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1# Hooks1# Hooks

2 2

~~3Experimental. Hooks are under active development. Windows support temporarily~~

~~4disabled.~~

6Hooks are an extensibility framework for Codex. They allow3Hooks are an extensibility framework for Codex. They allow

7you to inject your own scripts into the agentic loop, enabling features such as:4you to inject your own scripts into the agentic loop, enabling features such as:

8 5

12- Run a custom validation check when a conversation turn stops, enforcing standards9- Run a custom validation check when a conversation turn stops, enforcing standards

13- Customize prompting when in a certain directory10- Customize prompting when in a certain directory

14 11

~~15Hooks are behind a feature flag in `config.toml`:~~12Hooks are enabled by default. If you need to turn them off in `config.toml`,

13set:

16 14

17```toml15```toml

18[features]16[features]

~~19codex_hooks = true~~17hooks = false

20```18```

21 19

20Use `hooks` as the canonical feature key. `codex_hooks` still works as a

21deprecated alias.

23Admins can force hooks off the same way in `requirements.toml` with

24`[features].hooks = false`.

22Runtime behavior to keep in mind:26Runtime behavior to keep in mind:

23 27

24- Matching hooks from multiple files all run.28- Matching hooks from multiple files all run.

25- Multiple matching command hooks for the same event are launched concurrently,29- Multiple matching command hooks for the same event are launched concurrently,

~~26 so one hook can’t prevent another matching hook from starting.~~30 so one hook cannot prevent another matching hook from starting.

31- Non-managed command hooks must be reviewed and trusted before they run.

27- `PreToolUse`, `PermissionRequest`, `PostToolUse`, `UserPromptSubmit`, and32- `PreToolUse`, `PermissionRequest`, `PostToolUse`, `UserPromptSubmit`, and

28 `Stop` run at turn scope.33 `Stop` run at turn scope.

~~29- Hooks are currently disabled on Windows.~~

30 34

31## Where Codex looks for hooks35## Where Codex looks for hooks

32 36

~~33Codex discovers `hooks.json` next to active config layers.~~37Codex discovers hooks next to active config layers in either of these forms:

39- `hooks.json`

40- inline `[hooks]` tables inside `config.toml`

34 41

~~35In practice, the two most useful locations are:~~42Installed plugins can also bundle lifecycle config through their plugin

43manifest or a default `hooks/hooks.json` file. See [Build

44plugins](https://developers.openai.com/codex/plugins/build#bundled-mcp-servers-and-lifecycle-config) for the

45plugin packaging rules.

47In practice, the four most useful locations are:

36 48

37- `~/.codex/hooks.json`49- `~/.codex/hooks.json`

50- `~/.codex/config.toml`

38- `<repo>/.codex/hooks.json`51- `<repo>/.codex/hooks.json`

52- `<repo>/.codex/config.toml`

54If more than one hook source exists, Codex loads all matching hooks.

55Higher-precedence config layers don't replace lower-precedence hooks.

56If a single layer contains both `hooks.json` and inline `[hooks]`, Codex

57merges them and warns at startup. Prefer one representation per layer.

59Plugin hooks are off by default in this release. If

60`[features].plugin_hooks = true`, Codex can also discover hooks bundled with

61enabled plugins. Otherwise, enabled plugins won't run bundled hooks.

63Project-local hooks load only when the project `.codex/` layer is trusted. In

64untrusted projects, Codex still loads user and system hooks from their own

65active config layers.

39 66

~~40If more than one `hooks.json` file exists, Codex loads all matching hooks.~~67## Review and manage hooks

~~41Higher-precedence config layers don’t replace lower-precedence hooks.~~68

69Codex lists configured hooks before deciding which ones can run. Use `/hooks`

70in the CLI to inspect hook sources, review new or changed hooks, trust hooks, or

71disable individual non-managed hooks. If hooks need review at startup, Codex

72prints a warning that tells you to open `/hooks`.

74Managed hooks from system, MDM, cloud, or `requirements.toml` sources are marked

75as managed, trusted by policy, and can't be disabled from the user hook browser.

42 76

43## Config shape77## Config shape

44 78

127Notes:161Notes:

128 162

129- `timeout` is in seconds.163- `timeout` is in seconds.

130- `timeoutSec` is also accepted as an alias.

131- If `timeout` is omitted, Codex uses `600` seconds.164- If `timeout` is omitted, Codex uses `600` seconds.

132- `statusMessage` is optional.165- `statusMessage` is optional.

166- `async` is parsed, but async command hooks aren't supported yet. Codex skips

167 handlers with `async: true`.

