J said "let's go" → "next" (option 3): actual flip via Bun
mcp-server. Done. Real Bun-frontend traffic now reaches the Go
substrate via /_go/* on Bun :3700, routed to the persistent Go
gateway at :4110.
Companion change in /home/profit/lakehouse (Rust legacy):
mcp-server/index.ts: new /_go/* pass-through, opt-in via
GO_LAKEHOUSE_URL env var. Off-by-default (returns 503 on
/_go/* with rationale). Existing /api/* (Rust gateway) path
unchanged. Committed locally on the demo/post-pr11 branch.
System config:
/etc/systemd/system/lakehouse-agent.service.d/go-cutover.conf
adds Environment=GO_LAKEHOUSE_URL=http://127.0.0.1:4110 to
the systemd-managed Bun service. Reversible via systemctl
revert lakehouse-agent.
Live verification (operator curl through Bun frontend):
- /_go/health: gateway responds {"status":"ok","service":"gateway"}
- /_go/v1/embed: nomic-embed-text-v2-moe vectors, dim=768
- /_go/v1/matrix/search vs persistent 200-worker corpus:
rank=0 id=w-43 Brian Ramirez (Forklift Operator, Springfield IL)
rank=1 id=w-102 Laura Long (Forklift Operator, Cleveland OH)
rank=2 id=w-101 Terrence Gray (Forklift Operator, Champaign IL)
3/3 role match, top-1 in IL exactly
- /api/health: lakehouse ok (Rust path unchanged — control verified)
What this is NOT:
- Not an nginx flip — devop.live/lakehouse/* still goes through
/api/* → Rust :3100. /_go/* is parallel slice for opt-in.
- Not a tool-level cutover — each /_go/<path> is a manual choice;
no automatic mapping of Rust paths to Go equivalents.
- Not a transformation layer — caller sends Go-shaped requests
(e.g. /_go/v1/embed expects {texts, model}, not {text}).
Three cutover unit properties verified:
- ADDITIVE: zero modification to any existing Bun tool
- REVERSIBLE: unset GO_LAKEHOUSE_URL → /_go/* → 503
- ISOLATED: Rust gateway state unaffected (different port,
different binary, different MinIO bucket)
This is the cutover slice operators can use to validate Go-side
handlers under realistic frontend conditions before any
production-traffic flip. Next step (deferred): pick a specific
mcp-server tool to optionally route through Go with response-
shape adapter — that's a product-visible flip rather than this
infrastructure-visible slice.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>