## 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.
## Summary
Related to
https://openai.slack.com/archives/C095U48JNL9/p1777537279707449
TLDR:
We update the meaning of session ids and thread ids:
* thread_id stays as now
* session_id become a shared id between every thread under a /root
thread (i.e. every sub-agent share the same session id)
This PR introduces an explicit `SessionId` and threads it through the
protocol/client boundary so `session_id` and `thread_id` can diverge
when they need to, while preserving compatibility for older serialized
`session_configured` events.
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
App-server had repeated hand-built JSON-RPC error objects for standard
error shapes. Using the shared helpers keeps the common
`invalid_request`, `invalid_params`, and `internal_error` construction
in one place and reduces the chance of new call sites drifting from the
common error payload shape.
## What changed
- Replaced manual standard JSON-RPC error object creation with
`internal_error(...)`, `invalid_request(...)`, and `invalid_params(...)`
across app-server request processors and runtime paths.
- Removed local duplicate helper definitions from search and review
request handling.
- Preserved existing structured `data` payloads by creating the shared
helper error first and then attaching the existing metadata.
- Left custom non-standard errors and raw error-code assertions intact.
## Validation
- `cargo test -p codex-app-server`
Migrate token usage replay, rollback responses, and detached review
setup (a special case of forking) to be served from ThreadStore reads
rather direct rollout files.
- replay restored token usage from already-loaded `RolloutItem` history
instead of reopening `Thread.path`
- rebuild rollback responses from loaded `ThreadStore` snapshots and
history
- start detached reviews from store-backed parent history and stored
review-thread metadata
- remove obsolete app-server rollout-summary helper code that became
dead after the store-backed migration
- preserve response/notification ordering for resume, fork, rollback,
and detached review flows
- add integration test coverage for the affected paths
## Why
Whenever we return a thread's history (turns and items) over app-server,
always return the limited form as specified by the rollout policy
`EventPersistenceMode::Limited`, even if the thread was previously
started with `EventPersistenceMode::Extended`.
We're finding it is quite unscalable to be returning the extended
history, so let's apply the same filtering logic of the rollout policy
when we load and return the thread's history.
## What Changed
- Reuse the rollout persistence policy when reconstructing app-server
`ThreadItem` history so only `EventPersistenceMode::Limited` rollout
items are replayed into API turns.
- Route `thread/read`, `thread/resume`, `thread/fork`,
`thread/turns/list`, and rollback responses through the same filtered
app-server history projection.
- Keep live active turns intact when composing a response for a
currently running thread.
- Update command execution coverage so persisted extended command events
are excluded from returned history for `thread/read`, `thread/fork`, and
`thread/turns/list`.
## Test Plan
- `cargo test -p codex-app-server limited`
- `cargo test -p codex-app-server thread_shell_command`
- `cargo test -p codex-app-server thread_read`
- `cargo test -p codex-app-server thread_rollback`
- `cargo test -p codex-app-server thread_fork`
- `cargo test -p codex-app-server-protocol`
## Why
The app-server request path had grown around a large
`CodexMessageProcessor` plus separate API wrapper/helper modules. That
made the dependency graph hard to see and forced unrelated request
families to share broad processor state.
This PR makes the split mechanical and command-prefix oriented so
request families own only the dependencies they use.
## What changed
- Replaced `CodexMessageProcessor` with command-prefix request
processors under `app-server/src/request_processors/`.
- Removed the old config, device-key, external-agent-config, and fs API
wrapper files by moving their API handling into processors.
- Split apps, plugins, marketplace, catalog, account, MCP, command exec,
fs, git, feedback, thread, turn, thread goals, and Windows sandbox
handling into dedicated processors.
- Kept shared lifecycle, summary conversion, token usage replay, and
shared error mapping only where multiple processors use them; single-use
helpers were inlined into their owning processor.
- Removed the fallback processor path and moved processor tests to
`_tests` files.
## Validation
- `cargo test -p codex-app-server`
- `cargo check -p codex-app-server`
- `just fix -p codex-app-server`
jif-oai ·
pakrym-oai ·
Tom ·
Owen Lin ·