# Overview
MCP refreshes were rebuilding active threads from fresh disk-backed
config only, which dropped thread-start session overlays such as
app-injected MCP servers. This keeps refreshes current with disk config
while preserving the thread-local config that only the active thread
knows about.
# Changes
- Rebuild refreshed config per active thread using that thread's current
`cwd`, rather than fanning out one app-server config to every thread.
- Preserve each thread's `SessionFlags` layer while replacing reloadable
config layers with freshly loaded config, then derive the MCP refresh
payload from the rebuilt result.
- Move MCP refresh orchestration into app-server so manual refreshes
fail loudly while background refreshes remain best-effort, and route
plugin-triggered refreshes through the same per-thread reload path.
- Add regression coverage for session overlays, fresh project config,
plugin-derived MCP config, current requirements, and strict vs
best-effort refresh behavior.
# Verification
- Passed focused Rust coverage for the thread-config rebuild behavior
and deferred MCP refresh flow, plus `cargo test -p codex-app-server
--lib`.
- Verified end to end in the Codex dev app against the locally built
CLI: registered an MCP via thread config, verified that it could be used
successfully before refresh, manually triggered MCP refresh, and
verified that it continued to be available afterward.
## Why
Codex currently accepts dynamic tool names and namespaces that the
upstream Responses function-tool path does not actually support. In
practice, that means app-server can register a dynamic tool successfully
and only discover later that the LLM-facing tool contract will reject or
mishandle it.
This PR tightens the app-server-side dynamic tool contract to match the
Responses API before we stack dynamic tool hook support on top of it.
## What changed
- validate dynamic tool `name` against the Responses function-tool
identifier contract: `^[a-zA-Z0-9_-]+$`, length `1..128`
- validate dynamic tool `namespace` the same way, with the Responses
namespace length limit `1..64`
- reject namespaces that collide with the always-reserved Responses
runtime namespaces such as `functions`, `multi_tool_use`, `file_search`,
`web`, `browser`, `image_gen`, `computer`, `container`, `terminal`,
`python`, `python_user_visible`, `api_tool`, `tool_search`, and
`submodel_delegator`
- escape invalid identifiers in error messages so control characters do
not spill raw into logs or client-visible error text
- document the tightened dynamic tool identifier contract in
`codex-rs/app-server/README.md`
- add both unit coverage for the validator and an app-server integration
test that rejects a `thread/start` request with Responses-incompatible
dynamic tool identifiers
## Verification
- `cargo test -p codex-app-server validate_dynamic_tools_`
- `cargo test -p codex-app-server --test all
thread_start_rejects_dynamic_tools_not_supported_by_responses`
Extends `plugin/share/save` to accept optional discoverability and
shareTargets while uploading plugin contents, and adds
`plugin/share/updateTargets` for share-only target updates without
re-uploading.
## Summary
- make `thread_source` an explicit optional thread-level field on
`thread/start`, `thread/fork`, and returned thread payloads
- persist `thread_source` in rollout/session metadata so resumed live
threads retain the original value
- replace the old best-effort `session_source` -> `thread_source`
mapping with an explicit caller-supplied analytics classification
## Why
Before this change, analytics `thread_source` was populated by a
best-effort mapping from `session_source`. `session_source` describes
the runtime/client surface, not the actual thread-level origin, so that
projection was not accurate enough to distinguish cases such as `user`,
`subagent`, `memory_consolidation`, and future thread origins reliably.
Making `thread_source` explicit keeps one thread-level analytics field
while letting callers provide the real classification directly instead
of recovering it indirectly from `session_source`.
## Impact
For new analytics events, `thread_source` now reflects the explicit
thread-level classification supplied by the caller rather than an
inferred value derived from `session_source`. Existing protocol fields
remain optional; callers that omit `threadSource` now produce `null`
instead of a best-effort inferred value.
## Validation
- `just write-app-server-schema`
- `cargo test -p codex-analytics -p codex-core -p
codex-app-server-protocol --no-run`
- `cargo test -p codex-app-server-protocol
generated_ts_optional_nullable_fields_only_in_params`
- `cargo test -p codex-analytics
thread_initialized_event_serializes_expected_shape`
- `cargo test -p codex-core
resume_stopped_thread_from_rollout_preserves_thread_source`
## Summary
- Add plugin manifest keywords to core plugin marketplace/detail models
- Expose keywords on app-server v2 PluginSummary and generated
schema/types
- Populate keywords in plugin/list and plugin/read responses for local
plugins
Depends on https://github.com/openai/openai/pull/891087
## Validation
- just fmt
- just write-app-server-schema
- cargo test -p codex-app-server-protocol
- cargo test -p codex-core-plugins
- cargo test -p codex-app-server
plugin_list_keeps_valid_marketplaces_when_another_marketplace_fails_to_load
- cargo test -p codex-app-server
plugin_read_returns_plugin_details_with_bundle_contents
## Why
`skills/list` is already exposed through app-server v2 and covered by
the app-server test suite. Keeping the separate core `Op::ListSkills`
path leaves a duplicate legacy protocol surface that no longer needs to
be maintained.
