Reunify the custom and built-in handlers collections to avoid computing the collections per-request

src/OpenIddict.Abstractions/Descriptors/OpenIddictApplicationDescriptor.cs

@@ -36,24 +36,24 @@ namespace OpenIddict.Abstractions
         /// <summary>
         /// Gets the permissions associated with the application.
         /// </summary>
-        public ISet<string> Permissions { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> Permissions { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets the logout callback URLs
         /// associated with the application.
         /// </summary>
-        public ISet<Uri> PostLogoutRedirectUris { get; } = new HashSet<Uri>();
+        public HashSet<Uri> PostLogoutRedirectUris { get; } = new HashSet<Uri>();
 
         /// <summary>
         /// Gets the callback URLs
         /// associated with the application.
         /// </summary>
-        public ISet<Uri> RedirectUris { get; } = new HashSet<Uri>();
+        public HashSet<Uri> RedirectUris { get; } = new HashSet<Uri>();
 
         /// <summary>
         /// Gets the requirements associated with the application.
         /// </summary>
-        public ISet<string> Requirements { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> Requirements { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets or sets the application type

src/OpenIddict.Abstractions/Descriptors/OpenIddictAuthorizationDescriptor.cs

@@ -23,8 +23,7 @@ namespace OpenIddict.Abstractions
         /// <summary>
         /// Gets the scopes associated with the authorization.
         /// </summary>
-        public ISet<string> Scopes { get; } =
-            new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> Scopes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets or sets the status associated with the authorization.

src/OpenIddict.Abstractions/Descriptors/OpenIddictScopeDescriptor.cs

@@ -29,7 +29,6 @@ namespace OpenIddict.Abstractions
         /// <summary>
         /// Gets the resources associated with the scope.
         /// </summary>
-        public virtual ISet<string> Resources { get; }
-            = new HashSet<string>(StringComparer.Ordinal);
+        public virtual HashSet<string> Resources { get; } = new HashSet<string>(StringComparer.Ordinal);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkAuthorizationStore.cs

@@ -183,38 +183,37 @@ namespace OpenIddict.EntityFramework
             // To prevent an SQL exception from being thrown if a new associated entity is
             // created after the existing entries have been listed, the following logic is
             // executed in a serializable transaction, that will lock the affected tables.
-            using (var transaction = CreateTransaction())
+            using var transaction = CreateTransaction();
+
+            // Remove all the tokens associated with the authorization.
+            var tokens = await ListTokensAsync();
+            foreach (var token in tokens)
             {
-                // Remove all the tokens associated with the authorization.
-                var tokens = await ListTokensAsync();
-                foreach (var token in tokens)
-                {
-                    Tokens.Remove(token);
-                }
+                Tokens.Remove(token);
+            }
 
-                Authorizations.Remove(authorization);
+            Authorizations.Remove(authorization);
 
-                try
-                {
-                    await Context.SaveChangesAsync(cancellationToken);
-                    transaction?.Commit();
-                }
-
-                catch (DbUpdateConcurrencyException exception)
-                {
-                    // Reset the state of the entity to prevents future calls to SaveChangesAsync() from failing.
-                    Context.Entry(authorization).State = EntityState.Unchanged;
+            try
+            {
+                await Context.SaveChangesAsync(cancellationToken);
+                transaction?.Commit();
+            }
 
-                    foreach (var token in tokens)
-                    {
-                        Context.Entry(token).State = EntityState.Unchanged;
-                    }
+            catch (DbUpdateConcurrencyException exception)
+            {
+                // Reset the state of the entity to prevents future calls to SaveChangesAsync() from failing.
+                Context.Entry(authorization).State = EntityState.Unchanged;
 
-                    throw new OpenIddictExceptions.ConcurrencyException(new StringBuilder()
-                        .AppendLine("The authorization was concurrently updated and cannot be persisted in its current state.")
-                        .Append("Reload the authorization from the database and retry the operation.")
-                        .ToString(), exception);
+                foreach (var token in tokens)
+                {
+                    Context.Entry(token).State = EntityState.Unchanged;
                 }
+
+                throw new OpenIddictExceptions.ConcurrencyException(new StringBuilder()
+                    .AppendLine("The authorization was concurrently updated and cannot be persisted in its current state.")
+                    .Append("Reload the authorization from the database and retry the operation.")
+                    .ToString(), exception);
             }
         }
 
@@ -743,7 +742,7 @@ namespace OpenIddict.EntityFramework
             // entities in a single command without having to retrieve and materialize them first.
             // To work around this limitation, entities are manually listed and deleted using a batch logic.
 
-            IList<Exception> exceptions = null;
+            List<Exception> exceptions = null;
 
             DbContextTransaction CreateTransaction()
             {

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkTokenStore.cs

@@ -771,7 +771,7 @@ namespace OpenIddict.EntityFramework
             // entities in a single command without having to retrieve and materialize them first.
             // To work around this limitation, entities are manually listed and deleted using a batch logic.
 
-            IList<Exception> exceptions = null;
+            List<Exception> exceptions = null;
 
             DbContextTransaction CreateTransaction()
             {

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreAuthorizationStore.cs

@@ -805,7 +805,7 @@ namespace OpenIddict.EntityFrameworkCore
             // entities in a single command without having to retrieve and materialize them first.
             // To work around this limitation, entities are manually listed and deleted using a batch logic.
 
-            IList<Exception> exceptions = null;
+            List<Exception> exceptions = null;
 
             async ValueTask<IDbContextTransaction> CreateTransactionAsync()
             {

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreTokenStore.cs

@@ -820,7 +820,7 @@ namespace OpenIddict.EntityFrameworkCore
             // entities in a single command without having to retrieve and materialize them first.
             // To work around this limitation, entities are manually listed and deleted using a batch logic.
 
-            IList<Exception> exceptions = null;
+            List<Exception> exceptions = null;
 
             async ValueTask<IDbContextTransaction> CreateTransactionAsync()
             {

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbAuthorizationStore.cs

@@ -704,7 +704,7 @@ namespace OpenIddict.MongoDb
                     .DeleteManyAsync(token => buffer.Contains(token.AuthorizationId), cancellationToken);
             }
 
-            IEnumerable<IList<TSource>> Buffer<TSource>(IEnumerable<TSource> source, int count)
+            static IEnumerable<List<TSource>> Buffer<TSource>(IEnumerable<TSource> source, int count)
             {
                 List<TSource> buffer = null;
 

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreConfiguration.cs

@@ -54,10 +54,7 @@ namespace OpenIddict.Server.AspNetCore
             }
 
             // Register the built-in event handlers used by the OpenIddict ASP.NET Core server components.
-            foreach (var handler in OpenIddictServerAspNetCoreHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictServerAspNetCoreHandlers.DefaultHandlers);
         }
 
         /// <summary>

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreHandler.cs

@@ -29,19 +29,24 @@ namespace OpenIddict.Server.AspNetCore
         IAuthenticationSignInHandler,
         IAuthenticationSignOutHandler
     {
-        private readonly IOpenIddictServerProvider _provider;
+        private readonly IOpenIddictServerDispatcher _dispatcher;
+        private readonly IOpenIddictServerFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictServerAspNetCoreHandler"/> class.
         /// </summary>
         public OpenIddictServerAspNetCoreHandler(
-            [NotNull] IOpenIddictServerProvider provider,
+            [NotNull] IOpenIddictServerDispatcher dispatcher,
+            [NotNull] IOpenIddictServerFactory factory,
             [NotNull] IOptionsMonitor<OpenIddictServerAspNetCoreOptions> options,
             [NotNull] ILoggerFactory logger,
             [NotNull] UrlEncoder encoder,
             [NotNull] ISystemClock clock)
             : base(options, logger, encoder, clock)
-            => _provider = provider;
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         public async Task<bool> HandleRequestAsync()
         {
@@ -51,7 +56,7 @@ namespace OpenIddict.Server.AspNetCore
             if (transaction == null)
             {
                 // Create a new transaction and attach the HTTP request to make it available to the ASP.NET Core handlers.
-                transaction = await _provider.CreateTransactionAsync();
+                transaction = await _factory.CreateTransactionAsync();
                 transaction.Properties[typeof(HttpRequest).FullName] = new WeakReference<HttpRequest>(Request);
 
                 // Attach the OpenIddict server transaction to the ASP.NET Core features
@@ -60,7 +65,7 @@ namespace OpenIddict.Server.AspNetCore
             }
 
             var context = new ProcessRequestContext(transaction);
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled)
             {
@@ -84,7 +89,7 @@ namespace OpenIddict.Server.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled)
                 {
@@ -118,7 +123,7 @@ namespace OpenIddict.Server.AspNetCore
             if (context == null)
             {
                 context = new ProcessAuthenticationContext(transaction);
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 // Store the context object in the transaction so it can be later retrieved by handlers
                 // that want to access the authentication result without triggering a new authentication flow.
@@ -182,7 +187,7 @@ namespace OpenIddict.Server.AspNetCore
                 Response = new OpenIddictResponse()
             };
 
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled || context.IsRequestSkipped)
             {
@@ -201,7 +206,7 @@ namespace OpenIddict.Server.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -237,7 +242,7 @@ namespace OpenIddict.Server.AspNetCore
                 Response = new OpenIddictResponse()
             };
 
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled || context.IsRequestSkipped)
             {
@@ -256,7 +261,7 @@ namespace OpenIddict.Server.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -283,7 +288,7 @@ namespace OpenIddict.Server.AspNetCore
 
             transaction.Properties[typeof(AuthenticationProperties).FullName] = properties ?? new AuthenticationProperties();
 
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled || context.IsRequestSkipped)
             {
@@ -302,7 +307,7 @@ namespace OpenIddict.Server.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled || context.IsRequestSkipped)
                 {

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreHandlers.cs

@@ -80,6 +80,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<InferEndpointType>()
                     .SetOrder(int.MinValue + 50_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -119,7 +120,7 @@ namespace OpenIddict.Server.AspNetCore
 
                 return default;
 
-                static bool Matches(HttpRequest request, IList<Uri> addresses)
+                static bool Matches(HttpRequest request, IReadOnlyList<Uri> addresses)
                 {
                     for (var index = 0; index < addresses.Count; index++)
                     {
@@ -182,6 +183,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<InferIssuerFromHost>()
                     .SetOrder(InferEndpointType.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -253,6 +255,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireTransportSecurityRequirementEnabled>()
                     .UseSingletonHandler<ValidateTransportSecurityRequirement>()
                     .SetOrder(InferEndpointType.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -311,6 +314,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachHostChallengeError>()
                     .SetOrder(AttachDefaultChallengeError.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -354,6 +358,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachHostParameters<TContext>>()
                     .SetOrder(int.MaxValue - 150_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -414,6 +419,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractGetRequest<TContext>>()
                     .SetOrder(ValidateTransportSecurityRequirement.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -473,6 +479,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractGetOrPostRequest<TContext>>()
                     .SetOrder(ExtractGetRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -560,6 +567,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractPostRequest<TContext>>()
                     .SetOrder(ExtractGetOrPostRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -643,6 +651,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractBasicAuthenticationCredentials<TContext>>()
                     .SetOrder(ExtractPostRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -744,6 +753,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractAccessToken<TContext>>()
                     .SetOrder(ExtractBasicAuthenticationCredentials<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -798,6 +808,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<TFilter>()
                     .UseSingletonHandler<EnablePassthroughMode<TContext, TFilter>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -834,6 +845,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachHttpResponseCode<TContext>>()
                     .SetOrder(AttachCacheControlHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -897,6 +909,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachCacheControlHeader<TContext>>()
                     .SetOrder(AttachWwwAuthenticateHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -949,6 +962,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachWwwAuthenticateHeader<TContext>>()
                     .SetOrder(ProcessChallengeErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1066,6 +1080,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessChallengeErrorResponse<TContext>>()
                     .SetOrder(ProcessJsonResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1117,6 +1132,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessJsonResponse<TContext>>()
                     .SetOrder(ProcessPassthroughErrorResponse<TContext, IOpenIddictServerHandlerFilter<TContext>>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1179,6 +1195,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<TFilter>()
                     .UseSingletonHandler<ProcessPassthroughErrorResponse<TContext, TFilter>>()
                     .SetOrder(ProcessStatusCodePagesErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1230,6 +1247,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireStatusCodePagesIntegrationEnabled>()
                     .UseSingletonHandler<ProcessStatusCodePagesErrorResponse<TContext>>()
                     .SetOrder(ProcessLocalErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1292,6 +1310,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessLocalErrorResponse<TContext>>()
                     .SetOrder(ProcessEmptyResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1373,6 +1392,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessHostRedirectionResponse<TContext>>()
                     .SetOrder(ProcessEmptyResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1425,6 +1445,7 @@ namespace OpenIddict.Server.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessEmptyResponse<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionConfiguration.cs

