Pulse
Uptime monitoring with a public status page.
Checks your sites and APIs every 30 seconds, opens and resolves incidents on its own, and publishes a status page your customers can trust.
Demo instance: history before the last days is synthetic. Admin login with the password demo (read-only).
- Build time
- 53 min
- Agents
- 1 Claude Code agent
- Tests passing
- 112
- Lines of code
- 8,866
- Runtime dependencies
- 2
Built by one Claude Code agent inside Cadrix in 53 minutes of wall-clock time, with no human edits to the code. Times come from the build log the agent kept.
What it does
- HTTP checks with status ranges, keyword match and timeouts, at most 8 in flight, never blocking the server
- Incidents opened after consecutive failures and closed after recovery, with Investigating / Identified / Resolved updates
- Public page with 90-day uptime bars, 24 h latency sparklines and 24 h / 7 d / 30 d / 90 d uptime
- Admin with live KPIs, p50/p95 latency charts, pause, check now and webhook alerts with retries
- SSRF guard on every check and webhook: private and loopback addresses refused, DNS pinned for the real connection
- Raw checks for 48 h, hourly rollups for 30 days, daily for 90: the database stays small
How it was built
- 0–10 minDatabase migrations, SSRF guard and the HTTP probe
- 10–20 minScheduler, incident state machine and rollups
- 20–30 minAPI with auth, rate limit and read-only demo sessions
- 30–40 minStatus page and admin, charts drawn by hand in SVG
- 40–53 min112 tests, screenshot review on desktop and phone, one round of fixes
Problems the agents solved
- Sparklines came out empty: SQLite was doing float division on time buckets. The agent found it from the screenshots and added a test.
- Uptime read 85% for a service that was up: it switched to time-based uptime, the way public status pages report it.
- In review, the banner said "All systems operational" while one service was degraded. The banner now follows the worst current state.
Stack
Node 22Fastifynode:sqliteReactSVG chartsVitest
More screens
Build yours the same way.
A private machine with Claude Code, Codex and Pi on one canvas.