create-hook

Some rules should not be advice the AI can ignore — this turns one into an automatic check that runs at a set moment and can stop the action outright.

When to use

SCOPE

USE FOR

Turn a recurring 'always check before X' or 'never run Y' request into an enforced hook.
Have context injected automatically at session start, session end, or before a tool runs.
Decide whether a hook should block an action, warn about it, or just add context.

This is a saved copy of the skill's SKILL.md instructions. It may differ from the upstream file or the version you install.

In this document (4)

Related skill: agent-customization. Load and follow hooks.md for template and principles.

Guide the user to create a hook in .github/hooks/.

Extract from Conversation

First, review the conversation history. If the user has been expressing concerns about agent behavior (e.g., "don't run this command", "always check before doing X", "inject this context"), generalize that into a hook. Extract:

Actions that should be blocked or gated
Context that should be injected at certain points
Automation needs at session start/end or tool use

Clarify if Needed

If no clear policy need emerges from the conversation, clarify:

What event should trigger this hook? (e.g. PreToolUse, SessionStart, Stop)
Should it block, warn, or inject context?
Does it need a companion script?

Path Conventions

Hook commands and companion scripts run with cwd defaulting to the workspace root (when a workspace folder is available); otherwise cwd falls back to the user home directory. Relative paths resolve from cwd. Absolute paths are fine when intentional — just be deliberate about which you use.
Do not use environment variables for pathing. The only exception is plugin-provided environment variables in hooks shipped as part of an agent plugin; never use environment variables for pathing outside of a plugin context.

Iterate

Draft the hook JSON (and any scripts) and save them.
Identify the most ambiguous or weak parts and ask about those.
Once finalized, summarize what the hook enforces, suggest ways to test it, and propose related customizations to create next.

Remember to follow the agent-customization guidelines to create highly effective hooks.

Built into VS Code. Nothing to install there. The npx skills add command copies the same instructions into another agent, but they are written for VS Code and may call tools only VS Code has.

Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.

Install checklist

Check selected tools if a picker appears; Claude Code may be unchecked under Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms.
Without a tool picker, check Installing to: for your intended tool. Stop if it names a different tool.
If asked, choose Symlink (Recommended) for shared files or Copy to all agents for separate copies; review the summary before confirming installation.
Install the find-skills skill? defaults to Yes, adding another skill for all projects. Choose No if you don't want that extra installation.

Skills CLI 1.7.2 sends install data to skills.sh by default, including the source, skill names, target tools and file details; GitHub sources are reported only when GitHub confirms the repository is public, while other remote sources can also be reported. Confirmed-public GitHub sources also trigger a security-audit request. Before installing, set the environment variable DO_NOT_TRACK=1 or DISABLE_TELEMETRY=1 to disable both.

npx skills add microsoft/vscode --skill "create-hook" --full-depth

Once this skill is installed where Claude Code loads it, type /create-hook in Claude Code when you want to start it. Claude Code won't start this skill on its own.

View on GitHub

Extract from Conversation

Clarify if Needed

Path Conventions

Iterate

No requirements beyond installing this skill were found.

More skills

act-on-feedback

agent-customization

author-contributions

chronicle

code-review

commit