---
title: "Hooks Reference"
description: "Low-level hook surface reference: hook points, capabilities, execution modes, and payload fields."
icon: "anchor"
---

Use this page when you need exact hook vocabulary and structure rather than a procedural walkthrough.

## Core enums

| Type | Values |
|------|--------|
| `HookPoint` | `RunStarted`, `PreLlmRequest`, `PreToolExecution`, `TurnBoundary`, `PostLlmResponse`, `PostToolExecution`, `RunCompleted`, `RunFailed` |
| `HookCapability` | `Observe`, `Guardrail`, `Rewrite` (retired compatibility label; no patch authority) |
| `HookExecutionMode` | `Foreground`, `Background` |
| `HookFailurePolicy` | `FailOpen`, `FailClosed` |

## Runtime families

- in-process
- command
- HTTP

## Payload highlights

- `HookInvocation`
- `HookToolResult`
- `HookDecision`

## See also

- [Hooks guide](/guides/hooks)
- [Examples: Hooks](/examples/hooks)
