## Why
A long-running unified exec process started with `tty: false` could not
be interrupted via `write_stdin`: ordinary non-TTY stdin writes are
rejected once stdin is closed, but an exact U+0003 payload should still
map to a process interrupt. The interrupt should flow through the same
process lifecycle path as a real signal so Codex preserves
process-reported output and exit metadata instead of fabricating a
Ctrl-C exit code or tearing down the session early.
## What Changed
- Add `process/signal` to exec-server with `ProcessSignal::Interrupt`
and an empty response.
- Add a non-consuming `ProcessHandle::signal` path for spawned
processes; on Unix it sends SIGINT to the process group and leaves
terminate/hard-kill unchanged.
- Route non-TTY U+0003 `write_stdin` through `process.signal(...)`
instead of `terminate`, then let the normal post-write collection path
drain output and observe exit.
- Add exec-server coverage where a shell `trap INT` handler prints the
signal and exits with its own code.
- Add unified exec coverage where a `tty: false` process traps SIGINT,
emits output, and exits with its own code.
## Validation
- `just test -p codex-exec-server
exec_process_signal_interrupts_process`
- `just test -p codex-exec-server`
- `just test -p codex-core
write_stdin_ctrl_c_interrupts_non_tty_session`
## Why
Persisted MCP OAuth credentials were reported as authenticated whenever
a credential record existed. An expired token without a usable refresh
token could therefore appear as `OAuth` even though startup could not
authenticate with it, leaving users with a misleading status instead of
a login prompt.
## What changed
- Classify stored OAuth credentials as missing, usable, or requiring
authorization.
- Reuse the existing refresh window so near-expiry credentials without a
refresh path are also treated as logged out.
- Validate required credential fields before reporting OAuth
authentication.
- Add unit coverage for credential usability and integration coverage
for expired, unexpired, and refreshable persisted credentials.
## Validation
- `just test -p codex-rmcp-client`
## Why
Global instruction behavior spans thread creation, resume, forks,
subagents, and compaction. Characterization coverage is needed before
changing those semantics so preserved history can be distinguished from
newly loaded configuration.
## What changed
- Extends the existing `agents_md` suite with fresh-thread, warning,
resume, fork, and subagent lifecycle coverage.
- Extends the existing `compact` suite with manual, mid-turn, and
remote-v2 compaction coverage.
- Asserts rendered instruction fragments, reported source paths, and
structured request history before and after instruction-file mutations.
## Stack
- Base: #27184
- This PR is the second vertical and should be reviewed against
`jif/external-plugins-1`, not `main`.
## Why
CCA is moving toward a split runtime where the orchestrator may have no
filesystem or executor, but it still needs to activate remotely hosted
plugin components. HTTP MCP servers are the simplest complete example:
they need configuration and host authentication, but they do not need an
executor process.
The Apps MCP endpoint is currently synthesized by a special-purpose
loader inside the MCP runtime. That works locally, but it leaves hosted
MCP activation outside the extension model being established in #27184.
It also makes the Apps path a poor foundation for plugins whose skills,
MCP servers, connectors, and hooks may come from different sources or
execute in different places.
This PR moves that one behavior behind an extension-owned contribution
while preserving the existing local fallback. It deliberately does not
introduce a generic plugin activation framework.
## What changed
### MCP extension contribution
`codex-extension-api` gains an ordered `McpServerContributor` contract.
A contributor returns typed `Set` or `Remove` overlays for MCP server
configuration; later contributors win for the names they own.
The contract stays at the existing MCP configuration boundary.
Extensions do not create a second connection manager or transport
abstraction.
### Hosted Apps MCP extension
A new `codex-mcp-extension` contributes the reserved `codex_apps` server
from the existing Apps feature, ChatGPT base URL, path override, and
product SKU configuration.
When `apps_mcp_path_override` is enabled for `https://chatgpt.com`, the
resulting streamable HTTP endpoint is
`https://chatgpt.com/backend-api/ps/mcp`. The existing ChatGPT-auth gate
remains authoritative, so this server can run in an orchestrator-only
process without being exposed for API-key sessions.
