## Why
Thread startup, running-thread resume, and rollback could outlive their request handlers, allowing connection draining and request serialization to finish too early.
## What changed
- Await thread startup and listener completion for running-thread resume and rollback.
- Release the thread-list permit before waiting for resume completion so the listener can finish rollback responses.
- Release pending rollback waiters when clearing a listener, and discard queued requests when their connection closes.
## Testing
Add coverage for releasing queued requests and rollback waiters, and pipeline resume during rollback to check that both responses complete. Update diagnostics expectations to allow startup to remain in flight after its response is queued.
GitOrigin-RevId: 138156179afbc40de29965820db7fa9cd3669cc7
## What changed
- Add nullable `model` and `reasoningEffort` fields to the shared app-server `Thread` object and generated schemas.
- Report current settings for loaded threads and the latest persisted settings for unloaded threads across thread read, list, start, resume, rollback, metadata update, and notification paths.
- Keep unavailable legacy or filesystem-only settings nullable, and allow metadata reads without loading a thread or dispatching queued work.
## Testing
- Cover live-setting precedence, persisted settings after restart, null legacy values, and model metadata returned by thread lifecycle operations.
GitOrigin-RevId: 22ebe8a8d1910a820d90a97730d812a00d8c1372
## What changed
When `thread/start` omits `historyMode`, select `paginated` for durable
threads whose store supports `thread/turns/list` and `thread/items/list`.
Continue to default ephemeral threads and threads backed by stores without
those APIs to `legacy`.
Explicit `legacy` and `paginated` selections keep their existing behavior.
## Testing
- Verify durable threads use paginated history with the local store.
- Verify ephemeral threads and stores without history-list support use legacy
history.
GitOrigin-RevId: c94b6a3b522049d541da33c41618c4142370f1a7
## What changed
- Add typed helpers for initialized app-server instances, JSON-RPC requests,
responses, notifications, and thread startup.
- Add a composable `MockResponsesConfig` builder while preserving the existing
mock config writers.
- Migrate the app-server integration suite to the shared helpers, removing
repeated request ID management, deserialization, initialization, and config
assembly.
## Testing
- Add unit coverage for composing mock provider, feature, and extra config, and
for compatibility of the existing mock config writer.
GitOrigin-RevId: 62da177c1d6e8299400de64bd6766567bf1ba3d8
## What changed
- Allow `thread/start` to select experimental `historyMode: "paginated"` when the thread store supports turn and item pagination.
- Resume paginated threads with bounded model context and require `excludeTurns: true` instead of loading full history.
- Return `turnsBackwardsCursor` and `itemsBackwardsCursor` from `thread/resume` so clients can hydrate durable history through `thread/turns/list` and `thread/items/list` while newer records arrive through live notifications.
- Reject operations that still require full history, including `initialTurnsPage`, `thread/read` with `includeTurns: true`, `thread/rollback`, and detached review.
- Make item cursors independent of the optional `turnId` filter.
## Testing
- Cover paginated thread start, cold and live resume, backwards cursor hydration, metadata reads, unsupported operations, and stores without pagination support.
GitOrigin-RevId: c42f9b268e29d049843330f474fa3ecde12f5b8a
## Why
The TUI uses `thread/rollback` internally for user-facing flows such as
prompt cancellation/backtracking. After `thread/rollback` was marked
deprecated, those internal calls started surfacing `deprecationNotice`
messages in the TUI, even though the user did not explicitly call the
deprecated app-server API.
The endpoint should remain deprecated for external app-server clients,
but the built-in `codex-tui` client should not show this
implementation-detail warning during normal interaction.
## What changed
- Pass the initialized app-server client name into the `thread/rollback`
request processor.
- Suppress the `thread/rollback` deprecation notice only for
`codex-tui`.
- Preserve the existing `deprecationNotice` behavior for non-TUI
clients.
- Add regression coverage for the `codex-tui` suppression path.
## How to Test
1. Start Codex TUI from this branch.
2. Type text into the composer and press `Esc` to cancel/backtrack.
3. Confirm the TUI restores/cancels the prompt without showing
`thread/rollback is deprecated and will be removed soon`.
4. Also verify an external app-server client that calls
`thread/rollback` still receives `deprecationNotice`.
Targeted tests:
- `just test -p codex-app-server thread_rollback`
- `just argument-comment-lint`
## Why
Topology-neutral app-server integration tests should exercise automatic
environment selection so the same setup covers local and remote
executors.
## What
Migrate eligible tests to `TestAppServer::new_with_auto_env()` and
`send_thread_start_request_with_auto_env()`. Leave explicit-topology
tests unchanged, and skip the request-permissions case on Windows with a
TODO for cross-platform tool routing.
## Validation
- `just test -p codex-app-server`
- `bazel test //codex-rs/app-server:app-server-all-wine-exec-test
--test_output=errors`
Stacked on #29788.
This PR brought to you via VS Code rather than Codex...
- opened `codex-rs/app-server/tests/common/mcp_process.rs`
- put the cursor on `McpServer`
- hit `F2` and renamed the symbol to `TestAppServer`
- went to the file tree
- hit enter and renamed `mcp_process.rs` to `test_app_server.rs`
- ran **Save All Files** from the Command Palette
- ran `just fmt`
The End
(Admittedly, most of the local variables for `TestAppServer` are still
named `mcp`, though.)
## Summary
Adds an optional `clientId` field to app-server v2 `UserInput` and
carries it through the core `UserInput` model so clients can correlate
echoed user input items without relying on payload equality.
