Dynavera/mcp_agent/mcp_client.py

import httpx
import asyncio
import logging

logger = logging.getLogger(__name__)

class MCPClient:
    def __init__(self, server_url: str, timeout: int = 3600):
        self.server_url = server_url
        self.client = httpx.AsyncClient(timeout=timeout)
        logger.info(f"MCPClient initialized for {server_url} with timeout={timeout}s ({timeout//60} minutes)")

    async def send(self, tool: str, arguments: dict):
        logger.info(f"MCPClient: Sending request to {self.server_url}/execute for tool '{tool}'")
        try:
            response = await self.client.post(
                f"{self.server_url}/execute",
                json={
                    "tool": tool,
                    "arguments": arguments,
                },
            )
            logger.info(f"MCPClient: Received response with status={response.status_code}")
            logger.debug(f"MCPClient: Response headers: {response.headers}")
            
        except asyncio.TimeoutError as e:
            logger.error(f"MCPClient: Request timeout for tool '{tool}': {str(e)}")
            raise Exception(f"MCP tool '{tool}' request timed out (>3600s / 1 hour). Model loading or fine-tuning may be too slow.")
        except Exception as e:
            logger.error(f"MCPClient: Request failed for tool '{tool}': {str(e)}", exc_info=True)
            raise Exception(f"MCP tool '{tool}' request failed: {str(e)}")
        
        if response.status_code >= 400:
            error_data = {}
            try:
                error_data = response.json()
                logger.error(f"MCPClient: HTTP error {response.status_code}: {error_data}")
            except:
                logger.error(f"MCPClient: HTTP error {response.status_code} (could not parse JSON)")
                pass
            
            error_msg = error_data.get("error") or error_data.get("details") or f"HTTP {response.status_code}"
            raise Exception(f"MCP tool '{tool}' failed: {error_msg}. Full response: {error_data}")
        
        try:
            result = response.json()
            logger.debug(f"MCPClient: Parsed JSON response: status={result.get('status')}")
        except Exception as e:
            logger.error(f"MCPClient: Failed to parse response JSON: {str(e)}")
            logger.error(f"MCPClient: Raw response text: {response.text[:500]}")
            raise Exception(f"MCP tool '{tool}' returned invalid JSON: {str(e)}")
        
        if isinstance(result, dict) and result.get("status") == "failed":
            error_msg = result.get("error") or result.get("details") or "Unknown error"
            traceback_info = result.get("traceback", "")
            full_error = f"MCP tool '{tool}' returned failure: {error_msg}"
            if traceback_info:
                full_error += f"\n\nServer traceback:\n{traceback_info}"
            logger.error(f"MCPClient: {full_error}")
            raise Exception(full_error)
        
        logger.info(f"MCPClient: Tool '{tool}' completed successfully")
        return result

    async def health(self):
        response = await self.client.get(f"{self.server_url}/health")
        response.raise_for_status()
        return response.json()

    async def close(self):
        await self.client.aclose()


async def main():
    client = MCPClient("http://localhost:8001")

    result = await client.send(
        tool="echo",
        arguments={"message": "hello from client"},
    )

    print(result)
    await client.close()

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