense Qwen3 model from mmaped
-    /// safetensors. The same `safetensors_paths` list is sent to every
-    /// rank — the ShardedVarBuilder reads only the rank-local slice of
-    /// each tensor at materialisation time, so the worker's VRAM
-    /// footprint is `1 / world_size` of the full model (plus replicated
-    /// embedding/norm/lm_head).
-    LoadDenseShard {
-        /// Caller-supplied id for later `GenerateStep` / `UnloadModel`
-        /// lookups. Typically the HF model id verbatim.
-        model_id: String,
-        /// JSON-serialised `candle_transformers::models::qwen3::Config`
-        /// — the same blob the leader parsed from the HF cache's
-        /// `config.json`. Threaded through verbatim so the worker uses
-        /// identical hyperparameters.
-        config_json: String,
-        /// Absolute paths the worker should mmap. The same set on every
-        /// rank; ShardedVarBuilder slices into them per rank.
-        safetensors_paths: Vec<String>,
-        /// Optional in-situ quantization dtype (e.g. "q5k", "q8_0",
-        /// "q6k"). When set, each linear-layer weight is quantized
-        /// at load time to the named ggml format — saves ~3-5x vs
-        /// bf16/f16 at the cost of some accuracy. `None` keeps the
-        /// weights in the on-disk dtype (typically bf16).
-        #[serde(default)]
-        quant: Option<String>,
-    },
-
-    /// Run one forward step on this rank's loaded model. The worker
-    /// reaches into its NCCL Comm for the row-parallel `AllReduce`s
-    /// inside the model — and so blocks on every other rank issuing the
-    /// same op. The leader does *not* receive logits back over RPC; it
-    /// runs its own rank-0 forward in parallel and uses its own logits
-    /// for sampling.
-    GenerateStep {
-        model_id: String,
-        /// Input token ids for this step. For prefill, the whole prompt;
-        /// for decode, a single token. Identical on every rank.
-        tokens: Vec<u32>,
-        /// KV cache offset (count of tokens already in the cache before
-        /// this step).
-        offset: usize,
-    },
-
-    /// Reset the KV cache for this model on this rank. Sent at the
-    /// start of every inference so a fresh request doesn't accidentally
-    /// attend over the previous one's tokens.
-    ClearKvCache { model_id: String },
-
-    /// Drop this rank's shard for the given model. Releases the VRAM
-    /// the shard's weights occupied; subsequent `GenerateStep` calls
-    /// against the same `model_id` return an `Error`.
-    UnloadModel { model_id: String },
-
-    /// Worker should release resources and exit. Worker replies `Bye`
-    /// and then closes stdout / exits zero. The leader reaps the
-    /// child via the `tokio::process::Child` it kept.
-    Shutdown,
-}
-
-/// Worker → leader. Always exactly one of these per `WorkerRequest`.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(tag = "op", rename_all = "snake_case")]
-pub enum WorkerResponse {
-    /// Reply to `Ping`. Carries enough identity for the leader to log
-    /// what it actually got back.
-    Pong {
-        rank: u32,
-        world_size: u32,
-        cuda_device: u32,
-    },
-
-    /// Reply to `Init`. Empty payload — success is the absence of
-    /// `Error`. NCCL's internal blocking handshake means by the time
-    /// this comes back, every other rank has also reached
-    /// `Comm::from_rank`.
-    InitOk,
-
-    /// Reply to `NcclSanityCheck`. The observed sum after a single
-    /// `all_reduce(SUM, 1u32)` across all ranks. The leader checks
-    /// this matches `world_size`.
-    NcclSanityResult { observed_sum: u32 },
-
-    /// Reply to `LoadDenseShard`. Empty payload — success is the
-    /// absence of `Error`. By the time this comes back, the rank's
-    /// `TpQwen3ForCausalLM` is constructed in memory and ready for
-    /// `GenerateStep`.
-    LoadDenseShardOk,
-
-    /// Reply to `GenerateStep`. Empty payload — workers don't ship
-    /// logits over the wire. The leader uses its own rank-0 logits;
-    /// workers only need to confirm the collective completed.
-    GenerateStepOk,
-
-    /// Reply to `ClearKvCache`. Empty payload.
-    KvCacheCleared,
-
-    /// Reply to `UnloadModel`. Empty payload. The named model is no
-    /// longer present on this rank.
-    Unloaded,
-
-    /// Reply to `Shutdown`. Worker exits immediately after writing this.
-    Bye,
-
-    /// Any request can produce this instead of its dedicated success
-    /// variant. `kind` is a machine-readable category so the leader
-    /// can branch on failure mode without string-matching `message`.
-    Error {
-        /// Short tag — `nccl_init_failed`, `unknown_op`, etc.
-        kind: String,
-        /// Human-readable detail for logs.
-        message: String,
-    },
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn roundtrip<T>(value: &T) -> T
-    where
-        T: Serialize + for<'de> Deserialize<'de>,
-    {
-        serde_json::from_str(&serde_json::to_string(value).expect("serialise"))
-            .expect("deserialise")
-    }
-
-    #[test]
-    fn request_ping_round_trip() {
-        let req = WorkerRequest::Ping;
-        let wire = serde_json::to_string(&req).unwrap();
-        assert_eq!(wire, r#"{"op":"ping"}"#);
-        match roundtrip(&req) {
-            WorkerRequest::Ping => {}
-            other => panic!("expected Ping, got {other:?}"),
-        }
-    }
-
-    #[test]
-    fn request_init_carries_hex_id() {
-        let req = WorkerRequest::Init {
-            comm_id: "deadbeef".into(),
-        };
-        let wire = serde_json::to_string(&req).unwrap();
-        assert_eq!(wire, r#"{"op":"init","comm_id":"deadbeef"}"#);
-    }
-
-    #[test]
-    fn request_shutdown_round_trip() {
-        assert_eq!(
-            serde_json::to_string(&WorkerRequest::Shutdown).unwrap(),
-            r#"{"op":"shutdown"}"#
-        );
-    }
-
-    #[test]
-    fn response_pong_round_trip() {
-        let resp = WorkerResponse::Pong {
-            rank: 1,
-            world_size: 4,
-            cuda_device: 1,
-        };
-        let wire = serde_json::to_string(&resp).unwrap();
-        assert!(wire.contains(r#""op":"pong""#));
-        assert!(wire.contains(r#""rank":1"#));
-        assert!(wire.contains(r#""world_size":4"#));
-        match roundtrip(&resp) {
-            WorkerResponse::Pong {
-                rank,
-                world_size,
-                cuda_device,
-            } => {
-                assert_eq!(rank, 1);
-                assert_eq!(world_size, 4);
-                assert_eq!(cuda_device, 1);
-            }
-            other => panic!("expected Pong, got {other:?}"),
-        }
-    }
-
-    #[test]
-    fn response_error_carries_kind_and_message() {
-        let resp = WorkerResponse::Error {
-            kind: "nccl_init_failed".into(),
-            message: "could not bind device".into(),
-        };
-        let wire = serde_json::to_string(&resp).unwrap();
-        assert!(wire.contains(r#""op":"error""#));
-        assert!(wire.contains(r#""kind":"nccl_init_failed""#));
-    }
-
-    #[test]
-    fn response_sanity_result_round_trip() {
-        let resp = WorkerResponse::NcclSanityResult { observed_sum: 4 };
-        match roundtrip(&resp) {
-            WorkerResponse::NcclSanityResult { observed_sum } => {
-                assert_eq!(observed_sum, 4);
-            }
-            other => panic!("expected NcclSanityResult, got {other:?}"),
-        }
-    }
-
-    /// Unknown ops on the wire deserialise to an error rather than
-    /// silently mis-matching — confirms our `serde(tag = "op")`
-    /// configuration rejects unknowns instead of doing fuzzy matching.
-    #[test]
-    fn unknown_op_fails_to_parse() {
-        let result: Result<WorkerRequest, _> = serde_json::from_str(r#"{"op":"explode"}"#);
-        assert!(result.is_err(), "should reject unknown op, got {result:?}");
-    }
-}

crates/neuron/src/harness/tp/tp_linear.rs

@@ -1,283 +0,0 @@
-//! Tensor-parallel linear layers built on candle's `ShardedVarBuilder`
-//! and `Shard` sharding hints.
-//!
-//! candle reads only the rank's slice of each weight tensor from
-//! safetensors via `view.slice(start..stop)` — no full-tensor host
-//! materialisation. That's a memory-efficiency win over hand-rolled
-//! "load full + narrow" sharding (which the earlier
-//! `sharded_linear.rs` exploration demonstrated but didn't pay for).
-//!
-//! Two layer types:
-//!
-//! - [`ColumnParallelLinear`] — output-sharded; forward is a plain
-//!   local matmul. The downstream consumer either accepts a sharded
-//!   activation (next layer is also column-parallel) or all-gathers.
-//! - [`RowParallelLinear`] — input-sharded; forward = local matmul
-//!   then `AllReduce` `CustomOp1` to sum partials across ranks.
-//!
-//! Both assume **no bias** — every Qwen3-family weight layout we
-//! actually target (Qwen3, Qwen3-Coder, Qwen3.6 base, etc.) sets
-//! `attention_bias=false` and the MLP layers are no-bias. Adding bias
-//! support is mechanical when a future model needs it; the design
-//! choice would be: column-parallel shards the bias along dim 0;
-//! row-parallel holds the bias only on rank 0 so the post-`AllReduce`
-//! sum carries it exactly once.
-
-use anyhow::{Context, Result};
-use candle_core::quantized::{GgmlDType, QMatMul, QTensor};
-use candle_core::{Module, Tensor};
-use candle_nn::Linear;
-use candle_nn::var_builder::{Shard, ShardedVarBuilder};
-use std::sync::Arc;
-
-#[cfg(feature = "cuda")]
-use super::all_reduce::AllReduce;
-
-/// Linear primitive that holds either a plain `Linear` (bf16/f16/f32)
-/// or a quantized `QMatMul` (Q4K/Q5K/Q6K/Q8_0/etc.).
-///
-/// Constructed via [`MaybeQuantLinear::from_weight`] — pass `None` to
-/// keep the weight in its loaded dtype (no quantization), or
-/// `Some(dtype)` to quantize at load time.
-///
-/// On the forward path the two arms dispatch identically: `Module::forward`
-/// returns an output in the caller's input dtype (f32 fallback for the
-/// quantized matmul). Subsequent ops don't need to know whether the
-/// layer was quantized.
-pub enum MaybeQuantLinear {
-    Plain(Linear),
-    Quant(QMatMul),
-}
-
-impl MaybeQuantLinear {
-    /// Build a linear from a loaded weight tensor. If `quant` is set,
-    /// the weight is quantized in-situ and stored as a `QMatMul`;
-    /// otherwise it's wrapped in a plain `Linear`.
-    pub fn from_weight(weight: Tensor, quant: Option<GgmlDType>) -> Result<Self> {
-        match quant {
-            Some(dtype) => {
-                let qt = QTensor::quantize(&weight, dtype).with_context(|| {
-                    format!(
-                        "QTensor::quantize to {dtype:?} for shape {:?}",
-                        weight.shape()
-                    )
-                })?;
-                let qmm = QMatMul::from_arc(Arc::new(qt))
-                    .context("QMatMul::from_arc on freshly quantized weight")?;
-                Ok(Self::Quant(qmm))
-            }
-            None => Ok(Self::Plain(Linear::new(weight, None))),
-        }
-    }
-}
-
-/// Above this M (the product of all input dims except the last)
-/// dispatch the quantized matmul through `QMatMul::forward_via_f16`,
-/// which dequantizes the weight to f16 once and runs cuBLAS GEMM.
-/// At or below this M the GGUF GEMV kernel inside
-/// `QMatMul::forward` wins (it operates on quantized blocks directly
-/// and accumulates in registers).
-///
-/// Empirical: at M=30 on Qwen3.6-27B / RTX 5090, forward_via_f16 was
-/// slightly *slower* than the GGUF GEMV kernel — the per-call dequant
-/// cost (~30 MB f16 written to global memory per linear × ~480 calls
-/// per prefill) eats the cuBLAS GEMM speedup at small M. The
-/// crossover where the GEMM scaling actually beats the fixed dequant
-/// tax sits well above M=8.
-///
-/// 64 is a conservative crossover that keeps short-prompt prefills
-/// on the GGUF kernel (where the per-call cost is comparable to the
-/// f16 path but the dequant tax is zero) and only activates the
-/// dequant-then-GEMM path for long prefills where the GEMM size
-/// makes amortising worth it. A proper fix is either a dequant
-/// cache or a fused dequant+gemm cuda kernel — both larger projects.
-const QUANT_PREFILL_M_THRESHOLD: usize = 64;
-
-impl Module for MaybeQuantLinear {
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        match self {
-            Self::Plain(l) => l.forward(x),
-            Self::Quant(qm) => {
-                // Decode vs prefill split. `M` is the "rows of x" the
-                // matmul will iterate over — every dim except the last
-                // (which is in_features). For decode (`seq_len == 1`
-                // with batch 1) M is 1; for prefill with L>>1 it's L
-                // (or B*L).
-                let dims = x.dims();
-                let m: usize = dims.iter().take(dims.len() - 1).product();
-
-                if m > QUANT_PREFILL_M_THRESHOLD {
-                    // Prefill: dequantize the weight once into f16,
-                    // then run a real cuBLAS-backed GEMM. The cost of
-                    // the dequant is amortised across all M tokens.
-                    // `forward_via_f16` handles the dtype round-trip
-                    // internally (output matches input dtype).
-                    return qm.forward_via_f16(x);
-                }
-
-                // Decode (M <= threshold): use the on-the-fly GGUF
-                // GEMV kernel via `QMatMul::forward`. That kernel
-                // requires f32 inputs (it accumulates in f32 from the
-                // dequantized quant blocks); cast in/out at the
-                // boundary.
-                let in_dtype = x.dtype();
-                let x_f32 = if in_dtype == candle_core::DType::F32 {
-                    x.clone()
-                } else {
-                    x.to_dtype(candle_core::DType::F32)?
-                };
-                let y = qm.forward(&x_f32)?;
-                if y.dtype() == in_dtype {
-                    Ok(y)
-                } else {
-                    y.to_dtype(in_dtype)
-                }
-            }
-        }
-    }
-}
-
-/// Helper to build a [`Shard`] hint for a given dimension.
-pub(crate) fn shard(dim: usize, rank: u32, world_size: u32) -> Shard {
-    Shard {
-        dim,
-        rank: rank as usize,
-        world_size: world_size as usize,
-    }
-}
-
-/// Output-dim sharded linear (column-parallel). Holds a
-/// [`MaybeQuantLinear`] whose underlying weight is this rank's slice
-/// of the full `[out_features, in_features]` tensor along dim 0.
-pub struct ColumnParallelLinear {
-    inner: MaybeQuantLinear,
-}
-
-impl ColumnParallelLinear {
-    /// Load this rank's column-parallel slice from a
-    /// `ShardedVarBuilder`. The provided `vb` must already be `pp`-ed
-    /// to the layer's path (e.g. `vb.pp("model.layers.0.self_attn.q_proj")`).
-    ///
-    /// Backward-compatible variant — no in-situ quantization. For
-    /// quantized loads, use [`Self::load_with_quant`].
-    pub fn load(vb: &ShardedVarBuilder, rank: u32, world_size: u32) -> Result<Self> {
-        Self::load_with_quant(vb, rank, world_size, None)
-    }
-
-    /// Like [`Self::load`] but quantizes the per-rank weight in-situ
-    /// when `quant` is `Some(dtype)`. Saves ~3-5x vs bf16/f16.
-    pub fn load_with_quant(
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        quant: Option<GgmlDType>,
-    ) -> Result<Self> {
-        let weight = vb
-            .get_with_hints((), "weight", shard(0, rank, world_size))
-            .with_context(|| format!("load column-parallel '{}' weight", vb.prefix()))?;
-        let inner = MaybeQuantLinear::from_weight(weight, quant)
-            .with_context(|| format!("wrap column-parallel '{}'", vb.prefix()))?;
-        Ok(Self { inner })
-    }
-}
-
-impl Module for ColumnParallelLinear {
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        self.inner.forward(x)
-    }
-}
-
-/// Input-dim sharded linear (row-parallel).
-///
-/// Holds a sharded [`MaybeQuantLinear`] plus an `AllReduce` op the
-/// forward chains after the local matmul to recover the full activation.
-pub struct RowParallelLinear {
-    inner: MaybeQuantLinear,
-    #[cfg(feature = "cuda")]
-    all_reduce: AllReduce,
-    /// Whether the AllReduce should run. Column-parallel ↔ row-parallel
-    /// is a pair: the column output is sharded, the row input is
-    /// sharded, and the AllReduce gives back the full output. For
-    /// `world_size = 1` the AllReduce is a no-op so we skip it.
-    needs_reduce: bool,
-}
-
-impl RowParallelLinear {
-    /// Load this rank's row-parallel slice from a `ShardedVarBuilder`.
-    ///
-    /// Under `cuda`, `comm` is the NCCL communicator the row-parallel
-    /// `AllReduce` runs against. On CPU builds the parameter is
-    /// elided — forward returns the partial sum, which is the *wrong*
-    /// answer for inference but lets us compile-check the model.
-    ///
-    /// Backward-compatible variant — no in-situ quantization. For
-    /// quantized loads, use [`Self::load_with_quant`].
-    #[cfg(feature = "cuda")]
-    pub fn load(
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: std::sync::Arc<cudarc::nccl::Comm>,
-    ) -> Result<Self> {
-        Self::load_with_quant(vb, rank, world_size, comm, None)
-    }
-
-    /// Like [`Self::load`] but quantizes the per-rank weight in-situ.
-    #[cfg(feature = "cuda")]
-    pub fn load_with_quant(
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: std::sync::Arc<cudarc::nccl::Comm>,
-        quant: Option<GgmlDType>,
-    ) -> Result<Self> {
-        let weight = vb
-            .get_with_hints((), "weight", shard(1, rank, world_size))
-            .with_context(|| format!("load row-parallel '{}' weight", vb.prefix()))?;
-        let inner = MaybeQuantLinear::from_weight(weight, quant)
-            .with_context(|| format!("wrap row-parallel '{}'", vb.prefix()))?;
-        Ok(Self {
-            inner,
-            all_reduce: AllReduce::new(comm),
-            needs_reduce: world_size > 1,
-        })
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load(vb: &ShardedVarBuilder, rank: u32, world_size: u32) -> Result<Self> {
-        Self::load_with_quant(vb, rank, world_size, None)
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load_with_quant(
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        quant: Option<GgmlDType>,
-    ) -> Result<Self> {
-        let weight = vb
-            .get_with_hints((), "weight", shard(1, rank, world_size))
-            .with_context(|| format!("load row-parallel '{}' weight", vb.prefix()))?;
-        let inner = MaybeQuantLinear::from_weight(weight, quant)
-            .with_context(|| format!("wrap row-parallel '{}'", vb.prefix()))?;
-        Ok(Self {
-            inner,
-            needs_reduce: world_size > 1,
-        })
-    }
-}
-
-impl Module for RowParallelLinear {
-    /// Local matmul followed by an `AllReduce` (when `cuda` and
-    /// `world_size > 1`). On CPU or single-rank, returns the partial
-    /// output directly — which is *only* correct for `world_size == 1`.
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        let local = self.inner.forward(x)?;
-        #[cfg(feature = "cuda")]
-        if self.needs_reduce {
-            return local.apply_op1_no_bwd(&self.all_reduce);
-        }
-        let _ = self.needs_reduce;
-        Ok(local)
-    }
-}

