Error codes

Photon answers errors with an RFC 9457 problem document. The type field is a link to one of these pages; the code field is the same value without the URL, and is the stable thing to match on.

{"type":"https://photon.agenticmarket.dev/errors/not_found","title":"not found","status":404,"code":"not_found"}

Code	Status	Meaning
bad_request	400	The request was malformed: invalid JSON, a missing field, or a value the handler could not use.
unauthorized	401	The request has no valid credentials.
forbidden	403	The credentials are valid, but not allowed to do this.
not_found	404	No route matches the path, or the resource does not exist.
method_not_allowed	405	The path exists, but not for this HTTP method.
conflict	409	The request conflicts with the current state of the resource.
limit_exceeded	413	The request body is larger than the server accepts.
unsupported_media_type	415	The body is not in a format the endpoint accepts.
unprocessable	422	The request is well-formed but its content is not valid.
too_many_requests	429	The client is sending requests faster than it is allowed to.
too_many_headers	431	The request has more header fields than the server accepts.
header_value_too_large	431	One header value is longer than the server accepts.
canceled	499	The client closed the request before the server answered.
internal_error	500	The server failed while handling the request.
upstream_error	502	A service the server depends on, such as a model provider, failed.
unavailable	503	The server cannot handle the request right now.
server_at_capacity	503	The server is handling as many requests as it is configured to allow.
too_many_streams	503	The server has as many open streams as its memory budget allows.
timeout	504	The server, or a service it called, did not finish in time.

Your own handlers can return any of these with the constructors in photonerr, or define your own code with a &photonerr.Error{Status: ..., Code: ..., Message: ...} literal.