Insecure MCP Demo

import asyncio
from typing import Optional
from contextlib import AsyncExitStack

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

import sys

class MCPClient:
    def __init__(self):
        # Initialize session and client objects
        self.session: Optional[ClientSession] = None
        self.exit_stack = AsyncExitStack()

    async def connect_to_server(self, server_script_path: str):
        """Connect to an MCP server
        Args:
            server_script_path: Path to the server script (.py or .js)
        """
        is_python = server_script_path.endswith('.py')
        is_js = server_script_path.endswith('.js')
        if not (is_python or is_js):
            raise ValueError("Server script must be a .py or .js file")
        command = "python" if is_python else "node"
        server_params = StdioServerParameters(
            command=command,
            args=[server_script_path],
            env=None
        )
        stdio_transport = await self.exit_stack.enter_async_context(stdio_client(server_params))
        self.stdio, self.write = stdio_transport
        self.session = await self.exit_stack.enter_async_context(ClientSession(self.stdio, self.write))
        await self.session.initialize()
        # List available tools
        response = await self.session.list_tools()
        tools = response.tools
        print("\nConnected to server with tools:", [tool.name for tool in tools])

    async def call_tool(self, tool_name, **kwargs):
        result = await self.session.call_tool(tool_name, kwargs)
        # Print the most informative representation of the result
        if hasattr(result, 'content'):
            print(f"\nResult: {result.content}")
        elif hasattr(result, '__dict__'):
            print(f"\nResult: {result.__dict__}")
        else:
            print(f"\nResult: {result}")

    async def chat_loop(self):
        """Run an interactive chat loop"""
        print("\nMCP Client Started!")
        print("Type 'insert' to insert a record, 'query' to query records, or 'quit' to exit.")
        while True:
            try:
                cmd = input("\nCommand (insert/query/quit): ").strip().lower()
                if cmd == 'insert':
                    name = input("Enter name: ")
                    address = input("Enter address: ")
                    await self.call_tool('insert_record', name=name, address=address)
                elif cmd == 'query':
                    await self.call_tool('query_records')
                elif cmd == 'quit':
                    break
                else:
                    print("Unknown command.")
            except Exception as e:
                print(f"\nError: {str(e)}")

    async def cleanup(self):
        """Clean up resources"""
        await self.exit_stack.aclose()

async def main():
    if len(sys.argv) < 2:
        print("Usage: python good-mcp-client.py <path_to_server_script>")
        sys.exit(1)
    client = MCPClient()
    try:
        await client.connect_to_server(sys.argv[1])
        await client.chat_loop()
    finally:
        await client.cleanup()

if __name__ == "__main__":
    asyncio.run(main())