Kubernetes REST API
You can see all the API calls kubectl is making by passing --v=8 to any kubectl command
The REST API is fully documented on the Kubernetes website:https://kubernetes.io/docs/reference/using-api/api-overview/
It includes info on how to reach the API, be authorized to use the API, and a full breakdown of what API objects are available and what operations you can do on them.
The API is available to you outside of kubectl. In fact, my understanding is that underneath it all kubectl is just making REST calls to the API server. In a cluster using TLS certificates for authentication, a curl call to list your pods might look something like this (you can get your apiserver location/port with kubectl cluster-info | grep 'Kubernetes master'):
curl --cert myuser.pem --key myuser-key.pem --cacert /path/to/ca.pem https://my-prod-cluster-apiserver:6443/api/v1/podsThis doc shows how to use kubectl proxy to allow you to explore the Swagger-generated API docs on your own cluster.