Contract Gate - diff your OpenAPI spec and gate breaking changes

Diff two versions of a published API's OpenAPI spec and gate the breaking changes by your own policy, then write the changelog pipeline design and the traced changelog entries. Free in your browser: OpenAPI 3.x or Swagger 2.0, JSON or YAML; removed and added operations, deprecation and sunset dates, operations newly marked internal, parameters, request and response bodies with local $refs and allOf resolved, enums, required fields, types and security scopes, each change given a check id, a level from the default map or your own levels file and a fingerprint; acknowledgement rows matched and audited, the major-version bump checked, the gate judged and the pipeline rungs ranked, plus severity-map.md, the levels file, the generated ignore file and skeleton entries. A metered run writes the pipeline design, or the changelog entries. Built on the SkillSafe skill @samber/api-changelog-automation, from samber/developer-platform-skills (MIT), by Samuel Berthe.