## What
Introduce a `CodexResponsesMetadata` struct that defines all the core
metadata we send to Responses API. Example fields are `thread_id`,
`turn_id`, `window_id`, etc.
Going forward, `client_metadata["x-codex-turn-metadata"]` will be the
canonical way Codex sends metadata to Responses API across both HTTP and
websocket transports.
For now, we continue to emit the existing top-level HTTP headers and
top-level `client_metadata` fields from the same
`CodexResponsesMetadata` struct for compatibility reasons.
Also, app-server clients who specify additional
`responsesapi_client_metadata` via `turn/start` and `turn/steer` will
have those fields merged into
`client_metadata["x-codex-turn-metadata"]`, but cannot override the
reserved fields that core uses (i.e. the fields in
`CodexResponsesMetadata`).
## Why
Responses API request instrumentation is the source of truth for
downstream Codex analytics that join requests by Codex IDs such as
session, thread, turn, and context window. Before this change, those
values were assembled through several request-specific paths: HTTP
request bodies, websocket handshake headers, websocket `response.create`
payloads, compaction requests, and the rich `x-codex-turn-metadata`
envelope all had their own wiring.
That made metadata propagation easy to drift across API-key/direct
Responses API requests, ChatGPT-auth/proxied requests, websocket
requests, and compaction requests. It also made additions like
`window_id` error-prone because a field could be added to one transport
projection but missed in another.
## What changed
- Added `CodexResponsesMetadata` as the core-owned snapshot for Codex
metadata sent to ResponsesAPI.
- Render `client_metadata["x-codex-turn-metadata"]`, flat
`client_metadata` projections, and direct compatibility headers from
that same snapshot.
- Include the known Codex-owned fields in the turn metadata blob,
including installation/session/thread/turn/window IDs, request kind,
lineage, sandbox/workspace metadata, timing, and compaction details.
- Treat app-server `responsesapi_client_metadata` as enrichment for the
Codex turn metadata blob while preventing those extras from overriding
Codex-owned fields.
- Use the same metadata path for normal turns, websocket prewarm, local
compaction, remote v1 compaction, and remote v2 compaction.
- Keep websocket connection-only preconnect metadata separate so
handshakes carry compatibility identity headers without inventing a fake
turn metadata blob.
## Verification
- `cargo check -p codex-core`
- `just fix -p codex-core`
## Summary
- carry `workspace_kind` from Responses API client metadata into the
turn resolved analytics fact
- serialize the optional value on `codex_turn_event`
- cover both the turn metadata source and turn event serialization
The `workspace_kind` tells us whether a thread had a project attached vs
projectless. this is an indicator for who is adopting Codex for
knowledge work outside of coding
## Testing
- `env UV_CACHE_DIR=/private/tmp/uv-cache
/private/tmp/cargo-tools/bin/just fmt`
- `env PATH=/private/tmp/cargo-tools/bin:$PATH
CARGO_HOME=/private/tmp/cargo-home UV_CACHE_DIR=/private/tmp/uv-cache
/private/tmp/cargo-tools/bin/just test -p codex-analytics`
- `env PATH=/private/tmp/cargo-tools/bin:$PATH
CARGO_HOME=/private/tmp/cargo-home UV_CACHE_DIR=/private/tmp/uv-cache
/private/tmp/cargo-tools/bin/just test -p codex-core turn_metadata`
Paired with openai/openai#970661, which keeps forwarding the same
metadata key through Responses API headers.
## Why
This PR
https://github.com/openai/codex/pull/24161#discussion_r3325692763
revealed a subagent data modeling issue, where we overloaded
`forked_from_id` to also mean `parent_thread_id`. That's incorrect since
guardian and review subagents can be a subagent and NOT fork the main
thread's history.
The solution here is to explicitly store a new `parent_thread_id` on
`SessionMeta`, alongside `forked_from_id` which already exists. While
we're at it, also expose it in the app-server protocol on the `Thread`
object.
A thread->subagent relationship and a fork of thread history are
orthogonal concepts.
