1 Commits

• Forward app-server turn clientMetadata to Responses (#16009)

  ## 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.

  neil-oai · 2026-04-09 11:52:37 -07:00
  a92a5085bd