Subscribe for Microsoft Graph webhooks to be notified when your user's data changes, so you don't have to poll for changes.

This sample ASP.NET Core web application shows how to subscribe for webhooks using delegated permissions. It uses OpenID Connect for sign in / sign out using the Microsoft identity platform for developers, Microsoft Authentication Library for .NET (MSAL.NET) to obtain an access token using the auth code flow, and the Microsoft Graph Client Library for .NET (SDK) to call Microsoft Graph on behalf of a user that has successfully signed in to the web app. These complexities have been encapsulated into the Microsoft.Identity.Web reusable library project.

See the list of delegated permissions permitted for each supported resource in Microsoft Graph.

The sample app redirects to the Azure AD adminconsent endpoint so a tenant administrator can grant delegated permissions directly to the app. After the admin consents, users in the tenant can create a subscription and watch for notifications.

The following are common tasks that an application performs with webhooks subscriptions:

• Get consent to subscribe to users' resources and then get an access token.
• Use the access token to create a subscription to a resource.
• Send back a validation token to confirm the notification URL.
• Listen for notifications from Microsoft Graph and respond with a 202 status code.
• Request more information about changed resources using data in the notification.

The screenshot below shows the app's start page.

After the app creates a subscription for the signed-in user, Microsoft Graph sends a notification to the registered endpoint when events happen in the user's subscribed resource. The app then reacts to the event.

This sample app subscribes to the users/{user-id}/mailFolders('Inbox')/messages resource for created changes. When notified that subscribed users receive a mail message, the app then updates a page with information about the message. The page displays only messages belonging to the signed-in user.

To use the Microsoft Graph Webhook Sample for ASP.NET Core, you need the following:

• Visual Studio 2017 installed on your development computer.
• .NET Core 2.1 or later (for example for Windows) installed. You can follow the instructions at .NET and C# - Get Started in 10 Minutes. In addition to developing on Windows, you can develop on Linux, Mac, or Docker.
• A work, school or personal account. A tenant administrator account is required to grant application permissions.
• The application ID and key from the application that you register on the Azure Portal.
• A public HTTPS endpoint to receive and send HTTP requests. You can host this on Microsoft Azure or another service, or you can use ngrok or a similar tool while testing.

1. Sign in to the Azure portal using either a work or school account.
2. If your account is present in more than one Azure AD tenant:
   1. Select your profile from the menu on the top right corner of the page, and then Switch directory.
   2. Change your session to the Azure AD tenant where you want to create your application.

1. Navigate to the Azure portal > App registrations to register your app.

2. Select New registration.

3. When the Register an application page appears, enter your app's registration information:

   1. In the Name section, enter a meaningful name that will be displayed to users of the app. For example: MyWebApp
   2. In the Supported account types section, select Accounts in any organizational directory and personal Microsoft accounts (e.g. Skype, Xbox, Outlook.com).

      If there are more than one redirect URIs, you'll need to add these from the Authentication tab later after the app has been successfully created.

4. Select Register to create the app.

5. On the app's Overview page, find the Application (client) ID value and record it for later. You'll need this value to configure the Visual Studio configuration file for this project.

6. In the list of pages for the app, select Authentication.

   1. In the Redirect URIs section, select Web in the combo-box and enter the following redirect URIs:
      • https://localhost:44334/signin-oidc
      • https://localhost:44334/Account/GrantPermissions

7. Select Save.

8. From the Certificates & secrets page, in the Client secrets section, choose New client secret.

   1. Enter a key description (of instance app secret).

   2. Select a key duration of either In 1 year, In 2 years, or Never Expires.

   3. When you click the Add button, the key value will be displayed. Copy the key value and save it in a safe location.

      You'll need this key later to configure the project in Visual Studio. This key value will not be displayed again, nor retrievable by any other means, so record it as soon as it is visible from the Azure portal.

9. In the list of pages for the app, select API permissions.

   1. Click the Add a permission button and then make sure that the Microsoft APIs tab is selected.
   2. In the Commonly used Microsoft APIs section, select Microsoft Graph.
   3. In the Application permissions section, make sure that the Mail.Read. permission is checked. Use the search box if necessary.

   Also, in the Delegated permissions section, check the User.Read delegated permission for Azure Active Directory, so users can sign into the app to initiate the subscription process.

   1. Select the Add permissions button.

You must expose a public HTTPS endpoint to create a subscription and receive notifications from Microsoft Graph. While testing, you can use ngrok to temporarily allow messages from Microsoft Graph to tunnel to a localhost port on your computer.

You can use the ngrok web interface (http://127.0.0.1:4040) to inspect the HTTP traffic that passes through the tunnel. To learn more about using ngrok, see the ngrok website.

1. In Solution Explorer, right-click the GraphWebhooks-Core project and choose Properties.

2. On the Debug tab, copy the port number of the App URL.

   

3. Download ngrok for Windows.

4. Unzip the package and run ngrok.exe.

5. Replace the two {port-number} placeholder values in the following command with the port number you copied, and then run the command in the ngrok console.

   ngrok http {port-number} -host-header=localhost:{port-number}

   

6. Copy the HTTPS URL that's shown in the console. You'll use this to configure your notification URL in the sample.

   

Keep the console open while testing. If you close it, the tunnel also closes and you'll need to generate a new URL and update the sample.

