Hosting

You add the Duende IdentityServer engine to any ASP.NET Core application by adding the relevant services to the dependency injection (DI) system and adding the middleware to the processing pipeline.

While technically you could share the ASP.NET Core host between Duende IdentityServer, clients or APIs. We recommend putting your IdentityServer into a separate application.

DI system

You add the necessary services to the DI system by calling AddIdentityServer in your startup class:

public void ConfigureServices(IServiceCollection services)
{
    var builder = services.AddIdentityServer(options => { ... });
}

Many of the fundamental configuration settings can be set on the options. See the IdentityServerOptions reference for more details.

The builder object has a number of extension methods to add additional services to DI. You can see the full list in the reference section, but very commonly you start by adding the configuration stores for clients and resources, e.g.:

var builder = services.AddIdentityServer()
    .AddInMemoryClients(Config.Clients)
    .AddInMemoryIdentityResources(Config.IdentityResources)
    .AddInMemoryApiScopes(Config.ApiScopes)

The above is using the in-memory stores, but we also support EntityFramework-based implementations and custom stores. See here for more information.

Pipeline

You need to add the Duende IdentityServer middleware to the pipeline by calling AddIdentityServer.

Since ordering is important in the pipeline, you typically want to put the IdentityServer middleware after the static files, but before the UI framework like MVC.

This would be a very typical minimal pipeline:

public void Configure(IApplicationBuilder app)
{
    app.UseStaticFiles();
    
    app.UseRouting();
    app.UseIdentityServer();
    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapDefaultControllerRoute();
    });
}

UseIdentityServer includes a call to UseAuthentication, so it’s not necessary to have both.