## Why
Executor-scoped cleanup hooks need to observe an interrupted turn as well as a
normally completed one.
## What changed
- Allow bundled executor plugins to register the allowlisted `Interrupt` hook
alongside `Stop`, while preserving multiple allowed hook entries from the
selected executor environment.
- Run interrupt hooks with the interrupted turn's last step discovery and turn
metadata. Turns without a step context do not reuse discovery from an earlier
turn.
- Keep executor-scoped interrupt hooks asynchronous and omit public hook
lifecycle events for them, matching executor `Stop` hook behavior.
## Testing
Added coverage for hook filtering and registration, interrupt execution and
metadata propagation, environment selection, and turns without a step context.
GitOrigin-RevId: f0c536b3382a37cf3bf693c4573d21f6f66ace4e
## What changed
- Add an `Interrupt` hook event that runs for an active top-level turn before its
interrupted abort event is emitted.
- Flush the turn transcript before invoking the hook and provide the session,
turn, transcript, working directory, model, and permission mode in its input.
- Support command and MCP handlers, including asynchronous commands, with a
one-second default timeout and a three-second maximum.
- Expose the event through hook configuration, managed requirements, app-server
notifications, generated schemas, analytics, and the TUI hook views.
## Testing
- Cover handler discovery, timeout normalization, output parsing, protocol
compatibility, TUI rendering, and interrupt execution ordering.
GitOrigin-RevId: 163fa7c098d94ac2775f6d137f8e916f8ea9b6eb
## What changed
- Represent configured handlers by handler kind and route execution through the
hooks engine, while preserving command hook behavior.
- Reject MCP tool inputs containing values such as `null` that cannot be
represented in TOML for trust hashing.
## Testing
- Add coverage for rejecting `null` at the top level and within nested MCP tool
input objects and arrays.
GitOrigin-RevId: 3854a349c2a721691450467592f99cf57e6260ef
## What changed
- Parse `mcp_tool` hook handlers with a server, tool, JSON input, and optional timeout and status message.
- Return managed MCP tool hooks from `configRequirements/read` and include the handler in the generated protocol schemas.
- Skip MCP tool hooks during discovery with an explicit warning until execution is supported.
## Testing
- Cover MCP tool hook deserialization, including nested and null JSON input values.
- Extend the config requirements RPC test to verify the new handler shape.
GitOrigin-RevId: ff7e2d12b75b486c54d63469af547a29f9b31418
## What changed
- Add `additionalContextLimit` to command hook configuration for events that can emit `additionalContext`.
- Apply the limit independently to each hook's context before it is sent to the model. Unset values retain the 2,500-token default, while `0` disables spilling for that hook.
- Expose configured limits through app-server hook and requirements responses, and show them in the TUI hooks browser.
## Testing
- Cover JSON and TOML parsing, discovery and hashing, per-hook spilling behavior, app-server responses, and TUI rendering.
GitOrigin-RevId: 55ddc2dbbdf9067dceee3e1968c03617bbf6bcea
## What changed
- Add the `SessionEnd` hook event to hook configuration, protocol schemas, analytics, and the hooks browser.
- Run matching hooks for root threads during shutdown, including app-server archive, delete, idle unload, and graceful shutdown. Flush the transcript first and provide the session ID, transcript path, working directory, and `reason: "other"`.
- Keep teardown bounded: hook output is advisory, the default timeout is one second, configured timeouts are capped at three seconds, and async hooks run synchronously with a warning.
## Testing
- Cover transcript availability, matcher selection, timeout normalization, ignored control output, subagent exclusion, archive/delete ordering, and graceful shutdown of multiple loaded threads.
GitOrigin-RevId: 5d19a658677a137caf836ed5042dcb43f5eb6d1a
Addresses #25875.
## Summary
`hooks.json` accepted unknown top-level fields. A file with
`SessionStart` at the root parsed as an empty hook configuration without
warning.
## Repro
```json
{ "SessionStart": [...] }
```
Previously: zero hooks, zero warnings.
Now:
```text
unknown field `SessionStart`, expected `hooks`
```
The supported shape remains:
```json
{ "hooks": { "SessionStart": [...] } }
```
## Fix
Reject unknown top-level fields and surface the parse warning in human
and JSONL `codex exec` output.
# What
<img width="1792" height="1024" alt="image"
src="https://github.com/user-attachments/assets/8f81d232-5813-4994-a61d-e42a05a93a3e"
/>
`SubagentStop` runs when a thread-spawned subagent turn is about to
finish. Thread-spawned subagents use `SubagentStop` instead of the
normal root-agent `Stop` hook.
Configured handlers match on `agent_type`. Hook input includes the
normal stop fields plus:
- `agent_id`: the child thread id.
- `agent_type`: the resolved subagent type.
