The schema/api/npgapi.json is based on the AsyncAPI specification.
Old OAS3 https://app.swaggerhub.com/apis/npg/server/1.0.0
npx adg schema/api/npgapi.json
asyncapi-archived-repos/docgen#32
TBC
Projects are stored as JSON files and validated by the schema/project/schema.json schema.
The schema file was generated from schema/project/example.json, using quicktype.io.