Statsig MCP Server

Model Context Protocol server for Statsig feature flags and experimentation platform.

This MCP server enables AI assistants to interact with Statsig's feature management and experimentation platform, allowing them to check feature flags, retrieve dynamic configurations, get experiment assignments, and log custom events.

Features

• 🚩 Feature Gate Checking: Determine if features are enabled for users
• ⚙️ Dynamic Configuration: Retrieve configuration values based on user context
• 🧪 Experiment Assignment: Get experiment variations for A/B testing
• 📊 Layer Parameter Access: Retrieve values from Statsig layers
• 📈 Event Logging: Track custom events for analytics

Installation

Using uv (Recommended)

# Clone the repository
git clone https://github.com/GeLi2001/statsig-mcp.git
cd statsig-mcp

# Install dependencies with uv
uv sync

# Install with dev dependencies
uv sync --extra dev

Using pip

# Install from source
pip install -e .

# Or install with dev dependencies
pip install -e ".[dev]"

Quick Start

1. Run the Server

With uv (Recommended):

# Using command-line arguments (MCP best practice)
uv run -m statsig_mcp --api-key "your-secret-key"

# With additional options
uv run -m statsig_mcp \
  --api-key "your-secret-key" \
  --environment "production" \
  --api-timeout 5000 \
  --debug

# Or with environment variables
STATSIG_SERVER_SECRET_KEY="your-key" uv run -m statsig_mcp

With Python:

# Using flags (recommended)
python -m statsig_mcp --api-key "your-secret-key"

# Or environment variables
export STATSIG_SERVER_SECRET_KEY="your-secret-key"
python -m statsig_mcp

2. Configuration Options

The server supports both command-line arguments (recommended for MCP) and environment variables:

Command-Line Arguments (MCP Best Practice)

uv run -m statsig_mcp --help

Argument	Type	Default	Description
--api-key	string	None	Statsig server secret key (required)
--environment	string	development	Environment tier
--api-timeout	int	3000	API timeout in milliseconds
--disable-logging	flag	false	Disable event logging to Statsig
--debug	flag	false	Enable debug logging

Environment Variables (Fallback)

Variable	Description
STATSIG_SERVER_SECRET_KEY	Statsig server secret key
STATSIG_ENVIRONMENT	Environment tier
STATSIG_API_TIMEOUT	API timeout in milliseconds
STATSIG_DISABLE_LOGGING	Disable logging (true/false)
STATSIG_DEBUG	Enable debug mode (true/false)

3. MCP Client Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "statsig": {
      "command": "uv",
      "args": [
        "run",
        "-m",
        "statsig_mcp",
        "--api-key",
        "your-secret-key",
        "--environment",
        "production"
      ]
    }
  }
}

Alternative with Environment Variables

{
  "mcpServers": {
    "statsig": {
      "command": "uv",
      "args": ["run", "-m", "statsig_mcp"],
      "env": {
        "STATSIG_SERVER_SECRET_KEY": "your-secret-key",
        "STATSIG_ENVIRONMENT": "production"
      }
    }
  }
}

Available Tools

1. check_feature_gate

Check if a feature gate is enabled for a user.

Parameters:

• user_id (string): User identifier
• gate_name (string): Name of the feature gate
• user_email (string, optional): User email
• user_country (string, optional): User country code
• custom_attributes (object, optional): Custom user attributes

Example:

{
  "user_id": "user123",
  "gate_name": "new_checkout_flow",
  "user_email": "user@example.com",
  "custom_attributes": { "plan": "premium" }
}

2. get_dynamic_config

Get dynamic configuration values for a user.

Parameters:

• user_id (string): User identifier
• config_name (string): Name of the dynamic config
• user_email (string, optional): User email
• user_country (string, optional): User country code
• custom_attributes (object, optional): Custom user attributes

3. get_experiment

Get experiment assignment for a user.

Parameters:

• user_id (string): User identifier
• experiment_name (string): Name of the experiment
• user_email (string, optional): User email
• user_country (string, optional): User country code
• custom_attributes (object, optional): Custom user attributes

4. get_layer

Get layer parameter values for a user.