crates/neuron/src/harness/tp/tp_qwen3.rs

@@ -1,605 +0,0 @@
-//! Tensor-parallel Qwen3 dense model.
-//!
-//! Mirrors `candle_transformers::models::qwen3` structurally, but with:
-//!
-//! - Attention's `q_proj` / `k_proj` / `v_proj` as
-//!   [`ColumnParallelLinear`] (output sharded along the head dimension —
-//!   per-rank `num_heads = total/world_size`, ditto for kv heads).
-//! - Attention's `o_proj` as [`RowParallelLinear`] (input sharded; the
-//!   trailing `AllReduce` recovers the full activation).
-//! - MLP's `gate_proj` / `up_proj` as [`ColumnParallelLinear`] (sharded
-//!   along `intermediate_size`).
-//! - MLP's `down_proj` as [`RowParallelLinear`].
-//! - `embed_tokens`, all `RmsNorm`s, and `lm_head` **replicated** on
-//!   every rank. The per-rank duplicate weight is bounded and lets us
-//!   skip the embedding all-gather and the lm-head column-shard +
-//!   all-gather; both are pure latency optimisations that don't change
-//!   correctness.
-//! - `kv_cache` holds the per-rank slice of K/V already (because they
-//!   came out of a column-parallel projection). No cache resharding
-//!   needed across ranks.
-//!
-//! Divisibility requirement, checked at load time:
-//!
-//! - `num_attention_heads % world_size == 0`
-//! - `num_key_value_heads % world_size == 0`
-//! - `intermediate_size  % world_size == 0`
-//!
-//! Anything else bails — the safetensors slice would lose data otherwise.
-//! This is the same divisibility-bail pattern that landed in
-//! `EricLBuehler/mistral.rs` PR #2054.
-//!
-//! Replicated tensors (norms, embedding, lm_head) are loaded by asking
-//! the `ShardedVarBuilder` for the full tensor via `vb.get(shape, name)`
-//! — which defaults to `Shard { world_size: 1 }` and falls through to
-//! the unsharded backend path.
-
-use anyhow::{Context, Result, bail};
-use candle_core::{DType, Device, IndexOp, Module, Tensor};
-use candle_nn::var_builder::ShardedVarBuilder;
-use candle_nn::{Activation, Embedding, Linear, RmsNorm, kv_cache::ConcatKvCache};
-use candle_transformers::utils::repeat_kv;
-use std::sync::Arc;
-
-#[cfg(feature = "cuda")]
-use cudarc::nccl::Comm;
-
-use super::tp_linear::{ColumnParallelLinear, RowParallelLinear};
-
-pub use candle_transformers::models::qwen3::Config;
-
-/// Replicated rotary-embedding lookup. Re-implementation of the
-/// `pub(crate)` candle equivalent — we can't reach into the upstream
-/// type, so the inv-freq / sin / cos construction lives here.
-pub(crate) struct Qwen3RotaryEmbedding {
-    sin: Tensor,
-    cos: Tensor,
-}
-
-impl Qwen3RotaryEmbedding {
-    pub(crate) fn new(dtype: DType, cfg: &Config, dev: &Device) -> Result<Self> {
-        let dim = cfg.head_dim;
-        let max_seq_len = cfg.max_position_embeddings;
-        let inv_freq: Vec<_> = (0..dim)
-            .step_by(2)
-            .map(|i| 1f32 / cfg.rope_theta.powf(i as f64 / dim as f64) as f32)
-            .collect();
-        let inv_freq_len = inv_freq.len();
-        let inv_freq = Tensor::from_vec(inv_freq, (1, inv_freq_len), dev)?.to_dtype(DType::F32)?;
-        let t = Tensor::arange(0u32, max_seq_len as u32, dev)?
-            .to_dtype(DType::F32)?
-            .reshape((max_seq_len, 1))?;
-        let freqs = t.matmul(&inv_freq)?;
-        Ok(Self {
-            sin: freqs.sin()?.to_dtype(dtype)?,
-            cos: freqs.cos()?.to_dtype(dtype)?,
-        })
-    }
-
-    fn apply(
-        &self,
-        q: &Tensor,
-        k: &Tensor,
-        offset: usize,
-    ) -> candle_core::Result<(Tensor, Tensor)> {
-        let (_, _, seq_len, _) = q.dims4()?;
-        let cos = self.cos.narrow(0, offset, seq_len)?;
-        let sin = self.sin.narrow(0, offset, seq_len)?;
-        let q_embed = candle_nn::rotary_emb::rope(&q.contiguous()?, &cos, &sin)?;
-        let k_embed = candle_nn::rotary_emb::rope(&k.contiguous()?, &cos, &sin)?;
-        Ok((q_embed, k_embed))
-    }
-}
-
-/// Helper: load a replicated tensor by asking the ShardedVarBuilder for
-/// the full tensor (world_size=1 hint falls through to SimpleBackend).
-fn load_replicated<S: Into<candle_core::Shape>>(
-    vb: &ShardedVarBuilder,
-    shape: S,
-    name: &str,
-) -> Result<Tensor> {
-    vb.get(shape, name)
-        .with_context(|| format!("load replicated '{}/{name}'", vb.prefix()))
-}
-
-fn load_rms_norm(vb: &ShardedVarBuilder, size: usize, eps: f64) -> Result<RmsNorm> {
-    let weight = load_replicated(vb, size, "weight")?;
-    Ok(RmsNorm::new(weight, eps))
-}
-
-/// TP MLP. SwiGLU = `down(silu(gate(x)) * up(x))`.
-pub(crate) struct TpQwen3MLP {
-    gate_proj: ColumnParallelLinear,
-    up_proj: ColumnParallelLinear,
-    down_proj: RowParallelLinear,
-    act_fn: Activation,
-}
-
-impl TpQwen3MLP {
-    #[cfg(feature = "cuda")]
-    pub fn load(
-        cfg: &Config,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: Arc<Comm>,
-    ) -> Result<Self> {
-        if !cfg.intermediate_size.is_multiple_of(world_size as usize) {
-            bail!(
-                "intermediate_size {} not divisible by world_size {}",
-                cfg.intermediate_size,
-                world_size
-            );
-        }
-        Ok(Self {
-            gate_proj: ColumnParallelLinear::load(&vb.pp("gate_proj"), rank, world_size)?,
-            up_proj: ColumnParallelLinear::load(&vb.pp("up_proj"), rank, world_size)?,
-            down_proj: RowParallelLinear::load(&vb.pp("down_proj"), rank, world_size, comm)?,
-            act_fn: cfg.hidden_act,
-        })
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load(cfg: &Config, vb: &ShardedVarBuilder, rank: u32, world_size: u32) -> Result<Self> {
-        if !cfg.intermediate_size.is_multiple_of(world_size as usize) {
-            bail!(
-                "intermediate_size {} not divisible by world_size {}",
-                cfg.intermediate_size,
-                world_size
-            );
-        }
-        Ok(Self {
-            gate_proj: ColumnParallelLinear::load(&vb.pp("gate_proj"), rank, world_size)?,
-            up_proj: ColumnParallelLinear::load(&vb.pp("up_proj"), rank, world_size)?,
-            down_proj: RowParallelLinear::load(&vb.pp("down_proj"), rank, world_size)?,
-            act_fn: cfg.hidden_act,
-        })
-    }
-}
-
-impl Module for TpQwen3MLP {
-    fn forward(&self, x: &Tensor) -> candle_core::Result<Tensor> {
-        let lhs = x.apply(&self.gate_proj)?.apply(&self.act_fn)?;
-        let rhs = x.apply(&self.up_proj)?;
-        (lhs * rhs)?.apply(&self.down_proj)
-    }
-}
-
-/// TP attention. Carries per-rank head counts and the q/k per-head
-/// RmsNorms (which are replicated and operate on a flattened B*H*L
-/// axis, so the same code path works irrespective of how H was split).
-pub(crate) struct TpQwen3Attention {
-    q_proj: ColumnParallelLinear,
-    k_proj: ColumnParallelLinear,
-    v_proj: ColumnParallelLinear,
-    o_proj: RowParallelLinear,
-    q_norm: RmsNorm,
-    k_norm: RmsNorm,
-    local_num_heads: usize,
-    local_num_kv_heads: usize,
-    num_kv_groups: usize,
-    head_dim: usize,
-    local_hidden_size: usize,
-    rotary_emb: Arc<Qwen3RotaryEmbedding>,
-    kv_cache: ConcatKvCache,
-}
-
-impl TpQwen3Attention {
-    #[cfg(feature = "cuda")]
-    pub fn load(
-        cfg: &Config,
-        rotary_emb: Arc<Qwen3RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: Arc<Comm>,
-    ) -> Result<Self> {
-        Self::load_inner(
-            cfg,
-            rotary_emb,
-            vb,
-            rank,
-            world_size,
-            #[cfg(feature = "cuda")]
-            comm,
-        )
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load(
-        cfg: &Config,
-        rotary_emb: Arc<Qwen3RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-    ) -> Result<Self> {
-        Self::load_inner(cfg, rotary_emb, vb, rank, world_size)
-    }
-
-    fn load_inner(
-        cfg: &Config,
-        rotary_emb: Arc<Qwen3RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        #[cfg(feature = "cuda")] comm: Arc<Comm>,
-    ) -> Result<Self> {
-        if cfg.use_sliding_window {
-            bail!("sliding window is not yet supported in the TP path");
-        }
-        if cfg.attention_bias {
-            bail!("attention_bias=true is not supported by ColumnParallel/RowParallelLinear yet");
-        }
-        let ws = world_size as usize;
-        if !cfg.num_attention_heads.is_multiple_of(ws) {
-            bail!(
-                "num_attention_heads {} not divisible by world_size {}",
-                cfg.num_attention_heads,
-                world_size
-            );
-        }
-        if !cfg.num_key_value_heads.is_multiple_of(ws) {
-            bail!(
-                "num_key_value_heads {} not divisible by world_size {}",
-                cfg.num_key_value_heads,
-                world_size
-            );
-        }
-        let head_dim = cfg.head_dim;
-        let local_num_heads = cfg.num_attention_heads / ws;
-        let local_num_kv_heads = cfg.num_key_value_heads / ws;
-        let num_kv_groups = local_num_heads / local_num_kv_heads;
-        let local_hidden_size = head_dim * local_num_heads;
-
-        let q_proj = ColumnParallelLinear::load(&vb.pp("q_proj"), rank, world_size)?;
-        let k_proj = ColumnParallelLinear::load(&vb.pp("k_proj"), rank, world_size)?;
-        let v_proj = ColumnParallelLinear::load(&vb.pp("v_proj"), rank, world_size)?;
-        #[cfg(feature = "cuda")]
-        let o_proj = RowParallelLinear::load(&vb.pp("o_proj"), rank, world_size, comm)?;
-        #[cfg(not(feature = "cuda"))]
-        let o_proj = RowParallelLinear::load(&vb.pp("o_proj"), rank, world_size)?;
-
-        let q_norm = load_rms_norm(&vb.pp("q_norm"), head_dim, cfg.rms_norm_eps)?;
-        let k_norm = load_rms_norm(&vb.pp("k_norm"), head_dim, cfg.rms_norm_eps)?;
-
-        // dim=2 because we cat along the seq axis of (B, H, L, D) tensors.
-        let kv_cache = ConcatKvCache::new(2);
-
-        Ok(Self {
-            q_proj,
-            k_proj,
-            v_proj,
-            o_proj,
-            q_norm,
-            k_norm,
-            local_num_heads,
-            local_num_kv_heads,
-            num_kv_groups,
-            head_dim,
-            local_hidden_size,
-            rotary_emb,
-            kv_cache,
-        })
-    }
-
-    pub fn forward(
-        &mut self,
-        x: &Tensor,
-        attn_mask: Option<&Tensor>,
-        offset: usize,
-    ) -> candle_core::Result<Tensor> {
-        let (b, l, _) = x.dims3()?;
-
-        // 1. Projections (column-parallel → output is sharded).
-        let q = self.q_proj.forward(x)?;
-        let k = self.k_proj.forward(x)?;
-        let v = self.v_proj.forward(x)?;
-
-        // 2. Reshape: (B, L, H, D) → (B, H, L, D).
-        let q = q
-            .reshape((b, l, self.local_num_heads, self.head_dim))?
-            .transpose(1, 2)?;
-        let k = k
-            .reshape((b, l, self.local_num_kv_heads, self.head_dim))?
-            .transpose(1, 2)?;
-        let v = v
-            .reshape((b, l, self.local_num_kv_heads, self.head_dim))?
-            .transpose(1, 2)?;
-
-        // 3. Per-head RmsNorm (replicated weight, flat input).
-        let q_flat = q.flatten(0, 2)?;
-        let k_flat = k.flatten(0, 2)?;
-        let q_flat = self.q_norm.forward(&q_flat)?;
-        let k_flat = self.k_norm.forward(&k_flat)?;
-        let q = q_flat.reshape((b, self.local_num_heads, l, self.head_dim))?;
-        let k = k_flat.reshape((b, self.local_num_kv_heads, l, self.head_dim))?;
-
-        // 4. Rotary.
-        let (q, k) = self.rotary_emb.apply(&q, &k, offset)?;
-
-        // 5. Accumulate KV.
-        let (k, v) = self.kv_cache.append(&k, &v)?;
-
-        // 6. GQA repeat_kv on the rank-local K/V.
-        let k = repeat_kv(k, self.num_kv_groups)?.contiguous()?;
-        let v = repeat_kv(v, self.num_kv_groups)?.contiguous()?;
-
-        // 7. Attention scores.
-        let scale = 1.0 / (self.head_dim as f64).sqrt();
-        let mut scores = (q.matmul(&k.transpose(2, 3)?)? * scale)?;
-        if let Some(m) = attn_mask {
-            scores = scores.broadcast_add(m)?;
-        }
-        let probs = candle_nn::ops::softmax_last_dim(&scores)?;
-        let ctx = probs.matmul(&v)?;
-
-        // 8. Output projection (row-parallel → AllReduce inside).
-        ctx.transpose(1, 2)?
-            .reshape((b, l, self.local_hidden_size))?
-            .apply(&self.o_proj)
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        self.kv_cache.reset();
-    }
-}
-
-struct TpDecoderLayer {
-    self_attn: TpQwen3Attention,
-    mlp: TpQwen3MLP,
-    ln1: RmsNorm,
-    ln2: RmsNorm,
-}
-
-impl TpDecoderLayer {
-    #[cfg(feature = "cuda")]
-    fn load(
-        cfg: &Config,
-        rotary_emb: Arc<Qwen3RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: Arc<Comm>,
-    ) -> Result<Self> {
-        let self_attn = TpQwen3Attention::load(
-            cfg,
-            rotary_emb,
-            &vb.pp("self_attn"),
-            rank,
-            world_size,
-            comm.clone(),
-        )?;
-        let mlp = TpQwen3MLP::load(cfg, &vb.pp("mlp"), rank, world_size, comm)?;
-        let ln1 = load_rms_norm(&vb.pp("input_layernorm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-        let ln2 = load_rms_norm(
-            &vb.pp("post_attention_layernorm"),
-            cfg.hidden_size,
-            cfg.rms_norm_eps,
-        )?;
-        Ok(Self {
-            self_attn,
-            mlp,
-            ln1,
-            ln2,
-        })
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    fn load(
-        cfg: &Config,
-        rotary_emb: Arc<Qwen3RotaryEmbedding>,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-    ) -> Result<Self> {
-        let self_attn =
-            TpQwen3Attention::load(cfg, rotary_emb, &vb.pp("self_attn"), rank, world_size)?;
-        let mlp = TpQwen3MLP::load(cfg, &vb.pp("mlp"), rank, world_size)?;
-        let ln1 = load_rms_norm(&vb.pp("input_layernorm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-        let ln2 = load_rms_norm(
-            &vb.pp("post_attention_layernorm"),
-            cfg.hidden_size,
-            cfg.rms_norm_eps,
-        )?;
-        Ok(Self {
-            self_attn,
-            mlp,
-            ln1,
-            ln2,
-        })
-    }
-
-    fn forward(
-        &mut self,
-        x: &Tensor,
-        mask: Option<&Tensor>,
-        offset: usize,
-    ) -> candle_core::Result<Tensor> {
-        let h = self.ln1.forward(x)?;
-        let h = self.self_attn.forward(&h, mask, offset)?;
-        let x = (x + h)?;
-        let h2 = self.ln2.forward(&x)?;
-        let h2 = h2.apply(&self.mlp)?;
-        x + h2
-    }
-
-    fn clear_kv_cache(&mut self) {
-        self.self_attn.clear_kv_cache();
-    }
-}
-
-/// Base TP Qwen3 transformer — embedding, decoder stack, final norm.
-/// The lm_head sits on top in [`TpQwen3ForCausalLM`].
-pub struct TpQwen3Model {
-    embed_tokens: Embedding,
-    layers: Vec<TpDecoderLayer>,
-    norm: RmsNorm,
-    device: Device,
-    dtype: DType,
-}
-
-impl TpQwen3Model {
-    #[cfg(feature = "cuda")]
-    pub fn load(
-        cfg: &Config,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: Arc<Comm>,
-    ) -> Result<Self> {
-        let dtype = vb.dtype();
-        let device = vb.device().clone();
-        let rotary = Arc::new(Qwen3RotaryEmbedding::new(dtype, cfg, &device)?);
-
-        let embed_vb = vb.pp("model.embed_tokens");
-        let embed_weight = load_replicated(&embed_vb, (cfg.vocab_size, cfg.hidden_size), "weight")?;
-        let embed_tokens = Embedding::new(embed_weight, cfg.hidden_size);
-
-        let vb_l = vb.pp("model.layers");
-        let mut layers = Vec::with_capacity(cfg.num_hidden_layers);
-        for i in 0..cfg.num_hidden_layers {
-            layers.push(TpDecoderLayer::load(
-                cfg,
-                rotary.clone(),
-                &vb_l.pp(i),
-                rank,
-                world_size,
-                comm.clone(),
-            )?);
-        }
-        let norm = load_rms_norm(&vb.pp("model.norm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-
-        Ok(Self {
-            embed_tokens,
-            layers,
-            norm,
-            device,
-            dtype,
-        })
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load(cfg: &Config, vb: &ShardedVarBuilder, rank: u32, world_size: u32) -> Result<Self> {
-        let dtype = vb.dtype();
-        let device = vb.device().clone();
-        let rotary = Arc::new(Qwen3RotaryEmbedding::new(dtype, cfg, &device)?);
-
-        let embed_vb = vb.pp("model.embed_tokens");
-        let embed_weight = load_replicated(&embed_vb, (cfg.vocab_size, cfg.hidden_size), "weight")?;
-        let embed_tokens = Embedding::new(embed_weight, cfg.hidden_size);
-
-        let vb_l = vb.pp("model.layers");
-        let mut layers = Vec::with_capacity(cfg.num_hidden_layers);
-        for i in 0..cfg.num_hidden_layers {
-            layers.push(TpDecoderLayer::load(
-                cfg,
-                rotary.clone(),
-                &vb_l.pp(i),
-                rank,
-                world_size,
-            )?);
-        }
-        let norm = load_rms_norm(&vb.pp("model.norm"), cfg.hidden_size, cfg.rms_norm_eps)?;
-
-        Ok(Self {
-            embed_tokens,
-            layers,
-            norm,
-            device,
-            dtype,
-        })
-    }
-
-    pub fn embed_weight(&self) -> &Tensor {
-        self.embed_tokens.embeddings()
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        for l in &mut self.layers {
-            l.clear_kv_cache();
-        }
-    }
-
-    fn causal_mask(&self, b: usize, tgt: usize, offset: usize) -> candle_core::Result<Tensor> {
-        let minf = f32::NEG_INFINITY;
-        let mask: Vec<_> = (0..tgt)
-            .flat_map(|i| (0..(tgt + offset)).map(move |j| if j <= i + offset { 0. } else { minf }))
-            .collect();
-        Tensor::from_slice(&mask, (b, 1, tgt, tgt + offset), &self.device)?.to_dtype(self.dtype)
-    }
-
-    pub fn forward(&mut self, input: &Tensor, offset: usize) -> candle_core::Result<Tensor> {
-        let (b, l) = input.dims2()?;
-        let mut h = self.embed_tokens.forward(input)?;
-
-        let causal = if l == 1 {
-            None
-        } else {
-            Some(self.causal_mask(b, l, offset)?)
-        };
-
-        for layer in &mut self.layers {
-            h = layer.forward(&h, causal.as_ref(), offset)?;
-        }
-        self.norm.forward(&h)
-    }
-}
-
-/// TP Qwen3 with a (replicated) language-model head on top.
-pub struct TpQwen3ForCausalLM {
-    base: TpQwen3Model,
-    lm_head: Linear,
-}
-
-impl TpQwen3ForCausalLM {
-    #[cfg(feature = "cuda")]
-    pub fn load(
-        cfg: &Config,
-        vb: &ShardedVarBuilder,
-        rank: u32,
-        world_size: u32,
-        comm: Arc<Comm>,
-    ) -> Result<Self> {
-        let base = TpQwen3Model::load(cfg, vb, rank, world_size, comm)?;
-        let lm_head = build_lm_head(cfg, vb, &base)?;
-        Ok(Self { base, lm_head })
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    pub fn load(cfg: &Config, vb: &ShardedVarBuilder, rank: u32, world_size: u32) -> Result<Self> {
-        let base = TpQwen3Model::load(cfg, vb, rank, world_size)?;
-        let lm_head = build_lm_head(cfg, vb, &base)?;
-        Ok(Self { base, lm_head })
-    }
-
-    pub fn forward(&mut self, input: &Tensor, offset: usize) -> candle_core::Result<Tensor> {
-        let (_, l) = input.dims2()?;
-        let hidden = self.base.forward(input, offset)?;
-        hidden.i((.., l - 1.., ..))?.apply(&self.lm_head)
-    }
-
-    pub fn clear_kv_cache(&mut self) {
-        self.base.clear_kv_cache();
-    }
-
-    pub fn device(&self) -> &Device {
-        &self.base.device
-    }
-
-    pub fn dtype(&self) -> DType {
-        self.base.dtype
-    }
-}
-
-fn build_lm_head(cfg: &Config, vb: &ShardedVarBuilder, base: &TpQwen3Model) -> Result<Linear> {
-    if cfg.tie_word_embeddings {
-        Ok(Linear::new(base.embed_weight().clone(), None))
-    } else {
-        let weight = load_replicated(
-            &vb.pp("lm_head"),
-            (cfg.vocab_size, cfg.hidden_size),
-            "weight",
-        )?;
-        Ok(Linear::new(weight, None))
-    }
-}

