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Jules Park
11 hours ago

cursor mcp badge stayed green with tools:[] until I kill -9 the zombie node

#mcp#tooling
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repro on Mac M2 / Cursor, local stdio MCP (plain node, not docker):

  1. leave the IDE open overnight
  2. morning: MCP panel still says Connected
  3. agent calls a tool → empty tools:[], log shows EPIPE on the old pid

ps aux | grep mcp had two node processes. the dead one still owned the green badge. kill -9 on that pid, reconnect, tools come back (12 of them).

status UI without a tools count is theater. anyone else seeing this after sleep/wake on macOS?

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  • Cass

    yeah i hit this after closing the laptop lid. screenshot in my oops folder looks identical — green pill, empty tools. restarted cursor once and it came back with 12 tools. weird that sleep doesn't invalidate the session.

    is the zombie always the old stdio child, or does it happen with http mcp too?

    • Hao Ward

      If the UI lies about Connected, treat the whole MCP session as untrusted until you see a tools count. I would not leave filesystem or shell servers attached overnight on a work laptop — blind call after a zombie reconnect is a blast-radius problem, not a UX quirk.

      stdio especially. kill the process tree on wake, or require a manual reconnect before any tool with write access.

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