## Why
`codex-http-client` is the intended owner of `reqwest`, while direct first-party
dependencies are tracked as migration debt.
## What changed
- Build app-server test HTTP clients through `HttpClientBuilder`.
- Use `http` and `url` types directly where only protocol types are needed.
- Remove `reqwest` from `codex-app-server` and its temporary dependency-policy
exception.
GitOrigin-RevId: ff9f14a54bc20ec1ea39050bbe08c381ee376119
## What changed
- Build URL-based gRPC code-mode connections with `HttpClientFactory` so they support the application's outbound proxy and custom CA configuration.
- Accept `http` and `https` origins while rejecting endpoints with unsupported schemes, paths, queries, or fragments.
- Preserve custom tonic channel injection and gRPC frame-size limits through the new transport adapter.
GitOrigin-RevId: 142f0b572b3ab0154e8fe860cb304752a9af5784
## Why
Ollama requests need to honor Codex's configured outbound proxy policy and custom CA handling.
## What changed
- Replace Ollama's direct `reqwest` client with a route-aware client created by `codex-http-client`.
- Preserve the five-second connection timeout and legacy system-root fallback for default-routed requests.
- Reuse one Ollama client for connectivity, version, model discovery, and model-pull checks.
- Surface HTTP transport initialization errors instead of replacing them with the generic Ollama connection error.
## Testing
- Cover system-proxy routing and invalid `CODEX_CA_CERTIFICATE` and `SSL_CERT_FILE` values under both outbound proxy policies.
- Verify that version and model checks reuse the existing Ollama client.
GitOrigin-RevId: c7cc36845a9bceb57ce5524b9e1b3cbe317897a3
## Why
`codex-http-client` is the intended owner of `reqwest`, while direct first-party
dependencies are tracked as migration debt.
## What changed
- Use `http` header and status types directly in core code and tests.
- Build the MCP test readiness client through `HttpClientBuilder`.
- Remove `reqwest` from `codex-core` and its temporary dependency-policy
exception.
GitOrigin-RevId: 8d5c7c86256294a7bb8aa1ae10cc5bea4cb1fc56
## What changed
Classify `codex-responses-api-proxy` as an intentional `reqwest` exception in
`deny.toml` instead of a temporary migration exception. The proxy independently
owns its blocking upstream HTTP transport, and the allowed wrapper set remains
unchanged.
GitOrigin-RevId: 3db3281a13d67c9514051ea0009013ce50c439e6
## What changed
- Replace direct `reqwest` error types in `codex-protocol` with
`codex_http_client::HttpError`.
- Build the response-stream error test through
`codex_http_client::HttpResponse`.
- Remove `codex-protocol` from the direct `reqwest` dependency allowlist.
## Testing
- Update the response-stream failure test to cover status and URL propagation
through the shared HTTP response wrapper.
GitOrigin-RevId: 7abcbbe55f994acb13cccefef806a53c7008acde
## Why
Built-in pet downloads used a standalone blocking client, so CDN redirects did
not use Codex's configured route handling.
## What changed
- Download pet spritesheets asynchronously with a reusable
`RouteAwareClientPool`.
- Keep cache validation, asset installation, and pet decoding off the async
runtime while sharing one asset-and-load path across startup, previews, and
selection.
- Preserve the download size limit while consuming streamed response chunks,
and remove the TUI's direct `reqwest` dependency.
## Testing
Add coverage for oversized response chunks, cached built-in assets, pet loads
without an existing Tokio runtime, and stale preview and selection completions.
GitOrigin-RevId: 725e76f3ddb7e84b7212769892f28dc0add15741
## What changed
- Upgrade `ratatui`, `ratatui-macros`, `crossterm`, and `ansi-to-tui`, and adapt the TUI to their updated rendering, backend, color-conversion, and cell APIs.
- Use Ratatui's cell-width and continuation-cell metadata when mapping OSC 8 hyperlinks so links remain aligned across wrapped wide glyphs and halfwidth characters with dakuten.