crates/neuron/src/harness/tp/worker.rs

@@ -1,502 +0,0 @@
-//! Entry point for `neuron --worker`.
-//!
-//! The worker reads one newline-delimited JSON `WorkerRequest` from
-//! stdin per loop iteration, dispatches synchronously, and writes
-//! exactly one `WorkerResponse` JSON line to stdout. tracing goes to
-//! stderr so it doesn't collide with the RPC stream.
-//!
-//! NCCL operations (`Init`, `NcclSanityCheck`) and model lifecycle ops
-//! (`LoadDenseShard`, `GenerateStep`, `ClearKvCache`, `UnloadModel`)
-//! are real when built with the `cuda` feature; without it they reply
-//! with `Error{kind="cuda_feature_not_enabled"}` so the leader can tell
-//! the difference between a misconfigured build and a genuine NCCL or
-//! model failure.
-
-use anyhow::Result;
-use std::collections::HashMap;
-use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
-
-use super::nccl_state::NcclState;
-use super::rpc::{WorkerRequest, WorkerResponse};
-
-#[cfg(feature = "cuda")]
-use super::tp_qwen3::TpQwen3ForCausalLM;
-#[cfg(feature = "cuda")]
-use super::tp_qwen3_5::TpQwen3_5ForCausalLM;
-
-/// Worker-side discriminator over the architectures we can load via
-/// `LoadDenseShard`. Mirrors `super::TpLeaderModel` on the leader
-/// side — the dispatch happens on the `model_type` extracted from the
-/// config JSON.
-#[cfg(feature = "cuda")]
-enum WorkerModel {
-    Qwen3(TpQwen3ForCausalLM),
-    Qwen3_5(TpQwen3_5ForCausalLM),
-}
-
-#[cfg(feature = "cuda")]
-impl WorkerModel {
-    fn forward(
-        &mut self,
-        input: &candle_core::Tensor,
-        offset: usize,
-    ) -> candle_core::Result<candle_core::Tensor> {
-        match self {
-            WorkerModel::Qwen3(m) => m.forward(input, offset),
-            WorkerModel::Qwen3_5(m) => m.forward(input, offset),
-        }
-    }
-
-    fn clear_kv_cache(&mut self) {
-        match self {
-            WorkerModel::Qwen3(m) => m.clear_kv_cache(),
-            WorkerModel::Qwen3_5(m) => m.clear_kv_cache(),
-        }
-    }
-
-    fn device(&self) -> &candle_core::Device {
-        match self {
-            WorkerModel::Qwen3(m) => m.device(),
-            WorkerModel::Qwen3_5(m) => m.device(),
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-pub struct WorkerConfig {
-    pub rank: u32,
-    pub world_size: u32,
-    pub cuda_device: u32,
-}
-
-/// Drive the worker RPC loop until `Shutdown` or EOF on stdin.
-pub async fn run(config: WorkerConfig) -> Result<()> {
-    tracing::info!(
-        rank = config.rank,
-        world_size = config.world_size,
-        cuda_device = config.cuda_device,
-        "tp worker starting"
-    );
-
-    let mut state = WorkerState::new(config);
-    let stdin = tokio::io::stdin();
-    let mut reader = BufReader::new(stdin).lines();
-    let mut stdout = tokio::io::stdout();
-
-    while let Some(line) = reader.next_line().await? {
-        if line.trim().is_empty() {
-            continue;
-        }
-        let req: WorkerRequest = match serde_json::from_str(&line) {
-            Ok(r) => r,
-            Err(e) => {
-                let resp = WorkerResponse::Error {
-                    kind: "bad_request".into(),
-                    message: format!("parse {line:?}: {e}"),
-                };
-                write_response(&mut stdout, &resp).await?;
-                continue;
-            }
-        };
-
-        let resp = state.handle(req).await;
-        let is_bye = matches!(resp, WorkerResponse::Bye);
-        write_response(&mut stdout, &resp).await?;
-        if is_bye {
-            break;
-        }
-    }
-
-    tracing::info!(rank = config.rank, "tp worker exiting");
-    Ok(())
-}
-
-async fn write_response(stdout: &mut tokio::io::Stdout, resp: &WorkerResponse) -> Result<()> {
-    let mut line = serde_json::to_string(resp)?;
-    line.push('\n');
-    stdout.write_all(line.as_bytes()).await?;
-    stdout.flush().await?;
-    Ok(())
-}
-
-/// One rank's local state. Owns the rank's NCCL communicator (via
-/// `NcclState`) and the rank's shard of every loaded model.
-struct WorkerState {
-    config: WorkerConfig,
-    nccl: NcclState,
-    /// Loaded model shards keyed by `model_id`. Each entry wraps the
-    /// rank's TP architecture handle (Qwen3 or Qwen3-Next) — the
-    /// column/row-parallel layers hold an `Arc<Comm>` cloned from
-    /// `nccl`. Cuda-only: the underlying types reference cudarc types
-    /// that don't exist without the cuda feature.
-    #[cfg(feature = "cuda")]
-    models: HashMap<String, WorkerModel>,
-    /// Placeholder so the non-cuda build keeps the same field name set
-    /// and `WorkerState::new` reads the same on both.
-    #[cfg(not(feature = "cuda"))]
-    #[allow(dead_code)]
-    models: HashMap<String, ()>,
-}
-
-impl WorkerState {
-    fn new(config: WorkerConfig) -> Self {
-        Self {
-            config,
-            nccl: NcclState::new(),
-            models: HashMap::new(),
-        }
-    }
-
-    async fn handle(&mut self, req: WorkerRequest) -> WorkerResponse {
-        match req {
-            WorkerRequest::Ping => WorkerResponse::Pong {
-                rank: self.config.rank,
-                world_size: self.config.world_size,
-                cuda_device: self.config.cuda_device,
-            },
-            WorkerRequest::Init { comm_id } => self.nccl.init(self.config, &comm_id),
-            WorkerRequest::NcclSanityCheck => self.nccl.sanity_check(),
-            WorkerRequest::LoadDenseShard {
-                model_id,
-                config_json,
-                safetensors_paths,
-                quant,
-            } => self.handle_load_dense_shard(model_id, config_json, safetensors_paths, quant),
-            WorkerRequest::GenerateStep {
-                model_id,
-                tokens,
-                offset,
-            } => self.handle_generate_step(&model_id, tokens, offset),
-            WorkerRequest::ClearKvCache { model_id } => self.handle_clear_kv_cache(&model_id),
-            WorkerRequest::UnloadModel { model_id } => self.handle_unload_model(&model_id),
-            WorkerRequest::Shutdown => WorkerResponse::Bye,
-        }
-    }
-
-    #[cfg(feature = "cuda")]
-    fn handle_load_dense_shard(
-        &mut self,
-        model_id: String,
-        config_json: String,
-        safetensors_paths: Vec<String>,
-        quant: Option<String>,
-    ) -> WorkerResponse {
-        use crate::harness::arch::qwen3_5 as qwen3_5_arch;
-        use candle_core::{DType, Device};
-        use candle_nn::var_builder::ShardedSafeTensors;
-        use candle_transformers::models::qwen3 as qwen3_dense;
-        use std::path::PathBuf;
-
-        let quant_dtype = match parse_quant_string(quant.as_deref()) {
-            Ok(q) => q,
-            Err(e) => {
-                return WorkerResponse::Error {
-                    kind: "bad_request".into(),
-                    message: format!("parse quant: {e}"),
-                };
-            }
-        };
-
-        if self.models.contains_key(&model_id) {
-            return WorkerResponse::Error {
-                kind: "already_loaded".into(),
-                message: format!("model '{model_id}' already loaded on this rank"),
-            };
-        }
-        let comm = match self.nccl.comm() {
-            Some(c) => c,
-            None => {
-                return WorkerResponse::Error {
-                    kind: "nccl_not_initialised".into(),
-                    message: "LoadDenseShard requires Init to have completed first".into(),
-                };
-            }
-        };
-
-        // Peek at model_type so we know which architecture to build.
-        let model_type = serde_json::from_str::<serde_json::Value>(&config_json)
-            .ok()
-            .as_ref()
-            .and_then(|v| v.get("model_type"))
-            .and_then(|v| v.as_str())
-            .unwrap_or("")
-            .to_string();
-
-        let device = match Device::new_cuda(self.config.cuda_device as usize) {
-            Ok(d) => d,
-            Err(e) => {
-                return WorkerResponse::Error {
-                    kind: "cuda_unavailable".into(),
-                    message: format!("Device::new_cuda({}) failed: {e}", self.config.cuda_device),
-                };
-            }
-        };
-
-        let paths: Vec<PathBuf> = safetensors_paths.into_iter().map(PathBuf::from).collect();
-        // SAFETY: same invariant as the single-GPU dense path — the HF
-        // cache files are treated as immutable while the mmap is held.
-        let vb = match unsafe { ShardedSafeTensors::var_builder(&paths, DType::BF16, &device) } {
-            Ok(v) => v,
-            Err(e) => {
-                return WorkerResponse::Error {
-                    kind: "load_failed".into(),
-                    message: format!("ShardedSafeTensors::var_builder: {e}"),
-                };
-            }
-        };
-        // Separate mmap of the same paths for the direct fused-region
-        // loader in `fused_load`. Linux's page cache shares the
-        // underlying pages between the two mmaps; the cost is one
-        // extra set of safetensors-header parses.
-        let mmap = match unsafe { candle_core::safetensors::MmapedSafetensors::multi(&paths) } {
-            Ok(m) => m,
-            Err(e) => {
-                return WorkerResponse::Error {
-                    kind: "load_failed".into(),
-                    message: format!("MmapedSafetensors::multi: {e}"),
-                };
-            }
-        };
-
-        let loaded = match model_type.as_str() {
-            "qwen3" => {
-                let cfg: qwen3_dense::Config = match serde_json::from_str(&config_json) {
-                    Ok(c) => c,
-                    Err(e) => {
-                        return WorkerResponse::Error {
-                            kind: "bad_request".into(),
-                            message: format!("parse Qwen3 Config JSON: {e}"),
-                        };
-                    }
-                };
-                match TpQwen3ForCausalLM::load(
-                    &cfg,
-                    &vb,
-                    self.config.rank,
-                    self.config.world_size,
-                    comm,
-                ) {
-                    Ok(m) => WorkerModel::Qwen3(m),
-                    Err(e) => {
-                        return WorkerResponse::Error {
-                            kind: "load_failed".into(),
-                            message: format!("TpQwen3ForCausalLM::load: {e:#}"),
-                        };
-                    }
-                }
-            }
-            "qwen3_5" => {
-                let cfg: qwen3_5_arch::Config = match serde_json::from_str(&config_json) {
-                    Ok(c) => c,
-                    Err(e) => {
-                        return WorkerResponse::Error {
-                            kind: "bad_request".into(),
-                            message: format!("parse Qwen3-Next Config JSON: {e}"),
-                        };
-                    }
-                };
-                match TpQwen3_5ForCausalLM::load(
-                    cfg,
-                    &vb,
-                    &mmap,
-                    self.config.rank,
-                    self.config.world_size,
-                    comm,
-                    quant_dtype,
-                ) {
-                    Ok(m) => WorkerModel::Qwen3_5(m),
-                    Err(e) => {
-                        return WorkerResponse::Error {
-                            kind: "load_failed".into(),
-                            message: format!("TpQwen3_5ForCausalLM::load: {e:#}"),
-                        };
-                    }
-                }
-            }
-            other => {
-                return WorkerResponse::Error {
-                    kind: "unsupported_arch".into(),
-                    message: format!(
-                        "worker: unsupported model_type '{other}' (supported: qwen3, qwen3_5)"
-                    ),
-                };
-            }
-        };
-
-        self.models.insert(model_id.clone(), loaded);
-        tracing::info!(
-            rank = self.config.rank,
-            model = %model_id,
-            model_type = %model_type,
-            "loaded TP shard"
-        );
-        WorkerResponse::LoadDenseShardOk
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    fn handle_load_dense_shard(
-        &mut self,
-        _model_id: String,
-        _config_json: String,
-        _safetensors_paths: Vec<String>,
-        _quant: Option<String>,
-    ) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "LoadDenseShard requires --features cuda".into(),
-        }
-    }
-
-    #[cfg(feature = "cuda")]
-    fn handle_generate_step(
-        &mut self,
-        model_id: &str,
-        tokens: Vec<u32>,
-        offset: usize,
-    ) -> WorkerResponse {
-        use candle_core::Tensor;
-
-        let Some(model) = self.models.get_mut(model_id) else {
-            return WorkerResponse::Error {
-                kind: "model_not_loaded".into(),
-                message: format!("model '{model_id}' not loaded on rank {}", self.config.rank),
-            };
-        };
-        let device = model.device().clone();
-        let input = match Tensor::new(tokens.as_slice(), &device).and_then(|t| t.unsqueeze(0)) {
-            Ok(t) => t,
-            Err(e) => {
-                return WorkerResponse::Error {
-                    kind: "forward_failed".into(),
-                    message: format!("build input tensor: {e}"),
-                };
-            }
-        };
-        let start = std::time::Instant::now();
-        tracing::debug!(
-            rank = self.config.rank,
-            model = %model_id,
-            tokens = tokens.len(),
-            offset,
-            "worker GenerateStep: forward starting"
-        );
-        // Drop the resulting logits — the leader uses its own copy from
-        // rank 0. The forward's value here is the NCCL collectives it
-        // issues, which let the leader's rank-0 forward make progress.
-        if let Err(e) = model.forward(&input, offset) {
-            tracing::warn!(
-                rank = self.config.rank,
-                model = %model_id,
-                elapsed_ms = start.elapsed().as_millis(),
-                error = %e,
-                "worker GenerateStep: forward failed"
-            );
-            return WorkerResponse::Error {
-                kind: "forward_failed".into(),
-                message: format!("TP forward: {e}"),
-            };
-        }
-        tracing::debug!(
-            rank = self.config.rank,
-            model = %model_id,
-            elapsed_ms = start.elapsed().as_millis(),
-            "worker GenerateStep: forward done"
-        );
-        WorkerResponse::GenerateStepOk
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    fn handle_generate_step(
-        &mut self,
-        _model_id: &str,
-        _tokens: Vec<u32>,
-        _offset: usize,
-    ) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "GenerateStep requires --features cuda".into(),
-        }
-    }
-
-    #[cfg(feature = "cuda")]
-    fn handle_clear_kv_cache(&mut self, model_id: &str) -> WorkerResponse {
-        let Some(model) = self.models.get_mut(model_id) else {
-            return WorkerResponse::Error {
-                kind: "model_not_loaded".into(),
-                message: format!("model '{model_id}' not loaded on rank {}", self.config.rank),
-            };
-        };
-        model.clear_kv_cache();
-        WorkerResponse::KvCacheCleared
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    fn handle_clear_kv_cache(&mut self, _model_id: &str) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "ClearKvCache requires --features cuda".into(),
-        }
-    }
-
-    #[cfg(feature = "cuda")]
-    fn handle_unload_model(&mut self, model_id: &str) -> WorkerResponse {
-        if self.models.remove(model_id).is_none() {
-            return WorkerResponse::Error {
-                kind: "model_not_loaded".into(),
-                message: format!("model '{model_id}' not loaded on rank {}", self.config.rank),
-            };
-        }
-        tracing::info!(rank = self.config.rank, model = %model_id, "unloaded TP shard");
-        WorkerResponse::Unloaded
-    }
-
-    #[cfg(not(feature = "cuda"))]
-    fn handle_unload_model(&mut self, _model_id: &str) -> WorkerResponse {
-        WorkerResponse::Error {
-            kind: "cuda_feature_not_enabled".into(),
-            message: "UnloadModel requires --features cuda".into(),
-        }
-    }
-}
-
-/// Parse a `ModelSpec.quant` string into a `GgmlDType`. Accepts the
-/// common ggml format names (case-insensitive). `None` and `Some("")`
-/// both map to "no quantization".
-///
-/// Supported: `q4_0`, `q4_1`, `q5_0`, `q5_1`, `q8_0`, `q8_1`,
-/// `q2k`/`q2_k`, `q3k`/`q3_k`, `q4k`/`q4_k`, `q5k`/`q5_k`,
-/// `q6k`/`q6_k`, `q8k`/`q8_k`, `f16`, `bf16`, `f32`. The underscore
-/// is optional and the prefix is case-insensitive.
-#[cfg(feature = "cuda")]
-pub(crate) fn parse_quant_string(
-    s: Option<&str>,
-) -> anyhow::Result<Option<candle_core::quantized::GgmlDType>> {
-    use candle_core::quantized::GgmlDType;
-    let s = match s {
-        Some(s) if !s.is_empty() => s,
-        _ => return Ok(None),
-    };
-    let normalised = s.to_ascii_lowercase().replace('_', "");
-    let dtype = match normalised.as_str() {
-        "q40" => GgmlDType::Q4_0,
-        "q41" => GgmlDType::Q4_1,
-        "q50" => GgmlDType::Q5_0,
-        "q51" => GgmlDType::Q5_1,
-        "q80" => GgmlDType::Q8_0,
-        "q81" => GgmlDType::Q8_1,
-        "q2k" => GgmlDType::Q2K,
-        "q3k" => GgmlDType::Q3K,
-        "q4k" | "q4km" => GgmlDType::Q4K,
-        "q5k" | "q5km" => GgmlDType::Q5K,
-        "q6k" => GgmlDType::Q6K,
-        "q8k" => GgmlDType::Q8K,
-        "f16" => GgmlDType::F16,
-        "bf16" => GgmlDType::BF16,
-        "f32" => GgmlDType::F32,
-        other => anyhow::bail!(
-            "unknown quant '{other}' (expected one of: q4_0, q4_1, q5_0, q5_1, q8_0, \
-             q8_1, q2k, q3k, q4k, q5k, q6k, q8k, f16, bf16, f32)"
-        ),
-    };
-    Ok(Some(dtype))
-}

