🧲 Magg - The MCP Aggregator

A Model Context Protocol server that manages, aggregates, and proxies other MCP servers, enabling LLMs to dynamically extend their own capabilities.

What is Magg?

Magg is a meta-MCP server that acts as a central hub for managing multiple MCP servers. It provides tools that allow LLMs to:

• Search for new MCP servers and discover setup instructions
• Add and configure MCP servers dynamically
• Enable/disable servers on demand
• Aggregate tools from multiple servers under unified prefixes
• Persist configurations across sessions

Think of Magg as a "package manager for LLM tools" - it lets AI assistants install and manage their own capabilities at runtime.

Features

• Self-Service Tool Management: LLMs can search for and add new MCP servers without human intervention.
• Dynamic Configuration Reloading: Automatically detects and applies config changes without restarting.
• Automatic Tool Proxying: Tools from added servers are automatically exposed with configurable prefixes.
• ProxyMCP Tool: A built-in tool that proxies the MCP protocol to itself, for clients that don't support notifications or dynamic tool updates (which is most of them currently).
• Smart Configuration: Uses MCP sampling to intelligently configure servers from just a URL.
• Persistent Configuration: Maintains server configurations in .magg/config.json.
• Multiple Transport Support: Works with stdio, HTTP, and in-memory transports.
• Bearer Token Authentication: Optional RSA-based JWT authentication for secure HTTP access.
• Docker Support: Pre-built images for production, staging, and development workflows.
• Health Monitoring: Built-in magg_status and magg_check tools for server health checks.
• Real-time Messaging: Full support for MCP notifications and messages - receive tool/resource updates and progress notifications from backend servers.
• Python 3.12+ Support: Fully compatible with Python 3.12 and 3.13.
• Kit Management: Bundle related MCP servers into kits for easy loading/unloading as a group.
• MBro CLI: Included MCP Browser for interactive exploration and management of MCP servers, with script support for automation.

Installation

Prerequisites

• Python 3.12 or higher (3.13+ recommended)
• uv (recommended) - Install from astral.sh/uv

Quick Install (Recommended)

The easiest way to install Magg is as a tool using uv:

# Install Magg as a tool
uv tool install magg

# Run with stdio transport (for Claude Desktop, Cline, etc.)
magg serve

# Run with HTTP transport (for system-wide access)
magg serve --http

Alternative: Run Directly from GitHub

You can also run Magg directly from GitHub without installing:

# Run with stdio transport
uvx --from git+https://github.com/sitbon/magg.git magg

# Run with HTTP transport
uvx --from git+https://github.com/sitbon/magg.git magg serve --http

Local Development

For development, clone the repository and install in editable mode:

# Clone the repository
git clone https://github.com/sitbon/magg.git
cd magg

# Install in development mode with dev dependencies
uv sync --dev

# Or with poetry
poetry install --with dev

# Run the CLI
magg --help

Docker

Magg is available as pre-built Docker images from GitHub Container Registry:

# Run production image (WARNING log level)
docker run -p 8000:8000 ghcr.io/sitbon/magg:latest

# Run with authentication (mount or set private key)
docker run -p 8000:8000 \
  -v ~/.ssh/magg:/home/magg/.ssh/magg:ro \
  ghcr.io/sitbon/magg:latest

# Or with environment variable
docker run -p 8000:8000 \
  -e MAGG_PRIVATE_KEY="$(cat ~/.ssh/magg/magg.key)" \
  ghcr.io/sitbon/magg:latest

# Run beta image (INFO log level)
docker run -p 8000:8000 ghcr.io/sitbon/magg:beta

# Run with custom config directory
docker run -p 8000:8000 \
  -v /path/to/config:/home/magg/.magg \
  ghcr.io/sitbon/magg:latest

Docker Image Strategy

Magg uses a multi-stage Docker build with three target stages:

• pro (Production): Minimal image with WARNING log level, suitable for production deployments
• pre (Pre-production): Same as production but with INFO log level for staging/testing (available but not published)
• dev (Development): Includes development dependencies and DEBUG logging for troubleshooting

Images are automatically published to GitHub Container Registry with the following tags:

• Version tags (from main branch): 1.2.3, 1.2, dev, 1.2-dev, 1.2-dev-py3.12, etc.
• Branch tags (from beta branch): beta, beta-dev
• Python-specific dev tags: beta-dev-py3.12, beta-dev-py3.13, etc.