@@ -34,10 +34,7 @@ namespace OpenIddict.Server.DataProtection
             }
 
             // Register the built-in event handlers used by the OpenIddict Data Protection server components.
-            foreach (var handler in OpenIddictServerDataProtectionHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictServerDataProtectionHandlers.DefaultHandlers);
         }
 
         /// <summary>

src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionHandlers.cs

@@ -62,6 +62,7 @@ namespace OpenIddict.Server.DataProtection
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateDataProtectionToken>()
                     .SetOrder(ValidateIdentityModelToken.Descriptor.Order + 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -180,6 +181,7 @@ namespace OpenIddict.Server.DataProtection
                     .AddFilter<RequireDataProtectionFormatEnabled>()
                     .UseSingletonHandler<GenerateDataProtectionAccessToken>()
                     .SetOrder(GenerateIdentityModelAccessToken.Descriptor.Order - 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -244,6 +246,7 @@ namespace OpenIddict.Server.DataProtection
                     .AddFilter<RequireDataProtectionFormatEnabled>()
                     .UseSingletonHandler<GenerateDataProtectionAuthorizationCode>()
                     .SetOrder(GenerateIdentityModelAuthorizationCode.Descriptor.Order - 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -308,6 +311,7 @@ namespace OpenIddict.Server.DataProtection
                     .AddFilter<RequireDataProtectionFormatEnabled>()
                     .UseSingletonHandler<GenerateDataProtectionDeviceCode>()
                     .SetOrder(GenerateIdentityModelDeviceCode.Descriptor.Order - 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -372,6 +376,7 @@ namespace OpenIddict.Server.DataProtection
                     .AddFilter<RequireDataProtectionFormatEnabled>()
                     .UseSingletonHandler<GenerateDataProtectionRefreshToken>()
                     .SetOrder(GenerateIdentityModelRefreshToken.Descriptor.Order - 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -436,6 +441,7 @@ namespace OpenIddict.Server.DataProtection
                     .AddFilter<RequireDataProtectionFormatEnabled>()
                     .UseSingletonHandler<GenerateDataProtectionUserCode>()
                     .SetOrder(GenerateIdentityModelUserCode.Descriptor.Order - 500)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Server.Owin/OpenIddictServerOwinConfiguration.cs

@@ -26,10 +26,7 @@ namespace OpenIddict.Server.Owin
             }
 
             // Register the built-in event handlers used by the OpenIddict OWIN server components.
-            foreach (var handler in OpenIddictServerOwinHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictServerOwinHandlers.DefaultHandlers);
         }
 
         public void PostConfigure([CanBeNull] string name, [NotNull] OpenIddictServerOwinOptions options)

src/OpenIddict.Server.Owin/OpenIddictServerOwinHandler.cs

@@ -24,14 +24,21 @@ namespace OpenIddict.Server.Owin
     /// </summary>
     public class OpenIddictServerOwinHandler : AuthenticationHandler<OpenIddictServerOwinOptions>
     {
-        private readonly IOpenIddictServerProvider _provider;
+        private readonly IOpenIddictServerDispatcher _dispatcher;
+        private readonly IOpenIddictServerFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictServerOwinHandler"/> class.
         /// </summary>
-        /// <param name="provider">The OpenIddict server OWIN provider used by this instance.</param>
-        public OpenIddictServerOwinHandler([NotNull] IOpenIddictServerProvider provider)
-            => _provider = provider;
+        /// <param name="dispatcher">The OpenIddict server provider used by this instance.</param>
+        /// <param name="factory">The OpenIddict server factory used by this instance.</param>
+        public OpenIddictServerOwinHandler(
+            [NotNull] IOpenIddictServerDispatcher dispatcher,
+            [NotNull] IOpenIddictServerFactory factory)
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         protected override async Task InitializeCoreAsync()
         {
@@ -41,7 +48,7 @@ namespace OpenIddict.Server.Owin
             if (transaction == null)
             {
                 // Create a new transaction and attach the OWIN request to make it available to the OWIN handlers.
-                transaction = await _provider.CreateTransactionAsync();
+                transaction = await _factory.CreateTransactionAsync();
                 transaction.Properties[typeof(IOwinRequest).FullName] = new WeakReference<IOwinRequest>(Request);
 
                 // Attach the OpenIddict server transaction to the OWIN shared dictionary
@@ -50,7 +57,7 @@ namespace OpenIddict.Server.Owin
             }
 
             var context = new ProcessRequestContext(transaction);
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             // Store the context in the transaction so that it can be retrieved from InvokeAsync().
             transaction.SetProperty(typeof(ProcessRequestContext).FullName, context);
@@ -90,7 +97,7 @@ namespace OpenIddict.Server.Owin
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled)
                 {
@@ -127,7 +134,7 @@ namespace OpenIddict.Server.Owin
             if (context == null)
             {
                 context = new ProcessAuthenticationContext(transaction);
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 // Store the context object in the transaction so it can be later retrieved by handlers
                 // that want to access the authentication result without triggering a new authentication flow.
@@ -202,7 +209,7 @@ namespace OpenIddict.Server.Owin
                     Response = new OpenIddictResponse()
                 };
 
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 if (context.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -221,7 +228,7 @@ namespace OpenIddict.Server.Owin
                         }
                     };
 
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled || context.IsRequestSkipped)
                     {
@@ -250,7 +257,7 @@ namespace OpenIddict.Server.Owin
                     Response = new OpenIddictResponse()
                 };
 
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 if (context.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -269,7 +276,7 @@ namespace OpenIddict.Server.Owin
                         }
                     };
 
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled || context.IsRequestSkipped)
                     {
@@ -297,7 +304,7 @@ namespace OpenIddict.Server.Owin
                     Response = new OpenIddictResponse()
                 };
 
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 if (context.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -316,7 +323,7 @@ namespace OpenIddict.Server.Owin
                         }
                     };
 
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled || context.IsRequestSkipped)
                     {

src/OpenIddict.Server.Owin/OpenIddictServerOwinHandlers.cs

@@ -68,6 +68,7 @@ namespace OpenIddict.Server.Owin
                     // Note: this handler must be invoked before any other handler,
                     // including the built-in handlers defined in OpenIddict.Server.
                     .SetOrder(int.MinValue + 50_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -107,7 +108,7 @@ namespace OpenIddict.Server.Owin
 
                 return default;
 
-                static bool Matches(IOwinRequest request, IList<Uri> addresses)
+                static bool Matches(IOwinRequest request, IReadOnlyList<Uri> addresses)
                 {
                     for (var index = 0; index < addresses.Count; index++)
                     {
@@ -170,6 +171,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<InferIssuerFromHost>()
                     .SetOrder(InferEndpointType.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -241,6 +243,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireTransportSecurityRequirementEnabled>()
                     .UseSingletonHandler<ValidateTransportSecurityRequirement>()
                     .SetOrder(InferEndpointType.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -299,6 +302,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachHostChallengeError>()
                     .SetOrder(AttachDefaultChallengeError.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -345,6 +349,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractGetRequest<TContext>>()
                     .SetOrder(ValidateTransportSecurityRequirement.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -404,6 +409,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractGetOrPostRequest<TContext>>()
                     .SetOrder(ExtractGetRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -491,6 +497,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractPostRequest<TContext>>()
                     .SetOrder(ExtractGetOrPostRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -574,6 +581,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractBasicAuthenticationCredentials<TContext>>()
                     .SetOrder(ExtractPostRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -675,6 +683,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractAccessToken<TContext>>()
                     .SetOrder(ExtractBasicAuthenticationCredentials<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -729,6 +738,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<TFilter>()
                     .UseSingletonHandler<EnablePassthroughMode<TContext, TFilter>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -765,6 +775,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachHttpResponseCode<TContext>>()
                     .SetOrder(AttachCacheControlHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -828,6 +839,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachCacheControlHeader<TContext>>()
                     .SetOrder(AttachWwwAuthenticateHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -880,6 +892,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachWwwAuthenticateHeader<TContext>>()
                     .SetOrder(ProcessChallengeErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -997,6 +1010,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessChallengeErrorResponse<TContext>>()
                     .SetOrder(ProcessJsonResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1048,6 +1062,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessJsonResponse<TContext>>()
                     .SetOrder(ProcessPassthroughErrorResponse<TContext, IOpenIddictServerHandlerFilter<TContext>>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1110,6 +1125,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<TFilter>()
                     .UseSingletonHandler<ProcessPassthroughErrorResponse<TContext, TFilter>>()
                     .SetOrder(ProcessLocalErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1163,6 +1179,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessLocalErrorResponse<TContext>>()
                     .SetOrder(ProcessEmptyResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1244,6 +1261,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessHostRedirectionResponse<TContext>>()
                     .SetOrder(ProcessEmptyResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1296,6 +1314,7 @@ namespace OpenIddict.Server.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessEmptyResponse<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Server.Owin/OpenIddictServerOwinMiddleware.cs

@@ -19,26 +19,32 @@ namespace OpenIddict.Server.Owin
     /// </summary>
     public class OpenIddictServerOwinMiddleware : AuthenticationMiddleware<OpenIddictServerOwinOptions>
     {
-        private readonly IOpenIddictServerProvider _provider;
+        private readonly IOpenIddictServerDispatcher _dispatcher;
+        private readonly IOpenIddictServerFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictServerOwinMiddleware"/> class.
         /// </summary>
         /// <param name="next">The next middleware in the pipeline, if applicable.</param>
         /// <param name="options">The OpenIddict server OWIN options.</param>
-        /// <param name="provider">The OpenIddict server provider.</param>
+        /// <param name="dispatcher">The OpenIddict server dispatcher.</param>
+        /// <param name="factory">The OpenIddict server factory.</param>
         public OpenIddictServerOwinMiddleware(
             [CanBeNull] OwinMiddleware next,
             [NotNull] IOptionsMonitor<OpenIddictServerOwinOptions> options,
-            [NotNull] IOpenIddictServerProvider provider)
+            [NotNull] IOpenIddictServerDispatcher dispatcher,
+            [NotNull] IOpenIddictServerFactory factory)
             : base(next, options.CurrentValue)
-            => _provider = provider;
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         /// <summary>
         /// Creates and returns a new <see cref="OpenIddictServerOwinHandler"/> instance.
         /// </summary>
         /// <returns>A new instance of the <see cref="OpenIddictServerOwinHandler"/> class.</returns>
         protected override AuthenticationHandler<OpenIddictServerOwinOptions> CreateHandler()
-            => new OpenIddictServerOwinHandler(_provider);
+            => new OpenIddictServerOwinHandler(_dispatcher, _factory);
     }
 }

src/OpenIddict.Server.Owin/OpenIddictServerOwinMiddlewareFactory.cs

@@ -64,13 +64,14 @@ namespace OpenIddict.Server.Owin
             var middleware = new OpenIddictServerOwinMiddleware(
                 next: Next,
                 options: GetRequiredService<IOptionsMonitor<OpenIddictServerOwinOptions>>(provider),
-                provider: GetRequiredService<IOpenIddictServerProvider>(provider));
+                dispatcher: GetRequiredService<IOpenIddictServerDispatcher>(provider),
+                factory: GetRequiredService<IOpenIddictServerFactory>(provider));
 
             return middleware.Invoke(context);
 
             static T GetRequiredService<T>(IServiceProvider provider)
                 => provider.GetService<T>() ?? throw new InvalidOperationException(new StringBuilder()
-                    .AppendLine("The OpenIddict server authentication services cannot be resolved from the DI container.")
+                    .AppendLine("The OpenIddict server services cannot be resolved from the DI container.")
                     .Append("To register the OWIN services, use 'services.AddOpenIddict().AddServer().UseOwin()'.")
                     .ToString());
         }

src/OpenIddict.Server/IOpenIddictServerProvider.cs → src/OpenIddict.Server/IOpenIddictServerDispatcher.cs

@@ -10,9 +10,8 @@ using static OpenIddict.Server.OpenIddictServerEvents;
 
 namespace OpenIddict.Server
 {
-    public interface IOpenIddictServerProvider
+    public interface IOpenIddictServerDispatcher
     {
-        ValueTask<OpenIddictServerTransaction> CreateTransactionAsync();
         ValueTask DispatchAsync<TContext>([NotNull] TContext context) where TContext : BaseContext;
     }
 }

src/OpenIddict.Server/IOpenIddictServerFactory.cs

@@ -0,0 +1,15 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+using System.Threading.Tasks;
+
+namespace OpenIddict.Server
+{
+    public interface IOpenIddictServerFactory
+    {
+        ValueTask<OpenIddictServerTransaction> CreateTransactionAsync();
+    }
+}

src/OpenIddict.Server/OpenIddictServerBuilder.cs

@@ -56,7 +56,10 @@ namespace Microsoft.Extensions.DependencyInjection
                 throw new ArgumentNullException(nameof(configuration));
             }
 
