# Catalog Versioning Policy

## Policy

- Prefer additive contract evolution to keep consumer compatibility.
- Breaking changes require major version increments.
- Deprecated members remain through one deprecation cycle.

## Blueprint Compatibility

- Package descriptor metadata is implemented via `IBlueprintPackageContract` from `Core.Blueprint.Common.Contracts`.
- Catalog contracts consume Blueprint common contract primitives rather than redefining them.

## Compatibility Notes

- Consumers (`furniture-dal`, `furniture-service`, `furniture-bff`) update explicitly.
- Protocol adapters remain edge concerns; catalog contracts remain transport-neutral.