Why APIs need monitoring
When a website breaks, people notice. When an API breaks, webhooks stop arriving, mobile apps show stale data and scheduled syncs write nothing, often for days before anyone reports it.
An API has no visitors to report a problem, so a scheduled check is often the only way a failure is noticed quickly.
Monitor a health endpoint
The most useful endpoint to monitor is one built for it: a health endpoint that checks the service’s dependencies, such as the database and the queue, and returns an error status when any of them is unavailable.
One check then covers everything the service depends on, and a failure points to a cause rather than a symptom.
Check the response body
Many APIs return HTTP 200 with an error in the body. Frameworks and gateways often do this by default, and a check that reads only the status code treats it as healthy.
Requiring text from a healthy response, such as an "ok" status or a field that only appears on success, catches these failures without the check needing to understand your schema.
Unauthenticated checks
Checks do not send credentials. Monitors cannot store API keys, so the platform never holds a credential it would replay every minute.
Expose a health endpoint that needs no authentication and returns no sensitive data. If your API is fully authenticated, adding one is worthwhile.
Health endpoint best practices
Keep it lightweight. It can be checked every minute, so it should answer from a few quick queries rather than a full report.
Return meaningful status codes. Return 503 when a dependency is down. An endpoint that always returns 200 tells you nothing.
Keep sensitive data out. The endpoint is public and unauthenticated.
Watch response times. APIs usually slow down before they fail.
Frequently asked questions
- How is API monitoring different from website monitoring?
- It uses the same HTTP check. The difference is the target: an endpoint and an expected response instead of a page and a phrase.
- Can it send authenticated requests?
- No. Monitors cannot store API keys. Point the check at an unauthenticated health endpoint instead.
- Can it check POST endpoints?
- No. Checks are GET requests, so a monitor never creates data in your API.
- Can it validate the JSON structure?
- It checks that expected text appears in the response, which covers a status field or a known key without needing your schema.
- What if the API is slow but still responding?
- Response time is recorded on every check, so a slowdown is visible before it becomes an outage.
Key points
- Status code, response time and response content
- Designed for health check endpoints
- Catches 200 responses that contain errors
- No API keys stored
- Response time recorded on every check