Is there any REST API available by which we can fetch release id and phase id at once.
Release : 7.3
Component : CONTINUOUS DELIVERY DIRECTOR
You may use CDD REST API for getting the releases in a paginated form ( page by page ) and then get the phases for each release.
HTTP GET /cdd/design/00000000-0000-0000-0000-000000000000/v1/releases?page_number=0&page_size=100&status=DESIGN,RUNNING,RUNNING_WITH_FAILURES
HTTP GET /cdd/design/00000000-0000-0000-0000-000000000000/v1/releases/{release-id}/phases