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MCP Python SDK Backports a FastMCP Import Warning Because Users Were Filing Bugs on the Wrong Repos
v2.0.1, published 2026-08-26, is a one-off backport described as needed "due to a lot of people running into this error and making issues on other repos about it." SDK 2.0.0 moved everything under `mcp.server.fastmcp.*` to `mcp.server.mcpserver.*` and renamed the `FastMCP` class to `MCPServer`, so `pip install mcp` started producing `ModuleNotFoundError: No module named 'mcp.server.fastmcp'` in downstream servers whose maintainers had no idea why. The fix for your own project is one of two lines: pin `mcp>=1.28,<2`, or change the import and the constructor call, which leaves decorator arguments and handler signatures unchanged.
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