Apigee Corp. was a API management and predictive analytics software provider before its merger into Google Cloud
Apigee is a founding member of the OpenAPI Initiative OpenAPI Specification is an open-source standard for writing declarative structure of an Application Programming Interface (API)
It can be written in either JSON or YAML format
Cloud Service Providers (CSPs) will have a fully-managed API service offering like API Gateway which generally supports OpenAPI Standard
Three version present in GCP : Standard, Enterprise and Enterprise Plus