You can send 4xx errors yourself too. If the client needs to change something about the request, that’s a 4xx, like 400 Bad Request. If the server has an error and it’s not the client’s fault, that’s a 5xx like 502 Bad Gateway.
The wikipedia listing of all HTTP codes is quite helpful. People also forget you can send a custom response body with a 4xx or 5xx error. So you can still make a custom JSON error message.
Obviously you can, and i do returm 4xx codes if the initial parsing, authentication or something else goes wrong im the controller, but once im in the next api, or any number of systems down the chain, im probably gonna return a 200 with a status with a tracking code. It’s proven, at least for us very helpful to find issues fast on both sides. To me getting a 4xx back when it’s step 6 our of 13 that is the problem in the API but the request itself is fine doesn’t seem meaningful and just makes customers assume things. I guess if every endpoint only does one thing, i’d probably do like you.
A 2xx means success to its requester. If you have an error in step 6 out of 13 that breaks the resource action, you shouldn’t be returning a success.
You might argue what to return and what kind of information to include in the response (like tracking numbers), but it shouldn’t be a 2xx and I don’t see how a misleading 200 would be more helpful than a 400 bad request.
I mean sure, in the strict meaning of the code-guides you are probably correct. Most problems stems for us at least from cross-reference issues which are normally configuration problems in the underlying system or other data-related issues. Those are often not neither the responsibility of the server or the client, and sometimes its both. There are often no code that is suitable to respond, and to just send “Bad request” when it’s a good request - does not make sense. Therefore i think it’s better to let badrequest be for bad requests, instead tell the client that sure, this is a good request but for this reason it didn’t work this time. This has to happen for it to work. Either i can do it with a simple structure in json with maybe 5 status codes and a message, or i have to figure out what 20 http status codes both i and the client has to implement and give them meaning that isn’t their intended meaning.
