fix(mcp): shut down gracefully on stdin EOF instead of orphaning to PID 1 (#751) - #837
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The SDK's StdioServerTransport subscribes to stdin 'data'/'error' only and never notices 'end'/'close'. When the parent MCP client dies, no teardown runs: whenever anything still references the event loop (a warm llama.cpp model's native handles being the common case), the server reparents to PID 1, leaks RAM, and keeps the SQLite index open. Treat stdin EOF as a client disconnect: close the server/transport, give in-flight request handlers a bounded window to settle (a new InflightGate counts running tool/resource handlers so their store/llm dependencies are not torn down underneath them), release the llama.cpp resources, close the store, and set process.exitCode instead of calling process.exit() so beforeExit still fires and node-llama-cpp's auto-dispose runs before libc's static destructors - forced exits during native-addon unload have caused exit-time crashes before (#59, and mirrors the HTTP transport's idempotent stop() including its stderr breadcrumb. The shutdown is a shared promise that never rejects: 'end', 'close', an already-ended stdin at registration time, and manual invocations all collapse into one run. Every step including logging is failure-tolerant (the parent's death may have closed stderr too), and a successful shutdown preserves an earlier nonzero exit code instead of masking it. Related: modelcontextprotocol/typescript-sdk#2003 fixes the same gap at the transport layer; this stays correct alongside it because the teardown is idempotent, and qmd needs its own store/llm cleanup either way. Tests: unit tests drive registerStdioEofShutdown via injected stdin (ordering incl. in-flight drain, idempotency, failure tolerance, exit-code preservation, throwing stderr, already-ended stdin) plus createInflightGate unit tests; an end-to-end test spawns the real server, completes an initialize round-trip, closes stdin, and asserts a prompt code-0 exit through the EOF shutdown path (stderr breadcrumb).
This was referenced Aug 12, 2026
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Summary
Relands #767 onto current (#767) main (CHANGELOG conflict only). Fixes #751. (#751) qmd mcp (stdio) now shuts down gracefully when stdin reaches EOF instead of orphaning to PID 1 when the parent MCP client dies: close transport, bounded in-flight drain, close store (disposes llama.cpp), set process.exitCode (no forced process.exit()).
Test plan CI=true node ./node_modules/vitest/vitest.mjs run test/mcp-stdio-lifecycle.test.ts — 17/17 pass CI=true bun test --preload ./src/test-preload.ts test/mcp-stdio-lifecycle.test.ts — 17/17 pass
Supersedes #767. (#767) You can view, comment on, or merge this pull request online at: #837 (#837) Commit Summary b69669d fix(mcp): shut down gracefully when stdin reaches EOF (#751) (b69669d) File Changes
( 3 files) (https://github.com/tobi/qmd/pull/837/files) M CHANGELOG.md
(7) (https://github.com/tobi/qmd/pull/837/files#diff-06572a96a58dc510037d5efa622f9bec8519bc1beab13c9f251e97e657a9d4ed) M src/mcp/server.ts
(244) (https://github.com/tobi/qmd/pull/837/files#diff-9f457d54293270cc59a8245e10ad2f90e4b1bc82b1ec74ce6b1c415924069c73) A test/mcp-stdio-lifecycle.test.ts
(363) (https://github.com/tobi/qmd/pull/837/files#diff-1ddc3be2af909fe80af606cedf16a9a754c3f8e94feff2d7ac69e6dc1c563d1f) Patch Links: https://github.com/tobi/qmd/pull/837.patch (https://github.com/tobi/qmd/pull/837.patch) https://github.com/tobi/qmd/pull/837.diff (https://github.com/tobi/qmd/pull/837.diff)
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Summary
Relands #767 onto current
main(CHANGELOG conflict only). Fixes #751.qmd mcp(stdio) now shuts down gracefully when stdin reaches EOF instead of orphaning to PID 1 when the parent MCP client dies: close transport, bounded in-flight drain, close store (disposes llama.cpp), setprocess.exitCode(no forcedprocess.exit()).Test plan
CI=true node ./node_modules/vitest/vitest.mjs run test/mcp-stdio-lifecycle.test.ts— 17/17 passCI=true bun test --preload ./src/test-preload.ts test/mcp-stdio-lifecycle.test.ts— 17/17 passSupersedes #767.