I'm building a monitoring setup and want to check API uptime and response behavior

A good API monitoring setup usually checks availability, latency, and correctness.

What to monitor

1. Uptime / reachability

   • Send periodic GET or HEAD requests to a health endpoint.
   • Alert on timeouts, DNS failures, TCP failures, or non-2xx responses.

2. Response time

   • Track p50/p95/p99 latency.
   • Alert if latency exceeds your SLO for a sustained period.

3. Response behavior

   • Validate:
     • status code
     • response body schema
     • required fields
     • headers
     • auth behavior
   • Test both expected success and failure cases.

4. Synthetic checks

   • Run from multiple regions if users are global.
   • Monitor dependent flows, not just a single endpoint.

5. Error rates

   • Measure 4xx and 5xx rates separately.
   • Alert on spikes in specific codes like 429, 500, 502, 503, 504.

Typical checks

• Health endpoint: /health, /ready, or /status
• Core API endpoint: one representative real endpoint
• Auth check: verify token handling and expiry behavior
• Functional check: call an endpoint with known test data and verify the expected response

Alerting suggestions

• Immediate alert:
  • consecutive failures over N checks
  • 5xx responses
  • complete outage
• Warning:
  • latency above threshold
  • intermittent failures
  • rising error rate

Common tools

• Uptime monitoring: Pingdom, UptimeRobot, StatusCake
• Synthetic/API monitoring: Datadog, New Relic, Grafana Cloud, Better Stack
• Custom scripts: Python, Node.js, Bash + cron
• Prometheus + Blackbox Exporter for endpoint checks

Example minimal check

curl -fsS https://api.example.com/health

Better check with expected behavior

curl -s -o /tmp/resp.json -w "%{http_code} %{time_total}\n" \
  https://api.example.com/v1/example

Then verify:

• HTTP 200
• response time under threshold
• JSON contains expected keys

If you want, I can help you design:

• a Prometheus/Grafana solution,
• a Python script for checks,
• or a cloud-based monitoring architecture.