Resource not found Data not found (client error). Data not found (server error)

they are all the same thing; there is no useful, practical distinction between them

if we request a list of objects and nothing was found, because we asked for a date when there was no data, its not an error. But i suppose many still just throw around exceptions still instead of handle them properly

it’s an empty array: not found when requesting something specific is an error… that’s different to here is the complete set of 0 objects… like like if you have an array and request an index that doesn’t exist you get an exception, but that doesn’t mean an empty array is exceptional: it is in fact very valid

using an error code for a non-error

well, it is an error though. you have requested a URI for an object that doesn’t exist: it doesn’t matter whether it’s a resource or an individual thing

remember that HTTP youre asking the server for some object matching a URI: please give me the object matching /users/bananoidandroid and /userssssss/bananoidandroid may both not be found for the exact same reason: the object referenced by that string does not exist

here’s the spec definition for 404

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address. This status code is commonly used when the server does not wish to reveal exactly why the request has been refused, or when no other response is applicable.

when you’re dealing with specs, deciding not to follow them because you feel like they’re wrong is not appropriate… this leads to bugs and issues in compliant tools because they make assumptions about what things mean

200 means the thing that you asked completed successfully

here’s the definition of 200:

The request has succeeded. The information returned with the response is dependent on the method used in the request, for example:

GET an entity corresponding to the requested resource is sent in the response;

HEAD the entity-header fields corresponding to the requested resource are sent in the response without any message-body;

POST an entity describing or containing the result of the action;

TRACE an entity containing the request message as received by the end server.

*edit: when talking about compliant, standard tools the classic example is transparent cache: a GET should not transform the resource and thus a GET with response of 200 can be cached… an API that uses a GET to modify a resource may cause transparent proxies (or CDNs) to significantly mishandle the user request… same goes for 200 vs 4xx and 5xx: proxies know that 200 means what it means and may cache based on that, where 5xx should never be cached and 4xx is probably dependant on which specific 4xx