4.0 release scope

KlumAST 4.0 is an unreleased breaking release. Its headline change is Builder-first construction: factories configure mutable Builders, materialize a completed structurally immutable DSL Object graph, and then validate it. Read Builder First Migration before moving existing Schema, client, or extension code to 4.0.

The current 4.0 documentation set also includes version-matched Gradle onboarding, domain-first and target-contract journeys, completed-object support, and the asymmetric Jackson integration. The release notes in Changelog are the authoritative inventory of delivered user-visible behavior.

Content pending maintainer acceptance

Before the first public RC, the documentation content requires explicit maintainer acceptance under #544. Versioned rendering, Pages staging, aliases, and publication mechanics are owned separately by #456.

Layer 3 terminology, variants, and representative examples remain under #454. The current guidance states only the settled API–Schema–Model pattern and must not be read as a commitment to a broader Layer 3 contract.

Historical roadmap

The 2.x and 3.0 roadmap notes were planning material for releases that are now historical. Their migration guidance is preserved in Migration; this page intentionally does not present those earlier plans as current commitments.