Gemma MCP Client

A Python package that combines Google's Gemma language model with MCP (Model Content Protocol) server integration, enabling powerful function calling capabilities across both local functions and remote MCP tools.

Features

• Seamless integration with Google's Gemma language model
• Support for both local Python functions and remote MCP tools
• Automatic tool discovery and registration from MCP servers
• Python-style function calling syntax
• Proper resource management with async context managers
• Support for multiple MCP servers
• Easy testing through test server support

Installation

uv add gemma-mcp # or pip install gemma-mcp if you love the old way

Requirements

• Python 3.10+
• google-genai: Google Generative AI Python SDK
• FastMCP MCP utilities

Usage

Basic Usage

from gemma_mcp import GemmaMCPClient

# a standard MCP configuration
mcp_config = {
    "mcpServers": {
        "weather": {
            "url": "https://weather-api.example.com/mcp"
        },
        "assistant": {
            "command": "python",
            "args": ["./assistant_server.py"]
        }
    }
}

# Initialize client with MCP support
async with GemmaMCPClient(mcp_config=mcp_config).managed() as client:
    # Chat with automatic function execution
    response = await client.chat(
        "What's the weather like in London?",
        execute_functions=True
    )
    print(response)

Adding Local Functions

You can add local functions in three ways:

1. Using a callable:

async def my_function(param1: str, param2: int = 0):
    """Function description."""
    return {"result": param1 + str(param2)}

client.add_function(my_function)

1. Using a dictionary:

function_def = {
    "name": "my_function",
    "description": "Function description",
    "parameters": {
        "type": "object",
        "properties": {
            "param1": {"type": "string"},
            "param2": {"type": "integer", "default": 0}
        },
        "required": ["param1"]
    }
}
client.add_function(function_def)

1. Using a FunctionDefinition object:

from gemma_mcp import FunctionDefinition

function_def = FunctionDefinition(
    name="my_function",
    description="Function description",
    parameters={
        "type": "object",
        "properties": {
            "param1": {"type": "string"},
            "param2": {"type": "integer", "default": 0}
        },
        "required": ["param1"]
    },
    required=["param1"]
)
client.add_function(function_def)

MCP Server Configuration

The MCP configuration supports multiple server types:

1. servers with SSE transport:

mcp_config = {
    "mcpServers": {
        "server_name": {
            "url": "https://server-url/mcp"
        }
    }
}

1. servers with STDIO transport:

mcp_config = {
    "mcpServers": {
        "server_name": {
            "command": "python",
            "args": ["./server.py"]
        }
    }
}

Testing

The package includes support for testing with in-memory MCP servers:

from fastmcp import FastMCP
from gemma_mcp import GemmaMCPClient

# Create test server
mcp = FastMCP("Test Server")

# Initialize client with test server
client = GemmaMCPClient()
client.mcp_client.add_test_server(mcp)

# Use the client as normal
async with client.managed():
    response = await client.chat("Test message", execute_functions=True)

API Reference

GemmaMCPClient

The main client class that handles both Gemma model interactions and MCP tool integration.

Parameters

• api_key (str, optional): Gemini API key. If not provided, will look for GEMINI_API_KEY env var
• model (str): Model to use, defaults to "gemma-3-27b-it"
• temperature (float): Generation temperature, defaults to 0.7
• system_prompt (str, optional): Custom system prompt
• mcp_config (dict, optional): MCP configuration dictionary

Methods

• add_function(function): Add a function definition
• chat(message, execute_functions=False): Send a message and get response
• initialize(): Initialize the client and all components
• cleanup(): Clean up all resources

FunctionDefinition

A dataclass for representing function definitions.

Parameters

• name (str): Function name
• description (str): Function description
• parameters (dict): Function parameters schema
• required (list): List of required parameters
• callable (callable, optional): The actual callable function

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.