The Spring portfolio recently decided to switch to SemVer and CalVer format. This has an impact on the metadata that start.spring.io serves as the format for available bootVersions and the compatibilityRange can change.

For backward compatible reasons, any use of such version format is automatically translated to the documented format of application/vnd.initializr.v2.1+json. However, we need to transition so that STS understands the new format and can apply it. We've published a new metadata version, application/vnd.initializr.v2.2+json that does not perform this translation anymore.

The version infrastructure in the Spring Initializr project showcases the difference and what it takes to handle the new format.