-            var builder = OpenIddictServerHandlerDescriptor.CreateBuilder<TContext>();
+            // Note: handlers registered using this API are assumed to be custom handlers by default.
+            var builder = OpenIddictServerHandlerDescriptor.CreateBuilder<TContext>()
+                .SetType(OpenIddictServerHandlerType.Custom);
+
             configuration(builder);
 
             return AddEventHandler(builder.Build());
@@ -78,7 +81,7 @@ namespace Microsoft.Extensions.DependencyInjection
             // Register the handler in the services collection.
             Services.Add(descriptor.ServiceDescriptor);
 
-            return Configure(options => options.CustomHandlers.Add(descriptor));
+            return Configure(options => options.Handlers.Add(descriptor));
         }
 
         /// <summary>
@@ -98,19 +101,11 @@ namespace Microsoft.Extensions.DependencyInjection
 
             Services.PostConfigure<OpenIddictServerOptions>(options =>
             {
-                for (var index = options.CustomHandlers.Count - 1; index >= 0; index--)
-                {
-                    if (options.CustomHandlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
-                    {
-                        options.CustomHandlers.RemoveAt(index);
-                    }
-                }
-
-                for (var index = options.DefaultHandlers.Count - 1; index >= 0; index--)
+                for (var index = options.Handlers.Count - 1; index >= 0; index--)
                 {
-                    if (options.DefaultHandlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
+                    if (options.Handlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
                     {
-                        options.DefaultHandlers.RemoveAt(index);
+                        options.Handlers.RemoveAt(index);
                     }
                 }
             });

src/OpenIddict.Server/OpenIddictServerConfiguration.cs

@@ -134,8 +134,9 @@ namespace OpenIddict.Server
                 // If the degraded mode was enabled, ensure custom validation handlers
                 // have been registered for the endpoints that require manual validation.
 
-                if (options.AuthorizationEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.AuthorizationEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateAuthorizationRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -145,8 +146,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.DeviceEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.DeviceEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateDeviceRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -156,8 +158,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.IntrospectionEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.IntrospectionEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateIntrospectionRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -167,8 +170,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.LogoutEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.LogoutEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateLogoutRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -178,8 +182,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.RevocationEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.RevocationEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateRevocationRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -189,8 +194,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.TokenEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.TokenEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateTokenRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -200,8 +206,9 @@ namespace OpenIddict.Server
                         .ToString());
                 }
 
-                if (options.VerificationEndpointUris.Count != 0 && !options.CustomHandlers.Any(
+                if (options.VerificationEndpointUris.Count != 0 && !options.Handlers.Any(
                     descriptor => descriptor.ContextType == typeof(ValidateVerificationRequestContext) &&
+                                  descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                   descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                 {
                     throw new InvalidOperationException(new StringBuilder()
@@ -216,8 +223,9 @@ namespace OpenIddict.Server
 
                 if (options.GrantTypes.Contains(GrantTypes.DeviceCode))
                 {
-                    if (!options.CustomHandlers.Any(
+                    if (!options.Handlers.Any(
                         descriptor => descriptor.ContextType == typeof(ProcessAuthenticationContext) &&
+                                      descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                       descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                     {
                         throw new InvalidOperationException(new StringBuilder()
@@ -227,8 +235,9 @@ namespace OpenIddict.Server
                             .ToString());
                     }
 
-                    if (!options.CustomHandlers.Any(
+                    if (!options.Handlers.Any(
                         descriptor => descriptor.ContextType == typeof(ProcessSignInContext) &&
+                                      descriptor.Type == OpenIddictServerHandlerType.Custom &&
                                       descriptor.FilterTypes.All(type => !typeof(RequireDegradedModeDisabled).IsAssignableFrom(type))))
                     {
                         throw new InvalidOperationException(new StringBuilder()
@@ -240,6 +249,9 @@ namespace OpenIddict.Server
                 }
             }
 
+            // Sort the handlers collection using the order associated with each handler.
+            options.Handlers.Sort((left, right) => left.Order.CompareTo(right.Order));
+
             // Automatically add the offline_access scope if the refresh token grant has been enabled.
             if (options.GrantTypes.Contains(GrantTypes.RefreshToken))
             {

src/OpenIddict.Server/OpenIddictServerProvider.cs → src/OpenIddict.Server/OpenIddictServerDispatcher.cs

@@ -15,17 +15,17 @@ using static OpenIddict.Server.OpenIddictServerEvents;
 
 namespace OpenIddict.Server
 {
-    public class OpenIddictServerProvider : IOpenIddictServerProvider
+    public class OpenIddictServerDispatcher : IOpenIddictServerDispatcher
     {
-        private readonly ILogger<OpenIddictServerProvider> _logger;
+        private readonly ILogger<OpenIddictServerDispatcher> _logger;
         private readonly IOptionsMonitor<OpenIddictServerOptions> _options;
         private readonly IServiceProvider _provider;
 
         /// <summary>
-        /// Creates a new instance of the <see cref="OpenIddictServerProvider"/> class.
+        /// Creates a new instance of the <see cref="OpenIddictServerDispatcher"/> class.
         /// </summary>
-        public OpenIddictServerProvider(
-            [NotNull] ILogger<OpenIddictServerProvider> logger,
+        public OpenIddictServerDispatcher(
+            [NotNull] ILogger<OpenIddictServerDispatcher> logger,
             [NotNull] IOptionsMonitor<OpenIddictServerOptions> options,
             [NotNull] IServiceProvider provider)
         {
@@ -34,14 +34,6 @@ namespace OpenIddict.Server
             _provider = provider;
         }
 
-        public ValueTask<OpenIddictServerTransaction> CreateTransactionAsync()
-            => new ValueTask<OpenIddictServerTransaction>(new OpenIddictServerTransaction
-            {
-                Issuer = _options.CurrentValue.Issuer,
-                Logger = _logger,
-                Options = _options.CurrentValue
-            });
-
         public async ValueTask DispatchAsync<TContext>([NotNull] TContext context) where TContext : BaseContext
         {
             if (context == null)
@@ -82,14 +74,12 @@ namespace OpenIddict.Server
 
             async IAsyncEnumerable<IOpenIddictServerHandler<TContext>> GetHandlersAsync()
             {
-                var descriptors = new List<OpenIddictServerHandlerDescriptor>(
-                    capacity: _options.CurrentValue.CustomHandlers.Count +
-                              _options.CurrentValue.DefaultHandlers.Count);
-
-                descriptors.AddRange(_options.CurrentValue.CustomHandlers);
-                descriptors.AddRange(_options.CurrentValue.DefaultHandlers);
-
-                descriptors.Sort((left, right) => left.Order.CompareTo(right.Order));
+                // Note: the descriptors collection is sorted during options initialization for performance reasons.
+                var descriptors = _options.CurrentValue.Handlers;
+                if (descriptors.Count == 0)
+                {
+                    yield break;
+                }
 
                 for (var index = 0; index < descriptors.Count; index++)
                 {

src/OpenIddict.Server/OpenIddictServerEvents.Discovery.cs

@@ -107,78 +107,67 @@ namespace OpenIddict.Server
             /// <summary>
             /// Gets the list of claims supported by the authorization server.
             /// </summary>
-            public ISet<string> Claims { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> Claims { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets a list of the code challenge methods
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> CodeChallengeMethods { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> CodeChallengeMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets the list of grant types
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> GrantTypes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> GrantTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets a list of signing algorithms supported by the
             /// authorization server for signing the identity tokens.
             /// </summary>
-            public ISet<string> IdTokenSigningAlgorithms { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> IdTokenSigningAlgorithms { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets a list of client authentication methods supported by
             /// the introspection endpoint provided by the authorization server.
             /// </summary>
-            public ISet<string> IntrospectionEndpointAuthenticationMethods { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> IntrospectionEndpointAuthenticationMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets the list of response modes
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> ResponseModes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> ResponseModes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets the list of response types
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> ResponseTypes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> ResponseTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets a list of client authentication methods supported by
             /// the revocation endpoint provided by the authorization server.
             /// </summary>
-            public ISet<string> RevocationEndpointAuthenticationMethods { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> RevocationEndpointAuthenticationMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets the list of scope values
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> Scopes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> Scopes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets the list of subject types
             /// supported by the authorization server.
             /// </summary>
-            public ISet<string> SubjectTypes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> SubjectTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets a list of client authentication methods supported by
             /// the token endpoint provided by the authorization server.
             /// </summary>
-            public ISet<string> TokenEndpointAuthenticationMethods { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> TokenEndpointAuthenticationMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
         }
 
         /// <summary>
@@ -249,7 +238,7 @@ namespace OpenIddict.Server
             /// <summary>
             /// Gets the list of JSON Web Keys exposed by the JWKS endpoint.
             /// </summary>
-            public IList<JsonWebKey> Keys { get; } = new List<JsonWebKey>();
+            public List<JsonWebKey> Keys { get; } = new List<JsonWebKey>();
         }
 
         /// <summary>

src/OpenIddict.Server/OpenIddictServerEvents.Introspection.cs

@@ -84,8 +84,7 @@ namespace OpenIddict.Server
             /// Gets the list of audiences returned to the caller
             /// as part of the "aud" claim, if applicable.
             /// </summary>
-            public ISet<string> Audiences { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> Audiences { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets or sets the "client_id" claim
@@ -115,8 +114,7 @@ namespace OpenIddict.Server
             /// Gets the list of scopes returned to the caller
             /// as part of the "scope" claim, if applicable.
             /// </summary>
-            public ISet<string> Scopes { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> Scopes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets or sets the "sub" claim

src/OpenIddict.Server/OpenIddictServerEvents.Userinfo.cs

@@ -85,8 +85,7 @@ namespace OpenIddict.Server
             /// <summary>
             /// Gets or sets the values used for the "aud" claim.
             /// </summary>
-            public ISet<string> Audiences { get; } =
-                new HashSet<string>(StringComparer.Ordinal);
+            public HashSet<string> Audiences { get; } = new HashSet<string>(StringComparer.Ordinal);
 
             /// <summary>
             /// Gets or sets the value used for the "birthdate" claim.

src/OpenIddict.Server/OpenIddictServerExtensions.cs

@@ -36,7 +36,8 @@ namespace Microsoft.Extensions.DependencyInjection
             builder.Services.AddLogging();
             builder.Services.AddOptions();
 
-            builder.Services.TryAddScoped<IOpenIddictServerProvider, OpenIddictServerProvider>();
+            builder.Services.TryAddScoped<IOpenIddictServerDispatcher, OpenIddictServerDispatcher>();
+            builder.Services.TryAddScoped<IOpenIddictServerFactory, OpenIddictServerFactory>();
 
             // Register the built-in server event handlers used by the OpenIddict server components.
             // Note: the order used here is not important, as the actual order is set in the options.

src/OpenIddict.Server/OpenIddictServerFactory.cs

@@ -0,0 +1,38 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace OpenIddict.Server
+{
+    public class OpenIddictServerFactory : IOpenIddictServerFactory
+    {
+        private readonly ILogger<OpenIddictServerDispatcher> _logger;
+        private readonly IOptionsMonitor<OpenIddictServerOptions> _options;
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="OpenIddictServerDispatcher"/> class.
+        /// </summary>
+        public OpenIddictServerFactory(
+            [NotNull] ILogger<OpenIddictServerDispatcher> logger,
+            [NotNull] IOptionsMonitor<OpenIddictServerOptions> options)
+        {
+            _logger = logger;
+            _options = options;
+        }
+
+        public ValueTask<OpenIddictServerTransaction> CreateTransactionAsync()
+            => new ValueTask<OpenIddictServerTransaction>(new OpenIddictServerTransaction
+            {
+                Issuer = _options.CurrentValue.Issuer,
+                Logger = _logger,
+                Options = _options.CurrentValue
+            });
+    }
+}

src/OpenIddict.Server/OpenIddictServerHandlerDescriptor.cs

@@ -7,6 +7,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
@@ -47,6 +48,11 @@ namespace OpenIddict.Server
         /// </summary>
         public ServiceDescriptor ServiceDescriptor { get; private set; }
 
