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 Layer0 to the browser.
If the error is generated in Layer0 itself, the platform generates a 53x or 54x HTTP status code:
| CODE | NAME | DESCRIPTION |
|---|---|---|
| 412 | Precondition Failed | This code is returned when query string parameter layer0_prefetch equals 1 and the result is not found in the edge cache. |
| 530 | Internal Layer0 Error | Unexpected error in Layer0. Please contact support. |
| 531 | Project Upstream Timeout | Your project timed out while waiting for an upstream response. |
| 532 | Project Response Too Large | Your project returned a response size greater than the allowed 6MB. |
| 533 | Reserved | Not used by Layer0 at this time. |
| 534 | Project Unexpected Error | Your project's serverless code has failed unexpectedly. Use server logs to debug. |
| 535 | Unknown Project | The HTTP header host is missing or does not match any Layer0 deployment. Check your requesting URL and your project config. |
| 536 | Reserved | Not used by Layer0 at this time. |
| 537 | Reserved | Not used by Layer0 at this time. |
| 538 | Project Request Loop | The Layer0 project exceeded the maximum level (4) of nested Layer0 requests. “Nested” means an Layer0 site is the upstream of itself or of another Layer0 site. |
| 539 | Project Timeout | Your 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. |
| 540 | Out of Memory | Your project's serverless code caused an out-of-memory situation. Please contact support. |
| 541 | Layer0 Out of Workers | The traffic was so high that request could not be scheduled for processing within the scheduling timeout. Please contact support to upgrade your account. |
| 542 | Project Header Overflow | The Layer0 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.
Layer0 also issues these standard response codes:
| CODE | NAME | DESCRIPTION |
|---|---|---|
| 400 | Bad Request | The URL is too long or the request headers are too large. See limits |
| 404 | Not Found | The server cannot find the requested resource. This usually occurs when the browser requests a page that your app does not have. It will also occur when a request does not match any of the routes in your Layer0 router. See routing for more information. |
| 412 | Precondition Failed | The query string parameter layer0_prefetch equals 1 and the result is not found in the edge cache. |
| 503 | Service Unavailable | Your project's upstream was unavailable. See routing |