Welcome, here’s a API doc automatically generated by protoc-gen-doc.
Try out in your environment using curl.
$ go run ./cmd/server
$ curl \
--header "Content-Type: application/json" \
--data '{}' \
-XPOST http://localhost:8080/apis.v1.HealthService/Health
{"status":"OK"}
$ curl \
--header "Content-Type: application/json" \
--data '{"name": "Jane"}' \
http://localhost:8080/apis.v1.GreetService/Greet
{"greeting":"Hello, Jane"}