+        /// <summary>
+        /// Gets the type associated with the handler.
+        /// </summary>
+        public OpenIddictServerHandlerType Type { get; private set; }
+
         /// <summary>
         /// Creates a builder allowing to initialize an immutable descriptor.
         /// </summary>
@@ -64,6 +70,7 @@ namespace OpenIddict.Server
             private ServiceDescriptor _descriptor;
             private readonly List<Type> _filterTypes = new List<Type>();
             private int _order;
+            private OpenIddictServerHandlerType _type;
 
             /// <summary>
             /// Adds the type of a handler filter to the filters list.
@@ -131,6 +138,23 @@ namespace OpenIddict.Server
                 return this;
             }
 
+            /// <summary>
+            /// Sets the type associated to the handler.
+            /// </summary>
+            /// <param name="type">The handler type.</param>
+            /// <returns>The builder instance, so that calls can be easily chained.</returns>
+            public Builder<TContext> SetType(OpenIddictServerHandlerType type)
+            {
+                if (!Enum.IsDefined(typeof(OpenIddictServerHandlerType), type))
+                {
+                    throw new InvalidEnumArgumentException(nameof(type), (int) type, typeof(OpenIddictServerHandlerType));
+                }
+
+                _type = type;
+
+                return this;
+            }
+
             /// <summary>
             /// Configures the descriptor to use the specified inline handler.
             /// </summary>
@@ -192,7 +216,8 @@ namespace OpenIddict.Server
                 ContextType = typeof(TContext),
                 FilterTypes = _filterTypes.ToImmutableArray(),
                 Order = _order,
-                ServiceDescriptor = _descriptor ?? throw new InvalidOperationException("No service descriptor was set.")
+                ServiceDescriptor = _descriptor ?? throw new InvalidOperationException("No service descriptor was set."),
+                Type = _type
             };
         }
     }

src/OpenIddict.Server/OpenIddictServerHandlerType.cs

@@ -0,0 +1,29 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+namespace OpenIddict.Server
+{
+    /// <summary>
+    /// Represents the type of an OpenIddict server handler.
+    /// </summary>
+    public enum OpenIddictServerHandlerType
+    {
+        /// <summary>
+        /// The handler is of an unspecified type.
+        /// </summary>
+        Unknown = 0,
+
+        /// <summary>
+        /// The handler is a built-in handler, provided as part of the official OpenIddict packages.
+        /// </summary>
+        BuiltIn = 1,
+
+        /// <summary>
+        /// The handler is a custom handler, registered by the end user or a third-party package.
+        /// </summary>
+        Custom = 2
+    }
+}

src/OpenIddict.Server/OpenIddictServerHandlers.Authentication.cs

@@ -69,10 +69,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractAuthorizationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractAuthorizationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractAuthorizationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -103,7 +103,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractAuthorizationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -144,10 +144,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateAuthorizationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateAuthorizationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateAuthorizationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -178,7 +178,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateAuthorizationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the redirect_uri without triggering a new validation process.
@@ -219,10 +219,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleAuthorizationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleAuthorizationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleAuthorizationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -253,7 +253,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleAuthorizationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -284,7 +284,7 @@ namespace OpenIddict.Server
                             Response = new OpenIddictResponse()
                         };
 
-                        await _provider.DispatchAsync(@event);
+                        await _dispatcher.DispatchAsync(@event);
 
                         if (@event.IsRequestHandled)
                         {
@@ -322,10 +322,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyAuthorizationResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyAuthorizationResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyAuthorizationResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -356,7 +356,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyAuthorizationResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.Device.cs

@@ -67,10 +67,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractDeviceRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractDeviceRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractDeviceRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -101,7 +101,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractDeviceRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -142,10 +142,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateDeviceRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateDeviceRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateDeviceRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -176,7 +176,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateDeviceRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -208,10 +208,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleDeviceRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleDeviceRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleDeviceRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -242,7 +242,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleDeviceRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -280,7 +280,7 @@ namespace OpenIddict.Server
                         @event.Principal = principal;
                     }
 
-                    await _provider.DispatchAsync(@event);
+                    await _dispatcher.DispatchAsync(@event);
 
                     if (@event.IsRequestHandled)
                     {
@@ -317,10 +317,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyDeviceResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyDeviceResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyDeviceResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -351,7 +351,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyDeviceResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -849,10 +849,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractVerificationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractVerificationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractVerificationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -883,7 +883,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractVerificationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -924,10 +924,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateVerificationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateVerificationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateVerificationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -958,7 +958,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateVerificationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -990,10 +990,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleVerificationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleVerificationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleVerificationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1024,7 +1024,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleVerificationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -1055,7 +1055,7 @@ namespace OpenIddict.Server
                             Response = new OpenIddictResponse()
                         };
 
-                        await _provider.DispatchAsync(@event);
+                        await _dispatcher.DispatchAsync(@event);
 
                         if (@event.IsRequestHandled)
                         {
@@ -1093,10 +1093,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyVerificationResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyVerificationResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyVerificationResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1127,7 +1127,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyVerificationResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -1154,10 +1154,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class AttachUserCodePrincipal : IOpenIddictServerHandler<HandleVerificationRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public AttachUserCodePrincipal([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public AttachUserCodePrincipal([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1192,7 +1192,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ProcessAuthenticationContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the authentication result without triggering a new authentication flow.

src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs

@@ -71,10 +71,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractConfigurationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractConfigurationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractConfigurationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -105,7 +105,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractConfigurationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -146,10 +146,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateConfigurationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateConfigurationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateConfigurationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -180,7 +180,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateConfigurationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -212,10 +212,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleConfigurationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleConfigurationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleConfigurationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -246,7 +246,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleConfigurationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -307,10 +307,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyConfigurationResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyConfigurationResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyConfigurationResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -341,7 +341,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyConfigurationResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -394,33 +394,33 @@ namespace OpenIddict.Server
                     // Note: while OpenIddict allows specifying multiple endpoint addresses, the OAuth 2.0
                     // and OpenID Connect discovery specifications only allow a single address per endpoint.
 
-                    context.AuthorizationEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.AuthorizationEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.AuthorizationEndpointUris.FirstOrDefault());
 
-                    context.CryptographyEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.CryptographyEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.CryptographyEndpointUris.FirstOrDefault());
 
-                    context.DeviceEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.DeviceEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.DeviceEndpointUris.FirstOrDefault());
 
-                    context.IntrospectionEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.IntrospectionEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.IntrospectionEndpointUris.FirstOrDefault());
 
-                    context.LogoutEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.LogoutEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.LogoutEndpointUris.FirstOrDefault());
 
-                    context.RevocationEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.RevocationEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.RevocationEndpointUris.FirstOrDefault());
 
-                    context.TokenEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.TokenEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.TokenEndpointUris.FirstOrDefault());
 
-                    context.UserinfoEndpoint ??= GetEndpointAbsoluteUrl(context.Issuer,
+                    context.UserinfoEndpoint ??= GetEndpointAbsoluteUri(context.Issuer,
                         context.Options.UserinfoEndpointUris.FirstOrDefault());
 
                     return default;
 
-                    static Uri GetEndpointAbsoluteUrl(Uri issuer, Uri endpoint)
+                    static Uri GetEndpointAbsoluteUri(Uri issuer, Uri endpoint)
                     {
                         // If the endpoint is disabled (i.e a null address is specified), return null.
                         if (endpoint == null)
@@ -863,10 +863,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractCryptographyRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractCryptographyRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractCryptographyRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -897,7 +897,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractCryptographyRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -938,10 +938,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateCryptographyRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateCryptographyRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateCryptographyRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -972,7 +972,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateCryptographyRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -1004,10 +1004,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleCryptographyRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleCryptographyRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleCryptographyRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1038,7 +1038,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleCryptographyRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -1142,10 +1142,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyCryptographyResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyCryptographyResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyCryptographyResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1176,7 +1176,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyCryptographyResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs

@@ -74,10 +74,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractTokenRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractTokenRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractTokenRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -108,7 +108,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractTokenRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -149,10 +149,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateTokenRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateTokenRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateTokenRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -183,7 +183,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateTokenRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the principal without triggering a new validation process.
@@ -219,10 +219,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleTokenRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleTokenRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleTokenRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -253,7 +253,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleTokenRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -284,7 +284,7 @@ namespace OpenIddict.Server
                             Response = new OpenIddictResponse()
                         };
 
-                        await _provider.DispatchAsync(@event);
+                        await _dispatcher.DispatchAsync(@event);
 
                         if (@event.IsRequestHandled)
                         {
@@ -322,10 +322,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyTokenResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyTokenResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyTokenResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -356,7 +356,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyTokenResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -1332,10 +1332,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateToken : IOpenIddictServerHandler<ValidateTokenRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateToken([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateToken([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -1368,7 +1368,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ProcessAuthenticationContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the authentication result without triggering a new authentication flow.

src/OpenIddict.Server/OpenIddictServerHandlers.Introspection.cs

@@ -68,10 +68,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractIntrospectionRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractIntrospectionRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractIntrospectionRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -102,7 +102,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractIntrospectionRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -143,10 +143,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateIntrospectionRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateIntrospectionRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateIntrospectionRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -177,7 +177,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateIntrospectionRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the principal without triggering a new validation process.
@@ -213,10 +213,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleIntrospectionRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleIntrospectionRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleIntrospectionRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -247,7 +247,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleIntrospectionRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -325,10 +325,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyIntrospectionResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyIntrospectionResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyIntrospectionResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -359,7 +359,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyIntrospectionResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -752,10 +752,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateToken : IOpenIddictServerHandler<ValidateIntrospectionRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateToken([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateToken([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -781,7 +781,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ProcessAuthenticationContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.Revocation.cs

@@ -60,10 +60,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractRevocationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractRevocationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractRevocationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -94,7 +94,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractRevocationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -135,10 +135,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateRevocationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateRevocationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateRevocationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -169,7 +169,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateRevocationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the principal without triggering a new validation process.
@@ -205,10 +205,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleRevocationRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleRevocationRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleRevocationRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -239,7 +239,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleRevocationRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -271,10 +271,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyRevocationResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyRevocationResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyRevocationResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -305,7 +305,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyRevocationResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -698,10 +698,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateToken : IOpenIddictServerHandler<ValidateRevocationRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateToken([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateToken([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -727,7 +727,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ProcessAuthenticationContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.Session.cs

@@ -49,10 +49,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractLogoutRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractLogoutRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractLogoutRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -83,7 +83,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractLogoutRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -124,10 +124,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateLogoutRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateLogoutRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateLogoutRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -158,7 +158,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateLogoutRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the redirect_uri without triggering a new validation process.
@@ -194,10 +194,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleLogoutRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleLogoutRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleLogoutRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -228,7 +228,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleLogoutRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -256,7 +256,7 @@ namespace OpenIddict.Server
                         Response = new OpenIddictResponse()
                     };
 
-                    await _provider.DispatchAsync(@event);
+                    await _dispatcher.DispatchAsync(@event);
 
                     if (@event.IsRequestHandled)
                     {
@@ -293,10 +293,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyLogoutResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyLogoutResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyLogoutResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -327,7 +327,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyLogoutResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.Userinfo.cs

@@ -50,10 +50,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ExtractUserinfoRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ExtractUserinfoRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ExtractUserinfoRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -84,7 +84,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ExtractUserinfoRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -125,10 +125,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateUserinfoRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateUserinfoRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateUserinfoRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -159,7 +159,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ValidateUserinfoRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     // Store the context object in the transaction so it can be later retrieved by handlers
                     // that want to access the principal without triggering a new validation process.
@@ -195,10 +195,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class HandleUserinfoRequest : IOpenIddictServerHandler<ProcessRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public HandleUserinfoRequest([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public HandleUserinfoRequest([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -229,7 +229,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new HandleUserinfoRequestContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -296,10 +296,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ApplyUserinfoResponse<TContext> : IOpenIddictServerHandler<TContext> where TContext : BaseRequestContext
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ApplyUserinfoResponse([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ApplyUserinfoResponse([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -330,7 +330,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ApplyUserinfoResponseContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {
@@ -400,10 +400,10 @@ namespace OpenIddict.Server
             /// </summary>
             public class ValidateToken : IOpenIddictServerHandler<ValidateUserinfoRequestContext>
             {
-                private readonly IOpenIddictServerProvider _provider;
+                private readonly IOpenIddictServerDispatcher _dispatcher;
 