## What Changed
- Added top-level `parent_thread_id` persistence on `SessionMeta` and
runtime/session plumbing through `SessionConfiguredEvent`,
`CodexSpawnArgs`, `SessionConfiguration`, `ThreadConfigSnapshot`,
`TurnContext`, and `ModelClient`.
- Made turn metadata, request headers, analytics, and subagent-start
events read the separate runtime/top-level parent field instead of
deriving general parent lineage from `SessionSource` or
`forked_from_thread_id`.
- Passed parent lineage separately at delegated subagent, review,
guardian, agent-job, and multi-agent spawn construction sites;
copied-history fork lineage remains derived only from `InitialHistory`.
- Persisted and exposed parent lineage through rollout/thread-store
projections and app-server v2 `Thread.parentThreadId`.
- Updated app-server README text and regenerated app-server schema
fixtures for the additive `parentThreadId` response field.
## Why
We recently added `forked_from_thread_id` which lets us trace where a
thread's _context_ comes from, but we also want to understand subagent
lineage (e.g. which parent thread spawned this subagent? what kind of
subagent is it?) which is orthogonal.
This PR adds `parent_thread_id` and `subagent_kind` to the
`x-codex-turn-metadata` header sent to ResponsesAPI.
## What changed
- Adds `parent_thread_id` and `subagent_kind` to core-owned
`x-codex-turn-metadata`.
- Restores persisted `SessionSource` and `ThreadSource` from resumed
session metadata so cold-resumed subagent threads keep their lineage on
later Responses API requests.
- Centralizes parent-thread extraction on `SessionSource` /
`SubAgentSource` and reuses it in the Responses client, analytics, agent
control, and state parsing paths.
- Extends reserved-key, git-enrichment, thread-spawn, and app-server v2
metadata coverage for the new lineage fields.
## Verification
- Not run locally per request.
- Added focused coverage in `core/src/turn_metadata_tests.rs` and
`app-server/tests/suite/v2/client_metadata.rs`.
## Summary
- Add `request_kind` values for foreground turn, startup prewarm,
compaction, and detached memory model requests.
- Attach compaction dispatch metadata to local Responses, legacy
`/v1/responses/compact`, and remote v2 compact requests.
- Add the existing logical context-window identifier as `window_id` on
turn-owned model request metadata.
- Keep identity fields optional for detached memory requests, while
still emitting `request_kind="memory"` in non-git/no-sandbox workspaces.
## Root Cause
`x-codex-turn-metadata` has more than one producer. Foreground turns and
compaction requests own a real turn and should carry that turn identity.
Detached memory stage-one requests do not own a foreground turn, so
absent identity fields are valid rather than missing data. Startup
websocket prewarm is also a model request, but it has `generate=false`
and must not be counted as a foreground turn.
`thread_source` or session source identifies where a thread came from
(for example review, guardian, or another subagent). `request_kind`
identifies what the current outbound model request is doing (`turn`,
`prewarm`, `compaction`, or `memory`). A review or guardian thread can
issue either a normal turn request or a compaction request, so source
cannot replace request kind.
## Behavior / Impact
- Ordinary foreground requests send `request_kind="turn"`, their real
identity fields, and `window_id="<thread_id>:<window_generation>"`.
- Startup websocket warmup requests send `request_kind="prewarm"` so
they are not counted as foreground turns.
- Compaction requests send `request_kind="compaction"`, their real
owning turn identity, the existing `window_id`, and
`compaction.{trigger,reason,implementation,phase,strategy}`.
- Detached memory stage-one requests send `request_kind="memory"`
without `session_id`, `thread_id`, `turn_id`, or `window_id`; when no
workspace metadata exists, the kind-only header is still emitted.
- `session_id`, `thread_id`, `turn_id`, and `window_id` remain optional
in the header schema because detached memory requests do not own a
foreground turn or context window.
- `window_id` is not a new ID system: it is copied from the already-sent
`x-codex-window-id` / WS client metadata value at model-request dispatch
time.
- Existing `x-codex-window-id` HTTP/WS emission, value format,
generation advancement, resume behavior, and fork reset behavior are
unchanged.
- `request_kind`, `window_id`, and upstream turn-owned identity fields
remain schema-owned; input `responsesapi_client_metadata` cannot replace
their canonical values.
