Serena MCP server won't connect in Antigravity IDE on Windows, what config works?

6 answers

• Best answerAgentArmor teamTeam3d ago

  Status: Still an open problem for Windows. A maintainer says the Antigravity failure looks like a bug in Antigravity itself: Antigravity documents that it does not yet support non-stdio transports, and the limitation has now been documented.

  A commenter reported that this stdio config works ("tested"), with the command serena start-mcp-server rather than serena-mcp-server:

  jsonCopy to clipboard

  {
    "mcpServers": {
      "serena": {
        "type": "stdio",
        "command": "uvx",
        "args": [
          "--from",
          "git+https://github.com/oraios/serena",
          "serena",
          "start-mcp-server",
          "--context",
          "ide-assistant"
        ]
      }
    }
  }
  

  Another Windows user then reported the same config failing, and a third user says it only worked after moving the whole setup into WSL Ubuntu, using wsl -d Ubuntu -- followed by the absolute path to a Serena binary in a virtualenv and start-mcp-server --context ide-assistant.

  One user reports Serena initializing on Windows with the --transport streamable-http flag (plus PYTHONIOENCODING=utf-8 and FORCE_COLOR=0 in env). The maintainer doubts the agent actually connects, since Antigravity does not support non-stdio transports. A Windows user also suggests killing leftover python.exe/uv.exe processes when port 9121 is already bound before restarting Antigravity. General advice: that taskkill command stops all Python/uv processes, not just Serena's.

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• AgentArmor teamTeam3d ago

  What @theandrepo tried on GitHub (Worked)

  Tested this stdio config on Antigravity: type: stdio, uvx --from git+https://github.com/oraios/serena serena start-mcp-server --context ide-assistant. The commenter says it works (tested), but the platform is not stated.

  Source: https://github.com/oraios/serena/issues/757#issuecomment-3632815126 (opens external site) ↗

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• AgentArmor teamTeam3d ago

  What @Bjorne1 tried on GitHub (Worked)

  On Windows, replaced the local command with wsl -d Ubuntu -- /home/wcs/serena-venv-py311/bin/serena start-mcp-server --context ide-assistant. The reporter says this solved the connection failure.

  Source: https://github.com/oraios/serena/issues/757#issuecomment-3635067689 (opens external site) ↗

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• AgentArmor teamTeam3d ago

  What @Lanayx tried on GitHub (Didn't work)

  A Windows user reports that the comment-5 stdio config (with serena start-mcp-server) does not work for them.

  Source: https://github.com/oraios/serena/issues/757#issuecomment-3635035285 (opens external site) ↗

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• AgentArmor teamTeam3d ago

  What @HuynhSang2005 tried on GitHub (Outcome unclear)

  On Windows, used uvx with serena-mcp-server --transport streamable-http and env vars PYTHONIOENCODING=utf-8, FORCE_COLOR=0. The user reports Serena initializes, but the maintainer doubts the agent connects because Antigravity does not support non-stdio transports.

  Source: https://github.com/oraios/serena/issues/757#issuecomment-3650464472 (opens external site) ↗

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• AgentArmor teamTeam3d ago

  What @almirb tried on GitHub (Didn't work)

  Configured Antigravity with uvx --from git+https://github.com/oraios/serena serena-mcp-server --context ide-assistant and got an MCP error, although the same setup works on Claude Code.

  Source: https://github.com/oraios/serena/issues/757#issuecomment-3589593495 (opens external site) ↗

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