-                public ValidateToken([NotNull] IOpenIddictServerProvider provider)
-                    => _provider = provider;
+                public ValidateToken([NotNull] IOpenIddictServerDispatcher dispatcher)
+                    => _dispatcher = dispatcher;
 
                 /// <summary>
                 /// Gets the default descriptor definition assigned to this handler.
@@ -429,7 +429,7 @@ namespace OpenIddict.Server
                     }
 
                     var notification = new ProcessAuthenticationContext(context.Transaction);
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled)
                     {

src/OpenIddict.Server/OpenIddictServerHandlers.cs

@@ -132,6 +132,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateAuthenticationDemand>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -190,6 +191,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateTokenParameter>()
                     .SetOrder(ValidateAuthenticationDemand.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -263,6 +265,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDegradedModeDisabled>()
                     .UseSingletonHandler<NormalizeUserCode>()
                     .SetOrder(ValidateTokenParameter.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -333,6 +336,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<ValidateReferenceTokenIdentifier>()
                     .SetOrder(NormalizeUserCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -411,6 +415,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateIdentityModelToken>()
                     .SetOrder(ValidateReferenceTokenIdentifier.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -521,6 +526,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<NormalizeScopeClaims>()
                     .SetOrder(ValidateIdentityModelToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -571,6 +577,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<MapInternalClaims>()
                     .SetOrder(NormalizeScopeClaims.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -695,6 +702,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<RestoreReferenceTokenProperties>()
                     .SetOrder(MapInternalClaims.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -743,6 +751,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidatePrincipal>()
                     .SetOrder(RestoreReferenceTokenProperties.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -850,6 +859,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<ValidateTokenEntry>()
                     .SetOrder(ValidatePrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -1051,6 +1061,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationStorageEnabled>()
                     .UseScopedHandler<ValidateAuthorizationEntry>()
                     .SetOrder(ValidateTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -1106,6 +1117,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateExpirationDate>()
                     .SetOrder(ValidateTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1174,6 +1186,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessChallengeContext>()
                     .UseSingletonHandler<ValidateChallengeDemand>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1215,6 +1228,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessChallengeContext>()
                     .UseSingletonHandler<AttachDefaultChallengeError>()
                     .SetOrder(ValidateChallengeDemand.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1283,6 +1297,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<RejectDeviceCodeEntry>()
                     .SetOrder(AttachDefaultChallengeError.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1351,6 +1366,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<RejectUserCodeEntry>()
                     .SetOrder(RejectDeviceCodeEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1404,6 +1420,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<ValidateSignInDemand>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1497,6 +1514,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<RestoreInternalClaims>()
                     .SetOrder(ValidateSignInDemand.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1567,6 +1585,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<AttachDefaultScopes>()
                     .SetOrder(RestoreInternalClaims.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1607,6 +1626,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<AttachDefaultPresenters>()
                     .SetOrder(AttachDefaultScopes.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1646,6 +1666,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<InferResources>()
                     .SetOrder(AttachDefaultPresenters.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1687,6 +1708,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<EvaluateReturnedTokens>()
                     .SetOrder(InferResources.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1809,6 +1831,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationStorageEnabled>()
                     .UseScopedHandler<AttachAuthorization>()
                     .SetOrder(EvaluateReturnedTokens.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -1900,6 +1923,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAccessTokenIncluded>()
                     .UseSingletonHandler<PrepareAccessTokenPrincipal>()
                     .SetOrder(AttachAuthorization.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2023,6 +2047,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationCodeIncluded>()
                     .UseSingletonHandler<PrepareAuthorizationCodePrincipal>()
                     .SetOrder(PrepareAccessTokenPrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2112,6 +2137,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignInContext>()
                     .UseSingletonHandler<PrepareDeviceCodePrincipal>()
                     .SetOrder(PrepareAuthorizationCodePrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2196,6 +2222,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRefreshTokenIncluded>()
                     .UseSingletonHandler<PrepareRefreshTokenPrincipal>()
                     .SetOrder(PrepareDeviceCodePrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2281,6 +2308,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireIdentityTokenIncluded>()
                     .UseSingletonHandler<PrepareIdentityTokenPrincipal>()
                     .SetOrder(PrepareRefreshTokenPrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2398,6 +2426,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseSingletonHandler<PrepareUserCodePrincipal>()
                     .SetOrder(PrepareIdentityTokenPrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2486,6 +2515,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireTokenStorageEnabled>()
                     .UseScopedHandler<RedeemTokenEntry>()
                     .SetOrder(100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2588,6 +2618,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRollingTokensEnabled>()
                     .UseScopedHandler<RevokeExistingTokenEntries>()
                     .SetOrder(RedeemTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2664,6 +2695,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRollingTokensDisabled>()
                     .UseScopedHandler<ExtendRefreshTokenEntry>()
                     .SetOrder(RevokeExistingTokenEntries.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2748,6 +2780,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAccessTokenIncluded>()
                     .UseScopedHandler<CreateAccessTokenEntry>()
                     .SetOrder(ExtendRefreshTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2821,6 +2854,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAccessTokenIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelAccessToken>()
                     .SetOrder(CreateAccessTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -2950,6 +2984,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAccessTokenIncluded>()
                     .UseScopedHandler<ConvertReferenceAccessToken>()
                     .SetOrder(GenerateIdentityModelAccessToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3050,6 +3085,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationCodeIncluded>()
                     .UseScopedHandler<CreateAuthorizationCodeEntry>()
                     .SetOrder(ConvertReferenceAccessToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3123,6 +3159,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationCodeIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelAuthorizationCode>()
                     .SetOrder(CreateAuthorizationCodeEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3233,6 +3270,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAuthorizationCodeIncluded>()
                     .UseScopedHandler<ConvertReferenceAuthorizationCode>()
                     .SetOrder(GenerateIdentityModelAuthorizationCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3333,6 +3371,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDeviceCodeIncluded>()
                     .UseScopedHandler<CreateDeviceCodeEntry>()
                     .SetOrder(ConvertReferenceAuthorizationCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3411,6 +3450,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDeviceCodeIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelDeviceCode>()
                     .SetOrder(CreateDeviceCodeEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3521,6 +3561,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDeviceCodeIncluded>()
                     .UseScopedHandler<ConvertReferenceDeviceCode>()
                     .SetOrder(GenerateIdentityModelDeviceCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3620,6 +3661,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDeviceCodeIncluded>()
                     .UseScopedHandler<UpdateReferenceDeviceCodeEntry>()
                     .SetOrder(ConvertReferenceDeviceCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3722,6 +3764,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRefreshTokenIncluded>()
                     .UseScopedHandler<CreateRefreshTokenEntry>()
                     .SetOrder(UpdateReferenceDeviceCodeEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3795,6 +3838,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRefreshTokenIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelRefreshToken>()
                     .SetOrder(CreateRefreshTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3905,6 +3949,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireRefreshTokenIncluded>()
                     .UseScopedHandler<ConvertReferenceRefreshToken>()
                     .SetOrder(GenerateIdentityModelRefreshToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -3984,6 +4029,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseSingletonHandler<AttachDeviceCodeIdentifier>()
                     .SetOrder(ConvertReferenceRefreshToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4051,6 +4097,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseScopedHandler<CreateUserCodeEntry>()
                     .SetOrder(AttachDeviceCodeIdentifier.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4124,6 +4171,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelUserCode>()
                     .SetOrder(CreateUserCodeEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4224,6 +4272,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseScopedHandler<ConvertReferenceUserCode>()
                     .SetOrder(GenerateIdentityModelUserCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4315,6 +4364,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireIdentityTokenIncluded>()
                     .UseSingletonHandler<AttachTokenDigests>()
                     .SetOrder(ConvertReferenceUserCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4468,6 +4518,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireIdentityTokenIncluded>()
                     .UseScopedHandler<CreateIdentityTokenEntry>()
                     .SetOrder(AttachTokenDigests.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4541,6 +4592,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireIdentityTokenIncluded>()
                     .UseSingletonHandler<GenerateIdentityModelIdentityToken>()
                     .SetOrder(CreateIdentityTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4639,6 +4691,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireUserCodeIncluded>()
                     .UseSingletonHandler<BeautifyUserCode>()
                     .SetOrder(GenerateIdentityModelIdentityToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4692,6 +4745,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireAccessTokenIncluded>()
                     .UseSingletonHandler<AttachAccessTokenProperties>()
                     .SetOrder(BeautifyUserCode.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4743,6 +4797,7 @@ namespace OpenIddict.Server
                     .AddFilter<RequireDeviceCodeIncluded>()
                     .UseSingletonHandler<AttachDeviceCodeProperties>()
                     .SetOrder(AttachAccessTokenProperties.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -4759,7 +4814,7 @@ namespace OpenIddict.Server
                     throw new ArgumentNullException(nameof(context));
                 }
 
-                var address = GetEndpointAbsoluteUrl(context.Issuer, context.Options.VerificationEndpointUris.FirstOrDefault());
+                var address = GetEndpointAbsoluteUri(context.Issuer, context.Options.VerificationEndpointUris.FirstOrDefault());
                 if (address != null)
                 {
                     var builder = new UriBuilder(address)
@@ -4780,7 +4835,7 @@ namespace OpenIddict.Server
 
                 return default;
 
-                static Uri GetEndpointAbsoluteUrl(Uri issuer, Uri endpoint)
+                static Uri GetEndpointAbsoluteUri(Uri issuer, Uri endpoint)
                 {
                     // If the endpoint is disabled (i.e a null address is specified), return null.
                     if (endpoint == null)
@@ -4832,6 +4887,7 @@ namespace OpenIddict.Server
                 = OpenIddictServerHandlerDescriptor.CreateBuilder<ProcessSignOutContext>()
                     .UseSingletonHandler<ValidateSignOutDemand>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictServerHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Server/OpenIddictServerOptions.cs

@@ -31,7 +31,7 @@ namespace OpenIddict.Server
         /// OpenIddict server services. Note: the encryption credentials are not
         /// used to protect/unprotect tokens issued by ASP.NET Core Data Protection.
         /// </summary>
-        public IList<EncryptingCredentials> EncryptionCredentials { get; } = new List<EncryptingCredentials>();
+        public List<EncryptingCredentials> EncryptionCredentials { get; } = new List<EncryptingCredentials>();
 
         /// <summary>
         /// Gets the list of credentials used to sign the tokens issued by the OpenIddict server services.
@@ -39,17 +39,17 @@ namespace OpenIddict.Server
         /// Note that only asymmetric RSA and ECDSA keys can be exposed by the JWKS metadata endpoint and that the
         /// signing credentials are not used to protect/unprotect tokens issued by ASP.NET Core Data Protection.
         /// </summary>
-        public IList<SigningCredentials> SigningCredentials { get; } = new List<SigningCredentials>();
+        public List<SigningCredentials> SigningCredentials { get; } = new List<SigningCredentials>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the authorization endpoint.
         /// </summary>
-        public IList<Uri> AuthorizationEndpointUris { get; } = new List<Uri>();
+        public List<Uri> AuthorizationEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the configuration endpoint.
         /// </summary>
-        public IList<Uri> ConfigurationEndpointUris { get; } = new List<Uri>
+        public List<Uri> ConfigurationEndpointUris { get; } = new List<Uri>
         {
             new Uri("/.well-known/openid-configuration", UriKind.Relative),
             new Uri("/.well-known/oauth-authorization-server", UriKind.Relative)
@@ -58,7 +58,7 @@ namespace OpenIddict.Server
         /// <summary>
         /// Gets the absolute and relative URIs associated to the cryptography endpoint.
         /// </summary>
-        public IList<Uri> CryptographyEndpointUris { get; } = new List<Uri>
+        public List<Uri> CryptographyEndpointUris { get; } = new List<Uri>
         {
             new Uri("/.well-known/jwks", UriKind.Relative)
         };
@@ -66,37 +66,37 @@ namespace OpenIddict.Server
         /// <summary>
         /// Gets the absolute and relative URIs associated to the device endpoint.
         /// </summary>
-        public IList<Uri> DeviceEndpointUris { get; } = new List<Uri>();
+        public List<Uri> DeviceEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the introspection endpoint.
         /// </summary>
-        public IList<Uri> IntrospectionEndpointUris { get; } = new List<Uri>();
+        public List<Uri> IntrospectionEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the logout endpoint.
         /// </summary>
-        public IList<Uri> LogoutEndpointUris { get; } = new List<Uri>();
+        public List<Uri> LogoutEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the revocation endpoint.
         /// </summary>
-        public IList<Uri> RevocationEndpointUris { get; } = new List<Uri>();
+        public List<Uri> RevocationEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the token endpoint.
         /// </summary>
-        public IList<Uri> TokenEndpointUris { get; } = new List<Uri>();
+        public List<Uri> TokenEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the userinfo endpoint.
         /// </summary>
-        public IList<Uri> UserinfoEndpointUris { get; } = new List<Uri>();
+        public List<Uri> UserinfoEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets the absolute and relative URIs associated to the verification endpoint.
         /// </summary>
-        public IList<Uri> VerificationEndpointUris { get; } = new List<Uri>();
+        public List<Uri> VerificationEndpointUris { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets or sets the JWT handler used to protect and unprotect tokens.
@@ -215,16 +215,11 @@ namespace OpenIddict.Server
         public bool EnableDegradedMode { get; set; }
 