- No table, DAG, export, app-server API, or MCP `_meta` schema changes
are included.
A compaction attempt stopped by a pre-compact hook issues no model
request and therefore has no request header; its outcome remains in
analytics events. Status, error, duration, and token deltas also remain
analytics fields rather than request-header fields.
Future detached-memory attribution using a real initiating turn ID as
`trigger_turn_id` is intentionally not part of this PR.
## Sync With Main
- Final pushed head `716342e79` is rebased onto `origin/main@0d37db4b2`.
- The metadata conflict came from upstream `#24160`, which added
`forked_from_thread_id` on the same `turn_metadata` surface. Resolution
preserves that field and its protection from client metadata override
alongside this PR's request-kind, compaction, and window-id fields.
- While resolving the overlapping commits, I removed an accidental
recursive model-request overlay and a duplicate detached-memory header
builder before completing the rebase.
## Latency / User Experience Boundary
- Foreground turns perform no new filesystem, git, or network work. New
fields are inserted into metadata already serialized for outgoing
requests.
- Compaction issues the same model/HTTP requests with the same prompt,
model, service tier, and sampling settings; only metadata bytes change.
- Startup prewarm already sent metadata; it is now correctly classified
as `prewarm`.
- Non-git detached memory now sends a small kind-only metadata header
rather than no header.
- This client diff adds no user-visible latency mechanism beyond
negligible serialization and header bytes on already-existing requests.
## Validation
On conflict-resolved head `1d35c2cfb` based on `origin/main@487521733`:
- `just fmt` (passed)
- `just fix -p codex-core` (passed)
- `git diff --check origin/main...HEAD` (passed)
- `just test -p codex-core -E 'test(turn_metadata) |
test(websocket_first_turn_uses_startup_prewarm_and_create) |
test(responses_stream_includes_turn_metadata_header_for_git_workspace_e2e)
|
test(responses_websocket_forwards_turn_metadata_on_initial_and_incremental_create)
| test(remote_compact_v2_retries_failures_with_stream_retry_budget) |
test(window_id_advances_after_compact_persists_on_resume_and_resets_on_fork)'`
(`23 passed`; `bench-smoke` passed)
- `just test -p codex-app-server -E
'test(turn_start_forwards_client_metadata_to_responses_request_v2) |
test(turn_start_forwards_client_metadata_to_responses_websocket_request_body_v2)
| test(auto_compaction_remote_emits_started_and_completed_items)'` (`3
passed`; `bench-smoke` passed)
- `just test -p codex-memories-write` (`29 passed`; `bench-smoke`
passed)
## Why
When Codex calls responsesapi, we currently send `session_id`,
`thread_id`, and `turn_id` among other things as
`client_metadata["x-codex-turn-metadata"]`. This PR adds
`forked_from_thread_id` which helps explain the "lineage" of a forked
thread.
## What's changed
- Track the immediate history source copied into a forked thread through
thread/session creation, including subagent and review turn metadata
paths.
- Include `forked_from_thread_id` in Codex turn metadata while
preventing turn-scoped Responses API client metadata from overwriting
Codex-owned lineage fields.
- Add coverage for fork lineage in turn metadata and the app-server
Responses API request path.
## Why
Sandbox telemetry tags should be derived from the active permission
profile, not from a legacy `SandboxPolicy`, so the tagging code stays
aligned with the permissions migration and does not preserve a
policy-shaped production helper only for tests.
## What Changed
- Removed the production `sandbox_tag(&SandboxPolicy, ...)` helper.
- Updated sandbox tag tests to construct the relevant
`PermissionProfile` values directly.
- Kept the platform-specific sandbox tag behavior under the existing
`permission_profile_sandbox_tag` path.
## How To Review
The production change is in `codex-rs/core/src/sandbox_tags.rs`. Most of
the diff is test cleanup that replaces legacy policy setup with
permission profiles, so review the expected tag assertions rather than
the old helper mechanics.
## Verification
- `cargo test -p codex-core sandbox_tag`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/22791).
* #22795
* #22792
* __->__ #22791
## Why
- Similar change as https://github.com/openai/codex/pull/21219
- Without change: MCP tool calls receive
`_meta["x-codex-turn-metadata"]` with various key values.
