grpc-gateway/example/api/api.proto

syntax = "proto3";

package example.api;

import "google/api/annotations.proto";

service CustomerService {
    rpc GetCustomer(GetCustomerRequest) returns (GetCustomerResponse) {
		option (google.api.http) = {
			get: "/v1/customer/{id}"
		};
	}
}

message Customer {
    string id = 1;
    string name = 2;
}

message GetCustomerRequest {
    string id = 1;
}

message GetCustomerResponse {
    Customer customer = 1;
}