Initial Checks
Description
If the server dies during a tool call before it sends a response the client will get stuck forever.
Example Code
# server.py
from mcp.server.fastmcp import FastMCP
import sys
mcp = FastMCP("StatefulServer")
@mcp.tool()
def greet(name: str = "World") -> str:
"""Greet someone by name."""
sys.exit(0)
return f"Hello, {name}!"
if __name__ == "__main__":
mcp.run(transport="streamable-http")
# client.py
import asyncio
from mcp import ClientSession
from mcp.client.streamable_http import streamablehttp_client
async def main():
# Connect to a streamable HTTP server
async with streamablehttp_client("http://localhost:8000/mcp") as (
read_stream,
write_stream,
_,
):
# Create a session using the client streams
async with ClientSession(read_stream, write_stream) as session:
# Initialize the connection
await session.initialize()
res = await session.call_tool("greet", {"name": "World"})
print(res)
if __name__ == "__main__":
asyncio.run(main())
# Run server.py then client.py
# client.py will hang forever in the tool call and never complete. I would expect it to throw an error since the connection died and it will never get a response.Python & MCP Python SDK
Initial Checks
Description
If the server dies during a tool call before it sends a response the client will get stuck forever.
Example Code
Python & MCP Python SDK