         /// <summary>
-        /// Gets the list of the user-defined/custom handlers responsible of processing the OpenIddict server requests.
-        /// Note: the handlers added to this list must be also registered in the DI container using an appropriate lifetime.
+        /// Gets the list of the handlers responsible of processing the OpenIddict server operations.
+        /// Note: the list is automatically sorted based on the order assigned to each handler descriptor.
+        /// As such, it MUST NOT be mutated after options initialization to preserve the exact order.
         /// </summary>
-        public IList<OpenIddictServerHandlerDescriptor> CustomHandlers { get; } =
-            new List<OpenIddictServerHandlerDescriptor>();
-
-        /// <summary>
-        /// Gets the list of the built-in handlers responsible of processing the OpenIddict server requests
-        /// </summary>
-        public IList<OpenIddictServerHandlerDescriptor> DefaultHandlers { get; } =
+        public List<OpenIddictServerHandlerDescriptor> Handlers { get; } =
             new List<OpenIddictServerHandlerDescriptor>(OpenIddictServerHandlers.DefaultHandlers);
 
         /// <summary>
@@ -244,7 +239,7 @@ namespace OpenIddict.Server
         /// <summary>
         /// Gets the OAuth 2.0/OpenID Connect claims supported by this application.
         /// </summary>
-        public ISet<string> Claims { get; } = new HashSet<string>(StringComparer.Ordinal)
+        public HashSet<string> Claims { get; } = new HashSet<string>(StringComparer.Ordinal)
         {
             OpenIddictConstants.Claims.Audience,
             OpenIddictConstants.Claims.ExpiresAt,
@@ -286,12 +281,12 @@ namespace OpenIddict.Server
         /// Gets the OAuth 2.0 code challenge methods enabled for this application.
         /// By default, only the S256 method is allowed (if the code flow is enabled).
         /// </summary>
-        public ISet<string> CodeChallengeMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> CodeChallengeMethods { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets the OAuth 2.0/OpenID Connect flows enabled for this application.
         /// </summary>
-        public ISet<string> GrantTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> GrantTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets the OAuth 2.0/OpenID Connect response types enabled for this application.
@@ -299,7 +294,7 @@ namespace OpenIddict.Server
         /// but additional values can be added for advanced scenarios (e.g custom type support).
         /// </summary>
         [EditorBrowsable(EditorBrowsableState.Advanced)]
-        public ISet<string> ResponseTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> ResponseTypes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets the OAuth 2.0/OpenID Connect response modes enabled for this application.
@@ -307,7 +302,7 @@ namespace OpenIddict.Server
         /// but additional values can be added for advanced scenarios (e.g custom mode support).
         /// </summary>
         [EditorBrowsable(EditorBrowsableState.Advanced)]
-        public ISet<string> ResponseModes { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> ResponseModes { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets or sets a boolean indicating whether endpoint permissions should be ignored.
@@ -333,7 +328,7 @@ namespace OpenIddict.Server
         /// <summary>
         /// Gets the OAuth 2.0/OpenID Connect scopes enabled for this application.
         /// </summary>
-        public ISet<string> Scopes { get; } = new HashSet<string>(StringComparer.Ordinal)
+        public HashSet<string> Scopes { get; } = new HashSet<string>(StringComparer.Ordinal)
         {
             OpenIddictConstants.Scopes.OpenId
         };

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreConfiguration.cs

@@ -52,10 +52,7 @@ namespace OpenIddict.Validation.AspNetCore
             }
 
             // Register the built-in event handlers used by the OpenIddict ASP.NET Core validation components.
-            foreach (var handler in OpenIddictValidationAspNetCoreHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictValidationAspNetCoreHandlers.DefaultHandlers);
         }
 
         /// <summary>

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreHandler.cs

@@ -26,19 +26,24 @@ namespace OpenIddict.Validation.AspNetCore
     public class OpenIddictValidationAspNetCoreHandler : AuthenticationHandler<OpenIddictValidationAspNetCoreOptions>,
         IAuthenticationRequestHandler
     {
-        private readonly IOpenIddictValidationProvider _provider;
+        private readonly IOpenIddictValidationDispatcher _dispatcher;
+        private readonly IOpenIddictValidationFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictValidationAspNetCoreHandler"/> class.
         /// </summary>
         public OpenIddictValidationAspNetCoreHandler(
-            [NotNull] IOpenIddictValidationProvider provider,
+            [NotNull] IOpenIddictValidationDispatcher dispatcher,
+            [NotNull] IOpenIddictValidationFactory factory,
             [NotNull] IOptionsMonitor<OpenIddictValidationAspNetCoreOptions> options,
             [NotNull] ILoggerFactory logger,
             [NotNull] UrlEncoder encoder,
             [NotNull] ISystemClock clock)
             : base(options, logger, encoder, clock)
-            => _provider = provider;
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         public async Task<bool> HandleRequestAsync()
         {
@@ -48,7 +53,7 @@ namespace OpenIddict.Validation.AspNetCore
             if (transaction == null)
             {
                 // Create a new transaction and attach the HTTP request to make it available to the ASP.NET Core handlers.
-                transaction = await _provider.CreateTransactionAsync();
+                transaction = await _factory.CreateTransactionAsync();
                 transaction.Properties[typeof(HttpRequest).FullName] = new WeakReference<HttpRequest>(Request);
 
                 // Attach the OpenIddict validation transaction to the ASP.NET Core features
@@ -57,7 +62,7 @@ namespace OpenIddict.Validation.AspNetCore
             }
 
             var context = new ProcessRequestContext(transaction);
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled)
             {
@@ -81,7 +86,7 @@ namespace OpenIddict.Validation.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled)
                 {
@@ -115,7 +120,7 @@ namespace OpenIddict.Validation.AspNetCore
             if (context == null)
             {
                 context = new ProcessAuthenticationContext(transaction);
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 // Store the context object in the transaction so it can be later retrieved by handlers
                 // that want to access the authentication result without triggering a new authentication flow.
@@ -179,7 +184,7 @@ namespace OpenIddict.Validation.AspNetCore
                 Response = new OpenIddictResponse()
             };
 
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             if (context.IsRequestHandled || context.IsRequestSkipped)
             {
@@ -198,7 +203,7 @@ namespace OpenIddict.Validation.AspNetCore
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled || context.IsRequestSkipped)
                 {

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreHandlers.cs

@@ -74,6 +74,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<InferIssuerFromHost>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -144,6 +145,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractGetOrPostRequest>()
                     .SetOrder(InferIssuerFromHost.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -200,6 +202,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ExtractAccessToken>()
                     .SetOrder(ExtractGetOrPostRequest.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -251,6 +254,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachHostChallengeError>()
                     .SetOrder(int.MinValue + 50_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -294,6 +298,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachHttpResponseCode<TContext>>()
                     .SetOrder(AttachCacheControlHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -349,6 +354,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachCacheControlHeader<TContext>>()
                     .SetOrder(AttachWwwAuthenticateHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -401,6 +407,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<AttachWwwAuthenticateHeader<TContext>>()
                     .SetOrder(ProcessChallengeErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -509,6 +516,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessChallengeErrorResponse<TContext>>()
                     .SetOrder(ProcessJsonResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -560,6 +568,7 @@ namespace OpenIddict.Validation.AspNetCore
                     .AddFilter<RequireHttpRequest>()
                     .UseSingletonHandler<ProcessJsonResponse<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionConfiguration.cs

@@ -35,10 +35,7 @@ namespace OpenIddict.Validation.DataProtection
             }
 
             // Register the built-in event handlers used by the OpenIddict Data Protection validation components.
-            foreach (var handler in OpenIddictValidationDataProtectionHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictValidationDataProtectionHandlers.DefaultHandlers);
         }
 
         /// <summary>

src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionHandlers.cs

@@ -50,6 +50,7 @@ namespace OpenIddict.Validation.DataProtection
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateDataProtectionToken>()
                     .SetOrder(ValidateIdentityModelToken.Descriptor.Order + 500)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinConfiguration.cs

@@ -23,10 +23,7 @@ namespace OpenIddict.Validation.Owin
             }
 
             // Register the built-in event handlers used by the OpenIddict OWIN validation components.
-            foreach (var handler in OpenIddictValidationOwinHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictValidationOwinHandlers.DefaultHandlers);
         }
     }
 }

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinHandler.cs

@@ -24,14 +24,21 @@ namespace OpenIddict.Validation.Owin
     /// </summary>
     public class OpenIddictValidationOwinHandler : AuthenticationHandler<OpenIddictValidationOwinOptions>
     {
-        private readonly IOpenIddictValidationProvider _provider;
+        private readonly IOpenIddictValidationDispatcher _dispatcher;
+        private readonly IOpenIddictValidationFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictValidationOwinHandler"/> class.
         /// </summary>
-        /// <param name="provider">The OpenIddict validation OWIN provider used by this instance.</param>
-        public OpenIddictValidationOwinHandler([NotNull] IOpenIddictValidationProvider provider)
-            => _provider = provider;
+        /// <param name="dispatcher">The OpenIddict validation provider used by this instance.</param>
+        /// <param name="factory">The OpenIddict validation factory used by this instance.</param>
+        public OpenIddictValidationOwinHandler(
+            [NotNull] IOpenIddictValidationDispatcher dispatcher,
+            [NotNull] IOpenIddictValidationFactory factory)
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         protected override async Task InitializeCoreAsync()
         {
@@ -41,7 +48,7 @@ namespace OpenIddict.Validation.Owin
             if (transaction == null)
             {
                 // Create a new transaction and attach the OWIN request to make it available to the OWIN handlers.
-                transaction = await _provider.CreateTransactionAsync();
+                transaction = await _factory.CreateTransactionAsync();
                 transaction.Properties[typeof(IOwinRequest).FullName] = new WeakReference<IOwinRequest>(Request);
 
                 // Attach the OpenIddict validation transaction to the OWIN shared dictionary
@@ -50,7 +57,7 @@ namespace OpenIddict.Validation.Owin
             }
 
             var context = new ProcessRequestContext(transaction);
-            await _provider.DispatchAsync(context);
+            await _dispatcher.DispatchAsync(context);
 
             // Store the context in the transaction so that it can be retrieved from InvokeAsync().
             transaction.SetProperty(typeof(ProcessRequestContext).FullName, context);
@@ -90,7 +97,7 @@ namespace OpenIddict.Validation.Owin
                     }
                 };
 
-                await _provider.DispatchAsync(notification);
+                await _dispatcher.DispatchAsync(notification);
 
                 if (notification.IsRequestHandled)
                 {
@@ -124,7 +131,7 @@ namespace OpenIddict.Validation.Owin
             if (context == null)
             {
                 context = new ProcessAuthenticationContext(transaction);
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 // Store the context object in the transaction so it can be later retrieved by handlers
                 // that want to access the authentication result without triggering a new authentication flow.
@@ -199,7 +206,7 @@ namespace OpenIddict.Validation.Owin
                     Response = new OpenIddictResponse()
                 };
 
-                await _provider.DispatchAsync(context);
+                await _dispatcher.DispatchAsync(context);
 
                 if (context.IsRequestHandled || context.IsRequestSkipped)
                 {
@@ -218,7 +225,7 @@ namespace OpenIddict.Validation.Owin
                         }
                     };
 
-                    await _provider.DispatchAsync(notification);
+                    await _dispatcher.DispatchAsync(notification);
 
                     if (notification.IsRequestHandled || context.IsRequestSkipped)
                     {