168- Only `type: "command"` handlers run today. `prompt` and `agent` handlers are

169 parsed but skipped.

133- Commands run with the session `cwd` as their working directory.170- Commands run with the session `cwd` as their working directory.

134- For repo-local hooks, prefer resolving from the git root instead of using a171- For repo-local hooks, prefer resolving from the git root instead of using a

135 relative path such as `.codex/hooks/...`. Codex may be started from a172 relative path such as `.codex/hooks/...`. Codex may be started from a

136 subdirectory, and a git-root-based path keeps the hook location stable.173 subdirectory, and a git-root-based path keeps the hook location stable.

137 174

175Equivalent inline TOML in `config.toml`:

176

177```toml

178[[hooks.PreToolUse]]

179matcher = "^Bash$"

180

181[[hooks.PreToolUse.hooks]]

182type = "command"

183command = '/usr/bin/python3 "$(git rev-parse --show-toplevel)/.codex/hooks/pre_tool_use_policy.py"'

184timeout = 30

185statusMessage = "Checking Bash command"

186

187[[hooks.PostToolUse]]

188matcher = "^Bash$"

189

190[[hooks.PostToolUse.hooks]]

191type = "command"

192command = '/usr/bin/python3 "$(git rev-parse --show-toplevel)/.codex/hooks/post_tool_use_review.py"'

193timeout = 30

194statusMessage = "Reviewing Bash output"

195```

196

197## Managed hooks from `requirements.toml`

198

199Enterprise-managed requirements can also define hooks inline under `[hooks]`.

200This is useful when admins want to enforce the hook configuration while

201delivering the actual scripts through MDM or another device-management system.

202To enforce managed hooks even for users who disabled hooks locally, pin

203`[features].hooks = true` in `requirements.toml` alongside `[hooks]`.

204

205```toml

206[features]

207hooks = true

208

209[hooks]

210managed_dir = "/enterprise/hooks"

211windows_managed_dir = 'C:\enterprise\hooks'

212

213[[hooks.PreToolUse]]

214matcher = "^Bash$"

215

216[[hooks.PreToolUse.hooks]]

217type = "command"

218command = "python3 /enterprise/hooks/pre_tool_use_policy.py"

219timeout = 30

220statusMessage = "Checking managed Bash command"

221```

222

223Notes for managed hooks:

224

225- `managed_dir` is used on macOS and Linux.

226- `windows_managed_dir` is used on Windows.

227- Codex doesn't distribute the scripts in `managed_dir`; your enterprise

228 tooling must install and update them separately.

229- Managed hook commands should use absolute script paths under the configured

230 managed directory.

231

232## Plugin-bundled hooks

233

234Plugin-bundled hooks are opt-in for this release. When

235`[features].plugin_hooks = true` and a plugin is enabled, Codex can load

236lifecycle hooks from that plugin alongside user, project, and managed hooks.

237

238```toml

239[features]

240plugin_hooks = true

241```

242

243By default, Codex looks for `hooks/hooks.json` inside the plugin root. A plugin

244manifest can override that default with a `hooks` entry in

245`.codex-plugin/plugin.json`. The manifest entry can be a `./`-prefixed path, an

246array of `./`-prefixed paths, an inline hooks object, or an array of inline

247hooks objects.

248

249```json

250{

251 "name": "repo-policy",

252 "hooks": "./hooks/hooks.json"

253}

254```

255

256Manifest hook paths are resolved relative to the plugin root and must stay

257inside that root. If a manifest defines `hooks`, Codex uses those manifest

258entries instead of the default `hooks/hooks.json`.

259

260Plugin hook commands receive these environment variables:

261

262- `PLUGIN_ROOT` is a Codex-specific extension that points to the installed

263 plugin root.

264- `PLUGIN_DATA` is a Codex-specific extension that points to the plugin's

265 writable data directory.

266- Codex also sets `CLAUDE_PLUGIN_ROOT` and `CLAUDE_PLUGIN_DATA` for

267 compatibility with existing plugin hooks.

268

269Plugin hooks use the same event schema as other hooks. They are non-managed

270hooks, so they require trust review before they run.

271

138## Matcher patterns272## Matcher patterns

139 273

140The `matcher` field is a regex string that filters when hooks fire. Use `"*"`,274The `matcher` field is a regex string that filters when hooks fire. Use `"*"`,

144Only some current Codex events honor `matcher`:278Only some current Codex events honor `matcher`:

145 279

147| --- | --- | --- |281| ------------------- | ---------------------- | ------------------------------------------------------------ |

288

289\*For `apply_patch`, `matcher` values can also use `Edit` or `Write`.