crates/neuron/src/lib.rs

@@ -1,7 +1,5 @@
 pub mod api;
 pub mod config;
-pub mod cuda;
 pub mod discovery;
 pub mod harness;
 pub mod health;
-pub mod startup;

crates/neuron/src/main.rs

@@ -1,66 +1,21 @@
-use anyhow::{Context, Result};
+use anyhow::Result;
 use clap::Parser;
-use neuron::{
-    api,
-    config::NeuronConfig,
-    discovery,
-    harness::{HarnessRegistry, tp},
-    health, startup,
-};
+use neuron::{api, config::NeuronConfig, discovery, harness::HarnessRegistry, health};
 use std::sync::Arc;
 use std::time::Instant;
 use tokio::sync::RwLock;
 use tracing_subscriber::EnvFilter;
 
-/// Top-level CLI. The same binary runs as either the public neuron
-/// daemon (default), a tensor-parallel worker subprocess (when
-/// `--worker` is set, spawned by the leader on the same host), or a
-/// one-shot TP NCCL handshake check (when `--tp-smoke` is set).
 #[derive(Parser)]
 #[command(name = "neuron")]
 #[command(about = "Per-node daemon for cortex inference clusters")]
 #[command(version)]
 struct Args {
-    /// Run in tensor-parallel worker mode. The leader process spawns
-    /// one of these per non-zero NCCL rank and drives it over
-    /// newline-delimited JSON on stdin/stdout. Worker mode skips
-    /// discovery, the HTTP listener, and the health poller — it's a
-    /// pure RPC loop.
-    #[arg(long, default_value_t = false)]
-    worker: bool,
-
-    /// Run a one-shot TP smoke test: spawn `--tp-size - 1` worker
-    /// subprocesses on `--cuda-devices`, build the NCCL communicator,
-    /// run an `AllReduce` sanity check across every rank, and exit.
-    /// Used to validate the TP plumbing in isolation from model load
-    /// and inference. Diagnostic-only — not exposed through the daemon
-    /// HTTP API.
-    #[arg(long, default_value_t = false)]
-    tp_smoke: bool,
-
-    /// NCCL rank for worker mode. Ignored when `--worker` is not set.
-    #[arg(long, default_value_t = 0)]
-    rank: u32,
-
-    /// Total NCCL world size for worker mode or TP smoke mode.
-    #[arg(long, default_value_t = 1)]
-    tp_size: u32,
-
-    /// CUDA device index for worker mode. Ignored when `--worker` is
-    /// not set.
-    #[arg(long, default_value_t = 0)]
-    cuda_device: u32,
-
-    /// Comma-separated CUDA device indices for TP smoke mode (one per
-    /// rank, starting with rank 0). Must have `tp_size` entries.
-    #[arg(long, value_delimiter = ',')]
-    cuda_devices: Vec<u32>,
-
-    /// Port to listen on (overrides config file). Daemon mode only.
+    /// Port to listen on (overrides config file).
     #[arg(short, long)]
     port: Option<u16>,
 
-    /// Path to the neuron config file. Daemon mode only.
+    /// Path to the neuron config file.
     #[arg(short, long, default_value = "neuron.toml")]
     config: String,
 }
@@ -68,7 +23,6 @@ struct Args {
 #[tokio::main]
 async fn main() -> Result<()> {
     tracing_subscriber::fmt()
-        .with_writer(std::io::stderr)
         .with_env_filter(
             EnvFilter::try_from_default_env()
                 .unwrap_or_else(|_| EnvFilter::new("info,neuron=debug")),
@@ -77,85 +31,12 @@ async fn main() -> Result<()> {
 
     let args = Args::parse();
 
-    if args.worker {
-        return tp::worker::run(tp::worker::WorkerConfig {
-            rank: args.rank,
-            world_size: args.tp_size,
-            cuda_device: args.cuda_device,
-        })
-        .await;
-    }
-
-    if args.tp_smoke {
-        return tp_smoke(args.tp_size, args.cuda_devices).await;
-    }
-
-    daemon(args).await
-}
-
-/// One-shot tensor-parallel handshake. Spawns N-1 worker subprocesses
-/// (rank 0 stays in this process), builds the NCCL communicator across
-/// the full world, runs an AllReduce sanity check, and shuts everyone
-/// down. Output is plain log lines on stderr + a final summary on
-/// stdout in `key=value` form so an outer script can parse it.
-async fn tp_smoke(tp_size: u32, cuda_devices: Vec<u32>) -> Result<()> {
-    if tp_size < 2 {
-        anyhow::bail!("--tp-size must be at least 2 (got {tp_size})");
-    }
-    if cuda_devices.len() as u32 != tp_size {
-        anyhow::bail!(
-            "--cuda-devices must list exactly {tp_size} entries (got {})",
-            cuda_devices.len()
-        );
-    }
-
-    let exe = std::env::current_exe().context("resolve current_exe for worker spawn")?;
-    let leader_device = cuda_devices[0];
-
-    tracing::info!(
-        tp_size,
-        ?cuda_devices,
-        binary = %exe.display(),
-        "tp-smoke: spawning worker pool"
-    );
-    let mut pool = tp::WorkerPool::spawn(&exe, tp_size, &cuda_devices).await?;
-
-    tracing::info!("tp-smoke: pinging every worker");
-    let pongs = pool.ping_all().await?;
-    for p in &pongs {
-        tracing::info!(?p, "tp-smoke: pong");
-    }
-
-    tracing::info!(leader_device, "tp-smoke: initialising NCCL");
-    pool.init_nccl(leader_device).await?;
-
-    tracing::info!("tp-smoke: running AllReduce sanity check");
-    pool.nccl_sanity_check().await?;
-
-    tracing::info!("tp-smoke: shutting down pool");
-    pool.shutdown().await?;
-
-    println!("status=ok");
-    println!("tp_size={tp_size}");
-    println!(
-        "cuda_devices={}",
-        cuda_devices
-            .iter()
-            .map(|d| d.to_string())
-            .collect::<Vec<_>>()
-            .join(",")
-    );
-    Ok(())
-}
-
-async fn daemon(args: Args) -> Result<()> {
     let cfg = NeuronConfig::load(&args.config).unwrap_or_else(|e| {
         tracing::warn!(path = %args.config, error = %e, "config not found, using defaults");
         NeuronConfig::default()
     });
 
     let port = args.port.unwrap_or(cfg.port);
-    let bind_url = format!("http://localhost:{port}");
     let start_time = Instant::now();
 
     tracing::info!("running hardware discovery");
@@ -166,18 +47,9 @@ async fn daemon(args: Args) -> Result<()> {
         "discovery complete"
     );
 
-    // Build harness registry from config. In-process harnesses (candle)
-    // need to know neuron's own bind URL so they can return it from
-    // inference_endpoint.
-    let registry = HarnessRegistry::from_configs(&cfg.harnesses, &bind_url, &cfg.harness);
+    // Build harness registry from config.
+    let registry = HarnessRegistry::from_configs(&cfg.harnesses);
     discovery_result.harnesses = registry.names();
-    let candle = registry.candle();
-
-    // Activation: load default models before binding the listener.
-    // Each load may take tens of seconds to several minutes depending
-    // on model size and HF cache state — keep TimeoutStartSec in the
-    // systemd unit generous enough to cover the slowest entry.
-    startup::load_default_models(&registry, &cfg.default_models).await;
 
     let health_cache = Arc::new(health::HealthCache::new());
     health_cache
@@ -193,24 +65,13 @@ async fn daemon(args: Args) -> Result<()> {
         discovery: discovery_result,
         health_cache,
         registry: RwLock::new(registry),
-        candle,
     });
 
-    let app = api::neuron_routes().with_state(Arc::clone(&state));
+    let app = api::neuron_routes().with_state(state);
     let addr: std::net::SocketAddr = format!("0.0.0.0:{port}").parse()?;
     tracing::info!("neuron listening on {addr}");
     let listener = tokio::net::TcpListener::bind(addr).await?;
-    axum::serve(listener, app)
-        .with_graceful_shutdown(startup::shutdown_signal())
-        .await?;
-
-    // Deactivation: serve has returned (graceful shutdown signal
-    // received and connections drained). Release CUDA contexts / VRAM
-    // by unloading every model before exiting; systemd's TimeoutStopSec
-    // bounds how long this phase may take.
-    let registry = state.registry.read().await;
-    startup::unload_all_models(&registry).await;
-    tracing::info!("shutdown complete");
+    axum::serve(listener, app).await?;
 
     Ok(())
 }

crates/neuron/src/startup.rs

@@ -1,97 +0,0 @@
-//! Activation- and deactivation-time orchestration.
-//!
-//! Wired from `main.rs` around the HTTP listener — activation runs
-//! before bind, deactivation runs after axum returns from its
-//! graceful-shutdown future. Kept in its own module so the logic is
-//! unit-testable without spinning up a full neuron process.
-
-use crate::harness::HarnessRegistry;
-use cortex_core::harness::ModelSpec;
-use std::time::Instant;
-use tokio::signal;
-
-/// Load each spec sequentially against the registry, treating
-/// individual failures as warnings rather than fatal errors.
-///
-/// VRAM contention makes parallel loads risky; the sequential path is
-/// boring but correct. The function logs elapsed time per load so an
-/// operator can see which model is hogging activation.
-pub async fn load_default_models(registry: &HarnessRegistry, specs: &[ModelSpec]) {
-    if specs.is_empty() {
-        return;
-    }
-    tracing::info!(count = specs.len(), "loading default models");
-    for spec in specs {
-        let start = Instant::now();
-        match registry.load_model(spec).await {
-            Ok(()) => tracing::info!(
-                model = %spec.model_id,
-                elapsed_ms = start.elapsed().as_millis() as u64,
-                "loaded default model"
-            ),
-            Err(e) => tracing::warn!(
-                model = %spec.model_id,
-                error = %e,
-                elapsed_ms = start.elapsed().as_millis() as u64,
-                "failed to load default model, continuing"
-            ),
-        }
-    }
-}
-
-/// Future that resolves on SIGINT (Ctrl-C) or SIGTERM (systemd stop).
-///
-/// Wired into `axum::serve(...).with_graceful_shutdown(shutdown_signal())`
-/// so the HTTP listener stops accepting new connections, lets in-flight
-/// requests drain, and then yields control back to main for cleanup.
-pub async fn shutdown_signal() {
-    let ctrl_c = async {
-        signal::ctrl_c().await.ok();
-    };
-    let terminate = async {
-        signal::unix::signal(signal::unix::SignalKind::terminate())
-            .expect("install SIGTERM handler")
-            .recv()
-            .await;
-    };
-    tokio::select! {
-        _ = ctrl_c => tracing::info!("received SIGINT, shutting down"),
-        _ = terminate => tracing::info!("received SIGTERM, shutting down"),
-    }
-}
-
-/// Unload every model currently registered. Called from `main.rs` after
-/// axum's graceful shutdown future resolves, so CUDA contexts and VRAM
-/// are released before the process exits rather than left to the OS to
-/// reclaim. Per-model failures are logged and skipped — keep cleanup
-/// going even when one harness is unhealthy.
-pub async fn unload_all_models(registry: &HarnessRegistry) {
-    let listed = match registry.list_all_models().await {
-        Ok(m) => m,
-        Err(e) => {
-            tracing::warn!(error = %e, "failed to list models during shutdown");
-            return;
-        }
-    };
-
-    if listed.is_empty() {
-        return;
-    }
-
-    tracing::info!(count = listed.len(), "unloading models for shutdown");
-    for model in listed {
-        let start = Instant::now();
-        match registry.unload_model(&model.id).await {
-            Ok(()) => tracing::info!(
-                model = %model.id,
-                elapsed_ms = start.elapsed().as_millis() as u64,
-                "unloaded"
-            ),
-            Err(e) => tracing::warn!(
-                model = %model.id,
-                error = %e,
-                "unload failed during shutdown"
-            ),
-        }
-    }
-}

