Claude Code Hooks Examples

This directory contains examples for setting up Claude Code hooks with Emacs integration.

Files

• ../bin/claude-code-hook-wrapper - Generic wrapper script for emacsclient hook integration (moved to bin directory)
• example_settings.json - Example settings.json with proper hook configuration
• claude-code-hook-examples.el - Emacs Lisp hook handler examples

Quick Setup

1. Add the claude-code.el/bin directory to your PATH:

   Add this line to your bash configuration file (~/.bashrc, ~/.bash_profile, etc.) since Claude Code needs it available in the bash environment.

2. Update your ~/.claude/settings.json based on example_settings.json:

   {
     "hooks": {
       "PreToolUse": [{
         "matcher": "",
         "hooks": [{
           "type": "command", 
           "command": "claude-code-hook-wrapper pre-tool-use"
         }]
       }]
     }
   }
   

3. Load the hook handlers in Emacs:

   (load-file "/path/to/claude-code-hook-examples.el")
   

How It Works

The Wrapper Script Problem

When using emacsclient --eval with hooks that return JSON responses, emacsclient wraps the output in quotes like "{\\\\"json\\\\": \\\\"data\\\\"}". Claude Code expects clean JSON, so the wrapper script:

1. Calls emacsclient with the hook
2. Detects if the response is a quoted JSON string
3. Strips the outer quotes and unescapes inner quotes
4. Returns clean JSON to Claude Code

Hook Types

• PreToolUse: Shows minibuffer prompts for tool permissions (y/n/q responses)
• PostToolUse: Handles completion notifications and logging
• Notification: Processes Claude Code notifications
• Stop: Handles session stop events

JSON Response Format

Hooks can return JSON to control Claude Code behavior:

{
  "hookSpecificOutput": {
    "hookEventName": "PreToolUse",
    "permissionDecision": "allow",
    "permissionDecisionReason": "User approved via minibuffer"
  }
}

PreToolUse Minibuffer Integration

When Claude wants to use a tool, you'll see a minibuffer prompt with pretty-formatted JSON:

Claude wants to use WebFetch with args:
{
  "url": "https://example.com",
  "prompt": "What are the main features?"
}
Allow? (y/n/q):

• y/Y: Allow the tool use
• n/N: Deny the tool use
• q/Q: Request UI confirmation (falls back to Claude's permission dialog)
• ESC: Same as 'q' - request UI confirmation

Customization

Edit the .el files to customize hook behavior:

• Add custom tool permission logic
• Implement project-specific notifications
• Create custom logging and monitoring
• Add integration with other Emacs packages