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinHandlers.cs

@@ -71,6 +71,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<InferIssuerFromHost>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -141,6 +142,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractGetOrPostRequest>()
                     .SetOrder(InferIssuerFromHost.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -198,6 +200,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ExtractAccessToken>()
                     .SetOrder(ExtractGetOrPostRequest.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -249,6 +252,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachHostChallengeError>()
                     .SetOrder(int.MinValue + 50_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -295,6 +299,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachHttpResponseCode<TContext>>()
                     .SetOrder(AttachCacheControlHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -350,6 +355,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachCacheControlHeader<TContext>>()
                     .SetOrder(AttachWwwAuthenticateHeader<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -402,6 +408,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<AttachWwwAuthenticateHeader<TContext>>()
                     .SetOrder(ProcessChallengeErrorResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -515,6 +522,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessChallengeErrorResponse<TContext>>()
                     .SetOrder(ProcessJsonResponse<TContext>.Descriptor.Order - 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -566,6 +574,7 @@ namespace OpenIddict.Validation.Owin
                     .AddFilter<RequireOwinRequest>()
                     .UseSingletonHandler<ProcessJsonResponse<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinMiddleware.cs

@@ -19,26 +19,32 @@ namespace OpenIddict.Validation.Owin
     /// </summary>
     public class OpenIddictValidationOwinMiddleware : AuthenticationMiddleware<OpenIddictValidationOwinOptions>
     {
-        private readonly IOpenIddictValidationProvider _provider;
+        private readonly IOpenIddictValidationDispatcher _dispatcher;
+        private readonly IOpenIddictValidationFactory _factory;
 
         /// <summary>
         /// Creates a new instance of the <see cref="OpenIddictValidationOwinMiddleware"/> class.
         /// </summary>
         /// <param name="next">The next middleware in the pipeline, if applicable.</param>
         /// <param name="options">The OpenIddict validation OWIN options.</param>
-        /// <param name="provider">The OpenIddict validation provider.</param>
+        /// <param name="dispatcher">The OpenIddict validation dispatcher.</param>
+        /// <param name="factory">The OpenIddict validation factory.</param>
         public OpenIddictValidationOwinMiddleware(
             [CanBeNull] OwinMiddleware next,
             [NotNull] IOptionsMonitor<OpenIddictValidationOwinOptions> options,
-            [NotNull] IOpenIddictValidationProvider provider)
+            [NotNull] IOpenIddictValidationDispatcher dispatcher,
+            [NotNull] IOpenIddictValidationFactory factory)
             : base(next, options.CurrentValue)
-            => _provider = provider;
+        {
+            _dispatcher = dispatcher;
+            _factory = factory;
+        }
 
         /// <summary>
         /// Creates and returns a new <see cref="OpenIddictValidationOwinHandler"/> instance.
         /// </summary>
         /// <returns>A new instance of the <see cref="OpenIddictValidationOwinHandler"/> class.</returns>
         protected override AuthenticationHandler<OpenIddictValidationOwinOptions> CreateHandler()
-            => new OpenIddictValidationOwinHandler(_provider);
+            => new OpenIddictValidationOwinHandler(_dispatcher, _factory);
     }
 }

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinMiddlewareFactory.cs

@@ -64,13 +64,14 @@ namespace OpenIddict.Validation.Owin
             var middleware = new OpenIddictValidationOwinMiddleware(
                 next: Next,
                 options: GetRequiredService<IOptionsMonitor<OpenIddictValidationOwinOptions>>(provider),
-                provider: GetRequiredService<IOpenIddictValidationProvider>(provider));
+                dispatcher: GetRequiredService<IOpenIddictValidationDispatcher>(provider),
+                factory: GetRequiredService<IOpenIddictValidationFactory>(provider));
 
             return middleware.Invoke(context);
 
             static T GetRequiredService<T>(IServiceProvider provider)
                 => provider.GetService<T>() ?? throw new InvalidOperationException(new StringBuilder()
-                    .AppendLine("The OpenIddict validation authentication services cannot be resolved from the DI container.")
+                    .AppendLine("The OpenIddict validation services cannot be resolved from the DI container.")
                     .Append("To register the OWIN services, use 'services.AddOpenIddict().AddValidation().UseOwin()'.")
                     .ToString());
         }

src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpConfiguration.cs

@@ -35,10 +35,7 @@ namespace OpenIddict.Validation.SystemNetHttp
             }
 
             // Register the built-in event handlers used by the OpenIddict System.Net.Http validation components.
-            foreach (var handler in OpenIddictValidationSystemNetHttpHandlers.DefaultHandlers)
-            {
-                options.DefaultHandlers.Add(handler);
-            }
+            options.Handlers.AddRange(OpenIddictValidationSystemNetHttpHandlers.DefaultHandlers);
         }
 
         public void Configure([NotNull] HttpClientFactoryOptions options)

src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpHandlers.cs

@@ -41,6 +41,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<PrepareGetHttpRequest<TContext>>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public ValueTask HandleAsync([NotNull] TContext context)
@@ -74,6 +75,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<PreparePostHttpRequest<TContext>>()
                     .SetOrder(PrepareGetHttpRequest<TContext>.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public ValueTask HandleAsync([NotNull] TContext context)
@@ -107,6 +109,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<AttachQueryStringParameters<TContext>>()
                     .SetOrder(AttachFormParameters<TContext>.Descriptor.Order - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] TContext context)
@@ -156,6 +159,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<AttachFormParameters<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public ValueTask HandleAsync([NotNull] TContext context)
@@ -202,6 +206,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<SendHttpRequest<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] TContext context)
@@ -250,6 +255,7 @@ namespace OpenIddict.Validation.SystemNetHttp
                     .AddFilter<RequireHttpMetadataAddress>()
                     .UseSingletonHandler<ExtractJsonHttpResponse<TContext>>()
                     .SetOrder(int.MaxValue - 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] TContext context)

src/OpenIddict.Validation/IOpenIddictValidationProvider.cs → src/OpenIddict.Validation/IOpenIddictValidationDispatcher.cs

@@ -10,9 +10,8 @@ using static OpenIddict.Validation.OpenIddictValidationEvents;
 
 namespace OpenIddict.Validation
 {
-    public interface IOpenIddictValidationProvider
+    public interface IOpenIddictValidationDispatcher
     {
-        ValueTask<OpenIddictValidationTransaction> CreateTransactionAsync();
         ValueTask DispatchAsync<TContext>([NotNull] TContext context) where TContext : BaseContext;
     }
 }

src/OpenIddict.Validation/IOpenIddictValidationFactory.cs

@@ -0,0 +1,15 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+using System.Threading.Tasks;
+
+namespace OpenIddict.Validation
+{
+    public interface IOpenIddictValidationFactory
+    {
+        ValueTask<OpenIddictValidationTransaction> CreateTransactionAsync();
+    }
+}

src/OpenIddict.Validation/OpenIddictValidationBuilder.cs

@@ -55,7 +55,10 @@ namespace Microsoft.Extensions.DependencyInjection
                 throw new ArgumentNullException(nameof(configuration));
             }
 
-            var builder = OpenIddictValidationHandlerDescriptor.CreateBuilder<TContext>();
+            // Note: handlers registered using this API are assumed to be custom handlers by default.
+            var builder = OpenIddictValidationHandlerDescriptor.CreateBuilder<TContext>()
+                .SetType(OpenIddictValidationHandlerType.Custom);
+
             configuration(builder);
 
             return AddEventHandler(builder.Build());
@@ -77,7 +80,7 @@ namespace Microsoft.Extensions.DependencyInjection
             // Register the handler in the services collection.
             Services.Add(descriptor.ServiceDescriptor);
 
-            return Configure(options => options.CustomHandlers.Add(descriptor));
+            return Configure(options => options.Handlers.Add(descriptor));
         }
 
         /// <summary>
@@ -97,19 +100,11 @@ namespace Microsoft.Extensions.DependencyInjection
 
             Services.PostConfigure<OpenIddictValidationOptions>(options =>
             {
-                for (var index = options.CustomHandlers.Count - 1; index >= 0; index--)
-                {
-                    if (options.CustomHandlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
-                    {
-                        options.CustomHandlers.RemoveAt(index);
-                    }
-                }
-
-                for (var index = options.DefaultHandlers.Count - 1; index >= 0; index--)
+                for (var index = options.Handlers.Count - 1; index >= 0; index--)
                 {
-                    if (options.DefaultHandlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
+                    if (options.Handlers[index].ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType)
                     {
-                        options.DefaultHandlers.RemoveAt(index);
+                        options.Handlers.RemoveAt(index);
                     }
                 }
             });

src/OpenIddict.Validation/OpenIddictValidationConfiguration.cs

@@ -60,7 +60,7 @@ namespace OpenIddict.Validation
 
             if (options.ValidationType == OpenIddictValidationType.Introspection)
             {
-                if (!options.DefaultHandlers.Any(descriptor => descriptor.ContextType == typeof(ApplyIntrospectionRequestContext)))
+                if (!options.Handlers.Any(descriptor => descriptor.ContextType == typeof(ApplyIntrospectionRequestContext)))
                 {
                     throw new InvalidOperationException(new StringBuilder()
                         .AppendLine("An introspection client must be registered when using introspection.")
@@ -98,8 +98,8 @@ namespace OpenIddict.Validation
 
             if (options.Configuration == null && options.ConfigurationManager == null)
             {
-                if (!options.DefaultHandlers.Any(descriptor => descriptor.ContextType == typeof(ApplyConfigurationRequestContext)) ||
-                    !options.DefaultHandlers.Any(descriptor => descriptor.ContextType == typeof(ApplyCryptographyRequestContext)))
+                if (!options.Handlers.Any(descriptor => descriptor.ContextType == typeof(ApplyConfigurationRequestContext)) ||
+                    !options.Handlers.Any(descriptor => descriptor.ContextType == typeof(ApplyCryptographyRequestContext)))
                 {
                     throw new InvalidOperationException(new StringBuilder()
                         .AppendLine("A discovery client must be registered when using server discovery.")
@@ -159,6 +159,9 @@ namespace OpenIddict.Validation
                 }
             }
 
+            // Sort the handlers collection using the order associated with each handler.
+            options.Handlers.Sort((left, right) => left.Order.CompareTo(right.Order));
+
             // Attach the encryption credentials to the token validation parameters.
             options.TokenValidationParameters.TokenDecryptionKeys =
                 from credentials in options.EncryptionCredentials

src/OpenIddict.Validation/OpenIddictValidationProvider.cs → src/OpenIddict.Validation/OpenIddictValidationDispatcher.cs

@@ -15,17 +15,17 @@ using static OpenIddict.Validation.OpenIddictValidationEvents;
 
 namespace OpenIddict.Validation
 {
-    public class OpenIddictValidationProvider : IOpenIddictValidationProvider
+    public class OpenIddictValidationDispatcher : IOpenIddictValidationDispatcher
     {
-        private readonly ILogger<OpenIddictValidationProvider> _logger;
+        private readonly ILogger<OpenIddictValidationDispatcher> _logger;
         private readonly IOptionsMonitor<OpenIddictValidationOptions> _options;
         private readonly IServiceProvider _provider;
 
         /// <summary>
-        /// Creates a new instance of the <see cref="OpenIddictValidationProvider"/> class.
+        /// Creates a new instance of the <see cref="OpenIddictValidationDispatcher"/> class.
         /// </summary>
-        public OpenIddictValidationProvider(
-            [NotNull] ILogger<OpenIddictValidationProvider> logger,
+        public OpenIddictValidationDispatcher(
+            [NotNull] ILogger<OpenIddictValidationDispatcher> logger,
             [NotNull] IOptionsMonitor<OpenIddictValidationOptions> options,
             [NotNull] IServiceProvider provider)
         {
@@ -34,14 +34,6 @@ namespace OpenIddict.Validation
             _provider = provider;
         }
 
-        public ValueTask<OpenIddictValidationTransaction> CreateTransactionAsync()
-            => new ValueTask<OpenIddictValidationTransaction>(new OpenIddictValidationTransaction
-            {
-                Issuer = _options.CurrentValue.Issuer,
-                Logger = _logger,
-                Options = _options.CurrentValue
-            });
-
         public async ValueTask DispatchAsync<TContext>([NotNull] TContext context) where TContext : BaseContext
         {
             if (context == null)
@@ -82,14 +74,12 @@ namespace OpenIddict.Validation
 
             async IAsyncEnumerable<IOpenIddictValidationHandler<TContext>> GetHandlersAsync()
             {
-                var descriptors = new List<OpenIddictValidationHandlerDescriptor>(
-                    capacity: _options.CurrentValue.CustomHandlers.Count +
-                              _options.CurrentValue.DefaultHandlers.Count);
-
-                descriptors.AddRange(_options.CurrentValue.CustomHandlers);
-                descriptors.AddRange(_options.CurrentValue.DefaultHandlers);
-
-                descriptors.Sort((left, right) => left.Order.CompareTo(right.Order));
+                // Note: the descriptors collection is sorted during options initialization for performance reasons.
+                var descriptors = _options.CurrentValue.Handlers;
+                if (descriptors.Count == 0)
+                {
+                    yield break;
+                }
 
                 for (var index = 0; index < descriptors.Count; index++)
                 {

src/OpenIddict.Validation/OpenIddictValidationExtensions.cs

@@ -37,7 +37,8 @@ namespace Microsoft.Extensions.DependencyInjection
             builder.Services.AddOptions();
 
             builder.Services.TryAddSingleton<OpenIddictValidationService>();
-            builder.Services.TryAddScoped<IOpenIddictValidationProvider, OpenIddictValidationProvider>();
+            builder.Services.TryAddScoped<IOpenIddictValidationDispatcher, OpenIddictValidationDispatcher>();
+            builder.Services.TryAddScoped<IOpenIddictValidationFactory, OpenIddictValidationFactory>();
 
