Error Handling

Successful

Generally, the request is successful when the response code is 200, 201 or 204 (You could also check if the code is between 200 and 204)

Unsuccessful

Usually, when the request has an error the code is between 400 and 430.

Bad request 400: Something in your payload is missing! Or, the payload isn't there at all.

Unauthorized 401: Your token isn't correct (Or the headers hasn't a token at all!). Remember, every request (Except POST /accounts and POST /token) should be authenticated with a Bearer token!

Not found 404: You're trying to access an account that doesn't exist? Or maybe reading a non-existing message? Go check that!

Method not allowed 405: Maybe you're trying to GET a /token or POST a /messages. Check the path you're trying to make a request to and check if the method is the correct one.

I'm a teapot 418: Who knows? Maybe the server becomes a teapot!

Unprocessable entity 422: Some went wrong on your payload. Like, the username of the address while creating the account isn't long enough, or, the account's domain isn't correct. Things like that.

Too many requests 429: You exceeded the limit of 8 requests per second! Try delaying the request by one second!