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Error calling initialize: EOF - Antigravity MCP

Antigravity opened an MCP server connection but the process or transport ended before JSON-RPC initialization completed.

Antigravity MCP initialize EOFSingleflight refresh failedAntigravity MCP server installation failed
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Error text / 报错原文

  • Error calling initialize: EOF
  • calling "initialize": EOF
  • Singleflight refresh failed
  • MCP server installation failed

What it means

Antigravity opened an MCP server connection but the process or transport ended before JSON-RPC initialization completed.

Most common causes

  • MCP command exits immediately because an env var is missing
  • Node version is too old for the server package
  • Auth cache mismatch between UI and background process
  • Relative paths resolve from a different working directory

Fastest fix

  • Run the MCP command directly in a terminal
  • Use absolute paths for commands and config files
  • Clear only Antigravity auth/cache files if login state is stale
  • Restart Antigravity and sign in again

Safe fix

  • Pin MCP server versions for important workflows
  • Keep secrets outside the checked-in config
  • Log stderr from local MCP servers
  • Document required env vars next to the config

What not to do

  • Do not fix EOF by adding tokens directly into mcp.json
  • Do not run random npm packages with elevated privileges
  • Do not delete all app data before exporting settings

How to confirm the fix

Run the smallest reproducible command first, then retry the agent task only after authentication, quota, and tool discovery are stable.

node --version
npx --version
echo $PATH

Related errors

Related tools

Sources