Have you used gRPC-Gateway in your projects?

Yes, gRPC-Gateway is used for automatic generation of RESTful JSON API on top of a gRPC service. This allows clients that do not support gRPC to interact with the server via HTTP/JSON.

The main idea is to describe services in protobuf, and then generate both a gRPC server and an HTTP gateway that converts REST calls into gRPC.

Example of usage in Go:

// In the protobuf file, add options for HTTP
service ExampleService {
  rpc GetItem(GetItemRequest) returns (Item) {
    option (google.api.http) = {
      get: "/v1/items/{id}"
    };
  }
}

After code generation, you can run an HTTP server that proxies requests to the gRPC service.

This is convenient for supporting different clients and simplifying integration with frontend or third-party services.