HTTP status codes are how the web signals errors and other states from the server to the web browser. If there is an error from your backend website, the error is simply forwarded by the XDN to the browser.

If the error is generated in the XDN itself, the platform generates a 53x or 54x HTTP status code:

CODENAMEDESCRIPTION
412Precondition FailedThis code is returned when query string parameter xdn_prefetch equals 1 and the result is not found in the edge cache.
530Internal XDN ErrorUnexpected error in the Moovweb XDN. Please contact support.
531Project Upstream TimeoutYour project timed out while waiting for an upstream response.
532Project Response Too LargeYour project returned a response size greater than the allowed 6MB.
533ReservedNot used by Moovweb XDN at this time.
534Project Unexpected ErrorYour project's serverless code has failed unexpectedly. Use server logs to debug.
535Unknown ProjectThe HTTP header host is missing or does not match any Moovweb XDN deployment. Check your requesting URL and your project config.
536ReservedNot used by Moovweb XDN at this time.
537ReservedNot used by Moovweb XDN at this time.
538Project Request LoopThe XDN project exceeded the maximum level (4) of nested Moovweb XDN requests. “Nested” means an XDN site is the upstream of itself or of another XDN site.
539Project TimeoutYour project's serverless code did not respond on time, either due to slow upstreams or to badly handled asynchronous requests in code (e.g. missing await or call to callback). Use server logs and performance profiling to debug.
540ReservedReserved for experimental limits and features. Please contact support.
541XDN Out of WorkersThe traffic was so high that request could not be scheduled for processing within the scheduling timeout. Please contact support to upgrade your account.
542Project Header OverflowThe XDN project's request or response had too many HTTP headers. See limits

Obviously, your project can set status codes of their own, which may sometimes match codes above. We encourage you to avoid that to lower the troubleshooting overhead and other issues.

Moovweb XDN also issues these standard response codes:

CODENAMEDESCRIPTION
400Bad RequestThe URL is too long or the request headers are too large. See limits
404Not FoundThe request did not match any route that would send a response and there is no fallback. See routing
412Precondition FailedThe query string parameter xdn_prefetch equals 1 and the result is not found in the edge cache.
503Service UnavailableYour project's upstream was unavailable. See routing