             // Register the built-in validation event handlers used by the OpenIddict validation components.
             // Note: the order used here is not important, as the actual order is set in the options.

src/OpenIddict.Validation/OpenIddictValidationFactory.cs

@@ -0,0 +1,38 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace OpenIddict.Validation
+{
+    public class OpenIddictValidationFactory : IOpenIddictValidationFactory
+    {
+        private readonly ILogger<OpenIddictValidationDispatcher> _logger;
+        private readonly IOptionsMonitor<OpenIddictValidationOptions> _options;
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="OpenIddictValidationFactory"/> class.
+        /// </summary>
+        public OpenIddictValidationFactory(
+            [NotNull] ILogger<OpenIddictValidationDispatcher> logger,
+            [NotNull] IOptionsMonitor<OpenIddictValidationOptions> options)
+        {
+            _logger = logger;
+            _options = options;
+        }
+
+        public ValueTask<OpenIddictValidationTransaction> CreateTransactionAsync()
+            => new ValueTask<OpenIddictValidationTransaction>(new OpenIddictValidationTransaction
+            {
+                Issuer = _options.CurrentValue.Issuer,
+                Logger = _logger,
+                Options = _options.CurrentValue
+            });
+    }
+}

src/OpenIddict.Validation/OpenIddictValidationHandlerDescriptor.cs

@@ -7,6 +7,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
@@ -47,6 +48,11 @@ namespace OpenIddict.Validation
         /// </summary>
         public ServiceDescriptor ServiceDescriptor { get; private set; }
 
+        /// <summary>
+        /// Gets the type associated with the handler.
+        /// </summary>
+        public OpenIddictValidationHandlerType Type { get; private set; }
+
         /// <summary>
         /// Creates a builder allowing to initialize an immutable descriptor.
         /// </summary>
@@ -64,6 +70,7 @@ namespace OpenIddict.Validation
             private ServiceDescriptor _descriptor;
             private readonly List<Type> _filterTypes = new List<Type>();
             private int _order;
+            private OpenIddictValidationHandlerType _type;
 
             /// <summary>
             /// Adds the type of a handler filter to the filters list.
@@ -131,6 +138,23 @@ namespace OpenIddict.Validation
                 return this;
             }
 
+            /// <summary>
+            /// Sets the type associated to the handler.
+            /// </summary>
+            /// <param name="type">The handler type.</param>
+            /// <returns>The builder instance, so that calls can be easily chained.</returns>
+            public Builder<TContext> SetType(OpenIddictValidationHandlerType type)
+            {
+                if (!Enum.IsDefined(typeof(OpenIddictValidationHandlerType), type))
+                {
+                    throw new InvalidEnumArgumentException(nameof(type), (int) type, typeof(OpenIddictValidationHandlerType));
+                }
+
+                _type = type;
+
+                return this;
+            }
+
             /// <summary>
             /// Configures the descriptor to use the specified inline handler.
             /// </summary>
@@ -192,7 +216,8 @@ namespace OpenIddict.Validation
                 ContextType = typeof(TContext),
                 FilterTypes = _filterTypes.ToImmutableArray(),
                 Order = _order,
-                ServiceDescriptor = _descriptor ?? throw new InvalidOperationException("No service descriptor was set.")
+                ServiceDescriptor = _descriptor ?? throw new InvalidOperationException("No service descriptor was set."),
+                Type = _type
             };
         }
     }

src/OpenIddict.Validation/OpenIddictValidationHandlerType.cs

@@ -0,0 +1,29 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+namespace OpenIddict.Validation
+{
+    /// <summary>
+    /// Represents the type of an OpenIddict validation handler.
+    /// </summary>
+    public enum OpenIddictValidationHandlerType
+    {
+        /// <summary>
+        /// The handler is of an unspecified type.
+        /// </summary>
+        Unknown = 0,
+
+        /// <summary>
+        /// The handler is a built-in handler, provided as part of the official OpenIddict packages.
+        /// </summary>
+        BuiltIn = 1,
+
+        /// <summary>
+        /// The handler is a custom handler, registered by the end user or a third-party package.
+        /// </summary>
+        Custom = 2
+    }
+}

src/OpenIddict.Validation/OpenIddictValidationHandlers.cs

@@ -63,6 +63,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateAccessTokenParameter>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -121,6 +122,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireTokenEntryValidationEnabled>()
                     .UseScopedHandler<ValidateReferenceTokenIdentifier>()
                     .SetOrder(ValidateAccessTokenParameter.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -185,6 +187,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireLocalValidation>()
                     .UseSingletonHandler<ValidateIdentityModelToken>()
                     .SetOrder(ValidateReferenceTokenIdentifier.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -291,6 +294,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireIntrospectionValidation>()
                     .UseSingletonHandler<IntrospectToken>()
                     .SetOrder(ValidateIdentityModelToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -362,6 +366,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<NormalizeScopeClaims>()
                     .SetOrder(IntrospectToken.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -412,6 +417,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<MapInternalClaims>()
                     .SetOrder(NormalizeScopeClaims.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -534,6 +540,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireTokenEntryValidationEnabled>()
                     .UseScopedHandler<RestoreReferenceTokenProperties>()
                     .SetOrder(MapInternalClaims.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -581,6 +588,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidatePrincipal>()
                     .SetOrder(RestoreReferenceTokenProperties.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -647,6 +655,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateExpirationDate>()
                     .SetOrder(ValidatePrincipal.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -692,6 +701,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessAuthenticationContext>()
                     .UseSingletonHandler<ValidateAudience>()
                     .SetOrder(ValidateExpirationDate.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -771,6 +781,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireTokenEntryValidationEnabled>()
                     .UseScopedHandler<ValidateTokenEntry>()
                     .SetOrder(ValidateAudience.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -834,6 +845,7 @@ namespace OpenIddict.Validation
                     .AddFilter<RequireAuthorizationEntryValidationEnabled>()
                     .UseScopedHandler<ValidateAuthorizationEntry>()
                     .SetOrder(ValidateTokenEntry.Descriptor.Order + 1_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             public async ValueTask HandleAsync([NotNull] ProcessAuthenticationContext context)
@@ -875,6 +887,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<ProcessChallengeContext>()
                     .UseSingletonHandler<AttachDefaultChallengeError>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>
@@ -938,6 +951,7 @@ namespace OpenIddict.Validation
                 = OpenIddictValidationHandlerDescriptor.CreateBuilder<TContext>()
                     .UseSingletonHandler<HandleErrorResponse<TContext>>()
                     .SetOrder(int.MinValue + 100_000)
+                    .SetType(OpenIddictValidationHandlerType.BuiltIn)
                     .Build();
 
             /// <summary>

src/OpenIddict.Validation/OpenIddictValidationOptions.cs

@@ -24,7 +24,7 @@ namespace OpenIddict.Validation
         /// Gets the list of credentials used to encrypt the tokens issued by the
         /// OpenIddict validation services. Note: only symmetric credentials are supported.
         /// </summary>
-        public IList<EncryptingCredentials> EncryptionCredentials { get; } = new List<EncryptingCredentials>();
+        public List<EncryptingCredentials> EncryptionCredentials { get; } = new List<EncryptingCredentials>();
 
         /// <summary>
         /// Gets or sets the JWT handler used to protect and unprotect tokens.
@@ -35,16 +35,11 @@ namespace OpenIddict.Validation
         };
 
         /// <summary>
-        /// Gets the list of the user-defined/custom handlers responsible of processing the OpenIddict validation requests.
-        /// Note: the handlers added to this list must be also registered in the DI container using an appropriate lifetime.
+        /// Gets the list of the handlers responsible of processing the OpenIddict validation operations.
+        /// Note: the list is automatically sorted based on the order assigned to each handler descriptor.
+        /// As such, it MUST NOT be mutated after options initialization to preserve the exact order.
         /// </summary>
-        public IList<OpenIddictValidationHandlerDescriptor> CustomHandlers { get; } =
-            new List<OpenIddictValidationHandlerDescriptor>();
-
-        /// <summary>
-        /// Gets the list of the built-in handlers responsible of processing the OpenIddict validation requests
-        /// </summary>
-        public IList<OpenIddictValidationHandlerDescriptor> DefaultHandlers { get; } =
+        public List<OpenIddictValidationHandlerDescriptor> Handlers { get; } =
             new List<OpenIddictValidationHandlerDescriptor>(OpenIddictValidationHandlers.DefaultHandlers);
 
         /// <summary>
@@ -106,7 +101,7 @@ namespace OpenIddict.Validation
         /// Setting this property is recommended when the authorization
         /// server issues access tokens for multiple distinct resource servers.
         /// </summary>
-        public ISet<string> Audiences { get; } = new HashSet<string>(StringComparer.Ordinal);
+        public HashSet<string> Audiences { get; } = new HashSet<string>(StringComparer.Ordinal);
 
         /// <summary>
         /// Gets the token validation parameters used by the OpenIddict validation services.

src/OpenIddict.Validation/OpenIddictValidationService.cs

@@ -59,8 +59,9 @@ namespace OpenIddict.Validation
             // can be disposed of asynchronously if it implements IAsyncDisposable.
             try
             {
-                var provider = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationProvider>();
-                var transaction = await provider.CreateTransactionAsync();
+                var dispatcher = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationDispatcher>();
+                var factory = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationFactory>();
+                var transaction = await factory.CreateTransactionAsync();
 
                 var request = new OpenIddictRequest();
                 request = await PrepareConfigurationRequestAsync();
@@ -83,7 +84,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -110,7 +111,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -137,7 +138,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -165,7 +166,7 @@ namespace OpenIddict.Validation
                         Response = response
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -230,8 +231,9 @@ namespace OpenIddict.Validation
             // can be disposed of asynchronously if it implements IAsyncDisposable.
             try
             {
-                var provider = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationProvider>();
-                var transaction = await provider.CreateTransactionAsync();
+                var dispatcher = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationDispatcher>();
+                var factory = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationFactory>();
+                var transaction = await factory.CreateTransactionAsync();
 
                 var request = new OpenIddictRequest();
                 request = await PrepareCryptographyRequestAsync();
@@ -255,7 +257,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -282,7 +284,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -309,7 +311,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -337,7 +339,7 @@ namespace OpenIddict.Validation
                         Response = response
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -421,8 +423,9 @@ namespace OpenIddict.Validation
             // can be disposed of asynchronously if it implements IAsyncDisposable.
             try
             {
-                var provider = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationProvider>();
-                var transaction = await provider.CreateTransactionAsync();
+                var dispatcher = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationDispatcher>();
+                var factory = scope.ServiceProvider.GetRequiredService<IOpenIddictValidationFactory>();
+                var transaction = await factory.CreateTransactionAsync();
 
                 var request = new OpenIddictRequest();
                 request = await PrepareIntrospectionRequestAsync();
@@ -447,7 +450,7 @@ namespace OpenIddict.Validation
                         TokenType = type
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -474,7 +477,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -501,7 +504,7 @@ namespace OpenIddict.Validation
                         Request = request
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {
@@ -531,7 +534,7 @@ namespace OpenIddict.Validation
                         TokenType = type
                     };
 
-                    await provider.DispatchAsync(context);
+                    await dispatcher.DispatchAsync(context);
 
                     if (context.IsRejected)
                     {

test/OpenIddict.Server.Tests/OpenIddictServerBuilderTests.cs

@@ -197,8 +197,7 @@ namespace OpenIddict.Server.Tests
 
             // Assert
             Assert.DoesNotContain(services, x => x.ServiceType == descriptor.ServiceDescriptor.ServiceType);
-            Assert.DoesNotContain(options.CustomHandlers, x => x.ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType);
-            Assert.DoesNotContain(options.DefaultHandlers, x => x.ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType);
+            Assert.DoesNotContain(options.Handlers, x => x.ServiceDescriptor.ServiceType == descriptor.ServiceDescriptor.ServiceType);
         }
 
         [Fact]