If an API operation is asynchronous, but a client could track its progress, the response to such an asynchronous operation MUST return, in the case of success, the 202 Accepted status code together with an
application/hal+json representation of a new task-tracking resource.
Task Tracking Resource
The task-tracking resource SHOULD convey the information about the status of an asynchronous task.
Retrieval of such a resource using the HTTP GET Request Method SHOULD be designed as follows:
Task is Still Processing
Return 200 OK and representation of the current status.
Task Successfully Completed
Return 303 See Other together with HTTP Location Header with URI or a outcome resource.
Return 200 OK and
application/problem+jsonwith the problem detail information on the task has failed.
The asynchronous operation task-tracking resource can be either polled by client or the client might initially provide a callback to be executed when the operation finishes.
In the case of callback, the API and its client MUST agree on what HTTP method and request format is used for the callback invitation. If built within adidas, the "client" API is also the subject of the adidas API guidelines.