Error responses

The errors rws itself produces, as RFC 9457 problem details (application/problem+json), and how to get the plain-text bodies back.

Since 18.17.0 the errors rws produces itself, rather than your application, answer with RFC 9457 problem details:

HTTP/1.1 503 Service Unavailable
Content-Type: application/problem+json
Retry-After: 5

{"type":"about:blank","title":"Service Unavailable","status":503,"detail":"every backend is out of rotation"}

type is about:blank, so title is the status's reason phrase, and detail (when there is one) says what happened. Status codes and other headers (Retry-After, WWW-Authenticate, Allow) are unchanged.

Which errors

Status	When	`detail`
`400`	A request rws can't parse; a body an extractor rejects	The parse error
`401`	Basic / JWT / bearer auth, `PURGE` without the purge token, authorization without an identity	— or the reason
`403`	IP filter, blocklist, CSRF, authorization denied	—
`404`	No matching ingress rule; no matching Gateway API route	—
`408`	The request head took longer than 30 s	How long it may take
`413`	A body over `max_body_size`	The declared or reached size and the limit
`417`	An `Expect` value other than `100-continue`	The value
`421`	A Gateway API request for a host the connection isn't for	—
`429`	A rate limit	—
`431`	A request head over 64 KiB	The limit
`500`	An SSO callback that fails, a failing WASM plugin, a handler that errs	The reason
`501`	A method no built-in handles	The method
`502`	An upstream that can't be reached or answers garbage; an unreachable forward-auth service	— or the reason
`503`	Every backend out of rotation; maintenance mode; a route whose auth or plugin is misconfigured	The reason
`504`	An upstream or a handler that took too long	—

Not affected:

The 404 page for a missing static file (your 404.html, or the built-in one): that's your site's content.
APIs with their own error format: the admin API, MCP (JSON-RPC errors), the LLM proxy (OpenAI-style errors), the OAuth server (RFC 6749 errors), validation errors (422 with the field list).
HTTP/2 413/431 sent while the request is still arriving: those are headers only.

AppError::into_response() uses the same shape, so your own errors match rws's.

Plain text instead

error_format = "text"   # RWS_CONFIG_ERROR_FORMAT

brings back the bodies of earlier releases: 502 Bad Gateway, 503 Service Unavailable: every backend is out of rotation, and so on, as text/plain.

Error responses

Which errors#

Plain text instead#

Which errors

Plain text instead