The StackGres REST API offers a way to interact with StackGres in a similar way as using the kubernetes API through the StackGres CRDs but with more functionality, like creating secrets and configmap in the same call and leveraging the kubernetes RBAC permission system.
The API is provided by a kubernetes deployment that is installed together with the operator. It is mainly used by the Web UI that run in the same deployment.
Swagger is in essence an Interface Description Language for describing RESTful APIs expressed using JSON. Swagger is used together with a set of open-source software tools to design, build, document, and use RESTful web services. Swagger includes automated documentation, code generation (into many programming languages), and test-case generation.
To access those endpoints that require authentication you will need a valid JWT. You may obtain the JWT by authenticating using the login endpoint (see AUTH section above). To set up a user and permission see the RBAC authorization section.