## Why
A delegate bound at session creation cannot provide different callbacks for cells sharing that session. Each execution needs to retain its own delegate across yields and release it when the cell is cleaned up.
## What changed
- Pass `CodeModeSessionDelegate` to `execute` instead of session creation.
- Route tool calls, notifications, and cell closure callbacks through the execution's delegate in the in-process runtime and the gRPC and stdio transports.
- Retain delegates with pending executions and live cells, releasing them through closure and cancellation cleanup.
## Testing
Add coverage for distinct delegates across yielded cells, gRPC callbacks before cell admission, and delegate release after completion or abandoned execution cleanup. Update transport tests to verify callbacks reach the owning cell's delegate.
GitOrigin-RevId: 7469f52104b993e790a40c65fb800ad02b7fd606
## Why
Code mode wall time should measure the host operation itself, without including
client-side response delays or idle time between requests.
## What changed
- Measure each execute, wait, and terminate request in the code mode host.
- Carry the duration through the stdio and gRPC protocols and use it for
model-visible wall time.
- Emit a structured `codex.code_mode.host_timing` event correlated with the
conversation, turn, tool call, and cell.
## Testing
- Cover successful and failed execution timing, delayed response reads,
repeated waits, termination, and missing cells across stdio and gRPC.
- Verify timing survives protocol serialization and is reflected in app-server
model output and structured telemetry.
GitOrigin-RevId: d24af30c3fc5820521b4beba1f9970714dad6482
## 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
- Serve `GET /healthz` with a `200 OK` response over HTTP/1.1 and HTTP/2.
- Continue requiring HTTP/2 for all other requests so gRPC methods are not exposed over HTTP/1.1.
## Testing
- Add TCP listener integration coverage for HTTP/1.1 and HTTP/2 health checks and rejection of HTTP/1.1 gRPC requests.
GitOrigin-RevId: ae7bbf56323fbc76769375a6d8e90653e8adc860
## What changed
- Forward notification text to the session delegate without applying the previous 1,024-byte limit or appending a truncation suffix.
- Update the gRPC host integration test to verify that oversized multibyte notification text is delivered unchanged.
GitOrigin-RevId: 9a9e24b359a07540f70ec4e98b28524db3f7a4a0
## What changed
- Use a never-resolving promise when verifying that a session continues to
enforce its yield limit after terminating a cell.
- Use `yield_control()` to create the yielded cell in the notification-draining
test instead of relying on timer scheduling.
GitOrigin-RevId: 01cdaa94e5b8b5c89c6fa98c4bbdb28a690678e0
## What changed
- Accept root `http://` and `https://` URLs in `--code-mode-host` and use the
shared gRPC session provider for those endpoints.
- Keep `ws://` and `wss://` URLs on the existing WebSocket transport.
- Reject paths, queries, fragments, and credentials where unsupported, without
exposing gRPC URL credentials in command-line validation errors.
## Testing
- Cover argument parsing and transport selection for both remote protocols.
- Exercise a gRPC host shared across app-server threads and verify credential
rejection does not disclose usernames or passwords.
GitOrigin-RevId: b6516a85cf76db5c4cea620f89ef866d8af30cf0
## What changed
- Reopen a cached code-mode session when its gRPC host stops, while
serializing concurrent reconnection attempts and coordinating shutdown.
- Scope cell IDs to the new host generation so callbacks remain consistent
and stale `wait` or `terminate` requests are rejected.
- Accept both `unix://` and `unix:` endpoints for gRPC hosts on Unix systems.
## Testing
- Cover host restart recovery, concurrent execution after reconnection,
generation-aware callbacks and cell operations, stale cell rejection, and
Unix socket execution.
GitOrigin-RevId: 548e168fdcef7f7d54bd32262e614886bf7bdd32
## What changed
- Subscribe each gRPC code-mode session to nested tool calls and forward tool and notification callbacks to its delegate.
- Complete tool calls through the host while bounding oversized results and errors.
- Track callback ownership and cancellation so completed cells drain notifications, terminated cells cancel them, and shutdown revokes outstanding work.
- Validate callback identifiers, cell ownership, enabled tools, and pending callback limits without serializing independent callbacks or sessions.
## Testing
- Add integration and state tests for callback forwarding, completion ordering, cancellation, malformed callbacks, delegate panics, oversized results, and concurrent work.
GitOrigin-RevId: 005afbb90eea0eb77d746b930a1a96ca6dfcd4e7
## What changed
- Add `GrpcCodeModeSessionProvider` for opening code-mode sessions over HTTP/2 or an existing `tonic` channel.
