It is a read-only feed of Sprwt release notes, useful if you want to show what changed in your platform on an internal page or status site. GET /api/v1/versions/get_all?k=<key> returns every version with date, title, description and a categorised list of changes (New / Improvement / Fix) plus ready-made HTML; GET /api/v1/versions/get_version?k=<key>&version=latest (or a specific number like 1.81.2) returns one version. The key is the Versions API Key; without it (or with the wrong one) the feed answers Invalid Key. This field isn't shown anywhere on your normal Client Config screens, so in practice it is a value Sprwt sets and shares with you rather than one you self-serve.