- Preserve explicit hyperlinks in the sign-in success screen and empty MCP state without embedding escape sequences in the text passed to Ratatui.
## Testing
- Add regression coverage for hyperlink placement across wide glyphs and halfwidth dakuten, hyperlink preservation in onboarding and MCP output, and display-width handling.
GitOrigin-RevId: 8460873e5a266923acd0417bc46264845eab0134
## What changed
- Require callers to provide an HTTP client for MCP OAuth discovery and login, removing the separate direct `reqwest` path.
- Use the shared `http` and `url` types throughout the MCP client and drop its direct `reqwest` dependency.
- Preserve configured MCP headers when routing OAuth discovery through the provided client.
## Testing
- Add coverage that routed OAuth discovery forwards configured headers.
GitOrigin-RevId: 1345f56bd794626533133447597a5908e57b9b48
## What changed
- Store a request-logging-disabled `RouteAwareClientPool` in session services and use it for file creation, blob upload, and finalization requests.
- Preserve the existing system-root fallback for transport-default proxy routes, and emit a warning event when that fallback is used.
- Remove the direct `reqwest` dependency from `codex-api` now that uploads use the shared HTTP abstraction.
## Testing
- Add coverage for completing multiple uploads through a shared client pool.
GitOrigin-RevId: 01842415cad2d349a6bd3869abb3332e8110ebce
## What changed
- Update the `crossterm` Cargo patch to use the OpenAI OSS fork while retaining the existing revision.
- Refresh the Cargo and Bazel lockfiles and the `cargo-deny` Git-source allowlist for the new repository URL.
GitOrigin-RevId: 96c70abca95b9c5c8f19d1bc2d30976c5797ba8c
## What changed
- Rename `ReqwestHttpClient` to `RouteAwareHttpClient` to reflect that delegated HTTP uses Codex's shared route-aware transport.
- Use `codex_http_client` response and error types plus transport-neutral `http` and `url` types, removing the exec server's direct `reqwest` dependency.
## Testing
- Cover fragment stripping and Unicode hostname normalization for delegated HTTP requests.
GitOrigin-RevId: 8b0fc60a76004feb57198bfb4afb1371c9ceb1bd
## What changed
- Use the configured route-aware HTTP client pool for LM Studio server requests.
- Add connection-timeout support to `HttpClientBuilder` and route-aware pools, and keep LM Studio's five-second limit scoped to connection establishment.
- Verify that LM Studio accepts a response that arrives after the connection timeout has elapsed once the connection is established.
GitOrigin-RevId: c4300f4b5d37c4418822783ab09cb50d506ee423
## What changed
- Send the streaming SSE request-body drain test through `HttpClientFactory`.
- Replace the test-support crate's direct `reqwest` dependency with
`codex-http-client`.
- Remove `core_test_support` from the temporary direct-`reqwest` exceptions.
GitOrigin-RevId: 16ea4309d0b575592c2e59991eb6dce18d9467ed
## Why
`codex-http-client` is the intended owner of direct `reqwest` usage.
## What changed
- Build Codex's default and route-aware clients with `HttpClientBuilder`, and return `HttpClient` directly to API, model discovery, auth, remote control, skills, and extension callers.
- Preserve custom CA, proxy, Cloudflare cookie, sandbox, and request-logging policies while removing `codex-login`'s direct `reqwest` dependency.
- Use shared HTTP types for auth headers, status codes, transport errors, and login-server tests.
## Testing
- Add a Linux integration test verifying that a regular Responses API turn traverses the configured system proxy.
GitOrigin-RevId: 714695fb80762d2083e2f7a6414183e2b3b63854
## Why
`codex-http-client` is the intended owner of direct `reqwest` usage.
## What changed
- Route agent identity registration, task registration, and JWKS requests through `HttpClient`.
- Preserve retry classification using `HttpError` and `http::StatusCode`.
- Remove `codex-agent-identity` from the temporary direct-`reqwest` dependency exceptions.