- Support execution, waiting, termination, per-session limits, cell-closure callbacks, and graceful shutdown over the gRPC protocol.
- Bound transport waits and error messages, validate host identifiers and responses, and clean up abandoned executions and observers.
## Testing
- Add end-to-end TCP tests covering session persistence, cancellation, concurrent waits, shutdown, cell cleanup, and independent yield limits.
- Add unit coverage for protocol conversion, deadlines, and session lifecycle state.
GitOrigin-RevId: d4729ce608ad4b42a99744b07e1f230e46cb24ec
## What changed
- Move the host process harness and common session delegates into shared test
support modules.
- Allow the host harness to start either WebSocket or gRPC listeners and
validate the endpoint scheme they publish.
- Update the stdio and WebSocket integration tests to use the shared fixtures.
GitOrigin-RevId: a0408be7c88e4eb9ad1832b6d2698781de77168a
## 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
- Export `GrpcCodeModeHost` as a transport-independent implementation of the
code-mode gRPC API.
- Support leased sessions, execution and wait lifecycle operations, filtered
nested tool-call subscriptions, tool completions, and notification
acknowledgements.
- Share host-wide request and active-cell limits across the existing and gRPC
transports, and bound identifiers, metadata, subscriptions, and pending
callbacks.
## Testing
- Add coverage for request conversion, ordered callback routing, cancellation,
session cleanup, backpressure, malformed input, and resource-limit handling.
GitOrigin-RevId: f146ba7e6fe4e4aa02f25dd3f961120980516d0e
## What changed
- Add `create_session_with_limits` and session-scoped cell execution limits.
- Clamp execute and wait yield times to the session's `max_yield_time_ms`
without terminating the running cell.
- Negotiate support with remote code-mode hosts and include non-default limits
in `session/open`, while keeping unlimited sessions compatible with hosts and
providers that do not support limits.
## Testing
- Cover yield-time clamping, zero-timeout behavior, and isolation between
sessions.
- Cover wire serialization, capability negotiation, unsupported hosts, and
shared process-host execution.
GitOrigin-RevId: 9517321cd605bb87f93eeaa6ba331cc2e346e582
## Why
Large nested-tool callbacks can occupy a WebSocket and delay unrelated session
operations on the same code-mode connection.
## What changed
- Negotiate the optional `dual-websocket-v1` capability and pair a second,
token-scoped WebSocket with the control connection.
- Route nested-tool callbacks and their results over the bulk socket while
keeping session operations, notifications, and execution responses on the
control socket. Reject messages sent on the wrong lane.
- Preserve the single-connection transport when the capability is unavailable,
and bound pairing, queued callbacks, and deferred cross-socket messages.
- Defer callbacks that arrive before their execution-started response, and
return delegate errors without disconnecting the connection.
## Testing
Add protocol, transport, driver, and WebSocket integration coverage for
capability negotiation, lane routing, pairing failures, out-of-order messages,
and progress during large concurrent tool results.
GitOrigin-RevId: fa4504653e7cbf3c4ec930ae57aa0a41345bad66
## 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
- add `ProcessOwnedCodeModeSessionProvider` and logical session
generation/rebinding state
- add the supervised child-process connection, reader/writer tasks, and
driver state machine
- make dropped execute/wait/open callers cancellation-safe with explicit
ownership handoff and durable cleanup
- validate cell/delegate lifecycle state and reject invalid protocol
transitions
- add end-to-end stdio coverage for delegates, cancellation, frame
limits, child loss, stale generations, replacement, and long-lived
sessions
## Why
This final stage exposes the process-owned client only after the wire
protocol, host-safe runtime, and standalone host are independently in
place. Transport failure is fail-stop: the client closes local state,
cancels callbacks, reaps the child, and lazily rebuilds a fresh host
generation rather than transactionally recovering the old connection.
## Stack
This is **4 of 4** in the process-owned code-mode session stack.
- Depends on #30111
- Full stack: #30108 → #30110 → #30111 → this PR
## Validation
- `just test -p codex-code-mode -p codex-code-mode-host` — 86 passed
- `just fix -p codex-code-mode`
- `just fix -p codex-code-mode-host`
- `just bazel-lock-update`
- `just bazel-lock-check`
- `bazel test //codex-rs/code-mode:code-mode-unit-tests
//codex-rs/code-mode-host:code-mode-host-unit-tests
//codex-rs/code-mode-host:code-mode-host-stdio-test
//codex-rs/code-mode-protocol:code-mode-protocol-unit-tests` — 4/4
passed
- `just fmt`
