Claude Code Extensions

Add custom tools to Claude Code with simple YAML definitions

Quick Start • How It Works • Create Extensions • Built-in Tools • CLI Reference

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✨ Demo

$ claude "use cowsay to say 'Hello from custom extensions!'"

 __________________________________
< Hello from custom extensions!    >
 ----------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

$ claude "roll 4d6 for my D&D character"

Rolled 4d6: [6, 4, 5, 2] = 17

$ claude "what time is it right now?"

It's Monday, January 27, 2025 at 10:42:53 AM.

**These tools don't exist in Claude Code. They were added in 30 seconds.**

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🚀 Quick Start

1. Install

git clone https://github.com/hexcreator/claude-code-extensions.git
cd claude-code-extensions
npm install
npm link  # Makes 'claude-ext' available globally

2. Initialize & Start

claude-ext init    # Creates ~/.claude-extensions/
claude-ext start   # Starts the extension proxy

3. Use with Claude Code

ANTHROPIC_BASE_URL=http://localhost:8892 claude "roll a d20"

That's it! Claude Code now has access to custom tools.

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🎯 Why This Exists

Claude Code ships with ~3