GitOrigin-RevId: 7445c9f2521e6d8ef0969a1483c81f797bf91316
## Why
Remote plugin requests did not use Codex's effective outbound proxy policy, so
they could bypass configured system proxy and PAC routing.
## What changed
- Route remote plugin catalog, mutation, sharing, upload, and bundle download
requests through the configured route-aware HTTP client.
- Select routes using the complete request URL, including encoded query
parameters and backend-provided signed upload or download URLs.
- Preserve standard Codex headers and suppress diagnostics for URLs or headers
that may contain credentials.
## Testing
Add coverage for route selection of catalog queries, workspace plugin uploads,
and backend-provided bundle download URLs.
GitOrigin-RevId: 106936659e21decf145b6ab4d4be84992e386861
## Why
The PID-managed daemon updater downloaded the standalone installer directly,
bypassing Codex's configured outbound proxy policy.
## What changed
- Build the updater's HTTP client from the effective Codex configuration so
`features.respect_system_proxy` also applies to installer downloads.
- Use the route-aware client pool for the installer request.
- Warn and fall back to the default `reqwest` proxy behavior when configuration
cannot be loaded, allowing updates to continue.
## Testing
Added tests for proxy-policy selection, configuration-load fallback, exact
installer URL usage, byte preservation, and non-success HTTP responses.
GitOrigin-RevId: 559668eb40314d43afa6512da66e59e32cc1b93c
## What changed
- Build a route-aware API client from the cloud backend's configured HTTP
factory and reuse it for environment listing and autodetection.
- Replace direct `reqwest` environment requests with a small injectable HTTP
boundary while preserving status, content-type, body, and header handling.
- Centralize asynchronous environment-list loading around the initialized
backend context.
## Testing
- Add coverage for production header forwarding and response decoding.
- Verify repository-specific lookup, global fallback, endpoint selection,
deduplication, and merged environment metadata with a fake HTTP client.
GitOrigin-RevId: 2e6812015ec3eb01773184541a1fad135ed53edb
## Why
Backend-backed features need to use the same outbound routing configuration as the rest of Codex.
## What changed
- Build the backend client on a route-aware client pool supplied by `HttpClientFactory`.
- Pass the configured factory through app-server account requests, cloud config loading, cloud tasks, and memory rate-limit checks.
- Preserve task query encoding, authentication headers, JSON request bodies, and ChatGPT cookie handling during the migration.
## Testing
- Add backend-client tests for proxy-policy propagation, task query encoding, bearer authentication, and JSON request bodies.
GitOrigin-RevId: c17d162e0dce9cec758df7cdeecf982207c6512b
## Why
The `codex-http-client` migration now has a shared implementation and
several migrated request paths, but nothing prevents a new crate from
adding another direct `reqwest` dependency while the remaining call
sites are being converted. The dependency graph should both enforce the
direction of travel and make the remaining scope visible.
This PR adds that ratchet on top of #31363. It does not claim the
migration is complete: the allowlist deliberately records all 18
first-party crates that still depend on `reqwest` directly.
## What changed
- Ban `reqwest` with cargo-deny unless its immediate parent is an
explicitly listed wrapper.
- Identify `codex-http-client` as the intended owner.
- Record the 18 current first-party direct dependents as temporary
migration exceptions.
- Separately allow six third-party integrations that own their `reqwest`
dependency: `oauth2`, `opentelemetry-http`, `opentelemetry-otlp`,
`rmcp`, `sentry`, and `webrtc-sys-build`.
- Cover both `reqwest` 0.12 and 0.13 with the same package-level rule.
## Migration rule
A new first-party crate cannot add `reqwest`. When a listed crate
finishes migrating, its direct Cargo dependency and its wrapper entry
should be removed in the same PR, so the first-party list can only
shrink.
## Review guide
The entire change is the new `reqwest` entry in `codex-rs/deny.toml`:
1. `codex-http-client` is the permanent intended wrapper.
2. The next 18 entries are the first-party migration backlog.
3. The final six entries are separately documented third-party parents
required by cargo-deny graph semantics.