154 290

155Examples:291Examples:

156 292

157- `Bash`293- `Bash`

158- `startup|resume`294- `^apply_patch$`

159- `Edit|Write`295- `Edit|Write`

~~160~~ 296- `mcp__filesystem__read_file`

161That last example is still a valid regex, but current Codex `PreToolUse` and297- `mcp__filesystem__.*`

162`PostToolUse` events only emit `Bash`, so it won’t match anything today.298- `startup|resume|clear`

163 299

164## Common input fields300## Common input fields

165 301

168These are the shared fields you will usually use:304These are the shared fields you will usually use:

169 305

171| --- | --- | --- |307| ----------------- | ---------------- | ------------------------------------------- |

174| `cwd` | `string` | Working directory for the session |310| `cwd` | `string` | Working directory for the session |

177 313

178Turn-scoped hooks list `turn_id` in their event-specific tables.314Turn-scoped hooks list `turn_id` as a Codex-specific extension in their

315event-specific tables.

316

317`SessionStart`, `PreToolUse`, `PermissionRequest`, `PostToolUse`,

318`UserPromptSubmit`, and `Stop` also include `permission_mode`, which describes

319the current permission mode as `default`, `acceptEdits`, `plan`, `dontAsk`, or

320`bypassPermissions`.

321

322`transcript_path` points to a conversation transcript for convenience, but the

323transcript format is not a stable interface for hooks and may change over time.

179 324

180If you need the full wire format, see [Schemas](#schemas).325If you need the full wire format, see [Schemas](#schemas).

181 326

217Fields in addition to [Common input fields](#common-input-fields):362Fields in addition to [Common input fields](#common-input-fields):

218 363

220| --- | --- | --- |365| -------- | -------- | -------------------------------------------------------- |

222 367

223Plain text on `stdout` is added as extra developer context.368Plain text on `stdout` is added as extra developer context.

224 369

238 383

239### PreToolUse384### PreToolUse

240 385

241Work in progress386`PreToolUse` can intercept Bash, file edits performed through `apply_patch`,

~~242~~ 387and MCP tool calls. It's still a guardrail rather than a complete enforcement

243Currently `PreToolUse` only supports Bash tool interception. The model can388boundary because Codex can often perform equivalent work through another

244still work around this by writing its own script to disk and then running that389supported tool path.

245script with Bash, so treat this as a useful guardrail rather than a complete

246enforcement boundary

247 390

248This doesn't intercept all shell calls yet, only the simple ones. The newer391This doesn't intercept all shell calls yet, only the simple ones. The newer

249 `unified_exec` mechanism allows richer streaming stdin/stdout handling of392 `unified_exec` mechanism allows richer streaming stdin/stdout handling of

250shell, but interception is incomplete. Similarly, this doesn’t intercept MCP,393 shell, but interception is incomplete. Similarly, this doesn't intercept

251Write, WebSearch, or other non-shell tool calls.394 `WebSearch` or other non-shell, non-MCP tool calls.

252 395

253`matcher` is applied to `tool_name`, which currently always equals `Bash`.396`matcher` is applied to `tool_name` and matcher aliases. For file edits through

397`apply_patch`, `matcher` values can use `apply_patch`, `Edit`, or `Write`; hook input

398still reports `tool_name: "apply_patch"`.

254 399

255Fields in addition to [Common input fields](#common-input-fields):400Fields in addition to [Common input fields](#common-input-fields):

256 401

258| --- | --- | --- |403| ------------- | ------------ | ---------------------------------------------------------------------------------------------------------- |

263 408

264Plain text on `stdout` is ignored.409Plain text on `stdout` is ignored.

265 410

266JSON on `stdout` can use `systemMessage` and can block a Bash command with this411JSON on `stdout` can use `systemMessage`. To deny a supported tool call, return

267hook-specific shape:412this hook-specific shape:

268 413

269```json414```json

270{415{

287 432

288You can also use exit code `2` and write the blocking reason to `stderr`.433You can also use exit code `2` and write the blocking reason to `stderr`.

289 434

290`permissionDecision: "allow"` and `"ask"`, legacy `decision: "approve"`,435To add model-visible context without blocking, return

291`updatedInput`, `additionalContext`, `continue: false`, `stopReason`, and436`hookSpecificOutput.additionalContext`:

292`suppressOutput` are parsed but not supported yet, so they fail open.

293 437

294### PermissionRequest438```json

439{

440 "hookSpecificOutput": {

441 "hookEventName": "PreToolUse",

442 "additionalContext": "The pending command touches generated files."

