adding call api to web app

Calling a web API

To call a web API from your web app that signs-in users or your protected web API, you need to add a few lines:

• in the configuration file
• in Startup.cs
• in the controller

When you use Microsoft.Identity.Web, you have three usage options for calling an API:

• Option 1: Call Microsoft Graph with the Microsoft Graph SDK's GraphServiceClient
• Option 2: Call an Azure SDK using the Azure with TokenAcquisitionTokenCredential
• Option 3: Call a downstream web API with the helper class IDownstreamWebApi
• Option 4: Call a downstream web API without the helper class, acquiring a token yourself with ITokenAcquisition

See A web app/API that calls web APIs: Code configuration to see what to change in the configuration file, and startup.cs. See also Using client certificates if you want to use certificates instead of client secrests to authenticate your web app/API.

See A web app/API that calls web APIs: Call a web API for the changes to make in the controller.

Advanced scenarios

Requesting other scopes, tenant, authentication scheme when calling Microsoft Graph

See Calling Graph to learn how to specify delegated scopes or app permissions, specify a tenant, and or authentication scheme using .WithScopes, .WithScopes(scopes), .WithAppOnly(bool, tenantId), and .WithAuthenticationScheme(authenticationScheme)

Customizing the headers (or the HttpMessageRequest) when using IDownstreamWebApi

When using IDownstreamWebApi, you can override the Http headers by using the

string response = await _downstreamWebApi.GetForUser<string>("DownstreamAPI",
   options => {
      options.RelativePath = "me";
      options.CustomizeHttpRequestMessage = message =>
      {
       var headers = message.Headers;
       // Do what you want to change the HttpHeaders.
       // The Authorization header is already populated when the delegate is called
       
      };
   });