## What changed
- Add `codex-otel-trace-websocket` with a `TraceWebSocket` API that owns the
loopback OTLP receiver and WebSocket listener.
- Bind both listeners during startup, expose the exporter and bound listener
addresses, and surface listener failures through a single lifecycle method.
- Update `codex-code-mode-host` to use the new crate and shut down the bridge
after flushing its trace provider.
GitOrigin-RevId: ec5ca4c4369b6b3b1232875c2699730eb748ab1c
## What changed
- Add `--otel-trace-exporter` for sending OTLP/HTTP JSON traces directly to an exporter.
- Add the mutually exclusive `--otel-trace-listen` option for streaming raw OTLP trace batches over a trace-only WebSocket, backed by a loopback OTLP receiver.
- Instrument host startup, transport requests, and gRPC operations with request, session, execution, cell, wait, and tool-call identifiers where available.
- Flush the trace provider with a bounded timeout during shutdown.
GitOrigin-RevId: 4dcdb2bc3b15166dccd5041fb875caea74f3f6fe
## What changed
- Accept only `http://` and `https://` gRPC endpoints for app server
`--code-mode-host` connections.
- Limit the standalone code-mode host to stdio and gRPC listeners.
- Remove the WebSocket session provider, dual-WebSocket negotiation, transport
lanes, and related dependencies and tests.
- Keep coverage for shared and prewarmed gRPC hosts and reject WebSocket host
URLs in CLI parsing tests.
GitOrigin-RevId: 8792604e79ffd54ce776074a4dc3f7d55e63752a
## What changed
- Accept `grpc://IP:PORT` endpoints through `--listen` and serve the existing
code-mode gRPC service over TCP.
- Print the bound HTTP endpoint to stdout so callers can discover the port when
binding to port `0`.
- Apply the protocol frame-size limits and disable Nagle's algorithm on accepted
connections.
## Testing
- Add an end-to-end test that starts the host on an ephemeral port, connects a
gRPC client, and opens a session.
- Verify accepted gRPC sockets have `TCP_NODELAY` enabled.
GitOrigin-RevId: 51d6c21dff8cffb47068c0677ba10ff370385cec
## What changed
- Add a `--listen` option that accepts `stdio`, `stdio://`, or a
`ws://IP:PORT` endpoint, while retaining stdio as the default.
- Serve the existing length-prefixed protocol in binary WebSocket messages,
with isolated connections, shared host limits, and a `/readyz` endpoint.
- Reject browser-origin handshakes and contain malformed frames to the affected
connection.
## Testing
- Cover listen URL parsing and complete-frame encoding and decoding.
- Exercise readiness, cell execution, tool callbacks, large frames, concurrent
connections, malformed frames, and origin rejection through the WebSocket
listener.
GitOrigin-RevId: 01c8be4c6256b8ce4a3a0002440dcb3294e5f887
## Summary
- implement the standalone `codex-code-mode-host` stdio service
- route sessions, cells, delegate requests, responses, and cancellation
through a bounded host peer
- supervise request, writer, cell-forwarding, actor, and V8 failure
boundaries
- bound request/session tombstones and fail-stop the connection on
invalid protocol state
- add host-only duplex protocol tests and local Cargo/Bazel run recipes
## Why
This stage makes the host process independently runnable and reviewable
before exposing any remote client in Codex. Transport or runtime failure
closes the connection and relies on process replacement rather than
transactional recovery.
## Stack
This is **3 of 4** in the process-owned code-mode session stack.
- Depends on #30110
- The final client PR targets this branch
## Validation
- `just test -p codex-code-mode-host` — 7 host-only tests passed
- `just fix -p codex-code-mode-host`
- `just bazel-lock-update`
- `just bazel-lock-check`
- `just fmt`
This is phase 1 of a 4 phase stack:
1. **Add protocol and host crates for new IPC code mode implementation**
2. Create the new standalone binary
3. Create a new IPC `CodeModeSessionProvider` to use new binary
4. Remove v8 from core and only use IPC provider
## Add protocol and host crates for new IPC code mode implementation
Establish a clean process boundary without changing the existing
in-process behavior.
- Add the codex-code-mode-protocol crate for shared session, runtime,
response, and tool-definition types.
- Move protocol-facing code out of the V8-backed implementation.
- Add a buildable codex-code-mode-host crate as the foundation for the
standalone process.
- Keep the existing in-process runtime as the active implementation.
