Assert the contract
Check accepted status codes, required content, and a JSON value such as status equals ok.
API monitoring
Verify the API response, not just the open port.
Exercise a health or readiness endpoint, assert on the response your application expects, and keep authentication, latency, and failure evidence in the same incident workflow.
Starts an eligible 14-day Starter trial. No card required for the first trial.
Why this check matters
A reachable API can still return the wrong answer.
TCP reachability and a generic 200 response miss expired credentials, unhealthy JSON state, slow dependencies, and error text returned inside a successful response. API monitoring should assert on the contract that callers rely on.
What ServiceAlert checks
Reach protected endpoints
Use custom headers, OAuth2 client credentials, or an encrypted mTLS client certificate and key.
Separate slow from unavailable
Track response time, set expected latency, and distinguish degraded performance from a failed request.
How to set it up
- 1
Enter a health or readiness endpoint and apply the API preset.
- 2
Choose the method, authentication, accepted status, and JSON or content assertion.
- 3
Send confirmed failures into the same service, incident, and status-page workflow as your other checks.
What the results tell you
| Signal | Validation | Operational question |
|---|---|---|
| Transport | TLS connection and HTTP request | Can an external caller reach the endpoint? |
| Protocol | Expected HTTP status | Did the API return an accepted result? |
| Application state | Content or JSON assertion | Does the payload say the service is healthy? |
| Performance | Response time and latency baseline | Is the API working but outside its normal range? |
API monitoring FAQ
Can ServiceAlert monitor an authenticated API?
Yes. HTTP monitors support custom headers, OAuth2 client-credentials authentication, and encrypted mTLS client material.
Can an API monitor validate JSON?
Yes. The API preset includes a JSON value assertion, and you can change the path, comparison, and expected value before testing the monitor.
What is the difference between an API monitor and a transaction monitor?
An API monitor validates one endpoint. A transaction monitor runs multiple HTTP or browser steps, carries cookies and extracted values forward, and is available on Business plans.
Getting started
Turn your health endpoint into an operating signal.
Start with one API response, then attach it to the service, dependency, and incident context your team already uses.