title: Correct response to POST request for long running process
body: <p>I am trying to code an API which has a long running process to which an end user may make a POST request:</p>
  
  <pre><code>POST /things { "some":"json" }
  </code></pre>
  
  <p>The actual creation process can take some time, will often be queued.  It might take many minutes.  As a result I am not sure what I should be returning or when.  Is it the usual 201 plus object, returned after whatever time it takes my API to create the object?  Isn't this going to cause problems at the client end? Is there some other standard way to do this - such as an intermediate step?</p>
  
  <p>I'm using Rails &amp; Grape for my API if that helps.</p>