Failed Dependency
WebDAV: the request failed because a previous dependent request failed.
The 4xx class
4xx — Client errors. The request itself is at fault: bad syntax (400), missing authentication (401), forbidden (403), missing resource (404) or rate limited (429).
Monitoring for this code
Client-error responses on your own health checks usually mean a deployment or configuration bug (wrong route, missing credentials, rate limiting). Monitor the exact expected code — a 404 where you expect 200 should page you, while an expected 401 on a protected endpoint can be asserted as healthy.
Get alerted the moment your API returns a 5xx
ContinuumNexus checks your endpoints from multiple regions and emails you as soon as a status code goes wrong.