## Validation
- `cargo deny check bans --hide-inclusion-graph` (`bans ok`; existing
duplicate-version warnings remain warnings)
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/31431).
* #31837
* #31828
* #31825
* #31821
* #31637
* __->__ #31431
## Why
The `cargo-deny` job on `main` began failing after
[RUSTSEC-2026-0194](https://rustsec.org/advisories/RUSTSEC-2026-0194)
and
[RUSTSEC-2026-0195](https://rustsec.org/advisories/RUSTSEC-2026-0195)
flagged the workspace `quick-xml 0.38.4`. Both denial-of-service issues
are fixed in `quick-xml 0.41.0`.
A `quick-xml 0.39.4` copy must temporarily remain because the latest
`plist` and `wayland-scanner` releases have not adopted 0.41 yet.
Neither retained path accepts attacker-controlled XML at runtime:
`plist` does not exercise the affected APIs, and `wayland-scanner`
parses trusted protocol definitions at build time. Compatible upstream
bumps are already open in
[rust-plist#191](https://github.com/ebarnard/rust-plist/pull/191) and
[wayland-rs#938](https://github.com/Smithay/wayland-rs/pull/938).
## What changed
- Upgrade the workspace `quick-xml` dependency used by `codex-protocol`
to 0.41.0.
- Refresh `Cargo.lock` and `MODULE.bazel.lock`; this also updates
`plist` to 1.9.0 and `wayland-scanner` to 0.31.10.
- Add synchronized, temporary `cargo-deny` and `cargo-audit` exceptions
for the trusted `quick-xml 0.39.4` paths, with both upstream releases
recorded as the removal condition.
## Testing
- `cargo deny check`
- `just test -p codex-protocol` (238 tests)
- `just bazel-lock-check`
## Why
First-party async traits should expose their `Send` contracts explicitly
without requiring `async_trait`. This completes the migration pattern
established in #27303 and #27304.
## What changed
- Replaced the remaining first-party `async_trait` traits with native
return-position `impl Future + Send` where statically dispatched and
explicit boxed `Send` futures where object safety is required.
- Kept implementations behavior-preserving, outlining existing async
bodies into inherent methods where that keeps the diff reviewable.
- Removed all direct first-party `async-trait` dependencies and the
workspace dependency declaration.
- Added a cargo-deny policy that permits `async-trait` only through the
remaining transitive wrapper crates.
- Updated `rand` from 0.8.5 to 0.8.6 to resolve RUSTSEC-2026-0097 and
keep the full cargo-deny check passing.
## Validation
- `just test -p codex-exec-server`: 216 passed, 2 skipped.
- `just test -p codex-model-provider`: 39 passed.
- `just test -p codex-core` and `just test`: changed tests passed;
remaining failures are environment-sensitive suites unrelated to this
migration.
- `cargo deny check`
- `just fix`
- `just fmt`
- `cargo shear`
- `just bazel-lock-check`
## Summary
- ignore RUSTSEC-2026-0173 in cargo-deny and cargo-audit config
- document that proc-macro-error2 is pulled in transitively via
i18n-embed-fl/age/codex-secrets
- leave the ignore temporary until codex-secrets moves off age or age
drops i18n-embed-fl
## Validation
- just fmt
- cargo deny check --hide-inclusion-graph
## Why
`CODEX_RS_SSE_FIXTURE` let integration-style CLI, exec, and TUI tests
bypass the normal Responses transport by reading SSE from local files.
That kept test-only behavior wired through production client code. The
affected tests can stay hermetic by using the existing
`core_test_support::responses` mock server and passing `openai_base_url`
instead.
## What Changed
- Removed the `CODEX_RS_SSE_FIXTURE` flag,
`codex_api::stream_from_fixture`, the `env-flags` dependency, and the
checked-in SSE fixture files.
- Repointed the affected core, exec, and TUI tests at `MockServer` with
the existing SSE event constructors.
- Removed the Bazel test data plumbing for the deleted fixtures and
refreshed cargo/Bazel lock state.
