Tracking: ruvector MCP broken upstream (RuVector #715/#710) — local wrapper workaround in place until fixed

[pacphi]

What

ruvector registered as a user-scope MCP server (npx -y ruvector mcp start) shows ✗ failed in Claude Code. Diagnosed 2026-07-24 on ruvector 0.2.35 (latest at time of filing); two independent upstream defects, both already filed on ruvnet/RuVector:

1. mcp start: server registers handlers but never listens — mcp-server.js gates bootstrap on require.main === module, which cli.js can never satisfy ruvnet/RuVector#715 — mcp start never listens: cli.js require()s bin/mcp-server.js, so its if (require.main === module) main() bootstrap can never fire. Module-level init runs (banners on stderr), then the process idles forever; the stdio transport is never connected → Claude Code times out and marks the server failed.
2. mcp start: console.log in ONNX loader corrupts stdout JSON-RPC → 'Failed to connect' in Claude Code ruvnet/RuVector#710 — dist/core/onnx/loader.js:199 prints Disk cache hit: <model> via console.log. In MCP stdio mode stdout is the JSON-RPC channel, so even with #715 fixed this line corrupts the handshake.

Independent repro + workaround posted upstream: ruvnet/RuVector#715 (comment)

Workaround currently in place (machine-local, not shipped by ak)

• ruvector installed globally (stable path for bin/mcp-server.js).
• ~/.claude/ruvector-mcp-wrapper.mjs registered as the user-scope MCP command; it (a) spawns node <npm-root-g>/ruvector/bin/mcp-server.js directly so it runs as the main module, and (b) forwards only JSON frames from child stdout, rerouting stray lines to stderr.
• Verified: clean initialize response; claude mcp list → ruvector ✔ Connected.

Exit criteria (close this issue when all true)

• RuVector #715 fixed in a released version (mcp start connects the transport)
• RuVector #710 fixed in a released version (no non-JSON output on stdout in stdio mode)
• Local registration reverted to plain npx -y ruvector mcp start and verified connected
• ~/.claude/ruvector-mcp-wrapper.mjs deleted

Open question for ak (optional follow-up, not required to close)

ak already manages MCP registration (ak x mcp) and could detect a broken-known-version ruvector registration and offer the wrapper (or at least surface a status warning naming the upstream issues). If we want that, split it into its own issue — this one is purely tracking the upstream fixes.

🤖 Generated with Claude Code

[pacphi]

Closing — both upstream bugs are fixed and released:

• RuVector#715 (mcp start never listens): verified in the published 0.2.39 tarball — cli.js now does const { main } = require(mcpServerPath); main().catch(...) and mcp-server.js exports main.
• RuVector#710 (console.log corrupting stdout JSON-RPC): verified — every log in dist/core/onnx/loader.js (lines 153, 199, 277, 288, 368) now uses console.error.

Both closed 2026-07-27 16:10, shipped in 0.2.37, confirmed still present in 0.2.39.

Exit criteria completed on this machine:

• Upgraded global ruvector 0.2.35 → 0.2.39 (npm install -g ruvector@latest)
• Reverted registration to plain npx -y ruvector mcp start — claude mcp list shows ✔ Connected
• Deleted ~/.claude/ruvector-mcp-wrapper.mjs

🤖 Generated with Claude Code