One shared, detached daemon per project root: every `codegraph serve --mcp` is a thin stdio<->socket proxy (Unix socket / Windows named pipe) to it, so N agents in one repo share a single file watcher, SQLite connection, and tree-sitter warm-up instead of N copies. The daemon outlives any single session and reaps via client-refcount + idle timeout; `CODEGRAPH_NO_DAEMON=1` opts out.
Hardened during review: detached-process lifecycle (preserves the #277 watchdog via the proxy; the daemon no longer orphans on host SIGKILL), atomic lockfile + pid-verified stale-clear (no double-daemon on concurrent startup), realpath root canonicalization. Validated on macOS, Linux (Docker - 3x fewer inotify watches for 3 agents), and Windows (named pipes); A/B confirms byte-identical tool output vs direct mode. Closes#411.
Co-Authored-By: Colby McHenry <me@colbymchenry.com>
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The MCP `initialize` handler was awaiting `tryInitializeDefault` —
which opens the SQLite DB and runs `await initGrammars()` (tree-sitter
WASM bootstrap) — before sending the JSON-RPC response. On slow
filesystems (Docker Desktop VirtioFS on macOS, WSL2) this could exceed
Claude Code's ~30s handshake timeout, leaving the codegraph child
process alive and unresponsive with no tools visible in the client.
Send the response first; defer the open to a tracked background
promise. The lazy retry path used by `tools/list` and `tools/call`
now awaits that promise instead of racing it with `openSync`, so we
never double-open the SQLite file.
Adds a subprocess-based regression test that asserts the JSON-RPC
response arrives on stdout before `startWatching()` logs to stderr.
This ordering check catches the regression on any filesystem, not
just slow ones where the timing matters in practice.
Reported by @sashanclrp; isolated by @sgrimm's wire capture.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
