fix: exit orphaned stdio MCP servers on parent death - #8
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Clients can abandon sessions while a wrapper keeps stdin open, so EOF never arrives and leaked servers thrash swap. Exit on stdin close and add a parent-liveness watchdog (same approach as mcp-automem).
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Do not transport.close() or process.exit on stdin end/close — that trips SDK onclose and breaks one-shot pipe flows. Hard exit only on parent watchdog reparent and SIGTERM/SIGINT/SIGHUP. Capture parentPid before any await; unit tests assert stdin EOF alone does not exit.
Match mcp-automem wording: win32 does not reparent orphans, so the ppid probe is a documented no-op there.
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Summary
Stdio MCP servers can leak forever when a client (Claude Desktop / Cursor / Grok / Codex) abandons a session but an intermediate wrapper (
npx/npm exec/ launcher) keeps the stdin write-end open. No EOF arrives, the process stays in the event loop, and repeated leaks cause multi-GB swap thrashing.This mirrors the fix already shipped in
mcp-automem(#137):end/close(and transport/signal where applicable)ppidchanges from the startup parent (POSIX reparent), exit promptlyTest plan