The OpenAPI Specification (OAS) defines a standard, programming language-agnostic interface description for HTTP APIs, which allows both humans and computers to discover and understand the capabilities of a service without requiring access to source code, additional documentation, or inspection of network traffic (from https://spec.openapis.org/oas/v3.0.3).
https://medium.com/wolox/documenting-a-nodejs-rest-api-with-openapi-3-swagger-5deee9f50420
http://spec.openapis.org/oas/v3.0.3
https://api.gov.au/standards/national_api_standards/pagination.html