API monitoring

A 200 response is not enough.

Test APIs the way your application depends on them. Send real requests, validate response codes, headers, text, and JSON values, and get alerted when the contract breaks.

Start free trial Monitor APIs with uptime checks

Feature: Support GET, POST, PUT, PATCH, and DELETE
Feature: Send custom headers and request bodies
Feature: Validate JSON fields and response text
Feature: Alert when contracts break after deploys

Example

curl -X POST https://api.example.com/checkout \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"cart_id":"demo"}'

Catch bad data, not just downtime.: An endpoint can be online and still return the wrong payload, omit a field, or serve stale data. Assertions let you validate the parts of the response your app depends on.
Test authenticated endpoints.: Use bearer tokens, API keys, basic auth, and custom headers to monitor private endpoints and integration surfaces.
Monitor the edges of your product.: Use API checks for the endpoints that quietly break customer workflows: checkout creation, login callbacks, webhook receivers, search, billing, and partner integrations.
Alert the team that owns the contract.: A failing API check can go to the same alert routes as uptime checks, so backend, platform, and integration teams can respond where they already work.

Frequently asked questions

The short version. The docs have the details when you need them.

Can I monitor GraphQL APIs?: Yes. Use a POST request with the GraphQL body and assertions against the response payload.
Can I create API checks programmatically?: Yes. Use the OnlineOrNot API to create and manage checks from your own systems.
Can I send custom request bodies?: Yes. API checks support request methods, headers, and bodies, so you can monitor endpoints that need more than a simple GET request.
When should I use browser checks instead?: Use API monitoring when the contract is an HTTP response. Use browser checks when you need to verify a rendered page or multi-step flow in Chrome.

Start with api monitoring.

Start with the endpoint your product relies on most, then add assertions for the fields that must never silently change.

Get started for free Read the API monitoring guide