Magg - MCP Server

🧲 Magg - The MCP Aggregator

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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:

Stdio Mode (default) - For integration with Claude Desktop, Cline, Cursor, etc.:
```
magg serve
```
HTTP Mode - For system-wide access or web integrations:
```
magg serve --http --port 8000
```

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&gt; call magg_status
mbro:local-magg&gt; 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

Initialize authentication (creates RSA keypair):
```
magg auth init
```

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)

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:

Using the LLM (recommended):

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

Manual configuration via magg_add_server:

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

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 &gt; setup.mbro &lt;&lt;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