- Issue: MCP servers currently do not know if user input was requested
during the turn (Ex: Model decides to prompt the user for approval
mid-turn before making a possibly risky tool call). MCP servers may want
to know this when tracking latency metrics because these instances are
inflated.
## What Changed
- With change: MCP turn metadata now includes
`user_input_requested_during_turn` when a model-visible
`request_user_input` call happened earlier in the turn, propagated in
`_meta["x-codex-turn-metadata"]`.
- `mark_turn_user_input_requested()` is called when user input is
requested through either MCP elicitation (`mcp.rs`) or the
`request_user_input` tool (`mod.rs`).
- MCP tool call `_meta` is now built immediately before execution
(`mcp_tool_call.rs`) so user input requested earlier in the same turn,
including within the same tool call via elicitation, is reflected in the
metadata.
- Normal `/responses` turn metadata headers are unchanged.
## Verification
- `codex-rs/core/src/session/mcp_tests.rs`
- `codex-rs/core/src/tools/handlers/request_user_input_tests.rs`
- `codex-rs/core/src/turn_metadata_tests.rs`
- `codex-rs/core/tests/suite/search_tool.rs`
## Why
MCP tool calls already include `session_id` in `x-codex-turn-metadata`,
but descendant threads intentionally share that value with the root
thread. Consumers that need to correlate work at the concrete thread
level also need the current `thread_id`.
## What changed
- add `thread_id` to `x-codex-turn-metadata` while preserving
`session_id` as the shared session identity
- thread the two identities separately through normal turns and spawned
review threads
- add regression coverage for resumed sessions, reserved metadata
fields, and deferred MCP tool calls
## Verification
- added focused coverage in `core/src/session/tests.rs`,
`core/src/turn_metadata_tests.rs`, and `core/tests/suite/search_tool.rs`
## 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`
## 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
`x-codex-turn-metadata` is sent as an HTTP/WebSocket header, but Codex
was serializing the metadata JSON with raw UTF-8 string contents. When a
workspace path contains non-ASCII characters, common HTTP stacks can
reject or corrupt that header before the request reaches the provider.
Fixes#17468. Also addresses the duplicate WebSocket report in #19581.
## What changed
- Added `codex_utils_string::to_ascii_json_string`, a shared helper that
serializes JSON normally while escaping non-ASCII string content as
`\uXXXX`.
- Switched turn metadata header serialization, including merged
Responses API client metadata, to use the ASCII-safe JSON helper.
- Added coverage for non-ASCII workspace paths and non-ASCII client
metadata while preserving the same parsed JSON values.
## Verification
- `cargo test -p codex-utils-string`
- `cargo test -p codex-core turn_metadata`
- `just bazel-lock-check`
## Why
- Without change: MCP tool calls receive
`_meta["x-codex-turn-metadata"]` with `session_id` and `turn_id`.
- Issue: MCP servers may want the turn start timestamp to measure
internal latency relative to turn start.
## What Changed
- With change: turn metadata now includes `turn_started_at_unix_ms`,
which is propagated to MCP tool calls in
`_meta["x-codex-turn-metadata"]`.
## Verification
- `codex-rs/core/src/mcp_tool_call_tests.rs`
- `codex-rs/core/src/turn_metadata_tests.rs`
- `codex-rs/core/src/turn_timing_tests.rs`
- `codex-rs/core/tests/responses_headers.rs`
- `codex-rs/core/tests/suite/search_tool.rs`
## Why
This supersedes #19391. During stack repair, GitHub marked #19391 as
merged into a temporary stack branch rather than into `main`, so the
runtime-config change needed a fresh PR.
`PermissionProfile` is now the canonical permissions shape after #19231
because it can distinguish `Managed`, `Disabled`, and `External`
enforcement while also carrying filesystem rules that legacy
`SandboxPolicy` cannot represent cleanly. Core config and session state
still needed to accept profile-backed permissions without forcing every
profile through the strict legacy bridge, which rejected valid runtime
profiles such as direct write roots.
The unrelated CI/test hardening that previously rode along with this PR
has been split into #19683 so this PR stays focused on the permissions
model migration.
