ClientSession.initialize gets stuck if the MCP server process exits

[evilsocket]

Describe the bug

I'm using the brave_search MCP server which exits(1) if BRAVE_API_KEY is not set. https://github.com/modelcontextprotocol/servers/blob/main/src/brave-search/index.ts#L85

This causes ClientSession.initialize to get stuck forever.

To Reproduce

Steps to reproduce the behavior:

Use brave_search without setting BRAVE_API_KEY.

Expected behavior

When the process of an stdio_client exits an exception should be raised.

Screenshots

From this client implementation https://github.com/evilsocket/nerve/blob/main/nerve/tools/mcp/client.py

[evilsocket]

( i'm aware there's a read_timeout argument, but imo failure in initialization and especially if the process dies should be handled with its own check )

[mroch]

I think this is a duplicate of #332

[evilsocket]

@mroch yep totally, apologies somehow i couldn't find it!