Docker Compose

For easier management, use Docker Compose:

# Clone the repository
git clone https://github.com/sitbon/magg.git
cd magg

# Run production version
docker compose up magg

# Run staging version (on port 8001)
docker compose up magg-beta

# Run development version (on port 8008)
# This uses ./.magg/config.json for configuration
docker compose up magg-dev

# Build and run with custom registry
REGISTRY=my.registry.com docker compose build
REGISTRY=my.registry.com docker compose push

See compose.yaml and .env.example for configuration options.

Usage

Running Magg

Magg can run in three modes:

1. Stdio Mode (default) - For integration with Claude Desktop, Cline, Cursor, etc.:

   magg serve
   

2. HTTP Mode - For system-wide access or web integrations:

   magg serve --http --port 8000
   

3. Hybrid Mode - Both stdio and HTTP simultaneously:

   magg serve --hybrid
   magg serve --hybrid --port 8080  # Custom port
   

   This is particularly useful when you want to use Magg through an MCP client while also allowing HTTP access. For example:

   With Claude Code:

   # Configure Claude Code to use Magg in hybrid mode
   claude mcp add magg -- magg serve --hybrid --port 42000
   

   With mbro:

   # mbro hosts Magg and connects via stdio
   mbro connect magg "magg serve --hybrid --port 8080"
   
   # Other mbro instances can connect via HTTP
   mbro connect magg http://localhost:8080
   

Available Tools

Once Magg is running, it exposes the following tools to LLMs:

• magg_list_servers - List all configured MCP servers
• magg_add_server - Add a new MCP server
• magg_remove_server - Remove a server
• magg_enable_server / magg_disable_server - Toggle server availability
• magg_search_servers - Search for MCP servers online
• magg_list_tools - List all available tools from all servers
• magg_smart_configure - Intelligently configure a server from a URL
• magg_analyze_servers - Analyze configured servers and suggest improvements
• magg_status - Get server and tool statistics
• magg_check - Health check servers with repair actions (report/remount/unmount/disable)
• magg_reload_config - Reload configuration from disk and apply changes
• magg_load_kit - Load a kit and its servers into the configuration
• magg_unload_kit - Unload a kit and optionally its servers from the configuration
• magg_list_kits - List all available kits with their status
• magg_kit_info - Get detailed information about a specific kit

Quick Inspection with MBro

Magg includes the mbro (MCP Browser) CLI tool for interactive exploration. A unique feature is the ability to connect to Magg in stdio mode for quick inspection:

# Connect mbro to a Magg instance via stdio (no HTTP server needed)
mbro connect local-magg magg serve

# Now inspect your Magg setup from the MCP client perspective
mbro:local-magg> call magg_status
mbro:local-magg> call magg_list_servers

MBro also supports:

• Scripts: Create .mbro files with commands for automation
• Shell-style arguments: Use key=value syntax instead of JSON
• Tab completion: Rich parameter hints after connecting

See the MBro Documentation for details.

Authentication

Magg supports optional bearer token authentication to secure access:

Quick Start

1. Initialize authentication (creates RSA keypair):

   magg auth init
   

2. Generate a JWT token for clients:

   # Generate token (displays on screen)
   magg auth token
   
   # Export as environment variable
   export MAGG_JWT=$(magg auth token -q)
   

3. Connect with authentication:

   • Using MaggClient (auto-loads from MAGG_JWT):

     from magg.client import MaggClient
     
     async def main():
         async with MaggClient("http://localhost:8000/mcp") as client:
             tools = await client.list_tools()
     

   • Using FastMCP with explicit token:

     from fastmcp import Client
     from fastmcp.client import BearerAuth
     
     jwt_token = "your-jwt-token-here"
     async with Client("http://localhost:8000/mcp", auth=BearerAuth(jwt_token)) as client:
         tools = await client.list_tools()
     

Key Management

• Keys are stored in ~/.ssh/magg/ by default
• Private key can be set via MAGG_PRIVATE_KEY environment variable
• To disable auth, remove keys or set non-existent key_path in .magg/auth.json

Authentication Commands

• magg auth init - Initialize authentication (generates RSA keypair)
• magg auth status - Check authentication configuration
• magg auth token - Generate JWT token
• magg auth public-key - Display public key (for verification)
• magg auth private-key - Display private key (for backup)

See examples/authentication.py for more usage patterns.

Configuration

Magg stores its configuration in .magg/config.json in your current working directory. This allows for project-specific tool configurations.

