In order to get your file's processing status, take the session_id retrieved from the enhancement request and simply send a GET request to /enhance/<session_id>. Once the enhancement is complete, the return status response will be 'done', containing a downloadable URL.

waiting_for_fileSession created, waiting for a file to be uploaded to the Upload URL.
preprocessingMedia is being prepared for processing.
queuedThe system is waiting for an available resource to begin processing.
processingThe file is being processed.
doneThe job is complete, you can download the file from the Upload URL.
failureThe media file could not be processed successfully;
check "msg" for details.
Click Try It! to start a request and see the response here!