To determine the sort order in the REST API response, use the generic sort parameter and provide a comma-separated list of task fields. You can specify the sort order for each field. Use the dash sign (-) to specify descending order. The default sort order is ascending.
The following example shows how to sort the results:
GET http://localhost:8080/cmx/cs/localhost-orcl-DS_UI1/task?recordsToReturn=100&owner=sergey&status=OPEN&sort=-priority