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 application (app-only) permissions. It uses OpenID Connect for sign in, Azure AD Authentication Library for .NET (ADAL) to obtain an access token using the client credentials grant, and the Microsoft Graph Client Library for .NET (SDK) to interact with Microsoft Graph.

Currently, only Outlook messages, events, and contacts resources support application permissions. Application permissions are not yet supported for Group conversations or OneDrive drive root items.

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

Note: Although individual users initiate the subscription process for their own user account, the access token that's used to create the subscription carries an application-level role, not a user-level scope.

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 (using an app-only token), 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 2015 installed on your development computer.
• A work or school 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.

This app uses the Azure AD endpoint, so you'll register it in the Azure Portal.

1. Sign in to the portal using your work or school account.

2. Choose Azure Active Directory in the left-hand navigation pane.

3. Choose App registrations, and then choose New application registration.

4. Enter a name for the app, and choose Create application.

   a. Enter a friendly name for the application.

   b. Choose 'Web app/API' as the Application Type.

   c. Enter https://localhost:44334/signin-oidc for the Sign-on URL. This is the base callback URL for this sample.

   d. Click Create.

5. Choose your new application from the list of registered applications.

6. Copy and store the Application ID. This value is shown in the Essentials pane or in Settings > Properties.

7. Optional. To enable multi-tenanted support for the app, open Settings > Properties and set Multi-tenanted to Yes.

8. Open Settings > Reply URLs and add the following redirect URI:

   https://localhost:44334/Account/GrantPermissions

   This is the callback for the adminconsent endpoint. The sample will have two redirect URIs:

   • https://localhost:44334/signin-oidc
   • https://localhost:44334/Account/GrantPermissions

9. Configure Permissions for your application:

   a. Choose Settings > Required permissions > Add.

   b. Choose Select an API > Microsoft Graph, and then click Select.

   c. Choose Select permissions. Under Application Permissions, choose Read mail in all mailboxes, and then click Select.

   d. Click Done.

   Keep the User.Read delegated permission for Azure Active Directory so users can sign into the app to initiate the subscription process.

10. Choose Settings > Keys. Enter a description, choose a duration for the key, and then click Save.

Important: 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.

11. Copy the key value--this is your app's secret. You won't be able to access this value again after you leave this blade.

You'll use the application ID and secret to configure the app in Visual Studio.

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. 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.

2. Open the GraphWebhooks-Core.sln sample file in Visual Studio 2015.

3. In Solution Explorer, open the appsettings.json file in the root directory of the project.
   a. For the AppId key, replace ENTER_YOUR_APP_ID with the application ID of your registered Azure application.
   b. For the AppSecret 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.
   c. 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",

4. 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 and authorization.
• Startup.cs Configures the app and the services it uses, including authentication.

Controllers

• AccountController.cs Handles sign in, sign out, and admin consent.
• NotificationController.cs Receives notifications.
• SubscriptionContoller.cs Creates and deletes subscriptions.

Models

• Notification.cs Represents a change notification.

Helpers

• SampleAuthProvider.cs Gets an access token using ADAL's AcquireTokenAsync method.
• SDKHelper.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.

TokenStorage

• SampleTokenCache.cs Sample implementation of an in-memory token cache. Production apps will typically use some method of persistent storage.

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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