- `agent_transcript_path`: the child subagent transcript path.
- `transcript_path`: the parent thread transcript path.
- `last_assistant_message`: the final assistant message from the child
turn, when available.
- `stop_hook_active`: `true` when the child is already continuing
because an earlier stop-like hook blocked completion.
`SubagentStop` shares the same completion-control semantics as `Stop`,
scoped to the child turn:
- No decision allows the child turn to finish.
- `decision: "block"` with a non-empty `reason` records that reason as
hook feedback and continues the child with that prompt.
- `continue: false` stops the child turn. If `stopReason` is present,
Codex surfaces it as the stop reason.
# Lifecycle Scope
Only thread-spawned subagents run `SubagentStop`.
Internal/system subagents such as Review, Compact, MemoryConsolidation,
and Other do not run normal `Stop` hooks and do not run `SubagentStop`.
This avoids exposing synthetic matcher labels for internal
implementation paths.
# Stack
1. #22782: add `SubagentStart`.
2. This PR: add `SubagentStop`.
3. #22882: add subagent identity to normal hook inputs.
# What
`SubagentStart` runs once when Codex creates a thread-spawned subagent,
before that child sends its first model request. Thread-spawned
subagents use `SubagentStart` instead of the normal root-agent
`SessionStart` hook.
Configured handlers match on the subagent `agent_type`, using the same
value passed to `spawn_agent`. When no agent type is specified, Codex
uses the default agent type.
Hook input includes the normal session-start fields plus:
- `agent_id`: the child thread id.
- `agent_type`: the resolved subagent type.
`SubagentStart` may return `hookSpecificOutput.additionalContext`. That
context is added to the child conversation before the first model
request.
# Lifecycle Scope
Only thread-spawned subagents run `SubagentStart`.
Internal/system subagents such as Review, Compact, MemoryConsolidation,
and Other do not run normal `SessionStart` hooks and do not run
`SubagentStart`. This avoids exposing synthetic matcher labels for
internal implementation paths.
Also the `SessionStart` hook no longer fires for subagents, this matches
behavior with other coding agents' implementation
# Stack
1. This PR: add `SubagentStart`.
2. #22873: add `SubagentStop`.
3. #22882: add subagent identity to normal hook inputs.
# Why
Managed hook configs need a shared cross-platform shape without making
the existing `command` field polymorphic. The common case is still one
command string, with Windows needing a different entrypoint only when
the runtime is actually Windows.
Keeping `command` as the portable/default path and adding an optional
Windows override keeps the config easier to read, preserves the existing
scalar shape for non-Windows users, and avoids forcing every caller into
a `{ unix, windows }` object when only one platform needs special
handling.
# What
- Add optional `command_windows` / `commandWindows` alongside the
existing hook `command` field.
- Resolve `command_windows` only on Windows during hook discovery; other
platforms continue to use `command` unchanged.
- Keep trust hashing aligned to the effective command selected for the
current runtime.
# Docs
The Codex hooks/config reference should document `command_windows` as
the Windows-only override for command hooks.
Based on work from Vincent K -
https://github.com/openai/codex/pull/19060
<img width="1836" height="642" alt="CleanShot 2026-04-29 at 20 47 40@2x"
src="https://github.com/user-attachments/assets/b647bb89-65fe-40c8-80b0-7a6b7c984634"
/>
## Why
Compaction rewrites the conversation context that future model turns
receive, but hooks currently have no deterministic lifecycle point
around that rewrite. This adds compact lifecycle hooks so users can
audit manual and automatic compaction, surface hook messages in the UI,
and run post-compaction follow-up without overloading tool or prompt
hooks.
## What Changed
- Added `PreCompact` and `PostCompact` hook events across hook config,
discovery, dispatch, generated schemas, app-server notifications,
analytics, and TUI hook rendering.
- Added trigger matching for compact hooks with the documented `manual`
and `auto` matcher values.
- Wired `PreCompact` before both local and remote compaction, and
`PostCompact` after successful local or remote compaction.
- Kept compact hook command input to lifecycle metadata: session id,
Codex turn id, transcript path, cwd, hook event name, model, and
trigger.
- Made compact stdout handling consistent with other hooks: plain stdout
is ignored as debug output, while malformed JSON-looking stdout is
reported as failed hook output.
- Added integration coverage for compact hook dispatch, trigger
matching, post-compact execution, and the audited behavior that
`decision:"block"` does not block compaction.
## Out of Scope
- Hook-specific compaction blocking is not implemented;
`decision:"block"` and exit-code-2 blocking semantics are intentionally
unsupported for `PreCompact`.
- Custom compaction instructions are not exposed to compact hooks in
this PR.
- Compact summaries, summary character counts, and summary previews are
not exposed to compact hooks in this PR.
