Claude Hooks

Claude automatically installs several hooks to help ensure your Elixir code is production-ready. This library provides a batteries-included integration with Claude Code's hook system.

Documentation

For complete documentation on Claude Code's hook system:

• Official Hooks Reference - Complete API reference
• Hooks Guide - Getting started with examples

What Claude Installs

When you run mix igniter.install claude, it automatically sets up:

1. Format checking - Alerts when Elixir files need formatting
2. Compilation checking - Catches errors and warnings immediately
3. Pre-commit validation - Ensures clean code before commits

Configuration

Claude's hooks are configured in .claude.exs. You can add optional hooks or create custom ones:

%{
  hooks: [
    # Optional: Enable related files suggestions
    Claude.Hooks.PostToolUse.RelatedFiles,
    
    # Add your custom hooks
    MyApp.Hooks.CustomChecker
  ]
}

Creating Custom Hooks

You can extend Claude with your own hooks using the Claude.Hooks.Hook.Behaviour:

defmodule MyApp.Hooks.CustomChecker do
  use Claude.Hooks.Hook.Behaviour,
    event: :post_tool_use,
    matcher: [:write, :edit],
    description: "My custom validation hook"

  @impl true
  def run(json_input) when is_binary(json_input) do
    # Your hook logic here
    :ok
  end
end

Important Notes

• Format checking only: The formatter hook only checks if files need formatting - it doesn't automatically format. This gives you control over when formatting happens.
• Feedback to Claude: Hooks communicate with Claude through exit codes and stderr, allowing Claude to automatically see and respond to issues.
• Performance: Hooks run with a default 60-second timeout, configurable per hook.

For more details on hook events, configuration, and advanced usage, see the official documentation.