crates/neuron/tests/activation.rs

@@ -1,56 +0,0 @@
-//! Activation-time behaviour: load_default_models continues past
-//! individual failures so a single broken catalogue entry doesn't
-//! prevent the rest of the fleet from starting.
-
-use cortex_core::harness::{HarnessConfig, ModelSpec};
-use neuron::config::HarnessSettings;
-use neuron::harness::HarnessRegistry;
-use neuron::startup;
-
-#[tokio::test]
-async fn test_load_default_models_skips_unknown_harness() {
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:0",
-        &HarnessSettings::default(),
-    );
-
-    // Both entries fail synchronously inside the registry — no network
-    // call escapes (the harness lookup mismatches before hf-hub is
-    // touched). The function should still return cleanly.
-    let specs = vec![
-        ModelSpec {
-            model_id: "model-a".into(),
-            harness: "no-such-harness".into(),
-            quant: None,
-            tensor_parallel: None,
-            devices: None,
-        },
-        ModelSpec {
-            model_id: "model-b".into(),
-            harness: "no-such-harness".into(),
-            quant: None,
-            tensor_parallel: None,
-            devices: None,
-        },
-    ];
-
-    startup::load_default_models(&registry, &specs).await;
-
-    let listed = registry
-        .list_all_models()
-        .await
-        .expect("list_all_models should succeed");
-    assert!(
-        listed.is_empty(),
-        "no models should be loaded after failed entries"
-    );
-}
-
-#[tokio::test]
-async fn test_load_default_models_empty_is_noop() {
-    let registry = HarnessRegistry::new();
-    startup::load_default_models(&registry, &[]).await;
-}

crates/neuron/tests/api.rs

@@ -14,7 +14,6 @@ async fn spawn_neuron(discovery: DiscoveryResponse) -> String {
         discovery,
         health_cache,
         registry: RwLock::new(registry),
-        candle: None,
     });
 
     let app = api::neuron_routes().with_state(state);
@@ -136,30 +135,56 @@ async fn test_models_empty_registry() {
     assert!(body.as_array().unwrap().is_empty());
 }
 
-/// Verify the candle harness registers, list is empty by default, and a
-/// load attempt for an obviously-bogus model id returns a 4xx error
-/// without crashing the daemon. Real load/unload exercising actual GGUF
-/// download is covered by `tests/candle_lifecycle.rs` (cuda-integration).
+/// Spawn a mock mistral.rs backend and a neuron with the mistralrs harness
+/// pointing at it, then test the full model lifecycle through neuron's API.
 #[tokio::test]
-async fn test_candle_harness_registers_and_rejects_bogus_model() {
+async fn test_models_via_mistralrs_harness() {
+    use axum::routing::{get, post};
+    use axum::{Json, Router};
     use cortex_core::harness::HarnessConfig;
-    use neuron::config::HarnessSettings;
+    use serde_json::Value;
 
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:13131",
-        &HarnessSettings::default(),
-    );
+    // Mock mistral.rs backend.
+    let mock_app = Router::new()
+        .route(
+            "/v1/models",
+            get(|| async {
+                Json(json!({
+                    "data": [
+                        {"id": "test-model", "status": "loaded"},
+                        {"id": "other-model", "status": "unloaded"}
+                    ]
+                }))
+            }),
+        )
+        .route(
+            "/v1/models/unload",
+            post(|Json(_body): Json<Value>| async { Json(json!({"status": "ok"})) }),
+        )
+        .route(
+            "/v1/models/reload",
+            post(|Json(_body): Json<Value>| async { Json(json!({"status": "ok"})) }),
+        );
+
+    let mock_listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let mock_addr = mock_listener.local_addr().unwrap();
+    tokio::spawn(async move {
+        axum::serve(mock_listener, mock_app).await.unwrap();
+    });
+    let mock_url = format!("http://{mock_addr}");
+
+    // Build neuron with mistralrs harness pointing at mock.
+    let registry = HarnessRegistry::from_configs(&[HarnessConfig {
+        name: "mistralrs".into(),
+        endpoint: Some(mock_url.clone()),
+        systemd_unit: None,
+    }]);
 
-    let candle = registry.candle();
     let health_cache = Arc::new(HealthCache::new());
     let state = Arc::new(NeuronState {
         discovery: fake_discovery(),
         health_cache,
         registry: RwLock::new(registry),
-        candle,
     });
 
     let app = api::neuron_routes().with_state(state);
@@ -172,6 +197,7 @@ async fn test_candle_harness_registers_and_rejects_bogus_model() {
 
     let client = reqwest::Client::new();
 
+    // GET /models — should return models from mock mistralrs.
     let resp = client
         .get(format!("{neuron_url}/models"))
         .send()
@@ -179,140 +205,45 @@ async fn test_candle_harness_registers_and_rejects_bogus_model() {
         .unwrap();
     assert_eq!(resp.status(), 200);
     let models: Vec<serde_json::Value> = resp.json().await.unwrap();
-    assert!(models.is_empty());
+    assert_eq!(models.len(), 2);
+    assert_eq!(models[0]["id"], "test-model");
+    assert_eq!(models[0]["harness"], "mistralrs");
+    assert_eq!(models[0]["status"], "loaded");
+    assert_eq!(models[1]["id"], "other-model");
+    assert_eq!(models[1]["status"], "unloaded");
 
-    // Sending a wrong-harness spec should be rejected synchronously
-    // without touching the network or the model registry.
+    // GET /models/test-model/endpoint — should return mock URL.
+    let resp = client
+        .get(format!("{neuron_url}/models/test-model/endpoint"))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), 200);
+    let body: serde_json::Value = resp.json().await.unwrap();
+    assert_eq!(body["url"], mock_url);
+
+    // POST /models/unload — should succeed.
+    let resp = client
+        .post(format!("{neuron_url}/models/unload"))
+        .json(&json!({"model_id": "test-model"}))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), 200);
+    let body: serde_json::Value = resp.json().await.unwrap();
+    assert_eq!(body["status"], "unloaded");
+
+    // POST /models/load — should succeed.
     let resp = client
         .post(format!("{neuron_url}/models/load"))
-        .json(&json!({"model_id": "definitely/not-real", "harness": "not-candle"}))
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.status(), 400);
-
-    // Registry still empty.
-    let resp = client
-        .get(format!("{neuron_url}/models"))
-        .send()
-        .await
-        .unwrap();
-    let models: Vec<serde_json::Value> = resp.json().await.unwrap();
-    assert!(models.is_empty());
-}
-
-/// `/v1/chat/completions` returns 503 when no candle harness is registered.
-#[tokio::test]
-async fn test_chat_completions_no_candle_harness() {
-    let registry = HarnessRegistry::new();
-    let health_cache = Arc::new(HealthCache::new());
-    let state = Arc::new(NeuronState {
-        discovery: fake_discovery(),
-        health_cache,
-        registry: RwLock::new(registry),
-        candle: None,
-    });
-    let app = api::neuron_routes().with_state(state);
-    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
-    let addr = listener.local_addr().unwrap();
-    tokio::spawn(async move {
-        axum::serve(listener, app).await.unwrap();
-    });
-    let url = format!("http://{addr}");
-
-    let resp = reqwest::Client::new()
-        .post(format!("{url}/v1/chat/completions"))
         .json(&json!({
-            "model": "anything",
-            "messages": [{"role": "user", "content": "hi"}]
+            "model_id": "test-model",
+            "harness": "mistralrs"
         }))
         .send()
         .await
         .unwrap();
-    assert_eq!(resp.status(), 503);
-}
-
-/// `/v1/chat/completions` returns 404 when the requested model isn't loaded.
-#[tokio::test]
-async fn test_chat_completions_model_not_loaded() {
-    use cortex_core::harness::HarnessConfig;
-    use neuron::config::HarnessSettings;
-
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:0",
-        &HarnessSettings::default(),
-    );
-    let candle = registry.candle();
-    let health_cache = Arc::new(HealthCache::new());
-    let state = Arc::new(NeuronState {
-        discovery: fake_discovery(),
-        health_cache,
-        registry: RwLock::new(registry),
-        candle,
-    });
-    let app = api::neuron_routes().with_state(state);
-    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
-    let addr = listener.local_addr().unwrap();
-    tokio::spawn(async move {
-        axum::serve(listener, app).await.unwrap();
-    });
-    let url = format!("http://{addr}");
-
-    let resp = reqwest::Client::new()
-        .post(format!("{url}/v1/chat/completions"))
-        .json(&json!({
-            "model": "definitely/not-loaded",
-            "messages": [{"role": "user", "content": "hi"}]
-        }))
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.status(), 404);
-}
-
-/// `/v1/chat/completions` with `stream: true` returns 404 when the
-/// model isn't loaded — same surface as the non-streaming path. The
-/// streaming code only kicks in once the model lookup succeeds.
-#[tokio::test]
-async fn test_chat_completions_streaming_model_not_loaded() {
-    use cortex_core::harness::HarnessConfig;
-    use neuron::config::HarnessSettings;
-
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:0",
-        &HarnessSettings::default(),
-    );
-    let candle = registry.candle();
-    let health_cache = Arc::new(HealthCache::new());
-    let state = Arc::new(NeuronState {
-        discovery: fake_discovery(),
-        health_cache,
-        registry: RwLock::new(registry),
-        candle,
-    });
-    let app = api::neuron_routes().with_state(state);
-    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
-    let addr = listener.local_addr().unwrap();
-    tokio::spawn(async move {
-        axum::serve(listener, app).await.unwrap();
-    });
-    let url = format!("http://{addr}");
-
-    let resp = reqwest::Client::new()
-        .post(format!("{url}/v1/chat/completions"))
-        .json(&json!({
-            "model": "definitely/not-loaded",
-            "messages": [{"role": "user", "content": "hi"}],
-            "stream": true
-        }))
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.status(), 404);
+    assert_eq!(resp.status(), 200);
+    let body: serde_json::Value = resp.json().await.unwrap();
+    assert_eq!(body["status"], "loaded");
 }

crates/neuron/tests/candle_lifecycle.rs

@@ -1,87 +0,0 @@
-//! Real model load/unload lifecycle through the candle harness.
-//!
-//! Gated behind the `cuda-integration` feature because it downloads a
-//! real (small) GGUF from HuggingFace and materialises tensors on the
-//! configured device. Run on a host with network access and either a
-//! CUDA GPU (when built with `--features cuda`) or enough CPU RAM to
-//! hold the model.
-//!
-//! Usage:
-//!   cargo test -p neuron --features cuda-integration --test candle_lifecycle
-//!
-//! Optional environment variables:
-//!   NEURON_TEST_MODEL_ID — HuggingFace repo to load (default: a small
-//!     public Qwen3 GGUF repo).
-//!   NEURON_TEST_QUANT    — quant substring matched against GGUF
-//!     filenames (default: "Q4_K_M").
-//!   HF_HOME              — HuggingFace cache directory.
-
-#![cfg(feature = "cuda-integration")]
-
-use cortex_core::harness::{HarnessConfig, ModelSpec};
-use neuron::config::HarnessSettings;
-use neuron::harness::HarnessRegistry;
-use std::path::PathBuf;
-
-#[tokio::test]
-async fn test_candle_qwen3_load_unload_lifecycle() {
-    let _ = tracing_subscriber::fmt()
-        .with_test_writer()
-        .with_env_filter("info,neuron=debug")
-        .try_init();
-
-    let model_id = std::env::var("NEURON_TEST_MODEL_ID")
-        .unwrap_or_else(|_| "Qwen/Qwen3-0.6B-GGUF".to_string());
-    let quant = std::env::var("NEURON_TEST_QUANT").unwrap_or_else(|_| "Q4_K_M".to_string());
-
-    let mut settings = HarnessSettings::default();
-    if let Ok(home) = std::env::var("HF_HOME") {
-        settings.candle.hf_cache = Some(PathBuf::from(home));
-    }
-
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:13131",
-        &settings,
-    );
-
-    let spec = ModelSpec {
-        model_id: model_id.clone(),
-        harness: "candle".into(),
-        quant: Some(quant),
-        tensor_parallel: None,
-        devices: Some(vec![0]),
-    };
-
-    registry
-        .load_model(&spec)
-        .await
-        .expect("load_model should succeed");
-
-    let models = registry.list_all_models().await.expect("list_all_models");
-    assert_eq!(models.len(), 1, "expected exactly one loaded model");
-    assert_eq!(models[0].id, model_id);
-    assert_eq!(models[0].harness, "candle");
-    assert_eq!(models[0].status, "loaded");
-
-    let url = registry.inference_endpoint(&model_id).await;
-    assert_eq!(url, Some("http://localhost:13131".into()));
-
-    // Re-loading the same model should be rejected.
-    let again = registry.load_model(&spec).await;
-    assert!(again.is_err(), "second load should error");
-
-    registry
-        .unload_model(&model_id)
-        .await
-        .expect("unload_model should succeed");
-
-    let models = registry.list_all_models().await.expect("list_all_models");
-    assert!(models.is_empty(), "registry should be empty after unload");
-
-    // Unloading a model that isn't loaded should error.
-    let err = registry.unload_model(&model_id).await;
-    assert!(err.is_err(), "unload of missing model should error");
-}

crates/neuron/tests/shutdown.rs

@@ -1,32 +0,0 @@
-//! Deactivation behaviour: unload_all_models tolerates an empty
-//! registry and continues past per-model unload failures.
-
-use cortex_core::harness::HarnessConfig;
-use neuron::config::HarnessSettings;
-use neuron::harness::HarnessRegistry;
-use neuron::startup;
-
-#[tokio::test]
-async fn test_unload_all_models_empty_registry_is_noop() {
-    let registry = HarnessRegistry::new();
-    startup::unload_all_models(&registry).await;
-}
-
-#[tokio::test]
-async fn test_unload_all_models_with_no_loaded_models() {
-    let registry = HarnessRegistry::from_configs(
-        &[HarnessConfig {
-            name: "candle".into(),
-        }],
-        "http://localhost:0",
-        &HarnessSettings::default(),
-    );
-
-    startup::unload_all_models(&registry).await;
-
-    let listed = registry
-        .list_all_models()
-        .await
-        .expect("list_all_models should still succeed after shutdown cleanup");
-    assert!(listed.is_empty());
-}

