RabbitRpc.Server 4.0.1

RabbitRpc.Server

Server-side library for RabbitMQ RPC on .NET 10. Register implementations of contract interfaces with DI; a hosted service listens on the configured RabbitMQ route and dispatches each incoming request to the matching method.

v4.0 introduces a pluggable serialization layer — you must pair this package with one of the adapter packages:

• RabbitRpc.Serialization.XPacketRpc — binary, source-gen, recommended default.
• RabbitRpc.Serialization.MemoryPack — binary, MemoryPack-backed; works with vendor DTOs without [MemoryPackable].
• RabbitRpc.Serialization.SystemTextJson — JSON, for debugging and v3 wire compatibility.

Installation

dotnet add package RabbitRpc.Server
dotnet add package RabbitRpc.Serialization.XPacketRpc      # or .MemoryPack / .SystemTextJson

Pack for NuGet

dotnet pack -c Release

Configuration

Add the RabbitMqRpc section to appsettings.json:

{
  "RabbitMqRpc": {
    "HostName": "localhost",
    "Port": 5672,
    "VirtualHost": "/",
    "UserName": "guest",
    "Password": "guest",
    "ClientProvidedName": "rabbit-rpc-server",
    "RoutePrefix": "rpc.",
    "PrefetchCount": 1,
    "ConsumerDispatchConcurrency": null,
    "DefaultTimeoutSeconds": 30
  }
}

ConsumerDispatchConcurrency defaults to PrefetchCount; handlers must be thread-safe when it is > 1. Set it to 1 for the v3.0 sequential-dispatch behaviour.

Usage

Define a contract interface (shared between client and server) and implement it on the server:

public interface IMathService
{
    Task<int>     AddAsync(int a, int b);
    Task<UserDto> GetUserAsync(Guid id);
}

public sealed class MathService : IMathService
{
    public Task<int>     AddAsync(int a, int b) => Task.FromResult(a + b);
    public Task<UserDto> GetUserAsync(Guid id)  => Task.FromResult(new UserDto(id, "Alice"));
}

Register the server and handlers in Program.cs:

using AsbtCore.Broker.Server;
using AsbtCore.Broker.Serialization.XPacketRpc;   // pick one adapter

var builder = Host.CreateApplicationBuilder(args);

builder.Services
    .AddRabbitRpcServer(builder.Configuration)    // returns RpcServerBuilder
    .UseXPacketRpcSerialization()                 // required in v4.0
    .Register<IMathService, MathService>();

await builder.Build().RunAsync();

The hosted service declares one durable queue per RPC route (rpc.<InterfaceFullName>), one companion dead-letter queue (<route>.dead), and starts consuming. Server-side exceptions are serialized and rethrown on the client as RpcRemoteException. Poison messages (deserialization failure, unresolvable type, dispatcher error) are routed to the DLQ after a single attempt — no requeue loops; monitor *.dead depth for alerting.

Migration v3.x → v4.0

Startup throws OptionsValidationException with a helpful message if no IRpcSerializer is registered. See the repo migration guide for the full break list.

See Also

• RabbitRpc.Client — client-side library with typed proxies.
• RabbitRpc.Serialization.XPacketRpc — binary adapter (default since v4.0).
• RabbitRpc.Serialization.MemoryPack — MemoryPack binary adapter with reflection-friendly DTO discovery.
• RabbitRpc.Serialization.SystemTextJson — JSON adapter for v3 wire compatibility.