MCP Wikipedia Server

"""Prompts adapter for converting MCP prompts to LangChain messages. This module provides functionality to convert MCP prompt messages into LangChain message objects, handling both user and assistant message types. """ from typing import Any from langchain_core.messages import AIMessage, HumanMessage from mcp import ClientSession from mcp.types import PromptMessage def convert_mcp_prompt_message_to_langchain_message( message: PromptMessage, ) -> HumanMessage | AIMessage: """Convert an MCP prompt message to a LangChain message. Args: message: MCP prompt message to convert Returns: A LangChain message """ if message.content.type == "text": if message.role == "user": return HumanMessage(content=message.content.text) if message.role == "assistant": return AIMessage(content=message.content.text) msg = f"Unsupported prompt message role: {message.role}" raise ValueError(msg) msg = f"Unsupported prompt message content type: {message.content.type}" raise ValueError(msg) async def load_mcp_prompt( session: ClientSession, name: str, *, arguments: dict[str, Any] | None = None, ) -> list[HumanMessage | AIMessage]: """Load MCP prompt and convert to LangChain messages. Args: session: The MCP client session. name: Name of the prompt to load. arguments: Optional arguments to pass to the prompt. Returns: A list of LangChain messages converted from the MCP prompt. """ response = await session.get_prompt(name, arguments) return [ convert_mcp_prompt_message_to_langchain_message(message) for message in response.messages ]