crates/neuron/tests/tp_worker_lifecycle.rs

@@ -1,145 +0,0 @@
-//! Stage 7a-i: confirm the TP worker subprocess lifecycle round-trips.
-//!
-//! Spawns two worker subprocesses via the leader→worker stdio RPC,
-//! pings each, and cleanly shuts them down. No CUDA required —
-//! `Init` and `NcclSanityCheck` are stubbed in 7a-i, so this test
-//! runs on any host the workspace builds on.
-
-use neuron::harness::tp::{WorkerPool, rpc::WorkerResponse};
-
-/// Path to the neuron binary built by cargo for this test process.
-/// cargo populates `CARGO_BIN_EXE_neuron` at compile time for sibling-
-/// binary tests; production paths in main.rs use `/proc/self/exe`.
-const NEURON_BIN: &str = env!("CARGO_BIN_EXE_neuron");
-
-/// Two workers (so we spawn one subprocess: rank 0 is in-process,
-/// rank 1 is the child). Verify the spawned worker responds to Ping
-/// with its own identity, then shut it down cleanly.
-#[tokio::test]
-async fn test_spawn_ping_shutdown() {
-    // cuda_devices: rank 0 → device 0 (leader, unused here),
-    //               rank 1 → device 1 (worker; not actually opened in 7a-i).
-    let mut pool = WorkerPool::spawn(NEURON_BIN.as_ref(), 2, &[0, 1])
-        .await
-        .expect("spawn worker pool");
-
-    let pongs = pool.ping_all().await.expect("ping all workers");
-    assert_eq!(pongs.len(), 1, "expected one Pong (rank 1 only)");
-    match &pongs[0] {
-        WorkerResponse::Pong {
-            rank,
-            world_size,
-            cuda_device,
-        } => {
-            assert_eq!(*rank, 1);
-            assert_eq!(*world_size, 2);
-            assert_eq!(*cuda_device, 1);
-        }
-        other => panic!("expected Pong, got {other:?}"),
-    }
-
-    pool.shutdown().await.expect("clean shutdown");
-}
-
-/// Three workers — exercise the loop in `ping_all` / `shutdown`.
-#[tokio::test]
-async fn test_spawn_three_workers() {
-    let mut pool = WorkerPool::spawn(NEURON_BIN.as_ref(), 3, &[0, 1, 2])
-        .await
-        .expect("spawn worker pool");
-
-    let pongs = pool.ping_all().await.expect("ping all workers");
-    assert_eq!(pongs.len(), 2, "expected two Pongs (ranks 1 and 2)");
-    for (i, resp) in pongs.iter().enumerate() {
-        match resp {
-            WorkerResponse::Pong {
-                rank,
-                world_size,
-                cuda_device,
-            } => {
-                let expected_rank = (i + 1) as u32;
-                assert_eq!(*rank, expected_rank);
-                assert_eq!(*world_size, 3);
-                assert_eq!(*cuda_device, expected_rank);
-            }
-            other => panic!("expected Pong, got {other:?}"),
-        }
-    }
-
-    pool.shutdown().await.expect("clean shutdown");
-}
-
-/// 7a-ii: without the cuda feature, Init must fail with a clear
-/// `cuda_feature_not_enabled` marker rather than silently succeeding.
-/// This is the local-dev-box test; the real NCCL handshake is exercised
-/// by `tp_worker_lifecycle_cuda.rs` (gated on `cuda-integration`).
-#[tokio::test]
-async fn test_init_returns_cuda_feature_not_enabled_without_cuda() {
-    use neuron::harness::tp::rpc::WorkerRequest;
-    use std::process::Stdio;
-    use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
-    use tokio::process::Command;
-
-    // Spawn a single worker by hand to send Init directly (the pool's
-    // public API doesn't expose Init yet — that lands in 7a-ii).
-    let mut child = Command::new(NEURON_BIN)
-        .arg("--worker")
-        .arg("--rank")
-        .arg("1")
-        .arg("--tp-size")
-        .arg("2")
-        .arg("--cuda-device")
-        .arg("1")
-        .stdin(Stdio::piped())
-        .stdout(Stdio::piped())
-        .stderr(Stdio::null())
-        .kill_on_drop(true)
-        .spawn()
-        .expect("spawn worker");
-
-    let mut stdin = child.stdin.take().expect("stdin");
-    let stdout = child.stdout.take().expect("stdout");
-    let mut lines = BufReader::new(stdout).lines();
-
-    let req = WorkerRequest::Init {
-        comm_id: "ff".repeat(128),
-    };
-    let mut payload = serde_json::to_string(&req).unwrap();
-    payload.push('\n');
-    stdin.write_all(payload.as_bytes()).await.unwrap();
-    stdin.flush().await.unwrap();
-
-    let reply = lines
-        .next_line()
-        .await
-        .expect("read line")
-        .expect("got line");
-    let resp: WorkerResponse = serde_json::from_str(&reply).expect("parse reply");
-    match resp {
-        WorkerResponse::Error { kind, .. } => {
-            #[cfg(feature = "cuda")]
-            {
-                // With cuda enabled the response depends on whether
-                // CUDA hardware is actually present. Accept either
-                // the success contract or a real NCCL failure.
-                let _ = kind;
-            }
-            #[cfg(not(feature = "cuda"))]
-            assert_eq!(kind, "cuda_feature_not_enabled");
-        }
-        WorkerResponse::InitOk => {
-            // Real NCCL succeeded — only possible with cuda feature
-            // AND a working NCCL stack AND another rank actually
-            // joining. Don't fail; just acknowledge.
-            #[cfg(not(feature = "cuda"))]
-            panic!("InitOk without cuda feature is impossible");
-        }
-        other => panic!("expected Error or InitOk, got {other:?}"),
-    }
-
-    // Clean shutdown.
-    stdin.write_all(b"{\"op\":\"shutdown\"}\n").await.unwrap();
-    stdin.flush().await.unwrap();
-    let _ = lines.next_line().await; // Bye
-    let _ = child.wait().await;
-}

crates/neuron/tests/tp_worker_lifecycle_cuda.rs

@@ -1,43 +0,0 @@
-//! Stage 7a-ii: real NCCL handshake across the worker pool.
-//!
-//! Gated behind the `cuda-integration` feature because it requires
-//! libnccl AND multiple CUDA devices on the running host. Run on
-//! beast (2× RTX 5090) via:
-//!
-//!   cargo test -p neuron --features cuda-integration \
-//!         --test tp_worker_lifecycle_cuda
-//!
-//! Steps: spawn N-1 workers, call `init_nccl`, run `nccl_sanity_check`
-//! (every rank `all_reduce`s `1u32` with Sum; expected total =
-//! world_size), shut down cleanly.
-
-#![cfg(feature = "cuda-integration")]
-
-use neuron::harness::tp::WorkerPool;
-
-const NEURON_BIN: &str = env!("CARGO_BIN_EXE_neuron");
-
-#[tokio::test]
-async fn test_init_and_sanity_check_two_ranks() {
-    let _ = tracing_subscriber::fmt()
-        .with_test_writer()
-        .with_env_filter("info,neuron=debug")
-        .try_init();
-
-    // 2 ranks: leader = rank 0 on device 0, worker = rank 1 on device 1.
-    let mut pool = WorkerPool::spawn(NEURON_BIN.as_ref(), 2, &[0, 1])
-        .await
-        .expect("spawn worker pool");
-
-    pool.ping_all().await.expect("pong all workers");
-
-    pool.init_nccl(0)
-        .await
-        .expect("init_nccl: NCCL handshake across all ranks");
-
-    pool.nccl_sanity_check()
-        .await
-        .expect("nccl_sanity_check: observed_sum == world_size on all ranks");
-
-    pool.shutdown().await.expect("clean shutdown");
-}

data/cortex-firewalld.xml

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<service>
-  <short>cortex</short>
-  <description>Cortex — inference gateway for multi-node GPU clusters</description>
-  <port protocol="tcp" port="31313"/>
-  <port protocol="tcp" port="31314"/>
-</service>

data/neuron-firewalld.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<service>
-  <short>helexa-neuron</short>
-  <description>Neuron — per-node GPU discovery and harness daemon for cortex</description>
-  <port protocol="tcp" port="13131"/>
-</service>

data/neuron.service

@@ -10,22 +10,6 @@ Restart=on-failure
 RestartSec=5
 User=neuron
 Group=neuron
-# /var/lib/neuron is the neuron user's $HOME — hf-hub writes its
-# default cache there (~/.cache/huggingface/hub). Without this directive
-# systemd doesn't create the directory and hf-hub downloads fail with
-# "fetch GGUF <file>: failed to create cache dir".
-StateDirectory=neuron
-StateDirectoryMode=0755
-# Loading default_models from neuron.toml happens before the HTTP
-# listener binds; large models can take many minutes to download and
-# materialise on first activation. systemd's default TimeoutStartSec
-# (90s) is far too short; allow 30 minutes.
-TimeoutStartSec=1800s
-# On stop, neuron drains in-flight requests then unloads every model
-# to release CUDA contexts cleanly. Allow generous time for big-model
-# unloads; systemd will SIGKILL after this bound.
-TimeoutStopSec=120s
-KillSignal=SIGTERM
 
 [Install]
 WantedBy=multi-user.target

models.example.toml

@@ -2,49 +2,28 @@
 #
 # Copy to /etc/cortex/models.toml and adjust for your environment.
 # Describes how to serve each model. Cortex matches these profiles
-# against discovered neuron topologies for placement decisions; the
-# resulting `(catalogue × topology)` set is what `GET /v1/models`
-# returns and what the router can cold-load on demand.
-#
-# Field reference:
-#   id                 - HuggingFace model id, exact match.
-#   harness            - which engine handles inference (currently "candle").
-#   quant              - GGUF quantisation tag for the file in the HF repo
-#                        (e.g. "Q4_K_M"). Omit/empty for the dense
-#                        safetensors path. TP requires dense.
-#   vram_mb            - rough estimate; advisory only, not enforced.
-#   min_devices        - GPU count this profile needs. TP profiles use
-#                        the same value as the tensor-parallel size.
-#   min_device_vram_mb - each device must meet this VRAM floor for the
-#                        neuron to be considered "feasible".
-#   pinned_on          - optional whitelist of neuron names. Non-empty
-#                        narrows feasibility to just those neurons and
-#                        protects the model from LRU eviction there.
+# against discovered neuron topologies for placement decisions.
 
-# Tensor-parallel target — needs a neuron with at least 2 large GPUs.
-# The example pins to a specific neuron name; adjust or remove the
-# pinned_on entry for your own fleet.
 [[models]]
-id = "Qwen/Qwen3.6-27B"
-harness = "candle"
-vram_mb = 54000
-min_devices = 2
-min_device_vram_mb = 24000
-pinned_on = ["your-multi-gpu-neuron"]
-
-# Mid-size dense model — fits on any single GPU with ≥16 GB VRAM.
-[[models]]
-id = "Qwen/Qwen3-8B"
-harness = "candle"
-vram_mb = 18000
-min_devices = 1
-min_device_vram_mb = 16000
-
-# Small GGUF quantised — runs on any small GPU.
-[[models]]
-id = "unsloth/Qwen3-0.6B-GGUF"
-harness = "candle"
+id = "your-org/large-model"
+harness = "mistralrs"
 quant = "Q4_K_M"
-vram_mb = 500
+vram_mb = 19000
+min_devices = 2
+min_device_vram_mb = 10000
+pinned_on = ["gpu-large"]
+
+[[models]]
+id = "your-org/medium-model"
+harness = "mistralrs"
+quant = "Q6_K"
+vram_mb = 12000
+min_devices = 1
+pinned_on = ["gpu-medium"]
+
+[[models]]
+id = "your-org/embedding-model"
+harness = "mistralrs"
+quant = "Q8_0"
+vram_mb = 8000
 min_devices = 1
-min_device_vram_mb = 4000

neuron.example.toml

@@ -3,51 +3,14 @@
 # Copy to /etc/neuron/neuron.toml and adjust for your environment.
 #
 # Environment variable overrides use NEURON_ prefix with __ separators:
-#   NEURON_PORT=13131
+#   NEURON_PORT=9090
 
-port = 13131
+port = 9090
 
 # -- Harnesses ---------------------------------------------------------------
-# Each [[harnesses]] entry enables an inference engine. Currently only
-# "candle" is supported — it runs in-process and uses huggingface/candle
-# for inference on local CUDA devices (or CPU when CUDA is unavailable).
+# Each [[harnesses]] entry declares an inference engine managed by neuron.
 
 [[harnesses]]
-name = "candle"
-
-# -- Candle harness settings -------------------------------------------------
-# Optional tuning for the candle harness.
-
-[harness.candle]
-# HuggingFace cache directory for model weights.
-#
-# Resolution order (first hit wins):
-#   1. `hf_cache` here in this file.
-#   2. `HF_HUB_CACHE` env var — same convention as the Python
-#      `huggingface_hub` library, so an existing cache directory shared
-#      with other tooling can be reused without per-tool config.
-#   3. `HF_HOME` env var (cache appended as `$HF_HOME/hub`).
-#   4. hf-hub's default (`~/.cache/huggingface/hub`).
-#
-# For per-host overrides (e.g. one neuron has an SSD with prefetched
-# weights), prefer a systemd drop-in over editing this file:
-#   /etc/systemd/system/neuron.service.d/local.conf:
-#     [Service]
-#     Environment=HF_HUB_CACHE=/archive/hf-cache
-# hf_cache = "/var/lib/neuron/hf-cache"
-
-# -- Default models ----------------------------------------------------------
-# Models listed here are loaded automatically when the neuron service
-# activates. Loading is sequential — a slow or failing entry doesn't
-# block the rest of the fleet, but it does push out the time before
-# neuron starts serving HTTP, so keep the list short. Operators can
-# load additional models on demand via POST /models/load.
-#
-# Make sure data/neuron.service's TimeoutStartSec is generous enough to
-# cover the slowest entry's first-time download + materialisation.
-
-# [[default_models]]
-# model_id = "Qwen/Qwen3-0.6B-GGUF"
-# harness = "candle"
-# quant = "Q4_K_M"
-# devices = [0]
+name = "mistralrs"
+endpoint = "http://localhost:8080"
+systemd_unit = "mistralrs.service"

neuron.spec

@@ -1,10 +1,7 @@
-Name:           helexa-neuron
-Version:        0.1.16
+Name:           neuron
+Version:        0.1.8
 Release:        1%{?dist}
 Summary:        Per-node GPU discovery and harness management daemon for cortex
-# Package name disambiguates from Fedora's existing "neuron" package
-# (NEURON neural simulation environment from Yale). Binary, systemd
-# unit, and system user are still called "neuron" for brevity.
 
 License:        GPL-3.0-or-later
 URL:            https://git.lair.cafe/helexa/cortex
@@ -24,7 +21,6 @@ BuildRequires:  systemd-rpm-macros
 
 Requires(pre):  shadow-utils
 Requires:       systemd
-Requires:       firewalld-filesystem
 
 # systemd-rpm-macros ships a unit dep generator that parses User=/Group=
 # from our .service file and emits Requires: user(neuron)/group(neuron).
@@ -37,9 +33,8 @@ Provides:       user(neuron)
 
 %description
 Neuron is a per-node daemon for cortex inference clusters. It discovers
-local GPU hardware via nvidia-smi, runs in-process inference via
-huggingface/candle, and exposes an HTTP API for model lifecycle
-management (load, unload, list, inference endpoint).
+local GPU hardware via nvidia-smi, manages inference harnesses (mistral.rs,
+llama.cpp), and exposes an HTTP API for model lifecycle management.
 
 %prep
 %autosetup
@@ -60,7 +55,6 @@ cargo build --release -p neuron
 install -Dm755 target/release/neuron %{buildroot}%{_bindir}/neuron
 install -Dm644 data/neuron.service %{buildroot}%{_unitdir}/neuron.service
 install -Dm644 data/neuron-sysusers.conf %{buildroot}%{_sysusersdir}/neuron.conf
-install -Dm644 data/neuron-firewalld.xml %{buildroot}%{_prefix}/lib/firewalld/services/helexa-neuron.xml
 install -dm755 %{buildroot}%{_sysconfdir}/neuron
 install -Dm644 neuron.example.toml %{buildroot}%{_sysconfdir}/neuron/neuron.toml
 
@@ -82,20 +76,9 @@ install -Dm644 neuron.example.toml %{buildroot}%{_sysconfdir}/neuron/neuron.toml
 %{_bindir}/neuron
 %{_unitdir}/neuron.service
 %{_sysusersdir}/neuron.conf
-%{_prefix}/lib/firewalld/services/helexa-neuron.xml
 %dir %{_sysconfdir}/neuron
 %config(noreplace) %{_sysconfdir}/neuron/neuron.toml
 
 %changelog
-* Thu Apr 16 2026 Gitea Actions <actions@git.lair.cafe> - 0.1.16-1
-- chore: ignore local deploy script
-- chore: move default ports out of common-collision ranges
-- ci: drop actions/cache for cargo registry and target
-
-* Thu Apr 16 2026 Gitea Actions <actions@git.lair.cafe> - 0.1.14-1
-- ci: publish both packages to a single helexa/helexa COPR project
-- fix(rpm): rename neuron package to helexa-neuron
-- ci: commit generated %changelog entries back to main
-
 * Wed Apr 15 2026 Rob Thijssen <grenade@rob.tn> - 0.1.0-1
 - Initial package

rpm/cortex-prerelease.spec

@@ -1,106 +0,0 @@
-# Prebuilt-binary spec for cortex.
-#
-# Unlike cortex.spec (which builds from source via cargo), this spec
-# wraps a pre-built `cortex` binary produced by an upstream CI job and
-# packages it for rpm.lair.cafe. The %build phase is a no-op.
-#
-# Required defines at rpmbuild time:
-#   cortex_version    e.g. "0.1.16"
-#   cortex_prerelease e.g. "0.1.20260518140530.gitabcdef0"
-#                            ^^^^^^^^^^^^^^^^^^ ^^^^^^^^
-#                            commit time (sec)  commit sha
-#                           (used as Release; the timestamp prefix
-#                            keeps same-day builds strictly ordered.)
-
-%global _build_id_links none
-%global debug_package %{nil}
-%global __strip /usr/bin/true
-
-%{!?cortex_version: %global cortex_version 0.0.0}
-%if 0%{?cortex_prerelease:1}
-%global cortex_release %{cortex_prerelease}
-%else
-%global cortex_release 1
-%endif
-
-Name:           cortex
-Version:        %{cortex_version}
-Release:        %{cortex_release}%{?dist}
-Summary:        Inference gateway for multi-node GPU clusters (prebuilt)
-
-License:        GPL-3.0-or-later
-URL:            https://git.lair.cafe/helexa/cortex
-
-Source0:        cortex
-Source1:        cortex.service
-Source2:        cortex-sysusers.conf
-Source3:        cortex-firewalld.xml
-Source4:        cortex.example.toml
-Source5:        models.example.toml
-Source6:        LICENSE
-
-ExclusiveArch:  x86_64
-
-Requires(pre):  shadow-utils
-Requires:       systemd
-Requires:       firewalld-filesystem
-
-Provides:       user(cortex)
-
-%description
-Cortex is a Rust reverse-proxy that sits in front of multiple neuron
-inference daemons and presents a unified OpenAI and Anthropic
-compatible API surface.
-
-This package wraps a binary built upstream in CI; the source-build
-spec (cortex.spec) remains available for stable releases.
-
-%prep
-cp %{SOURCE0} ./cortex
-cp %{SOURCE1} .
-cp %{SOURCE2} .
-cp %{SOURCE3} .
-cp %{SOURCE4} .
-cp %{SOURCE5} .
-cp %{SOURCE6} .
-
-%build
-# Already built in the upstream CI build job.
-
-%install
-install -Dm755 cortex %{buildroot}%{_bindir}/cortex
-install -Dm644 cortex.service %{buildroot}%{_unitdir}/cortex.service
-install -Dm644 cortex-sysusers.conf %{buildroot}%{_sysusersdir}/cortex.conf
-install -Dm644 cortex-firewalld.xml %{buildroot}%{_prefix}/lib/firewalld/services/cortex.xml
-install -dm755 %{buildroot}%{_sysconfdir}/cortex
-install -Dm644 cortex.example.toml %{buildroot}%{_sysconfdir}/cortex/cortex.toml
-install -Dm644 models.example.toml %{buildroot}%{_sysconfdir}/cortex/models.toml
-
-%pre
-getent group cortex >/dev/null || groupadd -r cortex
-getent passwd cortex >/dev/null || \
-    useradd -r -g cortex -d /var/lib/cortex -s /sbin/nologin \
-        -c "Cortex inference gateway" cortex
-
-%post
-%systemd_post cortex.service
-
-%preun
-%systemd_preun cortex.service
-
-%postun
-%systemd_postun_with_restart cortex.service
-
-%files
-%license LICENSE
-%{_bindir}/cortex
-%{_unitdir}/cortex.service
-%{_sysusersdir}/cortex.conf
-%{_prefix}/lib/firewalld/services/cortex.xml
-%dir %{_sysconfdir}/cortex
-%config(noreplace) %{_sysconfdir}/cortex/cortex.toml
-%config(noreplace) %{_sysconfdir}/cortex/models.toml
-
-%changelog
-* Mon May 18 2026 Gitea Actions <actions@git.lair.cafe> - %{cortex_version}-%{cortex_release}
-- Prerelease build from upstream CI binary.