See Hosting without a tunnel and Why do I have to use a tunnel? for more information about using tunnels.

1. Follow these instructions to install the ASP.NET Core SignalR Javascript client package into the app.

2. Expose a public HTTPS notification endpoint. It can run on a service such as Microsoft Azure, or you can create a proxy web server by using ngrok or a similar tool.

3. Open the GraphWebhooks-Core.sln sample file in Visual Studio 2017.

4. In Solution Explorer, open the appsettings.json file in the root directory of the project.

   • For the NotificationUrl key, replace ENTER_YOUR_URL with the HTTPS URL. Keep the /notification/listen portion.

   If you're using ngrok, use the HTTPS URL that you copied. The value will look something like this:

   "NotificationUrl": "https://2885f9c5.ngrok.io/notification/listen",

   This is the url endpoint that will receive subscription validation callbacks and notification events from Graph, through the proxy server set up above (ngrok, for this sample).

5. Still within Solution Explorer, right-click on the project name and select Manage User Secrets. This app uses Secret Manager configuration in storing sensitive app data - ClientId and ClientSecret.

   • In the secret.json window that opens, paste the below code.

     "AzureAd": { "ClientId": "ENTER_YOUR_APP_ID", "ClientSecret": "ENTER_YOUR_SECRET" }

   • For the ClientId key, replace ENTER_YOUR_APP_ID with the application ID of your registered Azure application.

   • For the ClientSecret key, replace ENTER_YOUR_SECRET with the key of your registered Azure application. Note that in production apps you should always use certificates as your application secrets, but for this sample we will use a simple shared secret password.

6. Make sure that the ngrok console is still running, then press F5 to build and run the solution in debug mode.

   If you get errors while installing packages, make sure the local path where you placed the solution is not too long/deep. Moving the solution closer to the root drive resolves this issue.

1. Choose Sign in in the upper-right corner and sign in with a work or school account.

2. Consent to the View your basic profile and Sign in as you permissions.

3. On the sample home page, choose Grant admin consent. You'll be redirected to the adminconsent page.

4. Sign in as a tenant admin and consent to the Read mail in all mailboxes and Sign in and read user profile permissions. You'll be redirected back to the sample's home page.

   At this point, any user in your tenant can sign in and create a subscription. If you don't grant admin permissions first, you'll receive an Unauthorized error. You'll need to open the sample in a new browser session because this sample caches the initial token.

5. Choose Create subscription. The Subscription page loads with information about the subscription.

   This sample sets the subscription expiration to 15 minutes for testing purposes.

   

6. Choose the Watch for notifications button.

7. Send an email to your user account. The Notification page displays message properties. It may take several seconds for the page to update.

8. Optionally choose the Delete subscription button.

The following files contain code that's related to connecting to Microsoft Graph, creating subscriptions, and handling notifications.

• appsettings.json Contains values used for authentication, authorization and endpoint URLs.
• secrets.json Contains the ClientId and ClientSecret used for authentication and authorization. To check whether these have been configured for the project run the following command from the directory in which the .csproj file exists: dotnet user-secrets list
• Startup.cs Configures the app and the services it uses, including authentication.

• AccountController.cs Handles admin consent.
• NotificationController.cs Receives notifications.
• SubscriptionContoller.cs Creates and deletes subscriptions.

• Notification.cs Represents a change notification.
• MessageViewModel.cs Defines the MessageViewModel that represents the data displayed in the Notification view.

• GraphServiceClientFactory.cs Initiates the SDK client used to interact with Microsoft Graph.
• SubscriptionStore.cs Access layer for stored subscription information. The sample temporarily stores the info in HttpRuntime.Cache. Production apps will typically use some method of persistent storage.

• Helper library containing a set of reusable classes that are useful in helping with the below:

  • Authenticating and signing-in users with any Work, School or Microsoft Personal Accounts on the Microsoft identity platform v2.0 (AAD v2.0) using OpenId connect middleware and MSAL.NET.
  • Handling sign-out and removing the account from MSAL.NET cache.
  • Token acquisition on behalf of the signed in user.
  • Bootstrapping the web resource from the Startup.cs file in the application by just calling a few methods.

If you'd like to contribute to this sample, see CONTRIBUTING.MD.

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

We'd love to get your feedback about the Microsoft Graph Webhooks sample for ASP.NET Core. You can send your questions and suggestions to us in the Issues section of this repository.

Questions about Microsoft Graph in general should be posted to Stack Overflow. Make sure that your questions or comments are tagged with [MicrosoftGraph].

You can suggest changes for Microsoft Graph on UserVoice.

• Microsoft Graph Webhooks sample for ASP.NET 4.6 (Delegated permissions)
• Microsoft Graph Webhooks sample for Node.js (Delegated permissions)
• Working with Webhooks in Microsoft Graph
• Subscription resource
• Microsoft Graph documentation

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