Hook – AI Integration

Components

Hook

Hooks are deterministic configurations to execute a command, a prompt, a webhook call, etc. when an event is fired during the session runtime.

Events are triggered at various points: a session start (SessionStart), a user submitting an instruction (UserPromptSubmit), before a tool execution (PreToolUse), and many other cases (diversity depends on the agent runtime being used).

Typical hook use cases include limiting access to files, guarding commands to avoid destructive actions, telemetry, code linting, or even automatically saving and restoring session memories.

Format: Claude Code
Also read by: Copilot (only repository level)
Deep dive: events, matchers, actions

repository/
└── .claude/
    ├── settings.json
    └── settings.local.json
~/.claude/
└── settings.json
~/.claude/plugins/cache/<marketplace>/<plugin>/
└── hooks/
    └── hooks.json

{
    "hooks": {
        "PreToolUse": [
            {
                "matcher": "Bash",
                "hooks": [
                    {
                        "type": "command",
                        "command": ".claude/hooks/lint-check.sh",
                        "shell": "bash"
                    },
                    {
                        "type": "command",
                        "command": ".claude\\hooks\\lint-check.ps1",
                        "shell": "powershell"
                    }
                ]
            }
        ]
    }
}

Format: Codex
Deep dive: events, matchers, actions

repository/
└── .codex/
    └── hooks.json
~/.codex/
└── hooks.json
~/.codex/plugins/cache/<marketplace>/<plugin>/<version>/
└── hooks/
    └── hooks.json

{
    "hooks": {
        "PreToolUse": [
            {
                "matcher": "Bash",
                "hooks": [
                    {
                        "type": "command",
                        "command": ".codex/hooks/lint-check.sh",
                        "commandWindows": ".codex\\hooks\\lint-check.ps1"
                    }
                ]
            }
        ]
    }
}

Format: Copilot
Deep dive: events, matchers, actions

repository/
└── .github/
    ├── copilot/
    │   ├── settings.json
    │   └── settings.local.json
    └── hooks/
        └── lint-check.json
~/.copilot/
├── hooks/
│   └── lint-check.json
└── settings.json
~/.copilot/installed-plugins/<marketplace>/<plugin>/
└── hooks/
    └── hooks.json

{
    "version": 1,
    "hooks": {
        "preToolUse": [
            {
                "type": "command",
                "matcher": "bash",
                "bash": ".github/hooks/lint-check.sh",
                "powershell": ".github\\hooks\\lint-check.ps1"
            }
        ]
    }
}

Format: Cursor
Deep dive: events, matchers

repository/
└── .cursor/
    └── hooks.json
~/.cursor/
└── hooks.json
<plugin>/
└── .cursor-plugin/
    └── plugin.json

{
    "version": 1,
    "hooks": {
        "preToolUse": [
            {
                "command": "./hooks/lint-check.sh",
                "matcher": "Shell"
            }
        ]
    }
}

Format: Mistral Vibe
Deep dive: events, matchers, actions

repository/
└── .vibe/
    └── hooks.toml
~/.vibe/
└── hooks.toml

[[hooks]]
name = "lint-check"
type = "before_tool"
match = "bash"
command = "node .vibe/hooks/link-check.js"

Project hooks load before user hooks.

Format: Antigravity
Deep dive: events, matchers

repository/
└── .agents/
    └── hooks.json
~/.gemini/config/
└── hooks.json

{
    "PreToolUse": [
        {
            "matcher": "run_command",
            "hooks": [
                {
                    "type": "command",
                    "command": "./scripts/lint-check.sh"
                }
            ]
        }
    ]
}

Format: Devin
Deep dive: events

repository/
└── .devin/
    └── hooks.v1.json
~/.config/devin/
└── config.json
~/path/to/locally/installed/plugins/<name>/
└── hooks.json

{
    "PreToolUse": [
        {
            "matcher": "exec",
            "hooks": [
                {
                    "type": "command",
                    "command": "./scripts/lint-check.sh",
                    "timeout": 10
                }
            ]
        }
    ]
}

Format: Hermes Agent
Deep dive: events

<plugin>/
├── plugin.yaml
└── __init__.py

def register(ctx):
    ctx.register_hook("pre_tool_call", my_pre_tool_call)
    ctx.register_hook("post_tool_call", my_post_tool_call)
    ctx.register_hook("on_session_start", my_on_session_start)
    ctx.register_hook("pre_gateway_dispatch", my_pre_gateway_dispatch)