API Sentinel Fleet — Cloud-Native Agent Fleet

Inspiration

API failures cost real money — but dashboards only show up/down. We wanted a fleet that catches drift before it becomes downtime, using the same math that prices prediction markets.

What it does

API Sentinel Fleet polls N endpoints every 8s, scores each with a 3-model ensemble (latency-z vs rolling median, momentum tilt, staleness detector HEALTHY → WARN → FAILOVER), and auto-failovers when edge crosses the band. Generalized from predictrader-ai: loadMarkets() → loadEndpoints(), fetchOrderBook() → fetchAPIHealth(), SpotHistory → LatencyHistory — same Φ k=√2/π, 120-sample ring.

Live: https://api-sentinel-fleet.vercel.app · GitHub: https://github.com/binasalama12/api-sentinel-fleet

How we built it

• Stack: Next.js 14, TypeScript, Node fetch, viem patterns, Docker (Cloud Run node:20-slim, non-root, $PORT), OpenAPI 3.1 (5 routes, X-Fleet-Key)
• Infra: Vercel + Cloud Run, horizontal fleet scaling — one fleet hits API + Cloud + AI tracks at once
• Demo-safe: DEMO_FALLBACK keeps the dashboard live even when endpoints are idle

Challenges we ran into

Generalizing trading math to latency without losing the ensemble signal — z-score calibration and the 35% muzzle needed retuning. Also wiring openapi.yaml X-Fleet-Key to handlers (declared but not yet enforced — noted in repo).

Accomplishments that we're proud of

• One fleet, 8 sponsor tracks (Overall $12.5k + SerpApi + Perfect Corp + Xano + name.com + Nutrient + Foxit + Doctavian) — max EV from single build
• 5 sentinels shipped from 1 base (predictrader-ai → fleet/bio/rice/ethonline), all live 200 on Vercel
• Clean OpenAPI + Dockerfile for sponsor brownie points

What we learned

Trading infra is API infra — same polling, same ensemble, new domain. Sponsor-track thinking beats single-track: one good fleet > three thin projects.

What's next for API Sentinel Fleet

Wire X-Fleet-Key enforcement, add PagerDuty/Slack webhooks on FAILOVER, and scale fleet controller to N regions. PRs open at binasalama12/api-sentinel-fleet.

Built With

• cloud-run
• docker
• next.js
• node.js
• openapi-3.1
• tailwind
• typescript
• vercel