Heroku Platform API: New optional release ID parameter for pipeline promotions

Change effective on 25 September 2025

A new optional parameter source:release:id is available on the Pipeline Promotions Create API endpoint.

source:release:id is the ID of an unexpired release on the source app you want promoted. Use this parameter to promote a specific release on the source app to the target app. Without this optional parameter, we promote the current release on the source app by default.