## Details
- Adds `client_id: Option<String>` to core `UserInput` variants.
- Exposes the v2 app-server field as `clientId` on the wire and in
generated TypeScript.
- Preserves the id when converting between app-server v2 and core
protocol types.
- Regenerates app-server schema fixtures.
## Validation
- `just fmt`
- `just write-app-server-schema`
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-protocol`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-protocol`
- `git diff --check`
## Why
`session_id` and `thread_id` are separate identities after #20437, but
app-server only surfaced `sessionId` on the `thread/start`,
`thread/resume`, and `thread/fork` response envelopes. Other
thread-bearing surfaces such as `thread/list`, `thread/read`,
`thread/started`, `thread/rollback`, `thread/metadata/update`, and
`thread/unarchive` either lacked the grouping key or forced clients to
special-case those three responses.
Making `sessionId` part of the reusable `Thread` payload gives every v2
API surface one place to expose session-tree identity.
## Mental model
1. thread.sessionId lives on `Thread`
2. It is a view/runtime identity for the current live session tree, not
durable stored lineage metadata
3. When app-server has a live loaded thread, it copies the real value
from core’s session_configured.session_id
4. When it only has stored/unloaded data, it falls back to
thread.sessionId = thread.id
## What changed
- Added `sessionId` to the v2
[`Thread`](https://github.com/openai/codex/blob/8fc9e9b4cf81b6f61d432e71f1eb266f6f104b63/codex-rs/app-server-protocol/src/protocol/v2/thread_data.rs#L105-L109).
- Removed the duplicate top-level `sessionId` fields from
`thread/start`, `thread/resume`, and `thread/fork`; clients should now
read `response.thread.sessionId`.
- Populated `thread.sessionId` when building live thread responses,
replaying loaded threads, and returning stored-thread summaries so the
field is present across start, resume, fork, list, read, rollback,
metadata-update, unarchive, and `thread/started` paths. See
[`load_thread_from_resume_source_or_send_internal`](https://github.com/openai/codex/blob/8fc9e9b4cf81b6f61d432e71f1eb266f6f104b63/codex-rs/app-server/src/request_processors/thread_processor.rs#L2824-L2918)
and
[`thread_from_stored_thread`](https://github.com/openai/codex/blob/8fc9e9b4cf81b6f61d432e71f1eb266f6f104b63/codex-rs/app-server/src/request_processors/thread_processor.rs#L3671-L3719).
- Preserved the stored-thread fallback: if a thread has not been loaded
into a live session tree yet, `thread.sessionId` falls back to
`thread.id`; once the thread is live again, the field reports the active
session tree root.
- Regenerated the JSON/TypeScript schemas and updated the app-server
README examples to show
[`thread.sessionId`](https://github.com/openai/codex/blob/8fc9e9b4cf81b6f61d432e71f1eb266f6f104b63/codex-rs/app-server/README.md#L306-L310)
on the thread object.
Exposes through the app server updated names set for a thread. This
enables other surfaces to use the core as the source of truth for thread
naming. `threadName` is gathered using the helper functions used to
interact with `session_index.jsonl`, and is hydrated in:
- `thread/list`
- `thread/read`
- `thread/resume`
- `thread/unarchive`
- `thread/rollback`
We don't do this for `thread/start` and `thread/fork`.
Motivation
- Today, a newly connected client has no direct way to determine the
current runtime status of threads from read/list responses alone.
- This forces clients to infer state from transient events, which can
lead to stale or inconsistent UI when reconnecting or attaching late.
Changes
- Add `status` to `thread/read` responses.
- Add `statuses` to `thread/list` responses.
- Emit `thread/status/changed` notifications with `threadId` and the new
status.
- Track runtime status for all loaded threads and default unknown
threads to `idle`.
- Update protocol/docs/tests/schema fixtures for the revised API.
Testing
- Validated protocol API changes with automated protocol tests and
regenerated schema/type fixtures.
- Validated app-server behavior with unit and integration test suites,
including status transitions and notifications.
Add `thread/rollback` to app-server to support IDEs undo-ing the last N
turns of a thread.
For context, an IDE partner will be supporting an "undo" capability
where the IDE (the app-server client) will be responsible for reverting
the local changes made during the last turn. To support this well, we
also need a way to drop the last turn (or more generally, the last N
turns) from the agent's context. This is what `thread/rollback` does.
**Core idea**: A Thread rollback is represented as a persisted event
message (EventMsg::ThreadRollback) in the rollout JSONL file, not by
rewriting history. On resume, both the model's context (core replay) and
the UI turn list (app-server v2's thread history builder) apply these
markers so the pruned history is consistent across live conversations
and `thread/resume`.
Implementation notes:
- Rollback only affects agent context and appends to the rollout file;
clients are responsible for reverting files on disk.
- If a thread rollback is currently in progress, subsequent
`thread/rollback` calls are rejected.
- Because we use `CodexConversation::submit` and codex core tracks
active turns, returning an error on concurrent rollbacks is communicated
via an `EventMsg::Error` with a new variant
`CodexErrorInfo::ThreadRollbackFailed`. app-server watches for that and
sends the BAD_REQUEST RPC response.
Tests cover thread rollbacks in both core and app-server, including when
`num_turns` > existing turns (which clears all turns).
**Note**: this explicitly does **not** behave like `/undo` which we just
removed from the CLI, which does the opposite of what `thread/rollback`
does. `/undo` reverts local changes via ghost commits/snapshots and does
not modify the agent's context / conversation history.
Eric Traut