## Verification
- `cargo build -p codex-cli`
- `cargo test -p codex-api`
- `cargo test -p codex-core --test all responses_api_stream_cli`
- `cargo test -p codex-core --test all
integration_creates_and_checks_session_file`
- `cargo test -p codex-exec --test all ephemeral`
- `cargo test -p codex-exec --test all resume`
- `cargo test -p codex-tui --test all
resume_startup_does_not_consume_model_availability_nux_count`
- `just bazel-lock-update`
- `just bazel-lock-check`
- `just fix -p codex-api -p codex-core -p codex-exec -p codex-tui`
- `git diff --check`
## Summary
- Fix marketplace-add local path detection on Windows by using
`Path::is_absolute()`.
- Make marketplace-add local-source tests parse/write TOML through the
same helpers instead of raw string matching.
- Update `rand` 0.9.x to 0.9.3 and document the remaining audited `rand`
0.8.5 advisory exception.
- Refresh `MODULE.bazel.lock` after the Cargo.lock update.
## Why
Latest `main` had two independent CI blockers: marketplace-add tests
were not portable to Windows path/TOML escaping, and cargo-deny still
reported `RUSTSEC-2026-0097` after the recent rustls-webpki fix.
## Validation
- `cargo test -p codex-core marketplace_add -- --nocapture`
- `cargo deny --all-features check`
- `just bazel-lock-check`
- `just fix -p codex-core`
- `just fmt`
- `git diff --check`
## Summary
- Pin Rust git patch dependencies to immutable revisions and make
cargo-deny reject unknown git and registry sources unless explicitly
allowlisted.
- Add checked-in SHA-256 coverage for the current rusty_v8 release
assets, wire those hashes into Bazel, and verify CI override downloads
before use.
- Add rusty_v8 MODULE.bazel update/check tooling plus a Bazel CI guard
so future V8 bumps cannot drift from the checked-in checksum manifest.
- Pin release/lint cargo installs and all external GitHub Actions refs
to immutable inputs.
## Future V8 bump flow
Run these after updating the resolved `v8` crate version and checksum
manifest:
```bash
python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
python3 .github/scripts/rusty_v8_bazel.py check-module-bazel
```
The update command rewrites the matching `rusty_v8_<crate_version>`
`http_file` SHA-256 values in `MODULE.bazel` from
`third_party/v8/rusty_v8_<crate_version>.sha256`. The check command is
also wired into Bazel CI to block drift.
## Notes
- This intentionally excludes RustSec dependency upgrades and
bubblewrap-related changes per request.
- The branch was rebased onto the latest origin/main before opening the
PR.
## Validation
- cargo fetch --locked
- cargo deny check advisories
- cargo deny check
- cargo deny check sources
- python3 .github/scripts/rusty_v8_bazel.py check-module-bazel
- python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
- python3 -m unittest discover -s .github/scripts -p
'test_rusty_v8_bazel.py'
- python3 -m py_compile .github/scripts/rusty_v8_bazel.py
.github/scripts/rusty_v8_module_bazel.py
.github/scripts/test_rusty_v8_bazel.py
- repo-wide GitHub Actions `uses:` audit: all external action refs are
pinned to 40-character SHAs
- yq eval on touched workflows and local actions
- git diff --check
- just bazel-lock-check
## Hash verification
- Confirmed `MODULE.bazel` hashes match
`third_party/v8/rusty_v8_146_4_0.sha256`.
- Confirmed GitHub release asset digests for denoland/rusty_v8
`v146.4.0` and openai/codex `rusty-v8-v146.4.0` match the checked-in
hashes.
- Streamed and SHA-256 hashed all 10 `MODULE.bazel` rusty_v8 asset URLs
locally; every downloaded byte stream matched both `MODULE.bazel` and
the checked-in manifest.
## Pin verification
- Confirmed signing-action pins match the peeled commits for their tag
comments: `sigstore/cosign-installer@v3.7.0`, `azure/login@v2`, and
`azure/trusted-signing-action@v0`.
