Bringing Claude Code to Life with Custom Sounds: A Fun Introduction to Hooks

When Enthropic announced hooks for Claude Code, it opened a whole new world of possibilities for customizing how Claude interacts with your workflow. Inspired by a playful comment on the Claude AI subreddit—“I’m going to use this to make Claude meow. I’ve always wanted a cat, but I’m allergic”—I decided to dive in and create a unique sound-based notification system for Claude’s various events. The result? Claude meowing, beeping, and even speaking as it runs commands in the background.

Why Use Hooks in Claude Code?

Hooks are a powerful addition that let you run custom commands triggered by different Claude events. These events include:

• Pre-tool use: Before Claude uses a tool like bash, file editing, or fetching data from the web.
• Post-tool use: After Claude completes a task.
• Notification: When Claude is waiting for your approval.
• Stop: When Claude finishes its task.
• Pre-compact: Before autocompacting your session history.

By assigning sounds or commands to these events, you get real-time feedback about what Claude is doing, making it easier to understand and control its behavior.

Setting Up Hooks: Where to Start

To set up hooks, you edit your settings.json file within your project. This ensures your hooks are version-controlled and consistent across different work trees. Although you can also configure hooks in user-level settings, keeping them project-specific is a good starting point.

Here’s the gist of the setup:

• Create a hooks directory inside your .cloud folder.
• Define a list of hooks in your settings.json, specifying the event type and the command to run.
• Use a single Python script (hook_handler.py) to handle all hook events. This centralizes your logic and simplifies debugging.

Example snippet from settings.json:

json "hooks": [ { "event": "notification", "command": ["python3", "/path/to/hook_handler.py"] }, { "event": "stop", "command": ["python3", "/path/to/hook_handler.py"] }, { "event": "pre-tool-use", "command": ["python3", "/path/to/hook_handler.py"] } ]

The Magic Behind the Scenes: The Python Hook Handler

The hook_handler.py script receives JSON data from Claude via standard input whenever an event is triggered. This data includes session info, event name, tool name, and tool input, which you can log and analyze to determine what action to take.

I used Claude itself to generate and iteratively refine the Python script, making it as readable and maintainable as possible. The script’s responsibilities include:

• Logging incoming event data for debugging.
• Mapping specific events and commands to corresponding sounds or voice notifications.
• Playing sounds using predefined audio files stored in categorized directories (beeps, voices, meows).

Curating the Sounds: From Beeps to Meows

To keep things fun and engaging, I sourced sounds from Epidemic Sound, a platform I often use for my YouTube videos. They offer a wide range of sound effects, including beeps, cat meows, and even voice actors providing customizable voice clips.

Some tips for working with Epidemic Sound:

• Sounds often include multiple effects in one file, so use their segment tool to extract just the part you want.
• You can assign specific sounds to particular actions, for example:
• A "committing" voice clip when Claude commits code.
• Different beeps for bash commands, file edits, or pull request creation.
• Sad meows or playful cat sounds for other events.

This mapping helped me instantly recognize what Claude was doing just by listening.

Lessons Learned and Practical Uses for Hooks

Building this sound notification system was more than just a fun experiment; it was a fantastic way to understand Claude’s inner workings and the power of hooks. Here are some insights and practical applications:

• Understanding Cloud Code behavior: Assigning sounds to events revealed how often Claude updates to-dos or runs bash commands.
• Custom safeguards: You can create hooks that prevent dangerous commands like rm -rf from executing accidentally.
• Automation enforcement: Hooks can ensure tests run before opening pull requests or run linters automatically.
• Better notifications: Replace or supplement default notifications with customized alerts that better fit your workflow.

Getting Started Yourself

If you want to explore this yourself, check out the full code repository at hih high.ai/hooks. The Python script and example sounds are all there for you to experiment with and customize.

I’d love to hear how you’re using hooks in Claude Code—whether for fun like me or to build more pragmatic workflows. Hooks unlock a new layer of control and creativity, and I hope this post inspires you to dive in!

Summary

• Hooks allow running custom commands on Claude Code events.
• Setting hooks in settings.json keeps them project-specific and version-controlled.
• A Python script can handle multiple hook events for better maintainability.
• Assigning sounds to events helps understand Claude’s behaviors.
• Hooks can be used for both fun notifications and practical workflow controls.
• Check out the full project and share your hook ideas!

Happy coding—and meowing—with Claude Code! 🐱🎶