771a4e74ac
## Why App-server clients need a way to update a thread's next-turn settings without starting a turn, adding transcript content, or waiting for turn lifecycle events. This gives settings UI a direct path for durable thread settings while clients observe the eventual effective state through a notification. This is a simplified rework of PR https://github.com/openai/codex/pull/22509. In particular, it changes the `thread/settings/update` api to return immediately rather than waiting and returning the effective (updated) thread settings. This makes the new api consistent with `turn/start` and greatly reduces the complexity of the implementation relative to the earlier attempt. ## What Changed - Adds experimental `thread/settings/update` with partial-update request fields and an empty acknowledgment response. - Adds experimental `thread/settings/updated`, carrying full effective `ThreadSettings` and scoped by `threadId` to subscribed clients for the affected thread. - Shares durable settings validation with `turn/start`, including `sandboxPolicy` plus `permissions` rejection and `serviceTier: null` clearing. - Emits the same settings notification when `turn/start` overrides change the stored effective thread settings. - Regenerates app-server protocol schema fixtures and updates `app-server/README.md`.
codex-app-server-client
Shared in-process app-server client used by conversational CLI surfaces:
codex-execcodex-tui
Purpose
This crate centralizes startup and lifecycle management for an in-process
codex-app-server runtime, so CLI clients do not need to duplicate:
- app-server bootstrap and initialize handshake
- in-memory request/event transport wiring
- lifecycle orchestration around caller-provided startup identity
- graceful shutdown behavior
Startup identity
Callers pass both the app-server SessionSource and the initialize
client_info.name explicitly when starting the facade.
That keeps thread metadata (for example in thread/list and thread/read)
aligned with the originating runtime without baking TUI/exec-specific policy
into the shared client layer.
Transport model
The in-process path uses typed channels:
- client -> server:
ClientRequest/ClientNotification - server -> client:
InProcessServerEventServerRequestServerNotificationLegacyNotification
JSON serialization is still used at external transport boundaries (stdio/websocket), but the in-process hot path is typed.
Typed requests still receive app-server responses through the JSON-RPC result envelope internally. That is intentional: the in-process path is meant to preserve app-server semantics while removing the process boundary, not to introduce a second response contract.
Bootstrap behavior
The client facade starts an already-initialized in-process runtime, but thread bootstrap still follows normal app-server flow:
- caller sends
thread/startorthread/resume - app-server returns the immediate typed response
- richer session metadata may arrive later as a
SessionConfiguredlegacy event
Surfaces such as TUI and exec may therefore need a short bootstrap phase where they reconcile startup response data with later events.
Backpressure and shutdown
- Queues are bounded and use
DEFAULT_IN_PROCESS_CHANNEL_CAPACITYby default. - Full queues return explicit overload behavior instead of unbounded growth.
shutdown()performs a bounded graceful shutdown and then aborts if timeout is exceeded.
If the client falls behind on event consumption, the worker emits
InProcessServerEvent::Lagged and may reject pending server requests so
approval flows do not hang indefinitely behind a saturated queue.