SecretButler 🗝️

A secure local MCP server for managing API keys with user approval

Overview

SecretButler provides a secure way to manage and share API keys with MCP clients like Claude Desktop and Cursor. It runs as a local server with a native GUI that requires explicit user approval before sharing any secrets.

✨ Features

• 🔒 Secure: Stores API keys locally in ~/.secretbutler.toml
• 👤 User-controlled: GUI popup requires explicit approval for each request
• 🔌 MCP compatible: Works with any MCP client
• ⚙️ Easy setup: Simple TOML configuration
• 🍎 Native macOS: Uses native macOS GUI components

🚀 Installation

Add to your MCP client configuration:

{
    "mcpServers": {
        "SecretButler": {
            "command": "uvx",
            "args": ["secretbutler"],
            "env": {
                "CLIENT_NAME": "Claude"
            }
        }
    }
}

⚙️ Configuration

On first run, SecretButler creates ~/.secretbutler.toml:

[secrets]
OPENAI_API_KEY = "sk-..."
ANTHROPIC_API_KEY = "sk-ant-..."
HF_API_KEY = "hf_..."

Simply edit this file to add your API keys.

🛠️ MCP Tools

Tool	Description
list_secrets()	Returns available secret names (no approval needed)
request_secrets(secret_names, client_name)	Request specific secrets with user approval

🔐 Security

• ✅ Secrets stored locally only
• ✅ No sharing without explicit approval
• ✅ Clear approval dialogs show requested secrets and client
• ✅ Foreground GUI prevents unauthorized access

📄 License

MIT License