Parameters:

• user_id (string): User identifier
• layer_name (string): Name of the layer
• user_email (string, optional): User email
• user_country (string, optional): User country code
• custom_attributes (object, optional): Custom user attributes

5. log_event

Log a custom event.

Parameters:

• user_id (string): User identifier
• event_name (string): Name of the event
• value (string|number, optional): Event value
• metadata (object, optional): Event metadata
• user_email (string, optional): User email
• user_country (string, optional): User country code
• custom_attributes (object, optional): Custom user attributes

Example MCP Client Usage

from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

# Create server parameters with flags (recommended)
server_params = StdioServerParameters(
    command="uv",
    args=[
        "run", "-m", "statsig_mcp",
        "--api-key", "your-secret-key",
        "--environment", "production",
        "--debug"
    ]
)

async def main():
    async with stdio_client(server_params) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()

            # Check a feature gate
            result = await session.call_tool(
                "check_feature_gate",
                arguments={
                    "user_id": "user123",
                    "gate_name": "new_feature",
                    "custom_attributes": {"plan": "premium"}
                }
            )
            print(f"Feature gate result: {result}")

            # Get dynamic config
            config = await session.call_tool(
                "get_dynamic_config",
                arguments={
                    "user_id": "user123",
                    "config_name": "ui_config"
                }
            )
            print(f"Config: {config}")

            # Log an event
            await session.call_tool(
                "log_event",
                arguments={
                    "user_id": "user123",
                    "event_name": "button_click",
                    "metadata": {"button": "checkout"}
                }
            )

Development

Setup Development Environment

Using uv (Recommended):

# Clone and setup
git clone https://github.com/GeLi2001/statsig-mcp.git
cd statsig-mcp

# Install all dependencies including dev tools
uv sync --extra dev

# Run tests
uv run pytest

# Format code
uv run black .

# Type checking
uv run mypy .

# Linting
uv run ruff check .

Using pip:

# Install in development mode with dev dependencies
pip install -e ".[dev]"

# Run tests
pytest

# Format code
black .

# Type checking
mypy .

Running Commands

With uv, you can run any command in the virtual environment:

# Run the server with flags
uv run -m statsig_mcp --api-key "test-key" --debug

# Run tests with verbose output
uv run pytest -v

# Run validation script
uv run python validate.py

# Format and lint
uv run black .
uv run ruff check --fix .

Project Structure

statsig_mcp/
├── __init__.py
├── __main__.py        # Module entry point
├── server.py          # Main MCP server implementation
├── statsig_client.py  # Statsig client wrapper
└── types.py           # Type definitions

tests/                 # Test suite
├── test_server.py

pyproject.toml         # Project configuration
uv.lock               # Locked dependencies (uv)
.venv/                # Virtual environment (uv managed)

Security Notes

• Never expose your Statsig server secret key in client-side code
• Use command-line arguments or environment variables for API keys
• The server secret key provides full access to your Statsig project
• Consider using separate API keys for different environments

Requirements

• Python 3.10+
• uv (recommended) or pip for package management

Troubleshooting

Common Issues

1. "Statsig not initialized" error: Ensure --api-key is provided or STATSIG_SERVER_SECRET_KEY is set
2. Network timeouts: Increase timeout with --api-timeout 5000
3. Feature gate not found: Verify the gate name exists in your Statsig console
4. Python version error: This package requires Python 3.10+ (MCP requirement)

Debug Mode

Enable debug logging for troubleshooting:

# With command-line flag (recommended)
uv run -m statsig_mcp --api-key "your-key" --debug

# With environment variable
STATSIG_DEBUG=true uv run -m statsig_mcp --api-key "your-key"

Help

Get help with command-line options:

uv run -m statsig_mcp --help

License

MIT License - see LICENSE file for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Run tests and linting: uv run pytest && uv run ruff check
6. Submit a pull request

Resources

• Statsig Documentation
• Model Context Protocol
• Statsig Python SDK
• uv Documentation