GitHub user goutamadwant added a comment to the discussion: Is fastmcp 4.x supported? MCP server crash-loops after automatic upgrade from 3.4.7
FastMCP 4 is outside Superset 6.1.0's declared range: its [`fastmcp` extra](https://github.com/apache/superset/blob/6.1.0/pyproject.toml#L147) specifies `fastmcp>=3.1.0,<4.0`. The failure also has a concrete match in that release: [`middleware.py`](https://github.com/apache/superset/blob/6.1.0/superset/mcp_service/middleware.py#L27) imports `Tool` and `ToolResult` from `fastmcp.tools.tool`, which [FastMCP 4 removed](https://gofastmcp.com/getting-started/upgrading/from-fastmcp-3#removed-in-fastmcp-4). The CLI catches any `ImportError` during startup and prints “dependencies not installed”, so that message doesn't necessarily mean FastMCP itself is missing. For recovery, rebuild the MCP image with your previously working `fastmcp==3.4.7` pinned in its dependency inputs. For subsequent installs, use the versioned extra (`apache-superset[fastmcp]==6.1.0`) so the resolver sees Superset's constraint; avoid a later unrestricted `pip install --upgrade fastmcp` step. Verify the installed version and run `python -m pip check` inside that image before restarting it. A documentation correction would be useful: there is already an upper bound in the package metadata, but the unqualified install instruction loses it. I haven't verified a tracking issue or release date for 4.x support; changing that one import alone wouldn't establish compatibility. GitHub link: https://github.com/apache/superset/discussions/43822#discussioncomment-18325532 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