- Pinned the remaining tag-based action refs in Bazel CI/setup:
`actions/setup-node@v6`, `facebook/install-dotslash@v2`,
`bazelbuild/setup-bazelisk@v3`, and `actions/cache/restore@v5`.
- Normalized all `bazelbuild/setup-bazelisk@v3` refs to the peeled
commit behind the annotated tag.
- Audited Cargo git dependencies: every manifest git dependency uses
`rev` only, every `Cargo.lock` git source has `?rev=<sha>#<same-sha>`,
and `cargo deny check sources` passes with `required-git-spec = "rev"`.
- Shallow-fetched each distinct git dependency repo at its pinned SHA
and verified Git reports each object as a commit.
Adds the `[realtime].transport = "webrtc"` TUI media path using a new
`codex-realtime-webrtc` crate, while leaving app-server as the
signaling/event source.\n\nLocal checks: fmt, diff-check, dependency
tree only; test signal should come from CI.
---------
Co-authored-by: Codex <noreply@openai.com>
CHAINED PR - note that base is eternal/hooks-pretooluse-bash, not main
-- so the following PR should be first
Matching post-tool hook to the pre-tool functionality here:
https://github.com/openai/codex/pull/15211
So, PreToolUse calls for plain shell calls, allows blocking. This
PostToolUse call runs after the command executed
example run:
```
› as a test, run in parallel the following commands:
- echo 'one'
- echo '[block-pre-tool-use]'
- echo '[block-post-tool-use]'
⚠ MCP startup incomplete (failed: notion, linear)
• Cruising through those three commands in parallel now, and I’ll share the exact outputs right after
they land.
• Running PreToolUse hook: checking the observatory runes
• Running PreToolUse hook: checking the observatory runes
• Running PreToolUse hook: checking the observatory runes
PreToolUse hook (blocked)
warning: wizard-tower PreToolUse demo blocked a Bash command on purpose.
feedback: PreToolUse demo blocked the command. Remove [block-pre-tool-use] to continue.
PreToolUse hook (completed)
warning: wizard-tower PreToolUse demo inspected Bash: echo 'one'
PreToolUse hook (completed)
warning: wizard-tower PreToolUse demo inspected Bash: echo '[block-post-tool-use]'
• Ran echo '[block-post-tool-use]'
└ [block-post-tool-use]
• Ran echo 'one'
└ one
• Running PostToolUse hook: reading the observatory aftermath
• Running PostToolUse hook: reading the observatory aftermath
PostToolUse hook (blocked)
warning: wizard-tower PostToolUse demo blocked the Bash follow-through on purpose.
feedback: PostToolUse demo blocked the result after execution. Remove [block-post-tool-use] to
continue.
PostToolUse hook (completed)
warning: wizard-tower PostToolUse demo inspected Bash: echo 'one'
hook context: PostToolUse demo saw the Bash result. Response preview: one
──────────────────────────────────────────────────────────────────────────────────────────────────────
• Ran them in parallel. Little wave report:
- echo 'one' completed and returned one.
- echo '[block-pre-tool-use]' was blocked before execution by the PreToolUse hook.
- echo '[block-post-tool-use]' ran, but its result was blocked afterward by the PostToolUse hook.
The hook messages were:
- PreToolUse demo blocked the command. Remove [block-pre-tool-use] to continue.
- PostToolUse demo blocked the result after execution. Remove [block-post-tool-use] to continue.
› for the blocked messages (correctly blocked in this test) did the tool output land back into
context?
• Yeah, from this run:
- PreToolUse block: the command itself did not execute, so no command output landed in context. Only
the block message did.
- PostToolUse block: the command did execute, but the actual stdout did not come back into context.
Only the post-tool block message did.
So the blocked notifications landed in context, but the blocked command payloads themselves did not.
Nice clean guardrail, aloha.
```
- emit a typed `thread/realtime/transcriptUpdated` notification from
live realtime transcript deltas
- expose that notification as flat `threadId`, `role`, and `text` fields
instead of a nested transcript array
- continue forwarding raw `handoff_request` items on
`thread/realtime/itemAdded`, including the accumulated
`active_transcript`
- update app-server docs, tests, and generated protocol schema artifacts
to match the delta-based payloads
---------
Co-authored-by: Codex <noreply@openai.com>
This PR add an URI-based system to reference agents within a tree. This
comes from a sync between research and engineering.