rpm/helexa-neuron-prerelease.spec

@@ -1,126 +0,0 @@
-# Prebuilt-binary spec for helexa-neuron flavoured by CUDA compute capability.
-#
-# Unlike helexa-neuron.spec (which builds from source via cargo), this
-# spec wraps a pre-built `neuron-{flavour}` binary produced by an
-# upstream CI job and packages it for rpm.lair.cafe. The %build phase
-# is a no-op.
-#
-# Required defines at rpmbuild time:
-#   neuron_version    e.g. "0.1.16"
-#   neuron_flavour    e.g. "ada", "blackwell"  — matches the CI build
-#                     matrix's compute_cap label.
-#   neuron_prerelease e.g. "0.1.20260518140530.gitabcdef0"
-#                            ^^^^^^^^^^^^^^^^^^ ^^^^^^^^
-#                            commit time (sec)  commit sha
-#                           (used as Release; the timestamp prefix
-#                            keeps same-day builds strictly ordered.)
-#
-# One flavour can be installed at a time on a given host; flavour
-# packages Conflict with each other.
-
-%global _build_id_links none
-%global debug_package %{nil}
-%global __strip /usr/bin/true
-
-%{!?neuron_version: %global neuron_version 0.0.0}
-%{!?neuron_flavour: %global neuron_flavour blackwell}
-%if 0%{?neuron_prerelease:1}
-%global neuron_release %{neuron_prerelease}
-%else
-%global neuron_release 1
-%endif
-
-Name:           helexa-neuron-%{neuron_flavour}
-Version:        %{neuron_version}
-Release:        %{neuron_release}%{?dist}
-Summary:        Per-node GPU inference daemon (candle, %{neuron_flavour} flavour)
-
-License:        GPL-3.0-or-later
-URL:            https://git.lair.cafe/helexa/cortex
-
-Source0:        neuron-%{neuron_flavour}
-Source1:        neuron.service
-Source2:        neuron-sysusers.conf
-Source3:        neuron-firewalld.xml
-Source4:        neuron.example.toml
-Source5:        LICENSE
-
-ExclusiveArch:  x86_64
-
-# Binary links against the CUDA runtime, cuDNN, NCCL, etc. Suppress
-# auto-detected exact soname deps — users may have CUDA from various
-# sources (rpmfusion, nvidia-direct) at different compatible versions;
-# a runtime dlopen failure surfaces a clearer error than rpm dep
-# resolution would.
-%global __requires_exclude ^lib(cuda|cudart|cudnn|cublas|cublasLt|curand|nvrtc|nccl)
-
-Requires(pre):  shadow-utils
-Requires:       systemd
-Requires:       firewalld-filesystem
-
-Provides:       helexa-neuron = %{neuron_version}-%{neuron_release}
-Provides:       user(neuron)
-
-# Mutual exclusion across flavours and the source-build variant.
-Conflicts:      helexa-neuron
-Conflicts:      helexa-neuron-ada
-Conflicts:      helexa-neuron-ampere
-Conflicts:      helexa-neuron-blackwell
-# (The Conflicts: with self is filtered by rpm at install time.)
-
-%description
-Neuron is the per-node daemon for cortex inference clusters. It
-discovers local GPU hardware via nvidia-smi, runs in-process
-inference via huggingface/candle, and exposes an HTTP API for model
-lifecycle management (load, unload, list, inference endpoint).
-
-This is the %{neuron_flavour} flavour, built for that CUDA compute
-capability. Install the flavour matching the GPUs on this host.
-
-%prep
-cp %{SOURCE0} ./neuron
-cp %{SOURCE1} .
-cp %{SOURCE2} .
-cp %{SOURCE3} .
-cp %{SOURCE4} .
-cp %{SOURCE5} .
-
-%build
-# Already built in the upstream CI build job (with --features cuda).
-
-%install
-install -Dm755 neuron %{buildroot}%{_bindir}/neuron
-install -Dm644 neuron.service %{buildroot}%{_unitdir}/neuron.service
-install -Dm644 neuron-sysusers.conf %{buildroot}%{_sysusersdir}/neuron.conf
-install -Dm644 neuron-firewalld.xml %{buildroot}%{_prefix}/lib/firewalld/services/helexa-neuron.xml
-install -dm755 %{buildroot}%{_sysconfdir}/neuron
-install -Dm644 neuron.example.toml %{buildroot}%{_sysconfdir}/neuron/neuron.toml
-
-%pre
-getent group neuron >/dev/null || groupadd -r neuron
-getent passwd neuron >/dev/null || \
-    useradd -r -g neuron -d /var/lib/neuron -s /sbin/nologin \
-        -G video,render \
-        -c "Neuron GPU node daemon" neuron
-
-%post
-%systemd_post neuron.service
-
-%preun
-%systemd_preun neuron.service
-
-%postun
-%systemd_postun_with_restart neuron.service
-
-%files
-%license LICENSE
-%{_bindir}/neuron
-%{_unitdir}/neuron.service
-%{_sysusersdir}/neuron.conf
-%{_prefix}/lib/firewalld/services/helexa-neuron.xml
-%dir %{_sysconfdir}/neuron
-%config(noreplace) %{_sysconfdir}/neuron/neuron.toml
-
-%changelog
-* Mon May 18 2026 Gitea Actions <actions@git.lair.cafe> - %{neuron_version}-%{neuron_release}
-- Prerelease build from upstream CI binary (%{neuron_flavour} flavour).

rpm/rpmmacros

@@ -1 +0,0 @@
-%_openpgp_sign_id @GPG_NAME@

script/deploy.sh

@@ -1,275 +0,0 @@
-#!/bin/env bash
-#
-# Rolling deploy across the helexa fleet, driven by asset/manifest.yml.
-# Installs / upgrades cortex on the gateway host and the appropriate
-# helexa-neuron-<flavour> package on each neuron host, then restarts
-# their services.
-
-set -euo pipefail
-
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-REPO_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
-MANIFEST="${REPO_DIR}/asset/manifest.yml"
-
-if [[ ! -f "${MANIFEST}" ]]; then
-    echo "fatal: manifest not found at ${MANIFEST}" >&2
-    exit 1
-fi
-
-# Parse the manifest with yq. NOTE: this expects the pip-installed yq
-# (a jq wrapper using jq syntax) — `pip install yq`. The Fedora rpm
-# `yq` is mikefarah/yq and uses different (yaml-native) syntax; if a
-# host has that one instead these queries will fail.
-cortex_host=$(yq -r '.cortex.host' "${MANIFEST}")
-
-# Emit one TAB-separated 'host\tflavour' line per neuron.
-mapfile -t neuron_entries < <(
-    yq -r '.neurons[] | .host + "\t" + .flavour' "${MANIFEST}"
-)
-
-# Return the installed package's "version-release" string, or
-# "(not installed)" when rpm reports the package as absent. Capture
-# rpm's output into a variable so its "package X is not installed"
-# stdout message (rpm writes that to stdout, not stderr, when -q fails)
-# doesn't leak into the result.
-installed_nvr() {
-    local host="$1" pkg="$2"
-    local nvr
-    if nvr=$(ssh "${host}" "rpm -q --qf '%{version}-%{release}' ${pkg} 2>/dev/null"); then
-        echo "${nvr}"
-    else
-        echo "(not installed)"
-    fi
-}
-
-# Ensure the rpm.lair.cafe unstable repo is configured AND enabled on
-# the remote host.
-#
-# The upstream .repo file at https://rpm.lair.cafe/lair-cafe-unstable.repo
-# ships with `enabled=0` so a host that just fetched it won't start
-# pulling unstable packages by accident. We have to explicitly flip
-# enabled=1 via `dnf config-manager setopt`. Both addrepo and setopt
-# are idempotent.
-#
-# Non-fatal — if either step fails the subsequent `dnf install` will
-# surface a clearer diagnostic on its own.
-ensure_lair_repo() {
-    local host="$1"
-    if ! ssh "${host}" "test -f /etc/yum.repos.d/lair-cafe-unstable.repo" 2>/dev/null; then
-        echo "[${host}] adding rpm.lair.cafe unstable repo"
-        if ! ssh "${host}" sudo dnf config-manager addrepo \
-            --from-repofile=https://rpm.lair.cafe/lair-cafe-unstable.repo \
-            >/dev/null 2>&1; then
-            echo "[${host}] WARNING: failed to add lair.cafe repo file (proceeding anyway)"
-            return 0
-        fi
-    fi
-    # The .repo file ships enabled=0; flip it on. Cheap, idempotent.
-    if ! ssh "${host}" sudo dnf config-manager setopt \
-        lair-cafe-unstable.enabled=1 >/dev/null 2>&1; then
-        echo "[${host}] WARNING: failed to enable lair-cafe-unstable (proceeding anyway)"
-    fi
-}
-
-# Ensure libcudnn.so.9 is resolvable on the remote host so the
-# neuron binary (built with --features cudnn) doesn't fail at startup
-# with "cannot open shared object file: No such file or directory".
-#
-# Probes ldconfig first — if cuDNN was installed manually (.tar/.run
-# install), it'll be cached by ldconfig and we don't touch it.
-# Otherwise adds NVIDIA's RHEL9 CUDA repo (the Fedora 43 CUDA repo
-# doesn't ship cuDNN packages — only the RHEL9 one does) and installs
-# libcudnn9-cuda-13.
-ensure_cudnn_runtime() {
-    local host="$1"
-    if ssh "${host}" "ldconfig -p | grep -q libcudnn.so.9" 2>/dev/null; then
-        return 0
-    fi
-    echo "[${host}] installing cuDNN runtime"
-    if ! ssh "${host}" "test -f /etc/yum.repos.d/cuda-rhel9-x86_64.repo" 2>/dev/null; then
-        if ! ssh "${host}" sudo dnf config-manager addrepo \
-            --from-repofile=https://developer.download.nvidia.com/compute/cuda/repos/rhel9/x86_64/cuda-rhel9.repo \
-            >/dev/null 2>&1; then
-            echo "[${host}] WARNING: failed to add rhel9 CUDA repo (proceeding anyway)"
-        fi
-    fi
-    if ! ssh "${host}" sudo dnf install -y libcudnn9-cuda-13 >/dev/null 2>&1; then
-        echo "[${host}] WARNING: failed to install libcudnn9-cuda-13"
-        echo "[${host}]   neuron may fail to start; install cuDNN manually if so"
-    fi
-}
-
-# True when the named package needs to be installed or upgraded on the
-# remote host — either it's not present, or a newer version exists in
-# the repo. False only when the installed version is current.
-#
-# `dnf check-update <pkg>` returns 0 when the package isn't installed
-# at all (there's nothing to update), so we have to probe with rpm -q
-# first to distinguish "absent" from "current". Other dnf failures
-# collapse into "needs update" so the subsequent install step surfaces
-# the real diagnostic rather than this check swallowing it.
-needs_update() {
-    local host="$1" pkg="$2"
-    # Not installed → needs work.
-    if ! ssh "${host}" "rpm -q ${pkg}" >/dev/null 2>&1; then
-        return 0
-    fi
-    # Installed; ask dnf whether the repo has something newer.
-    if ssh "${host}" sudo dnf check-update --refresh -q "${pkg}" >/dev/null 2>&1; then
-        return 1
-    else
-        return 0
-    fi
-}
-
-# True if the named package is currently installed on the remote host.
-# Used to decide between `dnf install` (fresh) and `dnf upgrade` (stale):
-# dnf5's `install` is a no-op when the package is already present at
-# any version — it does NOT auto-upgrade to the latest available — so
-# the wrong command silently leaves the host on an old build.
-is_installed() {
-    local host="$1" pkg="$2"
-    ssh "${host}" "rpm -q ${pkg}" >/dev/null 2>&1
-}
-
-# Install or upgrade the named package on the remote, picking the
-# right dnf verb based on the installed-or-not state. Returns 0 with
-# dnf's combined stdout/stderr captured in __DNF_OUTPUT__ on success,
-# and 1 with the same captured output on failure.
-__DNF_OUTPUT__=""
-install_or_upgrade() {
-    local host="$1" pkg="$2"
-    local cmd
-    if is_installed "${host}" "${pkg}"; then
-        cmd="upgrade"
-    else
-        cmd="install"
-    fi
-    if __DNF_OUTPUT__=$(
-        ssh "${host}" sudo dnf "${cmd}" --refresh --allowerasing -y "${pkg}" 2>&1
-    ); then
-        return 0
-    else
-        return 1
-    fi
-}
-
-# ---------------------------------------------------------------------------
-# cortex (gateway)
-# ---------------------------------------------------------------------------
-
-ensure_lair_repo "${cortex_host}"
-cortex_nvr=$(installed_nvr "${cortex_host}" cortex)
-if needs_update "${cortex_host}" cortex; then
-    echo "[${cortex_host}] cortex update available (current: ${cortex_nvr})"
-    # Stop the service only if the unit file exists — fresh installs
-    # don't have it, and `systemctl stop` on a missing unit returns
-    # non-zero, which would otherwise short-circuit the install branch
-    # under set -e.
-    if ssh "${cortex_host}" "[ ! -f /usr/lib/systemd/system/cortex.service ] || sudo systemctl stop cortex.service"; then
-        echo "[${cortex_host}] stopped cortex service"
-        if install_or_upgrade "${cortex_host}" cortex; then
-            cortex_nvr=$(installed_nvr "${cortex_host}" cortex)
-            echo "[${cortex_host}] installed/upgraded cortex to ${cortex_nvr}"
-        else
-            echo "[${cortex_host}] failed to install/upgrade cortex:"
-            echo "${__DNF_OUTPUT__}" | sed "s/^/[${cortex_host}]   /"
-        fi
-    else
-        echo "[${cortex_host}] failed to stop cortex service"
-    fi
-else
-    echo "[${cortex_host}] cortex is up to date (${cortex_nvr})"
-    ssh "${cortex_host}" sudo systemctl stop cortex.service || true
-fi
-
-# Sync cortex.toml whether the package was upgraded or not — the config
-# can change without a package bump.
-if rsync \
-    --archive \
-    --compress \
-    --rsync-path 'sudo rsync' \
-    --chown root:root \
-    --chmod 644 \
-    "${REPO_DIR}/cortex.toml" \
-    "${cortex_host}:/etc/cortex/cortex.toml"; then
-    echo "[${cortex_host}] sync'd cortex.toml"
-else
-    echo "[${cortex_host}] failed to sync cortex.toml"
-fi
-
-# Sync models.toml on the same lifecycle as cortex.toml — operator-owned,
-# gitignored, drives /v1/models catalogue × topology resolution.
-if [[ -f "${REPO_DIR}/models.toml" ]]; then
-    if rsync \
-        --archive \
-        --compress \
-        --rsync-path 'sudo rsync' \
-        --chown root:root \
-        --chmod 644 \
-        "${REPO_DIR}/models.toml" \
-        "${cortex_host}:/etc/cortex/models.toml"; then
-        echo "[${cortex_host}] sync'd models.toml"
-    else
-        echo "[${cortex_host}] failed to sync models.toml"
-    fi
-else
-    echo "[${cortex_host}] no local models.toml — leaving /etc/cortex/models.toml untouched"
-fi
-
-ssh "${cortex_host}" sudo systemctl daemon-reload
-if ssh "${cortex_host}" systemctl is-active --quiet cortex.service; then
-    echo "[${cortex_host}] cortex service is active"
-elif ssh "${cortex_host}" sudo systemctl start cortex.service; then
-    echo "[${cortex_host}] started cortex service"
-else
-    echo "[${cortex_host}] failed to start cortex service"
-fi
-
-# ---------------------------------------------------------------------------
-# neuron (per-host, flavour from manifest)
-# ---------------------------------------------------------------------------
-
-for entry in "${neuron_entries[@]}"; do
-    IFS=$'\t' read -r neuron_host neuron_flavour <<< "${entry}"
-    package="helexa-neuron-${neuron_flavour}"
-
-    ensure_lair_repo "${neuron_host}"
-    ensure_cudnn_runtime "${neuron_host}"
-    neuron_nvr=$(installed_nvr "${neuron_host}" "${package}")
-    if needs_update "${neuron_host}" "${package}"; then
-        echo "[${neuron_host}] ${package} update available (current: ${neuron_nvr})"
-        if ssh "${neuron_host}" "[ ! -f /usr/lib/systemd/system/neuron.service ] || sudo systemctl stop neuron.service"; then
-            echo "[${neuron_host}] stopped neuron service"
-            # --allowerasing lets dnf swap out a previously-installed
-            # bare helexa-neuron or a different flavour without manual
-            # intervention. The Conflicts: clauses in the spec ensure
-            # only one flavour is ever resident.
-            if install_or_upgrade "${neuron_host}" "${package}"; then
-                neuron_nvr=$(installed_nvr "${neuron_host}" "${package}")
-                echo "[${neuron_host}] installed/upgraded ${package} to ${neuron_nvr}"
-                # Ensure firewalld allows neuron port
-                ssh "${neuron_host}" "sudo firewall-cmd --query-service=helexa-neuron --quiet 2>/dev/null || sudo firewall-cmd --add-service=helexa-neuron --permanent && sudo firewall-cmd --reload" 2>/dev/null || true
-                if ssh "${neuron_host}" "sudo systemctl daemon-reload && sudo systemctl start neuron.service"; then
-                    echo "[${neuron_host}] started neuron service"
-                else
-                    echo "[${neuron_host}] failed to start neuron service"
-                fi
-            else
-                echo "[${neuron_host}] failed to install ${package}:"
-                echo "${__DNF_OUTPUT__}" | sed "s/^/[${neuron_host}]   /"
-            fi
-        else
-            echo "[${neuron_host}] failed to stop neuron service"
-        fi
-    else
-        echo "[${neuron_host}] ${package} is up to date (${neuron_nvr})"
-        if ssh "${neuron_host}" systemctl is-active --quiet neuron.service; then
-            echo "[${neuron_host}] neuron service is active"
-        elif ssh "${neuron_host}" sudo systemctl start neuron.service; then
-            echo "[${neuron_host}] started neuron service"
-        else
-            echo "[${neuron_host}] failed to start neuron service"
-        fi
-    fi
-done

