## Why
Extensions that need to track runtime progress currently have no typed
host signal for tool execution. The goal extension in particular needs
to observe tool attempts without inspecting tool payloads, owning tool
implementations, or staying coupled to core-only runtime plumbing.
This adds a narrow lifecycle contributor API for host-owned tool
execution: extensions can observe when an accepted tool call starts and
how it finishes, while policy hooks and tool handlers continue to own
payload rewriting, blocking, and execution.
Relevant code:
-
[`ToolLifecycleContributor`](3ad2850ffc/codex-rs/ext/extension-api/src/contributors.rs (L119))
defines the extension-facing observer contract.
-
[`tool_lifecycle.rs`](3ad2850ffc/codex-rs/ext/extension-api/src/contributors/tool_lifecycle.rs)
defines the typed start/finish inputs, source, and outcome enums.
- [`notify_tool_start` /
`notify_tool_finish`](3ad2850ffc/codex-rs/core/src/tools/lifecycle.rs)
bridges core tool dispatch into the extension registry.
## What Changed
- Added `ToolLifecycleContributor` to `codex-extension-api`, including:
- `ToolStartInput`
- `ToolFinishInput`
- `ToolCallSource`
- `ToolCallOutcome`
- Added registration and lookup support on `ExtensionRegistryBuilder` /
`ExtensionRegistry`.
- Wired core tool dispatch to notify lifecycle contributors for:
- accepted tool starts
- completed tool calls, including the tool output success marker
- pre-tool-use blocks
- failures before or after the handler runs
- cancellation/abort in the parallel tool path
- Registered the goal extension as a lifecycle contributor and added the
outcome filter it will use for goal progress accounting.
## Test Coverage
- Added `dispatch_notifies_tool_lifecycle_contributors` to cover
lifecycle notification ordering and outcomes for successful and
handler-failed tool calls.
## Why
Goal creation and completion are moving through the goal extension, but
the rest of Codex still observes goal state through `ThreadGoalUpdated`
events. Without an event from the extension-owned tool path, a
model-initiated `create_goal` or `update_goal` can mutate the backend
and return a tool result while app-server and TUI listeners miss the
goal state transition.
## What changed
- Added `GoalEventEmitter` as a small wrapper around the host
`ExtensionEventSink` to build `EventMsg::ThreadGoalUpdated` events for
goal updates.
- Threaded the registry event sink into `GoalExtension` and the
`GoalToolExecutor`s created by the extension. The public
`GoalExtension::new` constructor keeps a `NoopExtensionEventSink`
fallback for standalone use.
- Emitted a goal update after successful `create_goal` and `update_goal`
tool calls. Until `ToolCall` exposes the current turn submission id,
these events use the tool call id as the event id and leave `turn_id`
unset.
Relevant code:
-
[`GoalEventEmitter::thread_goal_updated`](1fe2d73890/codex-rs/ext/goal/src/events.rs (L19-L32))
- [`GoalToolExecutor` emission
points](1fe2d73890/codex-rs/ext/goal/src/tool.rs (L161-L190))
## Testing
- `cargo test -p codex-goal-extension`
## Why
Extension lifecycle hooks sit on the host/extension boundary, but the
current trait surface only allows synchronous callbacks. That forces
extensions that need to seed, rehydrate, observe, or flush
extension-owned state during thread and turn transitions to either block
inside the callback or move async work into separate host plumbing.
This PR makes those lifecycle callbacks awaitable so extension
implementations can perform async work directly at the lifecycle point
where the host already has the relevant session, thread, or turn stores
available.
## What changed
- Makes `ThreadLifecycleContributor` and `TurnLifecycleContributor`
async in `codex-extension-api`.
- Awaits thread start/resume/stop and turn start/stop/abort lifecycle
callbacks from `codex-core`.
- Updates the guardian and memories extensions to implement the async
lifecycle trait surface.
- Updates the existing lifecycle tests to use async contributor
implementations.
- Adds `async-trait` to the crates that now expose or implement these
async object-safe lifecycle traits.
## Testing
- Existing `codex-core` lifecycle tests were updated to cover async
implementations for thread stop and turn abort ordering.
