simple-streamablehttp-stateless have member leak

[jenfmo]

Initial Checks

• I confirm that I'm using the latest version of MCP Python SDK
• I confirm that I searched for my issue in https://github.com/modelcontextprotocol/python-sdk/issues before opening this issue

Description

Run the example simple-streamablehttp-stateless and make concurrent calls to the tools/call interface; the memory will continue to increase.

Example Code

Python & MCP Python SDK

1.12.2

[felixweinberger]

Hi @jenfmo thank you for reporting this.

If this is still affecting you, could you provide a runnable example that demonstrates the memory profile increasing?

See #577 for a good example of how to provide a full repro