## What changed
- Add `TurnInputRequest` and typed submission results for atomically starting a turn, steering the active turn, or declining input with a specific reason.
- Expose `start_or_steer_turn`, `start_turn_if_idle`, and `steer_turn` on `CodexThread`, and migrate Core consumers to these APIs.
- Make app-server `turn/start` steer an active regular turn and return that turn's ID. Reject incompatible output schemas and non-steerable turns without applying settings or enqueueing input.
## Testing
- Cover concurrent start-or-steer submissions, accepted and rejected settings updates, output-schema compatibility, idle-start rejection, and app-server steering.
GitOrigin-RevId: dd9b5528d76ec650c019e97af420bc13190ea86a
## What changed
- Parse safety-buffering payloads from typed `response.metadata` SSE events.
- Preserve the existing top-level `safety_buffering` field as the authoritative value when it is present, including when it is null or malformed.
- Continue applying the header-provided fallback model when the metadata payload omits `retry_model`.
## Testing
- Add parser coverage for metadata fallback, top-level precedence, and unrelated metadata events.
- Exercise metadata-based safety-buffering delivery through the core SSE integration test.
GitOrigin-RevId: 7dadfd54be28f2f33c2283de92fd49da0557d98a
## Summary
- deserialize `retry_model` from streamed `safety_buffering` payloads
- preserve the existing downstream faster-model API and legacy header
fallback
- update SSE, WebSocket, and end-to-end safety-buffering coverage
## Root cause
Follow-up to #31064. The Responses API emits the retry target as
`retry_model`, but the client was looking for `faster_model`, so the
payload value was ignored in favor of the compatibility fallback.
## Behavior
A non-null `retry_model` from the buffering payload takes precedence. An
explicit null leaves the retry target unset, while an omitted field
continues to fall back to the existing response header.
## Validation
- `just test -p codex-api` (135 tests)
- `just test -p codex-core safety_buffering` (2 tests)
- `just fix -p codex-api`
- `just fmt`
- `git diff --check`
## Summary
- read optional faster-model metadata from streamed buffering payloads
- use the buffering payload itself to determine whether buffering UI
should be shown
- retain the existing header value as a compatibility fallback when the
payload omits the field
## Behavior
An object-valued buffering signal now enables the buffering UI. The
response event's faster-model field takes precedence when present, while
omitted fields fall back to existing response metadata. An explicit null
leaves the retry target unset.
## Validation
- `just test -p codex-api`
- `just fix -p codex-api`
- `cargo fmt --all -- --check`
- `git diff --check`
## Summary
- read the request-scoped safety-buffering treatment from HTTP response
headers and per-turn WebSocket metadata through one shared header parser
- combine that treatment with Responses API safety-buffering signals
- propagate `showBufferingUi` and nullable `fasterModel` through the
existing `model/safetyBuffering/updated` app-server notification
- update the app-server documentation and generated JSON and TypeScript
schemas
The public implementation contains no model mapping or real model
identifier. Tests and protocol examples use generic `current-model` and
`faster-model` placeholders only.
## Dependencies
- server-side treatment evaluation:
https://github.com/openai/openai/pull/1060247
- initial Responses API safety-buffering propagation:
https://github.com/openai/codex/pull/29371
- Codex App UI: https://github.com/openai/openai/pull/1057789
## Validation
- Codex API tests: 129 passed
- focused Codex core safety-buffering integration test passed
- app-server protocol tests passed after regenerating schema fixtures
- Clippy fix and repository formatting completed successfully
The broader app-server run compiled all changed crates and completed
with 1,269 passing tests. Its remaining failures were unrelated
environment limitations: macOS sandbox application was denied, one
expected test binary was unavailable, and several existing subprocess
tests timed out as a result.
Responses API safety buffering metadata currently stops at the transport
boundary, so app-server clients cannot render the in-progress safety
review state.
This change:
- decodes and deduplicates `safety_buffering` metadata from Responses
API SSE and WebSocket events without suppressing the original response
event
- emits a typed core event containing the requested model plus backend
use cases and reasons
- forwards that event as `turn/safetyBuffering/updated` through
app-server v2 and updates generated protocol schemas
- keeps the side-channel event out of persisted rollouts and turn timing
This supports the Codex Apps buffering UX and depends on the Responses
API backend work in https://github.com/openai/openai/pull/1044569 and
https://github.com/openai/openai/pull/1044571.
Validation:
- focused `codex-core` safety-buffering integration test passes
- `cargo check -p codex-core -p codex-app-server -p
codex-app-server-protocol`
- `just fix -p codex-api -p codex-protocol -p codex-core -p
codex-app-server-protocol -p codex-app-server -p codex-rollout -p
codex-rollout-trace -p codex-otel`
- `just fmt`
- broad package test run: 4,430/4,492 passed; 62 unrelated
local-environment/concurrency failures involved unavailable test
binaries, MCP subprocess setup, and app-server timeouts
