The Kubernetes api-server provides the list of available API commands by utilizing the OpenAPI specification. The OpenAPI Specification defines a standard, language-agnostic interface to REST APIs that allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection. It's very convenient to browse the API commands catalogue using the SwaggerUI tool that comes with Kubernetes api-server. You can also execute the HTTP commands using SwaggerUI.
Note that the SwaggerUI is not enabled by default if you are running the local cluster using Minikube. You will need to enable it during the cluster startup, using the following command:
$ minikube start --extra-config=apiserver.Features.EnableSwaggerUI=true
Having the api-server proxy still running using port 8080...