Antigravity Hub fails to connect to Roblox StudioMCP (server/discover during initialization)

Google Antigravity
1

I was redirected here by @manirajc from GitHub because this issue affects Antigravity Hub rather than Antigravity CLI.

Summary

Antigravity Hub is unable to connect to Roblox StudioMCP, while Antigravity IDE connects and works correctly using the exact same MCP configuration.

The failure appears to happen during the MCP initialization handshake.

Environment

  • Windows 11
  • Antigravity Hub 2.4.3
  • Antigravity IDE 2.4.3
  • Roblox StudioMCP 0.1.0

Expected behavior

Antigravity Hub should connect to Roblox StudioMCP successfully, just like Antigravity IDE.

Actual behavior

Hub immediately fails with:

expect initialized request, but received:
server/discover

connection closed:
calling "initialize": client is closing: EOF

What I tested

  • Reinstalled Antigravity Hub from scratch.
  • Deleted the Hub configuration folder.
  • Verified StudioMCP is running correctly.
  • Roblox Studio reports connected MCP clients.
  • Antigravity IDE connects successfully using the exact same MCP configuration.
  • The problem only occurs in Antigravity Hub.

Additional information

This issue persists after a clean reinstall.

Since Antigravity IDE works correctly with the exact same MCP configuration, it does not appear to be a StudioMCP installation issue.

If needed, I can provide logs, screenshots, or any additional debugging information.

2

Hi @Juany_Pazos,

Could you please recheck the Antigravity IDE version mentioned in the report is incorrect.

Additionally, please provide the following information if available:

  • Any relevant Antigravity Hub logs or Developer Tools/Console output.
  • If applicable, please provide a recording showing the following steps:
    1. Roblox StudioMCP running.
    2. Antigravity IDE successfully connecting with the MCP configuration.
    3. Antigravity Hub failing with the same configuration.
3

I was experiencing the identical error while using version 2.5.0.

As a workaround, downgrading to version 2.2.1 resolved the issue completely, it connects smoothly now and the error is completely gone. I’m not sure about the underlying fix for the 2.5 / 2.4.3 builds, but rolling back to 2.2.1 works for me.