## What Changed
- Adds `Permissions.permission_profile` and
`SessionConfiguration.permission_profile` as constrained runtime state,
while keeping `sandbox_policy` as a legacy compatibility projection.
- Introduces profile setters that keep `PermissionProfile`, split
filesystem/network policies, and legacy `SandboxPolicy` projections
synchronized.
- Uses a compatibility projection for requirement checks and legacy
consumers instead of rejecting profiles that cannot round-trip through
`SandboxPolicy` exactly.
- Updates config loading, config overrides, session updates, turn
context plumbing, prompt permission text, sandbox tags, and exec request
construction to carry profile-backed runtime permissions.
- Preserves configured deny-read entries and `glob_scan_max_depth` when
command/session profiles are narrowed.
- Adds `PermissionProfile::read_only()` and
`PermissionProfile::workspace_write()` presets that match legacy
defaults.
## Verification
- `cargo test -p codex-core direct_write_roots`
- `cargo test -p codex-core runtime_roots_to_legacy_projection`
- `cargo test -p codex-app-server
requested_permissions_trust_project_uses_permission_profile_intent`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19606).
* #19395
* #19394
* #19393
* #19392
* __->__ #19606
## Summary
Adds `thread_source` field to the existing Codex turn metadata sent to
Responses API
- Sends `thread_source: "user"` for user-initiated sessions: CLI, VS
Code, and Exec
- Sends `thread_source: "subagent"` for subagent sessions
- Omits `thread_source` for MCP, custom, and unknown session sources
- Uses the existing turn metadata transport:
- HTTP requests send through the `x-codex-turn-metadata` header
- WebSocket `response.create` requests send through
`client_metadata["x-codex-turn-metadata"]`
## Testing
- `cargo test -p codex-protocol
session_source_thread_source_name_classifies_user_and_subagent_sources`
- `cargo test -p codex-core turn_metadata_state`
- `cargo test -p codex-core --test responses_headers
responses_stream_includes_turn_metadata_header_for_git_workspace_e2e --
--nocapture`
## Summary
App-server v2 already receives turn-scoped `clientMetadata`, but the
Rust app-server was dropping it before the outbound Responses request.
This change keeps the fix lightweight by threading that metadata through
the existing turn-metadata path rather than inventing a new transport.
## What we're trying to do and why
We want turn-scoped metadata from the app-server protocol layer,
especially fields like Hermes/GAAS run IDs, to survive all the way to
the actual Responses API request so it is visible in downstream
websocket request logging and analytics.
The specific bug was:
- app-server protocol uses camelCase `clientMetadata`
- Responses transport already has an existing turn metadata carrier:
`x-codex-turn-metadata`
- websocket transport already rewrites that header into
`request.request_body.client_metadata["x-codex-turn-metadata"]`
- but the Rust app-server never parsed or stored `clientMetadata`, so
nothing from the app-server request was making it into that existing
path
This PR fixes that without adding a new header or a second metadata
channel.
## How we did it
### Protocol surface
- Add optional `clientMetadata` to v2 `TurnStartParams` and
`TurnSteerParams`
- Regenerate the JSON schema / TypeScript fixtures
- Update app-server docs to describe the field and its behavior
### Runtime plumbing
- Add a dedicated core op for app-server user input carrying turn-scoped
metadata: `Op::UserInputWithClientMetadata`
- Wire `turn/start` and `turn/steer` through that op / signature path
instead of dropping the metadata at the message-processor boundary
- Store the metadata in `TurnMetadataState`
### Transport behavior
- Reuse the existing serialized `x-codex-turn-metadata` payload
- Merge the new app-server `clientMetadata` into that JSON additively
- Do **not** replace built-in reserved fields already present in the
turn metadata payload
- Keep websocket behavior unchanged at the outer shape level: it still
sends only `client_metadata["x-codex-turn-metadata"]`, but that JSON
string now contains the merged fields
- Keep HTTP fallback behavior unchanged except that the existing
`x-codex-turn-metadata` header now includes the merged fields too
### Request shape before / after
Before, a websocket `response.create` looked like:
```json
{
"type": "response.create",
"client_metadata": {
"x-codex-turn-metadata": "{\"session_id\":\"...\",\"turn_id\":\"...\"}"
}
}
```
Even if the app-server caller supplied `clientMetadata`, it was not
represented there.
