`uvicorn` got eagerly imported via `sse-starlette`

[CNSeniorious000]

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

I noticed that you intend to lazy-import uvicorn because it's only used for HTTP/SSE transports. However, I found that it's still being imported immediately, as sse-starlette imports it eagerly, and sse-starlette is imported here:

https://github.com/search?q=repo%3Amodelcontextprotocol%2Fpython-sdk+sse_starlette+language%3APython&type=code

Example Code

import sys, mcp

assert "uvicorn" in sys.modules

Python & MCP Python SDK

1.23.3

[CNSeniorious000]

Sad to see #1771 only trims ~50 ms—even though import sse_starlette takes 400 ms, it turns out uvicorn itself is pretty light. Feel free to close if you're fine leaving things as-is.

[maxisbey]

Yea will leave as is for now :)