HTTP

common status codes

200 OK -
General status code. Most common code used to indicate success.

201 CREATED -
Successful creation occurred (via either POST or PUT).
Set the Location header to contain a link to the newly-created resource (on POST).
Response body content may or may not be present.

204 NO CONTENT -
Indicates success but nothing is in the response body, often used for DELETE and PUT operations.

400 BAD REQUEST -
General error when fulfilling the request would cause an invalid state.
Domain validation errors, missing data, etc. are some examples.

401 UNAUTHORIZED -
Error code response for missing or invalid authentication token.

403 FORBIDDEN -
Error code for user not authorized to perform the operation or the resource is
unavailable for some reason (e.g. time constraints, etc.).

404 NOT FOUND -
Used when the requested resource is not found, whether it doesn't exist or if there was a
401 or 403 that, for security reasons, the service wants to mask.

405 METHOD NOT ALLOWED -
Used to indicate that the requested URL exists, but the requested HTTP method is not applicable.
For example, POST /users/12345 where the API doesn't support creation of resources this way (with a provided ID). The Allow HTTP header must be set when returning a 405 to indicate the HTTP methods that are supported. In the previous case, the header would look like "Allow: GET, PUT, DELETE"

409 CONFLICT -
Whenever a resource conflict would be caused by fulfilling the request. Duplicate entries, such as trying to create two customers with the same information, and deleting root objects when cascade-delete is not supported are a couple of examples.

500 INTERNAL SERVER ERROR -
Never