> ## Documentation Index
> Fetch the complete documentation index at: https://humboldt.metaphi.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Hooks

> A command Humboldt runs at a point in the loop. It can block. Claude Code and Codex hook files run unchanged.

## Events

| Event              | Can                                |
| ------------------ | ---------------------------------- |
| `PreToolUse`       | Deny the call or rewrite its input |
| `PostToolUse`      | Add to what the model reads        |
| `Stop`             | Send the model back with a reason  |
| `UserPromptSubmit` | Act on your message                |
| `SessionStart`     | Set up                             |
| `Notification`     | Reach you: desktop, Slack, mail    |

## Files

`~/.hum/hooks.json`, `<repo>/.hum/hooks.json`, `.claude/settings.json`, `.codex/hooks.json`.

```json theme={"dark"}
{"hooks": {"Stop": [{"hooks": [{"type": "command", "command": "make test", "timeout": 300}]}],
           "PreToolUse": [{"matcher": "Bash", "hooks": [{"type": "command", "command": "$HUM_PROJECT_DIR/.hum/no-rm.sh"}]}]}}
```

## Contract

stdin: one JSON object (`hook_event_name`, `tool_name`, `tool_input`, `tool_response`, `prompt`, `last_message`, `cwd`, `session_id`).

| Exit | Meaning                                                                                                              |
| ---- | -------------------------------------------------------------------------------------------------------------------- |
| 0    | Continue. JSON on stdout may set `permissionDecision`, `updatedInput`, `additionalContext`, `continue`, `stopReason` |
| 2    | Block. stderr is the reason                                                                                          |

```
hum hooks             # what would fire here; /hooks in a session
```

```toml theme={"dark"}
[hooks]
enabled = true
foreign = true        # run Claude Code and Codex hook files too; HUM_HOOKS=0 disables all for one run
```