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gRPC Guide

Muonroi supports gRPC server and client registration for service-to-service communication.

Register server and clients​

In Program.cs, register the server and named clients:

services.AddGrpcServer();
services.AddGrpcClients(configuration, new Dictionary<string, Type>
{
    { "SampleService", typeof(SampleGrpc.SampleGrpcClient) }
});

The target service endpoints are typically stored in GrpcServicesConfig:

{
  "GrpcServicesConfig": {
    "Services": {
      "SampleService": {
        "Uri": "https://localhost:5001"
      }
    }
  }
}

Client forwarding defaults can also be configured centrally:

{
  "GrpcServicesConfig": {
    "ClientDefaults": {
      "ForwardAuthToken": true,
      "ForwardTenantId": true
    },
    "Services": {
      "SampleService": {
        "Uri": "https://localhost:5001",
        "ForwardAuthToken": true
      }
    }
  }
}

ForwardAuthToken uses the current ISystemExecutionContext.AccessToken. ForwardTenantId uses ISystemExecutionContext.TenantId. Per-service values override the defaults.

Wrap client calls​

You can inherit from BaseGrpcService so outbound calls automatically carry common metadata such as correlation and tenant context.

public class SampleGrpcService(
    MAuthenticateInfoContext auth,
    SampleGrpc.SampleGrpcClient client) : BaseGrpcService(auth)
{
    private readonly SampleGrpc.SampleGrpcClient _client = client;

    public Task<SampleReply> GetDataAsync(int id)
    {
        return CallGrpcServiceAsync(meta =>
            _client.GetDataAsync(new SampleRequest { Id = id }, meta));
    }
}

Aggregator pattern​

An aggregator service can depend on the wrapper and translate the gRPC result to an internal DTO.

public class AggregatorService(SampleGrpcService sample)
{
    public async Task<MyDto> GetAsync(int id)
    {
        SampleReply reply = await sample.GetDataAsync(id);
        return new MyDto { Message = reply.Message };
    }
}

Direct client factory usage​

If needed, you can resolve a named client directly through GrpcClientFactory.

public class AggregatorService(GrpcClientFactory factory, MAuthenticateInfoContext auth)
    : BaseGrpcService(auth)
{
    private readonly SampleGrpc.SampleGrpcClient _client =
        factory.CreateClient<SampleGrpc.SampleGrpcClient>("SampleService");
}

Use wrappers for repeated call patterns, retries, metadata propagation, and shared error handling. Use direct factory access only when a dedicated wrapper adds no value.

Forwarded metadata​

Track 8 adds GrpcClientAuthInterceptor, which appends outbound metadata from the current execution context when enabled:

  • authorization: Bearer <token> when ForwardAuthToken = true
  • x-tenant-id when ForwardTenantId = true
  • x-correlation-id whenever a correlation id is present

Existing client metadata is preserved. The interceptor will not overwrite a header that the caller already supplied explicitly.