The PR #3934 added a new gem for JSON validation - json_schemer which was needed for OpenAPI 3.1 validation, as the previous json-schema gem didn't support JSON Schema 2020-12 that OAS 3.1 is based on.

In fact, in porta we use a forked version, to support draft7 JSON schema, which is used for policies.

The abovementioned PR changes the validation gem only for OpenAPI 3.0 and 3.1, and keeps json-schema gem for old swagger versions. It should be possible to switch Swagger 2.0 to json_schemer, however I don't think it's compatible with Swagger 1.2.

I believe the Policies validation can also use json_schemer, so it needs to be evaluated.