## Verification
- `cargo test -p codex-hooks`
- `cargo test -p codex-core
manual_pre_compact_block_decision_does_not_block_compaction`
- `cargo test -p codex-app-server hooks_list`
- `cargo test -p codex-core config_schema_matches_fixture`
- `cargo test -p codex-tui hooks_browser`
## Docs
The developer documentation for Codex hooks should be updated alongside
this feature to document `PreCompact` and `PostCompact`, the
`manual`/`auto` matcher values, and the compact hook payload fields.
---------
Co-authored-by: Vincent Koc <vincentkoc@ieee.org>
# Why
We want shared hook trust that both the app and the TUI can build on,
but the metadata is only useful if runtime behavior agrees with it. This
PR adds a single backend trust model for hooks so unmanaged hooks cannot
run until the current definition has been reviewed, while managed hooks
remain runnable and non-configurable.
# What
- persist `trusted_hash` alongside hook state in `config.toml`
- expose `currentHash` and derived `trustStatus` through `hooks/list`
- derive trust from normalized hook definitions so equivalent hooks from
`config.toml` and `hooks.json` share the same trust identity
- gate unmanaged hooks on trust before they enter the runnable handler
set
# Reviewer Notes
- key file to review is `codex-rs/hooks/src/engine/discovery.rs`
- the only **core** change is schema related
## Why
After `hooks/list` exposes the hook inventory, clients need a way to
persist user hook preferences, make those changes effective in
already-open sessions, and distinguish user-controllable hooks from
managed requirements without adding another bespoke app-server write
API.
## What
- Extends `hooks/list` entries with effective `enabled` state.
- Persists user-level hook state under `hooks.state.<hook-id>` so the
model can grow beyond a single boolean over time.
- Uses the existing `config/batchWrite` path for hook state updates
instead of introducing a dedicated hook write RPC.
- Refreshes live session hook engines after config writes so
already-open threads observe updated enablement without a restart.
## Stack
1. openai/codex#19705
2. openai/codex#19778
3. This PR - openai/codex#19840
4. openai/codex#19882
## Reviewer Notes
The generated schema files account for much of the raw diff. The core
behavior is in:
- `hooks/src/config_rules.rs`, which resolves per-hook user state from
the config layer stack.
- `hooks/src/engine/discovery.rs`, which projects effective enablement
into `hooks/list` from source-derived managedness.
- `config/src/hook_config.rs`, which defines the new `hooks.state`
representation.
- `core/src/session/mod.rs`, which rebuilds live hook state after user
config reloads.
---------
Co-authored-by: Codex <noreply@openai.com>
## Summary
Support the existing hooks schema in inline TOML so hooks can be
configured from both `config.toml` and enterprise-managed
`requirements.toml` without requiring a separate `hooks.json` payload.
This gives enterprise admins a way to ship managed hook policy through
the existing requirements channel while still leaving script delivery to
MDM or other device-management tooling, and it keeps `hooks.json`
working unchanged for existing users.
This also lays the groundwork for follow-on managed filtering work such
as #15937, while continuing to respect project trust gating from #14718.
It does **not** implement `allow_managed_hooks_only` itself.
NOTE: yes, it's a bit unfortunate that the toml isn't formatted as
closely as normal to our default styling. This is because we're trying
to stay compatible with the spec for plugins/hooks that we'll need to
support & the main usecase here is embedding into requirements.toml
## What changed
- moved the shared hook serde model out of `codex-rs/hooks` into
`codex-rs/config` so the same schema can power `hooks.json`, inline
`config.toml` hooks, and managed `requirements.toml` hooks
- added `hooks` support to both `ConfigToml` and
`ConfigRequirementsToml`, including requirements-side `managed_dir` /
`windows_managed_dir`
- treated requirements-managed hooks as one constrained value via
`Constrained`, so managed hook policy is merged atomically and cannot
drift across requirement sources
- updated hook discovery to load requirements-managed hooks first, then
per-layer `hooks.json`, then per-layer inline TOML hooks, with a warning
when a single layer defines both representations
- threaded managed hook metadata through discovered handlers and exposed
requirements hooks in app-server responses, generated schemas, and
`/debug-config`
- added hook/config coverage in `codex-rs/config`, `codex-rs/hooks`,
`codex-rs/core/src/config_loader/tests.rs`, and
`codex-rs/core/tests/suite/hooks.rs`
## Testing
- `cargo test -p codex-config`
- `cargo test -p codex-hooks`
- `cargo test -p codex-app-server config_api`
## Documentation
Companion updates are needed in the developers website repo for:
- the hooks guide
- the config reference, sample, basic, and advanced pages
- the enterprise managed configuration guide
---------
Co-authored-by: Michael Bolin <mbolin@openai.com>
Krish Chainani