443 }

444}

445```

295 446

296Work in progress447`permissionDecision: "ask"`, legacy `decision: "approve"`, `updatedInput`,

448`continue: false`, `stopReason`, and `suppressOutput` are parsed but not

449supported yet, so they fail open.

450

451### PermissionRequest

297 452

298`PermissionRequest` runs when Codex is about to ask for approval, such as a453`PermissionRequest` runs when Codex is about to ask for approval, such as a

299shell escalation or managed-network approval. It can allow the request, deny454shell escalation or managed-network approval. It can allow the request, deny

300the request, or decline to decide and let the normal approval prompt continue.455the request, or decline to decide and let the normal approval prompt continue.

301It doesn't run for commands that don't need approval.456It doesn't run for commands that don't need approval.

302 457

303`matcher` is applied to `tool_name`, which currently always equals `Bash`.458`matcher` is applied to `tool_name` and matcher aliases. Current canonical

459values include `Bash`, `apply_patch`, and MCP tool names such as

460`mcp__server__tool`; `apply_patch` also matches `Edit` and `Write`.

304 461

305Fields in addition to [Common input fields](#common-input-fields):462Fields in addition to [Common input fields](#common-input-fields):

306 463

308| --- | --- | --- |465| ------------------------ | ---------------- | --------------------------------------------------------------------------------------------------------- |

313 470

314Plain text on `stdout` is ignored.471Plain text on `stdout` is ignored.

315 472

473Some tool inputs may include a human-readable description, but don't rely on a

474`tool_input.description` field for every tool.

475

316To approve the request, return:476To approve the request, return:

317 477

318```json478```json

350 510

351### PostToolUse511### PostToolUse

352 512

353Work in progress513`PostToolUse` runs after supported tools produce output, including Bash,

~~354~~ 514`apply_patch`, and MCP tool calls. For Bash, it also runs after commands that

355Currently `PostToolUse` only supports Bash tool results. It’s not limited to515exit with a non-zero status. It can't undo side effects from the tool that

356commands that exit successfully: non-interactive `exec_command` calls can still516already ran.

357trigger `PostToolUse` when Codex emits a Bash post-tool payload. It can’t undo

358side effects from the command that already ran.

359 517

360This doesn't intercept all shell calls yet, only the simple ones. The newer518This doesn't intercept all shell calls yet, only the simple ones. The newer

361 `unified_exec` mechanism allows richer streaming stdin/stdout handling of519 `unified_exec` mechanism allows richer streaming stdin/stdout handling of

362shell, but interception is incomplete. Similarly, this doesn’t intercept MCP,520 shell, but interception is incomplete. Similarly, this doesn't intercept

363Write, WebSearch, or other non-shell tool calls.521 `WebSearch` or other non-shell, non-MCP tool calls.

364 522

365`matcher` is applied to `tool_name`, which currently always equals `Bash`.523`matcher` is applied to `tool_name` and matcher aliases. For file edits through

524`apply_patch`, `matcher` values can use `apply_patch`, `Edit`, or `Write`; hook input

525still reports `tool_name: "apply_patch"`.

366 526

367Fields in addition to [Common input fields](#common-input-fields):527Fields in addition to [Common input fields](#common-input-fields):

368 528

370| --- | --- | --- |530| --------------- | ------------ | ---------------------------------------------------------------------------------------------------------- |

376 536

377Plain text on `stdout` is ignored.537Plain text on `stdout` is ignored.

378 538

411Fields in addition to [Common input fields](#common-input-fields):571Fields in addition to [Common input fields](#common-input-fields):

412 572

414| --- | --- | --- |574| --------- | -------- | ---------------------------------------------- |

417 577

449Fields in addition to [Common input fields](#common-input-fields):609Fields in addition to [Common input fields](#common-input-fields):

450 610

452| --- | --- | --- |612| ------------------------ | ---------------- | ------------------------------------------------- |

456 616

457`Stop` expects JSON on `stdout` when it exits `0`. Plain text output is invalid617`Stop` expects JSON on `stdout` when it exits `0`. Plain text output is invalid

458for this event.618for this event.

478 638

479## Schemas639## Schemas

480 640

641The linked `main` branch schemas may include hook fields that are not in the

642 current release. Use this page as the release behavior reference.

643

481If you need the exact current wire format, see the generated schemas in the644If you need the exact current wire format, see the generated schemas in the

482[Codex GitHub repository](https://github.com/openai/codex/tree/main/codex-rs/hooks/schema/generated).645[Codex GitHub repository](https://github.com/openai/codex/tree/main/codex-rs/hooks/schema/generated).

hooks.md Codex Docs, 2026-04-23 12:28 UTC → 2026-05-18 22:01 UTC