After, the same request shape is preserved, but the serialized payload
now includes the new turn-scoped fields:
```json
{
"type": "response.create",
"client_metadata": {
"x-codex-turn-metadata": "{\"session_id\":\"...\",\"turn_id\":\"...\",\"fiber_run_id\":\"fiber-start-123\",\"origin\":\"gaas\"}"
}
}
```
## Validation
### Targeted tests added / updated
- protocol round-trip coverage for `clientMetadata` on `turn/start` and
`turn/steer`
- protocol round-trip coverage for `Op::UserInputWithClientMetadata`
- `TurnMetadataState` merge test proving client metadata is added
without overwriting reserved built-in fields
- websocket request-shape test proving outbound `response.create`
contains merged metadata inside
`client_metadata["x-codex-turn-metadata"]`
- app-server integration tests proving:
- `turn/start` forwards `clientMetadata` into the outbound Responses
request path
- websocket warmup + real turn request both behave correctly
- `turn/steer` updates the follow-up request metadata
### Commands run
- `just write-app-server-schema`
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-protocol`
- `cargo test -p codex-core
turn_metadata_state_merges_client_metadata_without_replacing_reserved_fields
--lib`
- `cargo test -p codex-core --test all
responses_websocket_preserves_custom_turn_metadata_fields`
- `cargo test -p codex-app-server --test all client_metadata`
- `cargo test -p codex-app-server --test all
turn_start_forwards_client_metadata_to_responses_websocket_request_body_v2
-- --nocapture`
- `just fmt`
- `just fix -p codex-core -p codex-protocol -p codex-app-server-protocol
-p codex-app-server`
- `just fix -p codex-exec -p codex-tui-app-server`
- `just argument-comment-lint`
### Full suite note
`cargo test` in `codex-rs` still fails in:
-
`suite::v2::turn_interrupt::turn_interrupt_resolves_pending_command_approval_request`
I verified that same failure on a clean detached `HEAD` worktree with an
isolated `CARGO_TARGET_DIR`, so it is not caused by this patch.
## Summary
Some background. We're looking to instrument GA turns end to end. Right
now a big gap is grouping mcp tool calls with their codex sessions. We
send session id and turn id headers to the responses call but not the
mcp/wham calls.
Ideally we could pass the args as headers like with responses, but given
the setup of the rmcp client, we can't send as headers without either
changing the rmcp package upstream to allow per request headers or
introducing a mutex which break concurrency. An earlier attempt made the
assumption that we had 1 client per thread, which allowed us to set
headers at the start of a turn. @pakrym mentioned that this assumption
might break in the near future.
So the solution now is to package the turn metadata/session id into the
_meta field in the post body and pull out in codex-backend.
- send turn metadata to MCP servers via `tools/call` `_meta` instead of
assuming per-thread request headers on shared clients
- preserve the existing `_codex_apps` metadata while adding
`x-codex-turn-metadata` for all MCP tool calls
- extend tests to cover both custom MCP servers and the codex apps
search flow
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
PR #13783 moved the `codex.rs` unit tests into `codex_tests.rs`. This
applies the same extraction pattern across the rest of `codex-rs/core`
so the production modules stay focused on runtime code instead of large
inline test blocks.
Keeping the tests in sibling files also makes follow-up edits easier to
review because product changes no longer have to share a file with
hundreds or thousands of lines of test scaffolding.
## What changed
- replaced each inline `mod tests { ... }` in `codex-rs/core/src/**`
with a path-based module declaration
- moved each extracted unit test module into a sibling `*_tests.rs`
file, using `mod_tests.rs` for `mod.rs` modules
- preserved the existing `cfg(...)` guards and module-local structure so
the refactor remains structural rather than behavioral
## Testing
- `cargo test -p codex-core --lib` (`1653 passed; 0 failed; 5 ignored`)
- `just fix -p codex-core`
- `cargo fmt --check`
- `cargo shear`