Getting started with the Azure Web PubSub integration

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Azure Web PubSub is a fully managed real-time messaging service that enables you to build real-time web applications using WebSockets and publish-subscribe patterns. The Aspire Azure Web PubSub Hosting integration provides methods to create Azure Web PubSub resources from code in your Aspire AppHost project.

In this introduction, you'll see how to install and use the Aspire Azure Web PubSub integrations in a simple configuration. If you already have this knowledge, see Azure Web PubSub Hosting integration for full reference details.

Note

To follow this guide, you must have created an Aspire solution to work with. To learn how to do that, see Build your first Aspire app.

Set up hosting integration

To begin, install the Aspire Azure Web PubSub Hosting integration in your Aspire AppHost project. This integration allows you to create and manage Azure Web PubSub resources from your Aspire hosting projects:

Install the NuGet package
dotnet add package Aspire.Hosting.Azure.WebPubSub

Next, in the AppHost project, create an Azure Web PubSub resource and pass it to the consuming client projects:

var builder = DistributedApplication.CreateBuilder(args);
  
var webPubSub = builder.AddAzureWebPubSub("web-pubsub");
  
var myService = builder.AddProject<Projects.MyService>()
    .WithReference(webPubSub);
  
// After adding all resources, run the app...
  
builder.Build().Run();

The preceding code adds an Azure Web PubSub resource named web-pubsub to the AppHost project and passes the connection information to the consuming project.

Caution

When you call AddAzureWebPubSub, it implicitly calls AddAzureProvisioning—which adds support for generating Azure resources dynamically during app startup. The app must configure the appropriate subscription and location. For more information, see Local provisioning: Configuration.

Tip

This is the simplest implementation of Azure Web PubSub resources in the AppHost. There are many more options you can choose from to address your requirements, including adding hubs and event handlers. For full details, see Azure Web PubSub Hosting integration.

Set up client integration

To use Azure Web PubSub from your client applications, install the Aspire Azure Web PubSub client integration in your client project:

Install the NuGet package
dotnet add package Aspire.Azure.Messaging.WebPubSub

In the Program.cs file of your client-consuming project, call the AddAzureWebPubSubServiceClient extension method to register a WebPubSubServiceClient for use via the dependency injection container:

builder.AddAzureWebPubSubServiceClient(connectionName: "web-pubsub");

Tip

The connectionName parameter must match the name used when adding the Web PubSub resource in the AppHost project.

Use injected Azure Web PubSub properties

In the AppHost, when you used the WithReference method to pass an Azure Web PubSub resource to a consuming client project, Aspire injects several configuration properties that you can use in the consuming project.

Aspire exposes each property as an environment variable named [RESOURCE]_[PROPERTY]. For instance, the Uri property of a resource called web-pubsub becomes WEB_PUBSUB_URI.

Use the GetValue() method to obtain these environment variables in consuming projects:

string webPubSubUri = builder.Configuration.GetValue<string>("WEB_PUBSUB_URI");

Tip

The full set of properties that Aspire injects depends on the Azure Web PubSub resource configuration. For more information, see Properties of the Azure Web PubSub resources.

Add Azure Web PubSub resources in client code

After adding the WebPubSubServiceClient, you can retrieve the connection instance using dependency injection:

public class ExampleService(WebPubSubServiceClient client)
{
    // Use client...
}

For full details on using the client integration, see Azure Web PubSub Client integration.

Next steps

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