diff --git a/osu.Game.Tests/Online/TestDummyAPIRequestHandling.cs b/osu.Game.Tests/Online/TestDummyAPIRequestHandling.cs
new file mode 100644
index 0000000000..5ef01d5702
--- /dev/null
+++ b/osu.Game.Tests/Online/TestDummyAPIRequestHandling.cs
@@ -0,0 +1,115 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Chat;
+using osu.Game.Tests.Visual;
+using osu.Game.Users;
+
+namespace osu.Game.Tests.Online
+{
+    public class TestDummyAPIRequestHandling : OsuTestScene
+    {
+        [Test]
+        public void TestGenericRequestHandling()
+        {
+            AddStep("register request handling", () => ((DummyAPIAccess)API).HandleRequest = req =>
+            {
+                switch (req)
+                {
+                    case CommentVoteRequest cRequest:
+                        cRequest.TriggerSuccess(new CommentBundle());
+                        break;
+                }
+            });
+
+            CommentVoteRequest request = null;
+            CommentBundle response = null;
+
+            AddStep("fire request", () =>
+            {
+                response = null;
+                request = new CommentVoteRequest(1, CommentVoteAction.Vote);
+                request.Success += res => response = res;
+                API.Queue(request);
+            });
+
+            AddAssert("response event fired", () => response != null);
+
+            AddAssert("request has response", () => request.Result == response);
+        }
+
+        [Test]
+        public void TestQueueRequestHandling()
+        {
+            registerHandler();
+
+            LeaveChannelRequest request;
+            bool gotResponse = false;
+
+            AddStep("fire request", () =>
+            {
+                gotResponse = false;
+                request = new LeaveChannelRequest(new Channel(), new User());
+                request.Success += () => gotResponse = true;
+                API.Queue(request);
+            });
+
+            AddAssert("response event fired", () => gotResponse);
+        }
+
+        [Test]
+        public void TestPerformRequestHandling()
+        {
+            registerHandler();
+
+            LeaveChannelRequest request;
+            bool gotResponse = false;
+
+            AddStep("fire request", () =>
+            {
+                gotResponse = false;
+                request = new LeaveChannelRequest(new Channel(), new User());
+                request.Success += () => gotResponse = true;
+                API.Perform(request);
+            });
+
+            AddAssert("response event fired", () => gotResponse);
+        }
+
+        [Test]
+        public void TestPerformAsyncRequestHandling()
+        {
+            registerHandler();
+
+            LeaveChannelRequest request;
+            bool gotResponse = false;
+
+            AddStep("fire request", () =>
+            {
+                gotResponse = false;
+                request = new LeaveChannelRequest(new Channel(), new User());
+                request.Success += () => gotResponse = true;
+                API.PerformAsync(request);
+            });
+
+            AddAssert("response event fired", () => gotResponse);
+        }
+
+        private void registerHandler()
+        {
+            AddStep("register request handling", () => ((DummyAPIAccess)API).HandleRequest = req =>
+            {
+                switch (req)
+                {
+                    case LeaveChannelRequest cRequest:
+                        cRequest.TriggerSuccess();
+                        break;
+                }
+            });
+        }
+    }
+}
diff --git a/osu.Game/Online/API/APIRequest.cs b/osu.Game/Online/API/APIRequest.cs
index 6a6c7b72a8..47600e4f68 100644
--- a/osu.Game/Online/API/APIRequest.cs
+++ b/osu.Game/Online/API/APIRequest.cs
@@ -16,20 +16,27 @@ namespace osu.Game.Online.API
     {
         protected override WebRequest CreateWebRequest() => new OsuJsonWebRequest<T>(Uri);
 
-        public T Result => ((OsuJsonWebRequest<T>)WebRequest)?.ResponseObject;
+        public T Result { get; private set; }
 
         protected APIRequest()
         {
-            base.Success += onSuccess;
+            base.Success += () => TriggerSuccess(((OsuJsonWebRequest<T>)WebRequest)?.ResponseObject);
         }
 
-        private void onSuccess() => Success?.Invoke(Result);
-
         /// <summary>
         /// Invoked on successful completion of an API request.
         /// This will be scheduled to the API's internal scheduler (run on update thread automatically).
         /// </summary>
         public new event APISuccessHandler<T> Success;
+
+        internal void TriggerSuccess(T result)
+        {
+            if (Result != null)
+                throw new InvalidOperationException("Attempted to trigger success more than once");
+
+            Result = result;
+            Success?.Invoke(result);
+        }
     }
 
     /// <summary>
@@ -96,10 +103,15 @@ namespace osu.Game.Online.API
             {
                 if (cancelled) return;
 
-                Success?.Invoke();
+                TriggerSuccess();
             });
         }
 
+        internal void TriggerSuccess()
+        {
+            Success?.Invoke();
+        }
+
         public void Cancel() => Fail(new OperationCanceledException(@"Request cancelled"));
 
         public void Fail(Exception e)
diff --git a/osu.Game/Online/API/DummyAPIAccess.cs b/osu.Game/Online/API/DummyAPIAccess.cs
index a1c3475fd9..7800241904 100644
--- a/osu.Game/Online/API/DummyAPIAccess.cs
+++ b/osu.Game/Online/API/DummyAPIAccess.cs
@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -30,6 +31,11 @@ namespace osu.Game.Online.API
 
         private readonly List<IOnlineComponent> components = new List<IOnlineComponent>();
 
+        /// <summary>
+        /// Provide handling logic for an arbitrary API request.
+        /// </summary>
+        public Action<APIRequest> HandleRequest;
+
         public APIState State
         {
             get => state;
@@ -55,11 +61,16 @@ namespace osu.Game.Online.API
 
         public virtual void Queue(APIRequest request)
         {
+            HandleRequest?.Invoke(request);
         }
 
-        public void Perform(APIRequest request) { }
+        public void Perform(APIRequest request) => HandleRequest?.Invoke(request);
 
-        public Task PerformAsync(APIRequest request) => Task.CompletedTask;
+        public Task PerformAsync(APIRequest request)
+        {
+            HandleRequest?.Invoke(request);
+            return Task.CompletedTask;
+        }
 
         public void Register(IOnlineComponent component)
         {