## What Changed
- Removed `Op::ListSkills` and `EventMsg::ListSkillsResponse` from the
core protocol.
- Deleted the corresponding core session handler and stale core
integration tests.
- Removed rollout/MCP ignore branches and protocol v1 docs references
for the deleted event/op.
- Left app-server `skills/list` and its existing coverage intact.
## Validation
- `cargo test -p codex-protocol`
- `cargo test -p codex-core --test all suite::skills`
- `cargo check -p codex-mcp-server -p codex-rollout -p
codex-rollout-trace`
- `just fix -p codex-core`
## Why
The core protocol still exposed a `ListModels` submission op even though
no client sends it and the core submission loop treated it as an ignored
unknown op. Keeping the dead variant made the protocol surface look
supported while the active model listing API is the app-server
`model/list` JSON-RPC request.
## What Changed
- Removed the unused `Op::ListModels` variant from `codex-rs/protocol`.
- Removed its `Op::kind()` mapping.
The existing app-server `model/list` endpoint is unchanged.
## Verification
- `cargo test -p codex-protocol`
## Why
BUGB-15601 showed that the Windows safe-command path had drifted from
the generic Git classifier. The Windows-specific Git parser could
classify a PowerShell-wrapped `git` command as safe as soon as it found
a safelisted subcommand, without applying the generic checks for unsafe
subcommand options such as `--output`, `--ext-diff`, `--textconv`,
`--paginate`, or `cat-file --filters`.
The generic classifier already models the Git command boundary and the
read-only argument checks more carefully, so Windows should reuse that
logic instead of maintaining a smaller parallel parser.
## What Changed
- Extracted the existing generic Git classification logic into
`is_safe_git_command`.
- Updated `windows_safe_commands.rs` to call that shared helper for
parsed PowerShell `git` commands.
- Removed the Windows-only Git subcommand safelist, including the
`cat-file` allowance that was part of the reported bypass.
- Added a Windows regression test that keeps PowerShell-wrapped Git
commands with side-effecting options classified unsafe.
- Made the full-path PowerShell test discover the installed PowerShell
executable instead of depending on one hard-coded `pwsh.exe` path.
## Verification
- `cargo test -p codex-shell-command
rejects_git_subcommand_options_with_side_effects`
- `cargo test -p codex-shell-command
git_global_override_flags_are_not_safe`
- `cargo test -p codex-shell-command
windows_powershell_full_path_is_safe -- --nocapture`
Co-authored-by: Codex <codex@openai.com>
## Why
- Similar change as https://github.com/openai/codex/pull/19473.
- Without change: MCP tool calls receive
`_meta["x-codex-turn-metadata"]` with `session_id`, `turn_id`, and
`turn_started_at_unix_ms`.
- Issue: MCP servers may want the model and reasoning effort to better
understand tool-call behavior and latency relative to turn start.
## What Changed
- With change: MCP turn metadata now includes `model` and
`reasoning_effort`, propagated in `_meta["x-codex-turn-metadata"]`.
- Normal `/responses` turn metadata headers are unchanged.
## Verification
- `codex-rs/core/src/mcp_tool_call_tests.rs`
- `codex-rs/core/src/turn_metadata_tests.rs`
- `codex-rs/core/tests/suite/search_tool.rs`
## Why
Thread names are app-server metadata now, backed by the thread store and
sqlite state database. Keeping a core `SetThreadName` op plus a rollout
`thread_name_updated` event made rename persistence live in the wrong
layer and required historical replay support for an event that new
app-server flows should not write.
## What changed
- Removed `Op::SetThreadName` and `EventMsg::ThreadNameUpdated` from the
core protocol and deleted the core handler path that appended rename
events to rollouts.
- Updated app-server `thread/name/set` so both loaded and unloaded
threads write through thread-store metadata and app-server emits
`thread/name/updated` notifications.
- Updated local thread-store name metadata updates to write sqlite title
metadata and the legacy thread-name index without appending rollout
events.
- Removed state extraction and rollout handling for the deleted
thread-name event.
## Validation
- `cargo test -p codex-app-server thread_name_updated_broadcasts`
- `cargo test -p codex-app-server
thread_name_set_is_reflected_in_read_list_and_resume`
- `cargo test -p codex-thread-store
update_thread_metadata_sets_name_on_active_rollout_and_indexes_name`
- `cargo test -p codex-state`
- `cargo check -p codex-mcp-server -p codex-rollout-trace`
- `just fix -p codex-app-server -p codex-thread-store -p codex-state -p
codex-mcp-server -p codex-rollout-trace`
## Docs
No external documentation update is expected for this internal ownership
change.