The main agent (the one manually spawned by a user) is always called
`/root`. Any sub-agent spawned by it will be `/root/agent_1` for example
where `agent_1` is chosen by the model.
Any agent can contact any agents using the path.
Paths can be used either in absolute or relative to the calling agents
Resume is not supported for now on this new path
## Summary
Adds syntax highlighting to the TUI for fenced code blocks in markdown
responses and file diffs, plus a `/theme` command with live preview and
persistent theme selection. Uses syntect (~250 grammars, 32 bundled
themes, ~1 MB binary cost) — the same engine behind `bat`, `delta`, and
`xi-editor`. Includes guardrails for large inputs, graceful fallback to
plain text, and SSH-aware clipboard integration for the `/copy` command.
<img width="1554" height="1014" alt="image"
src="https://github.com/user-attachments/assets/38737a79-8717-4715-b857-94cf1ba59b85"
/>
<img width="2354" height="1374" alt="image"
src="https://github.com/user-attachments/assets/25d30a00-c487-4af8-9cb6-63b0695a4be7"
/>
## Problem
Code blocks in the TUI (markdown responses and file diffs) render
without syntax highlighting, making it hard to scan code at a glance.
Users also have no way to pick a color theme that matches their terminal
aesthetic.
## Mental model
The highlighting system has three layers:
1. **Syntax engine** (`render::highlight`) -- a thin wrapper around
syntect + two-face. It owns a process-global `SyntaxSet` (~250 grammars)
and a `RwLock<Theme>` that can be swapped at runtime. All public entry
points accept `(code, lang)` and return ratatui `Span`/`Line` vectors or
`None` when the language is unrecognized or the input exceeds safety
guardrails.
2. **Rendering consumers** -- `markdown_render` feeds fenced code blocks
through the engine; `diff_render` highlights Add/Delete content as a
whole file and Update hunks per-hunk (preserving parser state across
hunk lines). Both callers fall back to plain unstyled text when the
engine returns `None`.
3. **Theme lifecycle** -- at startup the config's `tui.theme` is
resolved to a syntect `Theme` via `set_theme_override`. At runtime the
`/theme` picker calls `set_syntax_theme` to swap themes live; on cancel
it restores the snapshot taken at open. On confirm it persists `[tui]
theme = "..."` to config.toml.
## Non-goals
- Inline diff highlighting (word-level change detection within a line).
- Semantic / LSP-backed highlighting.
- Theme authoring tooling; users supply standard `.tmTheme` files.
## Tradeoffs
| Decision | Upside | Downside |
| ------------------------------------------------ |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
-----------------------------------------------------------------------------------------------------------------------
|
| syntect over tree-sitter / arborium | ~1 MB binary increase for ~250
grammars + 32 themes; battle-tested crate powering widely-used tools
(`bat`, `delta`, `xi-editor`). tree-sitter would add ~12 MB for 20-30
languages or ~35 MB for full coverage. | Regex-based; less structurally
accurate than tree-sitter for some languages (e.g. language injections
like JS-in-HTML). |
| Global `RwLock<Theme>` | Enables live `/theme` preview without
threading Theme through every call site | Lock contention risk
(mitigated: reads vastly outnumber writes, single UI thread) |
| Skip background / italic / underline from themes | Terminal BG
preserved, avoids ugly rendering on some themes | Themes that rely on
these properties lose fidelity |
| Guardrails: 512 KB / 10k lines | Prevents pathological stalls on huge
diffs or pastes | Very large files render without color |
## Architecture
```
config.toml ─[tui.theme]─> set_theme_override() ─> THEME (RwLock)
│
┌───────────────────────────────────────────┘
│
markdown_render ─── highlight_code_to_lines(code, lang) ─> Vec<Line>
diff_render ─── highlight_code_to_styled_spans(code, lang) ─> Option<Vec<Vec<Span>>>
│
│ (None ⇒ plain text fallback)
│
/theme picker ─── set_syntax_theme(theme) // live preview swap
─── current_syntax_theme() // snapshot for cancel
─── resolve_theme_by_name(name) // lookup by kebab-case
```
Key files:
- `tui/src/render/highlight.rs` -- engine, theme management, guardrails
- `tui/src/diff_render.rs` -- syntax-aware diff line wrapping
- `tui/src/theme_picker.rs` -- `/theme` command builder
- `tui/src/bottom_pane/list_selection_view.rs` -- side content panel,
callbacks
- `core/src/config/types.rs` -- `Tui::theme` field
- `core/src/config/edit.rs` -- `syntax_theme_edit()` helper
## Observability
- `tracing::warn` when a configured theme name cannot be resolved.
