Microsoft.Azure.WebPubSub.AspNetCore 1.3.0

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dotnet add package Microsoft.Azure.WebPubSub.AspNetCore --version 1.3.0                
NuGet\Install-Package Microsoft.Azure.WebPubSub.AspNetCore -Version 1.3.0                
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="Microsoft.Azure.WebPubSub.AspNetCore" Version="1.3.0" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Microsoft.Azure.WebPubSub.AspNetCore --version 1.3.0                
#r "nuget: Microsoft.Azure.WebPubSub.AspNetCore, 1.3.0"                
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install Microsoft.Azure.WebPubSub.AspNetCore as a Cake Addin
#addin nuget:?package=Microsoft.Azure.WebPubSub.AspNetCore&version=1.3.0

// Install Microsoft.Azure.WebPubSub.AspNetCore as a Cake Tool
#tool nuget:?package=Microsoft.Azure.WebPubSub.AspNetCore&version=1.3.0                

Azure Web PubSub service middleware client library for .NET

Azure Web PubSub Service is a service that enables you to build real-time messaging web applications using WebSockets and the publish-subscribe pattern. Any platform supporting WebSocket APIs can connect to the service easily, e.g. web pages, mobile applications, edge devices, etc. The service manages the WebSocket connections for you and allows up to 100K concurrent connections. It provides powerful APIs for you to manage these clients and deliver real-time messages.

Any scenario that requires real-time publish-subscribe messaging between server and clients or among clients, can use Azure Web PubSub service. Traditional real-time features that often require polling from server or submitting HTTP requests, can also use Azure Web PubSub service.

This library can be used to do the following actions. Details about the terms used here are described in Key concepts section.

  • Parse upstream requests under CloudNative CloudEvents
  • Add validation options for upstream request
  • API to add user defined functionality to handle different upstream events
Source code
API reference documentation
Product documentation

Getting started

Install the package

Install the client library from NuGet

dotnet add package Microsoft.Azure.WebPubSub.AspNetCore


Authenticate the client

In order to interact with the service, you'll need to provide the Web PubSub service with a valid credential. To make this possible, you'll need the connection string or a key, which you can access in the Azure portal. Besides, if you want to invoke service REST API, you can call AddWebPubSubServiceClient<THub>() where THub is user implemented WebPubSubHub listening to important events.

Configure Web PubSub service options

Configure with connection string:

public void ConfigureServices(IServiceCollection services)
    services.AddWebPubSub(o =>
        o.ServiceEndpoint = new("<connection-string>");

Configure with Azure Identity:

public void ConfigureServices(IServiceCollection services)
    services.AddWebPubSub(o =>
        o.ServiceEndpoint = new WebPubSubServiceEndpoint(new Uri("<endpoint"), new DefaultAzureCredential());

Map WebPubSubHub to endpoint routing

public void Configure(IApplicationBuilder app)
    app.UseEndpoints(endpoint =>

Key concepts

For information about general Web PubSub concepts Concepts in Azure Web PubSub


WebPubSubHub is an abstract class to let users implement the subscribed Web PubSub service events. After user register the event handler in service side, these events will be forwarded from service to server. And WebPubSubHub provides 4 methods mapping to the service events to enable users deal with these events, for example, client management, validations or working with Azure.Messaging.WebPubSub to broadcast the messages. See samples below for details.


Among the 4 methods, OnConnectAsync() and OnMessageReceivedAsync() are blocking events that service will respect server returns. Besides the mapped correct response, server can throw exceptions whenever the request is against the server side logic. And UnauthorizedAccessException and AuthenticationException will be converted to 401Unauthorized and rest will be converted to 500InternalServerError along with exception message to return service. Then service will drop current client connection.


Handle upstream Connect event

private sealed class SampleHub : WebPubSubHub
    internal WebPubSubServiceClient<SampleHub> _serviceClient;

    // Need to ensure service client is injected by call `AddServiceHub<SampleHub>` in ConfigureServices.
    public SampleHub(WebPubSubServiceClient<SampleHub> serviceClient)
        _serviceClient = serviceClient;

    public override ValueTask<ConnectEventResponse> OnConnectAsync(ConnectEventRequest request, CancellationToken cancellationToken)
        var response = new ConnectEventResponse
            UserId = request.ConnectionContext.UserId
        return new ValueTask<ConnectEventResponse>(response);


Setting up console logging

You can also easily enable console logging if you want to dig deeper into the requests you're making against the service.

Next steps

Please take a look at the Samples directory for detailed examples on how to use this library.


This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact with any additional questions or comments.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp3.1 is compatible. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

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Version Downloads Last updated
1.3.0 22,605 4/11/2024
1.2.0 77,646 8/30/2023
1.1.0 12,018 7/13/2023
1.0.0 37,213 4/13/2023
1.0.0-beta.4 22,156 11/11/2022
1.0.0-beta.3 18,140 1/7/2022
1.0.0-beta.2 194 12/9/2021
1.0.0-beta.1 1,066 11/12/2021