### One resolved runtime view
`McpManager` now distinguishes three views:
- **configured:** config- and plugin-backed servers before extension
overlays;
- **runtime:** configured servers plus host-installed extension
contributions;
- **effective:** runtime servers after auth gating and compatibility
built-ins.
App-server installs the hosted MCP extension and uses the runtime view
for thread startup, refresh, status, threadless resource reads,
connector discovery, and MCP OAuth lookup. This keeps
`mcpServer/oauth/login` consistent with the servers exposed by the other
MCP APIs. The hosted Apps server itself continues to use existing
ChatGPT host authentication rather than MCP OAuth.
## Compatibility
Hosts that do not install the MCP extension retain the existing Apps MCP
synthesis path. This preserves current local-only, CLI, and
standalone-host behavior while app-server exercises the extension path.
Disabling Apps removes the reserved `codex_apps` entry, and losing
ChatGPT auth removes it from the effective runtime view. Executor
availability is not consulted for this HTTP transport.
## Follow-ups
The next vertical will resolve a manifest-declared stdio MCP server from
an executor-selected plugin root and execute it in the environment that
owns that root. Later verticals can add backend-owned skills, connector
metadata, hooks, durable selection semantics, and incremental local
convergence without changing the component-specific runtime boundaries
introduced here.
## Verification
Focused coverage was added for:
- contributing the hosted Apps MCP at `/backend-api/ps/mcp` without an
executor;
- requiring ChatGPT auth in the effective runtime view;
- removing a reserved configured Apps server when the Apps feature is
disabled.
`cargo check -p codex-app-server -p codex-mcp-extension -p
codex-extension-api -p codex-mcp` passed. Tests and Clippy were not run
locally under the current development instruction; CI provides the full
validation pass.
## Why
Goal continuation turns are emitted by the existing runtime as separate
physical turns. The Python SDK needs private thread-scoped routing
before it can present those notifications as one logical operation,
without changing ordinary turn routing or the app-server protocol.
## What
- add private goal operation state and thread-scoped notification
routing
- add internal wrappers for the existing `thread/goal/clear` and
`thread/goal/set` RPCs
- include existing goal notifications in the SDK notification union
- preserve ordinary turn-ID routing unchanged
- add focused routing coverage
This PR does not expose a public goal API. It is the first PR in the
Python goal operations stack.
## Test plan
- online CI, including the Python SDK suite
- focused typed-notification routing coverage
## Why
The TUI still reached through `app-server-client::legacy_core` for
thread-name normalization and project-instruction filename details. In
particular, checking the TUI's local filesystem for `/init` is incorrect
for remote app-server sessions, where the server owns the working
directory and instruction discovery.
## What changed
- use the instruction source paths supplied by the app server to decide
whether `/init` should avoid overwriting project instructions
- keep the small thread-name normalization helper local to the TUI
- remove the now-unused instruction filename constants, utility module,
and other unused `legacy_core` re-exports
- make status helper tests independent of concrete instruction filenames
## Verification
- `just test -p codex-app-server-client`
- `just test -p codex-tui
slash_init_skips_when_project_instructions_are_loaded`
- `just test -p codex-tui` ran 2,799 tests; 2,797 passed and two
unrelated guardian feature-flag tests failed reproducibly in untouched
code
### Manual test
Started an app server over WebSocket with a remote workspace containing
`AGENTS.md`, then connected the TUI using `--remote`. After confirming
`thread/start` returned the file in `instructionSources`, deleted
`AGENTS.md` and ran `/init` in the existing session.
The TUI still reported that project instructions already existed and
skipped `/init`. The trace contained no `turn/start` request, confirming
the decision came from app-server session state rather than a new
client-local filesystem check.
## Why
Users have indicated that they want an agent to be able to create a new
goal for itself after completing the previous goal. Currently, that's
not possible because agents cannot overwrite an existing goal even if
it's complete. This PR removes this limitation and allows `create_goal`
to overwrite an existing goal if it is in the `complete` state.
## What changed
`create_goal` now replaces the existing goal only when its status is
`complete`. The replacement is performed atomically in the goal store,
creates a fresh active goal with reset usage, and continues to reject
creation while any unfinished goal exists. App server clients see a
single `thread/goal/updated` event when the previous goal is replaced
with the new one.
