Example

This page demonstrates the complete RPC workflow using the ASP.NET Core integration package.

The examples are conceptually based on the demo application:

ServiceBus.Ms.Demo.Net10

---

Architecture

graph LR

    Client

    RabbitMQ

    ASPNET["ASP.NET Core"]

    Controller

    Client --> RabbitMQ

    RabbitMQ --> ASPNET

    ASPNET --> Controller

---

Request Contract

public sealed record CalculatePriceRequest(
    Guid ProductId,
    int Quantity);

---

Response Contract

public sealed record CalculatePriceResponse(
    decimal TotalPrice);

---

ASP.NET Core Endpoint

[ApiController]
[Route("api/pricing")]
public sealed class PricingController : ControllerBase
{
    [HttpPost("calculate")]
    public CalculatePriceResponse Calculate(
        CalculatePriceRequest request)
    {
        return new CalculatePriceResponse(
            request.Quantity * 10m);
    }
}

---

Client Request

var response =
    await publisher.PublishAsync<
        CalculatePriceRequest,
        CalculatePriceResponse>(
            request,
            cancellationToken);

---

Runtime Flow

sequenceDiagram

    participant Client

    participant Publisher

    participant RabbitMQ

    participant ASPNET

    Client->>Publisher: Request

    Publisher->>RabbitMQ: Publish

    RabbitMQ->>ASPNET: Deliver

    ASPNET-->>RabbitMQ: Response

    RabbitMQ-->>Publisher: Deliver Response

    Publisher-->>Client: Result

---

When To Use RPC

Recommended scenarios:

• validation services;
• calculation services;
• lookup services;
• synchronous business operations.

---

When Not To Use RPC

Avoid RPC when:

• eventual consistency is acceptable;
• responses are not required;
• workflows are naturally event-driven.

In those scenarios, traditional Publish/Subscribe messaging is generally a better choice.