Dynamic Configuration Reloading

Magg supports automatic configuration reloading without requiring a restart:

• Automatic file watching: Detects changes to config.json and reloads automatically (uses watchdog when available)
• SIGHUP signal: Send kill -HUP <pid> to trigger immediate reload (Unix-like systems)
• MCP tool: Use magg_reload_config tool from any MCP client
• Smart transitions: Only affected servers are restarted during reload

Configuration reload is enabled by default. You can control it with:

• MAGG_AUTO_RELOAD=false - Disable automatic reloading
• MAGG_RELOAD_POLL_INTERVAL=5.0 - Set polling interval in seconds (when watchdog unavailable)

See Configuration Reload Documentation for detailed information.

Environment Variables

Magg supports several environment variables for configuration:

• MAGG_CONFIG_PATH - Path to config file (default: .magg/config.json)
• MAGG_LOG_LEVEL - Logging level: DEBUG, INFO, WARNING, ERROR, CRITICAL (default: INFO)
• MAGG_STDERR_SHOW=1 - Show stderr output from subprocess MCP servers (default: suppressed)
• MAGG_AUTO_RELOAD - Enable/disable config auto-reload (default: true)
• MAGG_RELOAD_POLL_INTERVAL - Config polling interval in seconds (default: 1.0)
• MAGG_READ_ONLY=true - Run in read-only mode
• MAGG_SELF_PREFIX - Prefix for Magg tools (default: "magg"). Tools will be named as {prefix}{sep}{tool} (e.g., magg_list_servers)
• MAGG_PREFIX_SEP - Separator between prefix and tool name (default: "_")

Example configuration:

{
  "servers": {
    "calculator": {
      "name": "calculator",
      "source": "https://github.com/executeautomation/calculator-mcp",
      "command": "npx @executeautomation/calculator-mcp",
      "prefix": "calc",
      "enabled": true
    }
  }
}

Adding Servers

Servers can be added in several ways:

1. Using the LLM (recommended):

   "Add the Playwright MCP server"
   "Search for and add a calculator tool"
   

2. Manual configuration via magg_add_server:

   name: playwright
   url: https://github.com/microsoft/playwright-mcp
   command: npx @playwright/mcp@latest
   prefix: pw
   

3. Direct config editing: Edit .magg/config.json directly

Real-time Notifications with MaggClient

The MaggClient now supports real-time notifications from backend MCP servers:

from magg import MaggClient, MaggMessageHandler

# Using callbacks
handler = MaggMessageHandler(
    on_tool_list_changed=lambda n: print("Tools changed!"),
    on_progress=lambda n: print(f"Progress: {n.params.progress}")
)

async with MaggClient("http://localhost:8000/mcp", message_handler=handler) as client:
    # Client will receive notifications while connected
    tools = await client.list_tools()

See Messaging Documentation for advanced usage including custom message handlers.

Kit Management

Magg supports organizing related MCP servers into "kits" - bundles that can be loaded and unloaded as a group:

# List available kits
magg kit list

# Load a kit (adds all its servers)
magg kit load web-tools

# Unload a kit (removes servers only in that kit)
magg kit unload web-tools

# Get information about a kit
magg kit info web-tools

You can also manage kits programmatically through Magg's tools when connected via an MCP client:

• magg_list_kits - List all available kits
• magg_load_kit - Load a kit and its servers
• magg_unload_kit - Unload a kit
• magg_kit_info - Get detailed kit information

Kits are JSON files stored in ~/.magg/kit.d/ or .magg/kit.d/ that define a collection of related servers. See Kit Documentation for details on creating and managing kits.

MBro Scripts

Automate common workflows with MBro scripts:

# Create a setup script
cat > setup.mbro <<EOF
# Connect to Magg and check status
connect magg magg serve
call magg_status
call magg_list_servers

# Add a new server if needed
call magg_add_server name=calculator source="npx -y @modelcontextprotocol/server-calculator"
EOF

# Run the script
mbro -x setup.mbro

Documentation

For more documentation, see docs/.

Appearances

Magg appears in multiple locations. Please feel free to submit a PR to add more appearances below in alphabetical order.

Listing, Index, and other MCP Sites

• DeepWiki - AI-generated documentation
• Glama.ai - MCP server listing and hosting

Awesome GitHub MCP Lists

• @modelcontextprotocol/servers
• @punkpeye/awesome-mcp-servers
• @wong2/awesome-mcp-servers