The tool description and error message now reflect these semantics.
## What didn't change
Agents are not allowed to create a new goal (overwrite their existing
goal) if an existing goal is still active, blocked, paused, or in any
other state other than "completed".
## Why
`just test` currently uses the CI-oriented nextest profile, which
serializes app-server integration tests even on developer machines that
can run several safely. Bounded local parallelism substantially shortens
this common iteration loop without changing CI behavior.
Eight-worker experiments were faster, but keeping them reliable required
relaxing several test deadlines. Four workers for integration tests is a
solid tradeoff that speeds up local testing without needing to change
test logic.
## What changed
- Add a `local` nextest profile that inherits the existing defaults.
- Allow up to four app-server integration tests to run concurrently
under that profile.
- Make `just test` select the local profile on Unix and Windows.
- Keep the default CI profile serialized and leave all test deadlines
unchanged.
The tests use separate processes, randomized temporary `CODEX_HOME`
directories, and ephemeral ports. The remaining shared constraints are
system resources; each app-server also uses a multi-thread Tokio
runtime, and fuzzy-search tests can create additional worker threads, so
the local cap remains intentionally conservative.
## Performance and validation
All measurements below are warm, execution-only app-server runs with
nextest retries disabled.
On the current rebased branch, an AMD EPYC 7763 machine with 16 logical
CPUs and 62 GiB RAM completed three consecutive runs:
| Run | Nextest time | Wall time | Result |
| --- | ---: | ---: | --- |
| 1 | 142.941s | 145.17s | 836/836 passed |
| 2 | 143.402s | 145.59s | 836/836 passed |
| 3 | 142.870s | 145.08s | 836/836 passed |
The mean wall time was 145.28s. The slow-inventory, approval replay, and
zsh-fork tests all passed with their original deadlines.
Earlier measurements on the same Linux machine, before the suite grew,
showed the scaling that motivated the change:
| App-server concurrency | Nextest time | Result |
| --- | ---: | --- |
| 1 | 369.5s | 572/572 passed |
| 2 | 194.5s | 572/572 passed |
| 4 | 111.0s mean over 3 runs | 3/3 clean |
Four workers reduced that execution time by about 70%, a roughly 3.3x
speedup over serialization.
## Why
- `ThreadSource` currently defines a closed set of core-owned values
- Product features also create threads for background or scheduled work
- Adding every product-specific value to the core enum would require
repeated `codex-rs` protocol changes
- Feature-backed values let product callers provide precise attribution
while preserving the existing core classifications
## What Changed
- Adds `ThreadSource::Feature(String)` for app-owned thread source
values
- Represents all app-server v2 thread sources as scalar strings, so a
feature source is supplied as `"automation"`
- Persists and emits the feature's plain string label, so `"automation"`
produces `thread_source="automation"` in analytics
- Keeps `user`, `subagent`, and `memory_consolidation` as explicit
core-owned values and regenerates the app-server schemas and TypeScript
bindings
## Verification
- `just write-app-server-schema`
- `cargo check --workspace`
- `just test -p codex-protocol
feature_thread_source_serializes_as_its_app_owned_label`
- `just test -p codex-app-server-protocol
thread_sources_round_trip_as_scalar_labels`
- `cargo test -p codex-analytics
thread_initialized_event_serializes_expected_shape`
- `just fmt`
## Why
`codex-extension-api` defines contracts shared by extension crates and
their hosts, but it had no direct test suite. Host and feature tests
cover downstream behavior, while regressions in the API crate's own
typed state, registry ordering, and capability adapters could go
unnoticed.
## What
- Add public-surface integration tests for `ExtensionData`, including
concurrent initialization and poison recovery.
- Cover contributor registration order, approval short-circuiting, event
sink retention, no-op response injection, and closure-based agent
spawning.
- Add the test-only dependencies used by the suite.
## Validation
- `just test -p codex-extension-api`
- `just argument-comment-lint -p codex-extension-api`
- `just bazel-lock-check`