script/generate-packages-json.py

@@ -1,154 +0,0 @@
-#!/usr/bin/env python3
-"""Parse RPM repodata and emit a packages.json manifest for the UI."""
-
-import argparse
-import gzip
-import json
-import os
-import subprocess
-import sys
-import xml.etree.ElementTree as ET
-from datetime import datetime, timezone
-
-RPM_NS = "http://linux.duke.edu/metadata/common"
-OTHER_NS = "http://linux.duke.edu/metadata/other"
-REPO_NS = "http://linux.duke.edu/metadata/repo"
-
-
-def find_repodata_file(repodata_dir, data_type):
-    """Read repomd.xml and return the path to a specific data type's file."""
-    repomd_path = os.path.join(repodata_dir, "repomd.xml")
-    tree = ET.parse(repomd_path)
-    root = tree.getroot()
-
-    for data in root.findall(f"{{{REPO_NS}}}data"):
-        if data.get("type") == data_type:
-            location = data.find(f"{{{REPO_NS}}}location")
-            if location is not None:
-                href = location.get("href", "")
-                return os.path.join(os.path.dirname(repodata_dir), href)
-
-    return None
-
-
-def open_compressed(path):
-    """Open a gzip or zstd compressed file for reading."""
-    if path.endswith(".zst"):
-        result = subprocess.run(
-            ["zstdcat", path], capture_output=True, check=True
-        )
-        import io
-        return io.BytesIO(result.stdout)
-    else:
-        return gzip.open(path, "rb")
-
-
-def parse_primary(repodata_dir):
-    """Parse primary.xml.{gz,zst} and return package metadata."""
-    path = find_repodata_file(repodata_dir, "primary")
-    if not path:
-        print("error: primary metadata not found in repomd.xml", file=sys.stderr)
-        sys.exit(1)
-
-    packages = {}
-    with open_compressed(path) as f:
-        tree = ET.parse(f)
-
-    for pkg in tree.getroot().findall(f"{{{RPM_NS}}}package"):
-        if pkg.get("type") != "rpm":
-            continue
-
-        name = pkg.findtext(f"{{{RPM_NS}}}name", "")
-        version_el = pkg.find(f"{{{RPM_NS}}}version")
-        ver = version_el.get("ver", "") if version_el is not None else ""
-        rel = version_el.get("rel", "") if version_el is not None else ""
-        arch = pkg.findtext(f"{{{RPM_NS}}}arch", "")
-
-        size_el = pkg.find(f"{{{RPM_NS}}}size")
-        size = int(size_el.get("package", "0")) if size_el is not None else 0
-
-        time_el = pkg.find(f"{{{RPM_NS}}}time")
-        build_time = int(time_el.get("build", "0")) if time_el is not None else 0
-
-        location_el = pkg.find(f"{{{RPM_NS}}}location")
-        filename = os.path.basename(location_el.get("href", "")) if location_el is not None else ""
-
-        key = f"{name}-{ver}-{rel}"
-        packages[key] = {
-            "name": name,
-            "version": ver,
-            "release": rel,
-            "arch": arch,
-            "summary": pkg.findtext(f"{{{RPM_NS}}}summary", ""),
-            "size": size,
-            "buildTime": build_time,
-            "rpmFilename": filename,
-            "changelog": [],
-        }
-
-    return packages
-
-
-def parse_other(repodata_dir, packages):
-    """Parse other.xml.gz and attach changelog entries to packages."""
-    path = find_repodata_file(repodata_dir, "other")
-    if not path:
-        return
-
-    with open_compressed(path) as f:
-        tree = ET.parse(f)
-
-    for pkg in tree.getroot().findall(f"{{{OTHER_NS}}}package"):
-        name = pkg.get("name", "")
-        version_el = pkg.find(f"{{{OTHER_NS}}}version")
-        ver = version_el.get("ver", "") if version_el is not None else ""
-        rel = version_el.get("rel", "") if version_el is not None else ""
-        key = f"{name}-{ver}-{rel}"
-
-        if key not in packages:
-            continue
-
-        for entry in pkg.findall(f"{{{OTHER_NS}}}changelog"):
-            packages[key]["changelog"].append({
-                "author": entry.get("author", ""),
-                "date": int(entry.get("date", "0")),
-                "text": (entry.text or "").strip(),
-            })
-
-
-def main():
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        "--repodata-dir",
-        required=True,
-        help="path to the repodata/ directory",
-    )
-    parser.add_argument(
-        "--output",
-        required=True,
-        help="path to write packages.json",
-    )
-    parser.add_argument(
-        "--base-url",
-        required=True,
-        help="public base URL for the repo (e.g. https://rpm.lair.cafe/fedora/43/x86_64)",
-    )
-    args = parser.parse_args()
-
-    packages = parse_primary(args.repodata_dir)
-    parse_other(args.repodata_dir, packages)
-
-    manifest = {
-        "generated": datetime.now(timezone.utc).isoformat(),
-        "baseUrl": args.base_url,
-        "packages": list(packages.values()),
-    }
-
-    with open(args.output, "w") as f:
-        json.dump(manifest, f, indent=2)
-
-    print(f"wrote {len(packages)} packages to {args.output}")
-
-
-if __name__ == "__main__":
-    main()

script/tp-smoke.sh

@@ -1,60 +0,0 @@
-#!/bin/env bash
-#
-# TP smoke test against a deployed neuron host.
-#
-# SSHes into the target host and runs `neuron --tp-smoke --tp-size N
-# --cuda-devices ...` directly — no HTTP API involved. The smoke
-# subcommand spawns N-1 worker subprocesses, joins them in an NCCL
-# communicator, runs one AllReduce(Sum) of `1u32` across every rank, and
-# verifies the observed sum equals world_size on every rank.
-#
-# This validates the lower-half of the TP stack (NCCL + IPC topology +
-# subprocess lifecycle) without touching model load, inference, or HTTP.
-# A failure here means the host cannot run any TP model and there is no
-# point debugging the higher layers.
-#
-# Usage:
-#   script/tp-smoke.sh [host] [tp_size] [cuda_devices]
-#
-# Defaults:
-#   host         = beast.hanzalova.internal  (only fleet host with 2 GPUs)
-#   tp_size      = 2
-#   cuda_devices = 0,1
-
-set -euo pipefail
-
-HOST="${1:-beast.hanzalova.internal}"
-TP_SIZE="${2:-2}"
-CUDA_DEVICES="${3:-0,1}"
-
-say() { printf '[%s] %s\n' "${HOST}" "$*" >&2; }
-die() { say "FAIL: $*"; exit 1; }
-
-say "running neuron --tp-smoke --tp-size ${TP_SIZE} --cuda-devices ${CUDA_DEVICES}"
-
-# Run as root via sudo because:
-#   - cuda contexts under a user account require either the nvidia
-#     uvm/peer devices to be world-readable or the user to be in a
-#     priviliged group (neither is true on stock fc43);
-#   - the installed binary lives at /usr/bin/neuron with no setuid;
-# Running through root is the simplest path that matches how
-# systemd-managed neuron sees the GPUs in production.
-#
-# The smoke command is read-only — it allocates a transient NCCL comm
-# and a 1u32 buffer per rank, then tears it all down.
-if ! ssh -o BatchMode=yes "${HOST}" \
-    sudo /usr/bin/neuron \
-        --tp-smoke \
-        --tp-size "${TP_SIZE}" \
-        --cuda-devices "${CUDA_DEVICES}" 2>&1 | tee /tmp/tp-smoke-"${HOST}".log
-then
-    die "tp-smoke exited non-zero (see /tmp/tp-smoke-${HOST}.log)"
-fi
-
-# Final stdout line is `status=ok` on success.
-if grep -q '^status=ok$' /tmp/tp-smoke-"${HOST}".log; then
-    say "PASS — NCCL handshake + AllReduce sanity check OK across ${TP_SIZE} ranks"
-    exit 0
-else
-    die "no status=ok line in output"
-fi

script/validate-neuron.sh

@@ -1,188 +0,0 @@
-#!/bin/env bash
-#
-# End-to-end smoke test for a deployed neuron.
-#
-# Confirms the daemon is reachable, loads a small public Qwen3 GGUF,
-# fires a reasoning probe at /v1/chat/completions, and prints the
-# answer. Used to validate the candle harness on a real GPU host
-# before trusting it for production traffic, and as a regression test
-# after pushing new neuron builds.
-#
-# Usage:
-#   script/validate-neuron.sh [host] [model_id] [quant] [tp_size]
-#
-# Defaults:
-#   host     = beast.hanzalova.internal
-#   model_id = unsloth/Qwen3-0.6B-GGUF  (official Qwen3-*-GGUF repos
-#              ship Q8_0 only; unsloth's mirror ships the full Q-spectrum
-#              including Q4_K_M)
-#   quant    = Q4_K_M  (empty = dense safetensors path)
-#   tp_size  = unset   (= 1 = single-GPU; pass 2 to drive the TP path)
-
-set -euo pipefail
-
-HOST="${1:-beast.hanzalova.internal}"
-MODEL_ID="${2:-unsloth/Qwen3-0.6B-GGUF}"
-# `${3-Q4_K_M}` (no colon) only uses the default when the arg is
-# UNSET — passing an explicit empty string drives the dense path.
-QUANT="${3-Q4_K_M}"
-# tp_size > 1 forces the dense path (TP requires safetensors) and adds
-# `tensor_parallel: N` to the load payload. The harness picks device
-# indices 0..N-1 by default; override by passing NEURON_DEVICES="0,1,..."
-# in the environment.
-TP_SIZE="${4-1}"
-PORT="${NEURON_PORT:-13131}"
-BASE="http://${HOST}:${PORT}"
-
-# Reasoning probe — concrete, low-temperature answer that small models
-# can still get right. "Paris" is a strong signal of basic competence
-# beyond gibberish.
-PROBE_PROMPT='What is the capital of Georgia (Caucasus)? Respond with the city name only, no punctuation.'
-EXPECT_SUBSTR='Tbilisi'
-# Qwen3 prepends <think>...</think> reasoning before the answer when the
-# chat template enables thinking mode, which eats most of a small token
-# budget. 256 leaves enough room for thinking + final answer.
-MAX_TOKENS=256
-
-# /models/load is synchronous — neuron blocks the response until the
-# hf-hub download + (GGUF parse or safetensors mmap) + tensor
-# materialisation is done. Small GGUF (0.6B-Q4_K_M, ~400 MB) is
-# typically a minute on a warm cache, several on a cold one. A
-# Qwen3.6-class dense model is ~54 GB and can easily take an hour to
-# download cold over a residential link, so default high. Override
-# with NEURON_LOAD_TIMEOUT=N (seconds) for smaller targets if you'd
-# rather fail fast.
-LOAD_TIMEOUT="${NEURON_LOAD_TIMEOUT:-3600}"
-INFER_TIMEOUT="${NEURON_INFER_TIMEOUT:-120}"
-
-# Status messages go to stderr so command substitutions like
-# `raw=$(run_probe)` capture only the function's intended return value
-# (an HTTP body), not the progress chatter.
-say() { printf '[%s] %s\n' "${HOST}" "$*" >&2; }
-die() { say "FAIL: $*"; exit 1; }
-
-probe_health() {
-    curl --silent --fail --max-time 5 "${BASE}/health" >/dev/null \
-        || die "neuron not reachable at ${BASE}/health"
-}
-
-list_loaded_ids() {
-    # The manifest is YAML and uses yq; HTTP responses are JSON and use
-    # jq directly. pip-yq parses input as YAML by default, which trips
-    # on JSON content that happens to look like YAML aliases (chatcmpl
-    # ids, escaped quotes inside `<think>...</think>` blocks, etc.).
-    curl --silent --fail "${BASE}/models" | jq -r '.[].id'
-}
-
-is_loaded() {
-    list_loaded_ids 2>/dev/null | grep -Fxq "${MODEL_ID}"
-}
-
-trigger_load() {
-    # Build the per-rank CUDA device list as a JSON array. Either
-    # honour NEURON_DEVICES (`0,1,2`) verbatim or default to
-    # `[0, 1, ..., tp_size - 1]`.
-    local devices_json
-    if [[ -n "${NEURON_DEVICES:-}" ]]; then
-        devices_json=$(jq -n -c --arg s "${NEURON_DEVICES}" \
-            '$s | split(",") | map(tonumber)')
-    else
-        devices_json=$(jq -n -c --argjson n "${TP_SIZE}" '[range(0; $n)]')
-    fi
-    say "POST /models/load ${MODEL_ID} (quant=${QUANT:-<dense>}, tp=${TP_SIZE}, devices=${devices_json})"
-    say "  (synchronous; may take a minute on first run while HF downloads)"
-    # Build the payload via jq so optional fields are omitted entirely
-    # when not in use. `tensor_parallel` is dropped when tp_size == 1;
-    # `quant` is dropped when empty. Both can coexist: tp_size > 1 +
-    # ISQ quant (q5k/q8_0/etc.) loads safetensors and quantizes the
-    # per-rank shard at load time. GGUF quants (Q4_K_M) are incompatible
-    # with TP — but the harness rejects that combination at load time
-    # rather than here.
-    local payload
-    local base
-    base=$(jq -n -c \
-        --arg id "${MODEL_ID}" \
-        --argjson devices "${devices_json}" \
-        '{model_id: $id, harness: "candle", devices: $devices}')
-    if [[ -n "${QUANT}" ]]; then
-        base=$(echo "${base}" | jq -c --arg q "${QUANT}" '. + {quant: $q}')
-    fi
-    if (( TP_SIZE > 1 )); then
-        base=$(echo "${base}" | jq -c --argjson tp "${TP_SIZE}" '. + {tensor_parallel: $tp}')
-    fi
-    payload="${base}"
-    # --write-out captures the response code on a separate line so we
-    # can surface a real diagnostic instead of relying on --fail.
-    local resp http_code body
-    resp=$(curl --silent --show-error --max-time "${LOAD_TIMEOUT}" \
-        --write-out '\n__HTTP__%{http_code}' \
-        -X POST "${BASE}/models/load" \
-        -H 'content-type: application/json' \
-        --data "${payload}") || die "curl /models/load failed: $?"
-    http_code=$(echo "${resp}" | grep -oP '(?<=__HTTP__)\d+$' | tail -1)
-    body=$(echo "${resp}" | sed '$ s/__HTTP__.*$//')
-    if [[ "${http_code}" != "200" ]]; then
-        die "load returned HTTP ${http_code}: ${body}"
-    fi
-    say "load returned ${http_code}: ${body}"
-}
-
-run_probe() {
-    say "POST /v1/chat/completions (probe: ${PROBE_PROMPT})"
-    local payload
-    payload=$(jq -n -c \
-        --arg model "${MODEL_ID}" \
-        --arg content "${PROBE_PROMPT}" \
-        --argjson tokens "${MAX_TOKENS}" \
-        '{
-            model: $model,
-            messages: [{role: "user", content: $content}],
-            temperature: 0.1,
-            max_tokens: $tokens
-        }')
-    local resp http_code body
-    resp=$(curl --silent --show-error --max-time "${INFER_TIMEOUT}" \
-        --write-out '\n__HTTP__%{http_code}' \
-        -X POST "${BASE}/v1/chat/completions" \
-        -H 'content-type: application/json' \
-        --data "${payload}") || die "curl /v1/chat/completions failed: $?"
-    http_code=$(echo "${resp}" | grep -oP '(?<=__HTTP__)\d+$' | tail -1)
-    body=$(echo "${resp}" | sed '$ s/__HTTP__.*$//')
-    if [[ "${http_code}" != "200" ]]; then
-        die "inference returned HTTP ${http_code}: ${body}"
-    fi
-    echo "${body}"
-}
-
-say "validating neuron at ${BASE}"
-probe_health
-say "/health OK"
-
-if is_loaded; then
-    say "${MODEL_ID} already loaded"
-else
-    trigger_load
-fi
-
-raw=$(run_probe)
-echo "---"
-# Dump the raw JSON. Don't pipe through `yq -r '.'` — yq's default
-# YAML output mode chokes on JSON strings that contain `<` (and the
-# `<think>` markers Qwen3 emits during reasoning are a perfect
-# example). The targeted `yq -r '.path'` calls below work fine
-# because jq's path filter mode bypasses the YAML re-emit.
-echo "${raw}"
-echo "---"
-
-content=$(echo "${raw}" | jq -r '.choices[0].message.content // empty')
-if [[ -z "${content}" ]]; then
-    die "no content in chat completion response"
-fi
-say "assistant said: ${content}"
-
-if echo "${content}" | grep -qiF "${EXPECT_SUBSTR}"; then
-    say "PASS — response contains expected substring '${EXPECT_SUBSTR}'"
-    exit 0
-else
-    die "response did not contain '${EXPECT_SUBSTR}'"
-fi