Hooks

Run code on tool calls, prompt submit, and stop events.

Hooks let the harness execute commands around Claude's tool calls. Use them for guardrails, automatic formatting, notifications, and policy enforcement.

All hooks questions (3)

How do I let Claude work autonomously without approving every command?

Auto mode replaces permission prompts with a background classifier that blocks anything dangerous and lets routine work through. It's narrower than bypassPermissions, available on Max/Team/Enterprise/API only, and quietly drops some of your existing allow rules on entry.
How do I run my formatter automatically after Claude edits a file?

A PostToolUse hook on Edit and Write runs prettier (or any formatter) so Claude's output matches your house style.
How do I run untrusted `npm install` without my SSH keys leaking?

Claude Code's bash tool can run inside an OS-level sandbox (Seatbelt on macOS, bubblewrap on Linux/WSL2) that restricts filesystem and network access. Here's how to enable it, the configuration that matters, and the network-isolation footgun that catches people.