**Summary**
- Build Linux `bwrap` before the main release binaries.
- Export the release `bwrap` SHA-256 as `CODEX_BWRAP_SHA256` so the
Codex binary can verify the bundled fallback.
- Sign, stage, and upload `bwrap` alongside the primary Linux release
artifacts.
**Verification**
- YAML parse check for `.github/workflows/rust-release.yml`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/21256).
* #21257
* __->__ #21256
**Summary**
- Add `codex-bwrap`, a standalone `bwrap` binary built from the existing
vendored bubblewrap sources.
- Remove the linked vendored bwrap path from `codex-linux-sandbox`;
runtime now prefers system `bwrap` and falls back to bundled
`codex-resources/bwrap`.
- Add bundled SHA-256 verification with missing/all-zero digest as the
dev-mode skip value, then exec the verified file through
`/proc/self/fd`.
- Keep `launcher.rs` focused on choosing and dispatching the preferred
launcher. Bundled lookup, digest verification, and bundled exec now live
in `linux-sandbox/src/bundled_bwrap.rs`; Bazel runfiles lookup lives in
`linux-sandbox/src/bazel_bwrap.rs`; shared argv/fd exec helpers live in
`linux-sandbox/src/exec_util.rs`.
- Teach Bazel tests to surface the Bazel-built `//codex-rs/bwrap:bwrap`
through `CARGO_BIN_EXE_bwrap`; `codex-linux-sandbox` only honors that
fallback in debug Bazel runfiles environments so release/user runtime
lookup stays tied to `codex-resources/bwrap`.
- Allow `codex-exec-server` filesystem helpers to preserve just the
Bazel bwrap/runfiles variables they need in debug Bazel builds, since
those helpers intentionally rebuild a small environment before spawning
`codex-linux-sandbox`.
- Verify the Bazel bwrap target in Linux release CI with a build-only
check. Running `bwrap --version` is too strong for GitHub runners
because bubblewrap still attempts namespace setup there.
**Verification**
- Latest update: `cargo test -p codex-linux-sandbox`
- Latest update: `just fix -p codex-linux-sandbox`
- `cargo check --target x86_64-unknown-linux-gnu -p codex-linux-sandbox`
could not run locally because this macOS machine does not have
`x86_64-linux-gnu-gcc`; GitHub Linux Bazel CI is expected to cover the
Linux-only modules.
- Earlier in this PR: `cargo test -p codex-bwrap`
- Earlier in this PR: `cargo test -p codex-exec-server`
- Earlier in this PR: `cargo check --release -p codex-exec-server`
- Earlier in this PR: `just fix -p codex-linux-sandbox -p
codex-exec-server`
- Earlier in this PR: `bazel test --nobuild
//codex-rs/linux-sandbox:linux-sandbox-all-test
//codex-rs/core:core-all-test
//codex-rs/exec-server:exec-server-file_system-test
//codex-rs/app-server:app-server-all-test` (analysis completed; Bazel
then refuses to run tests under `--nobuild`)
- Earlier in this PR: `bazel build --nobuild //codex-rs/bwrap:bwrap`
- Prior to this update: `just bazel-lock-update`, `just
bazel-lock-check`, and YAML parse check for
`.github/workflows/bazel.yml`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/21255).
* #21257
* #21256
* __->__ #21255
## Why
`codex-rs/app-server-protocol/src/protocol/v2.rs` had grown into a
single ~12k-line definition file for the entire app-server v2 API.
This is purely a mechanical refactor to break up the monolithic `v2.rs`
file that contains all app-server API v2 types into more modular files,
grouped by resource (e.g. account, thread, turn, etc.).
`just write-app-server-schema` shows no real changes, so we can be sure
that this is purely an internal organizational change.
## What changed
- Replaced the monolithic `protocol/v2.rs` with a `protocol/v2/` module
tree and a small `mod.rs` that only declares and reexports modules.
- Grouped v2 API definitions by conceptual owner, including `account`,
`apps`, `collaboration_mode`, `command_exec`, `config`, `device_key`,
`experimental_feature`, `feedback`, `fs`, `hook`, `item`, `mcp`,
`model`, `notification`, `permissions`, `plugin`, `process`, `realtime`,
`review`, `thread`, `thread_data`, `turn`, and `windows_sandbox`.
- Moved v2 tests into `protocol/v2/tests.rs` so `mod.rs` stays small.
- Kept shared protocol helpers in `protocol/v2/shared.rs`, including the
enum mirroring macro and common cross-resource types.
- Co-located resource-specific notifications and server-request payloads
with the modules that own those resources.
- Regenerated app-server protocol schema fixtures. The schema diffs are
non-semantic newline-only changes after the refactor.
## Verification
- `cargo check -p codex-app-server-protocol`
- `cargo test -p codex-app-server-protocol`
- `just write-app-server-schema`
Michael Bolin