Files
pipecat/src/pipecat/services/mcp_service.py
2025-05-20 11:16:59 -05:00

214 lines
8.6 KiB
Python

import json
from typing import Any, Dict, List, Optional, Union
from loguru import logger
from pipecat.adapters.schemas.function_schema import FunctionSchema
from pipecat.adapters.schemas.tools_schema import ToolsSchema
from pipecat.utils.base_object import BaseObject
try:
from mcp import ClientSession, StdioServerParameters, types
from mcp.client.session import ClientSession
from mcp.client.sse import sse_client
from mcp.client.stdio import stdio_client
except ModuleNotFoundError as e:
logger.error(f"Exception: {e}")
logger.error("In order to use an MCP client, you need to `pip install pipecat-ai[mcp]`.")
raise Exception(f"Missing module: {e}")
class MCPClient(BaseObject):
def __init__(
self,
server_params: Union[StdioServerParameters, str],
**kwargs,
):
super().__init__(**kwargs)
self._server_params = server_params
self._session = ClientSession
if isinstance(server_params, StdioServerParameters):
self._client = stdio_client
self._register_tools = self._stdio_register_tools
elif isinstance(server_params, str):
self._client = sse_client
self._register_tools = self._sse_register_tools
else:
raise TypeError(
f"{self} invalid argument type: `server_params` must be either StdioServerParameters or an SSE server url string."
)
async def register_tools(self, llm) -> ToolsSchema:
tools_schema = await self._register_tools(llm)
return tools_schema
def _convert_mcp_schema_to_pipecat(
self, tool_name: str, tool_schema: Dict[str, Any]
) -> FunctionSchema:
"""Convert an mcp tool schema to Pipecat's FunctionSchema format.
Args:
tool_name: The name of the tool
tool_schema: The mcp tool schema
Returns:
A FunctionSchema instance
"""
logger.debug(f"Converting schema for tool '{tool_name}'")
logger.trace(f"Original schema: {json.dumps(tool_schema, indent=2)}")
properties = tool_schema["input_schema"].get("properties", {})
required = tool_schema["input_schema"].get("required", [])
schema = FunctionSchema(
name=tool_name,
description=tool_schema["description"],
properties=properties,
required=required,
)
logger.trace(f"Converted schema: {json.dumps(schema.to_default_dict(), indent=2)}")
return schema
async def _sse_register_tools(self, llm) -> ToolsSchema:
"""Register all available mcp.run tools with the LLM service.
Args:
llm: The Pipecat LLM service to register tools with
Returns:
A ToolsSchema containing all registered tools
"""
async def mcp_tool_wrapper(
function_name: str,
tool_call_id: str,
arguments: Dict[str, Any],
llm: any,
context: any,
result_callback: any,
) -> None:
"""Wrapper for mcp.run tool calls to match Pipecat's function call interface."""
logger.debug(f"Executing tool '{function_name}' with call ID: {tool_call_id}")
logger.trace(f"Tool arguments: {json.dumps(arguments, indent=2)}")
try:
async with self._client(self._server_params) as (read, write):
async with self._session(read, write) as session:
await session.initialize()
await self._call_tool(session, function_name, arguments, result_callback)
except Exception as e:
error_msg = f"Error calling mcp tool {function_name}: {str(e)}"
logger.error(error_msg)
logger.exception("Full exception details:")
await result_callback(error_msg)
logger.debug("Starting registration of mcp.run tools")
tool_schemas: List[FunctionSchema] = []
async with self._client(self._server_params) as (read, write):
async with self._session(read, write) as session:
await session.initialize()
tools_schema = await self._list_tools(session, mcp_tool_wrapper, llm)
return tools_schema
async def _stdio_register_tools(self, llm) -> ToolsSchema:
"""Register all available mcp.run tools with the LLM service.
Args:
llm: The Pipecat LLM service to register tools with
Returns:
A ToolsSchema containing all registered tools
"""
async def mcp_tool_wrapper(
function_name: str,
tool_call_id: str,
arguments: Dict[str, Any],
llm: any,
context: any,
result_callback: any,
) -> None:
"""Wrapper for mcp.run tool calls to match Pipecat's function call interface."""
logger.debug(f"Executing tool '{function_name}' with call ID: {tool_call_id}")
logger.trace(f"Tool arguments: {json.dumps(arguments, indent=2)}")
try:
async with self._client(self._server_params) as streams:
async with self._session(streams[0], streams[1]) as session:
await session.initialize()
await self._call_tool(session, function_name, arguments, result_callback)
except Exception as e:
error_msg = f"Error calling mcp tool {function_name}: {str(e)}"
logger.error(error_msg)
logger.exception("Full exception details:")
await result_callback(error_msg)
logger.debug("Starting registration of mcp.run tools")
async with self._client(self._server_params) as streams:
async with self._session(streams[0], streams[1]) as session:
await session.initialize()
tools_schema = await self._list_tools(session, mcp_tool_wrapper, llm)
return tools_schema
async def _call_tool(self, session, function_name, arguments, result_callback):
logger.debug(f"Calling mcp tool '{function_name}'")
try:
results = await session.call_tool(function_name, arguments=arguments)
except Exception as e:
error_msg = f"Error calling mcp tool {function_name}: {str(e)}"
logger.error(error_msg)
response = ""
if results:
if hasattr(results, "content") and results.content:
for i, content in enumerate(results.content):
if hasattr(content, "text") and content.text:
logger.debug(f"Tool response chunk {i}: {content.text}")
response += content.text
else:
# logger.debug(f"Non-text result content: '{content}'")
pass
logger.info(f"Tool '{function_name}' completed successfully")
logger.debug(f"Final response: {response}")
else:
logger.error(f"Error getting content from {function_name} results.")
final_response = response if len(response) else "Sorry, could not call the mcp tool"
await result_callback(final_response)
async def _list_tools(self, session, mcp_tool_wrapper, llm):
available_tools = await session.list_tools()
tool_schemas: List[FunctionSchema] = []
try:
logger.debug(f"Found {len(available_tools)} available tools")
except:
pass
for tool in available_tools.tools:
tool_name = tool.name
logger.debug(f"Processing tool: {tool_name}")
logger.debug(f"Tool description: {tool.description}")
try:
# Convert the schema
function_schema = self._convert_mcp_schema_to_pipecat(
tool_name,
{"description": tool.description, "input_schema": tool.inputSchema},
)
# Register the wrapped function
logger.debug(f"Registering function handler for '{tool_name}'")
llm.register_function(tool_name, mcp_tool_wrapper)
# Add to list of schemas
tool_schemas.append(function_schema)
logger.debug(f"Successfully registered tool '{tool_name}'")
except Exception as e:
logger.error(f"Failed to register tool '{tool_name}': {str(e)}")
logger.exception("Full exception details:")
continue
logger.debug(f"Completed registration of {len(tool_schemas)} tools")
tools_schema = ToolsSchema(standard_tools=tool_schemas)
return tools_schema