feature

Hooks

Small commands that fire automatically at set moments — like running your formatter every time Claude saves a file.

A hook is an action the tool runs *for* you at a specific point: before a command, after an edit, when a session starts. Use them to enforce a rule ("never let it touch the main branch"), keep things tidy ("format every file Claude edits"), or log activity. Set it once; it just happens.

A hook is a command the tool runs for you, automatically, at a specific moment in the work. The moments are named: a PreToolUse hook fires before Claude runs a command or edits a file; a PostToolUse hook fires after; others fire when a session starts or ends. You pick the moment, you supply the command, and from then on it just happens.

That gives you three useful jobs. Enforce a rule — a PreToolUse hook can inspect what’s about to happen and block it (“never let it touch the main branch”), so the guardrail is mechanical, not a thing you have to remember. Tidy — run your formatter on every file Claude edits, and the diff is always clean. Log — record what happened, for an audit trail or just peace of mind.

One rule of thumb keeps hooks pleasant: keep the command fast. Hooks run inline, in the flow of the work, so a slow hook slows down every action it’s attached to. See what you’ve got configured with /hooks. Where a scheduled agent runs on the clock, a hook runs on an event — the “always do this, right when X happens” chore you’d otherwise forget.

Generator

Build a settings.json

Pick permission rules and hooks, then copy out a settings.json for your .claude/ folder.

Permissions

allow run without asking

ask always confirm first

deny never, full stop

Hooks

.claude/settings.json

{
  "permissions": {
    "allow": [
      "Bash(npm run test:*)"
    ],
    "deny": [
      "Read(./.env)",
      "Bash(rm -rf:*)"
    ]
  },
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "hooks": [
          {
            "type": "command",
            "command": "npx prettier --write ."
          }
        ]
      }
    ]
  }
}

A starting point — copy it into your project and adapt.

why it helps Automate the 'always do this after' chores so you never forget them.

examples

Format every file Claude edits

After every edit, run `prettier --write` on the changed file.

See your configured hooks

/hooks

tips & best practices

Hooks are for the 'always do this' chores — formatting, linting, logging — that you'd forget.
Use a PreToolUse hook to block risky actions (like touching main) before they happen.
Keep hook commands fast; they run inline, so a slow hook slows every action it's attached to.