Adding more API Endpoints

You can add more API endpoints to the application hosting IdentityServer4.

You typically want to protect those APIs by the very instance of IdentityServer they are hosted in. That’s not a problem. Simply add the token validation handler to the host (see here):

public void ConfigureServices(IServiceCollection services)

    // details omitted

        .AddIdentityServerAuthentication("token", isAuth =>
            isAuth.Authority = "base_address_of_identityserver";
            isAuth.ApiName = "name_of_api";

On your API, you need to add the [Authorize] attribute and explicitly reference the authentication scheme you want to use (this is token in this example, but you can choose whatever name you like):

public class TestController : ControllerBase
    [Authorize(AuthenticationSchemes = "token")]
    public IActionResult Get()
        var claims = User.Claims.Select(c => new { c.Type, c.Value }).ToArray();
        return Ok(new { message = "Hello API", claims });

If you want to call that API from browsers, you additionally need to configure CORS (see here).


You can also add your endpoints to the discovery document if you want, e.g like this:

services.AddIdentityServer(options =>
    options.Discovery.CustomEntries.Add("custom_endpoint", "~/api/custom");