- `Config::startup_warnings` surfaces the same message as a TUI banner.
- `tracing::error` when persisting theme selection fails.
## Tests
- Unit tests in `highlight.rs`: language coverage, fallback behavior,
CRLF stripping, style conversion, guardrail enforcement, theme name
mapping exhaustiveness.
- Unit tests in `diff_render.rs`: snapshot gallery at multiple terminal
sizes (80x24, 94x35, 120x40), syntax-highlighted wrapping, large-diff
guardrail, rename-to-different-extension highlighting, parser state
preservation across hunk lines.
- Unit tests in `theme_picker.rs`: preview rendering (wide + narrow),
dim overlay on deletions, subtitle truncation, cancel-restore, fallback
for unavailable configured theme.
- Unit tests in `list_selection_view.rs`: side layout geometry, stacked
fallback, buffer clearing, cancel/selection-changed callbacks.
- Integration test in `lib.rs`: theme warning uses the final
(post-resume) config.
## Cargo Deny: Unmaintained Dependency Exceptions
This PR adds two `cargo deny` advisory exceptions for transitive
dependencies pulled in by `syntect v5.3.0`:
| Advisory | Crate | Status |
|----------|-------|--------|
| RUSTSEC-2024-0320 | `yaml-rust` | Unmaintained (maintainer
unreachable) |
| RUSTSEC-2025-0141 | `bincode` | Unmaintained (development ceased;
v1.3.3 considered complete) |
**Why this is safe in our usage:**
- Neither advisory describes a known security vulnerability. Both are
"unmaintained" notices only.
- `bincode` is used by syntect to deserialize pre-compiled syntax sets.
Again, these are **static vendored artifacts** baked into the binary at
build time. No user-supplied bincode data is ever deserialized. - Attack
surface is zero for both crates; exploitation would require a
supply-chain compromise of our own build artifacts.
- These exceptions can be removed when syntect migrates to `yaml-rust2`
and drops `bincode`, or when alternative crates are available upstream.
This add a new crate, `codex-network-proxy`, a local network proxy
service used by Codex to enforce fine-grained network policy (domain
allow/deny) and to surface blocked network events for interactive
approvals.
- New crate: `codex-rs/network-proxy/` (`codex-network-proxy` binary +
library)
- Core capabilities:
- HTTP proxy support (including CONNECT tunneling)
- SOCKS5 proxy support (in the later PR)
- policy evaluation (allowed/denied domain lists; denylist wins;
wildcard support)
- small admin API for polling/reload/mode changes
- optional MITM support for HTTPS CONNECT to enforce “limited mode”
method restrictions (later PR)
Will follow up integration with codex in subsequent PRs.
## Testing
- `cd codex-rs && cargo build -p codex-network-proxy`
- `cd codex-rs && cargo run -p codex-network-proxy -- proxy`
See https://rustsec.org/advisories/RUSTSEC-2026-0002.
Though our `ratatui` fork has a transitive dep on an older version of
the `lru` crate, so to get CI green ASAP, this PR also adds an exception
to `deny.toml` for `RUSTSEC-2026-0002`, but hopefully this will be
short-lived.
