diff --git a/frontend/src/Activity/Blocklist/BlocklistDetailsModal.tsx b/frontend/src/Activity/Blocklist/BlocklistDetailsModal.tsx
index ec026ae92..b90f40d37 100644
--- a/frontend/src/Activity/Blocklist/BlocklistDetailsModal.tsx
+++ b/frontend/src/Activity/Blocklist/BlocklistDetailsModal.tsx
@@ -16,13 +16,19 @@ interface BlocklistDetailsModalProps {
   protocol: DownloadProtocol;
   indexer?: string;
   message?: string;
+  source?: string;
   onModalClose: () => void;
 }
 
-function BlocklistDetailsModal(props: BlocklistDetailsModalProps) {
-  const { isOpen, sourceTitle, protocol, indexer, message, onModalClose } =
-    props;
-
+function BlocklistDetailsModal({
+  isOpen,
+  sourceTitle,
+  protocol,
+  indexer,
+  message,
+  source,
+  onModalClose,
+}: BlocklistDetailsModalProps) {
   return (
     <Modal isOpen={isOpen} onModalClose={onModalClose}>
       <ModalContent onModalClose={onModalClose}>
@@ -50,6 +56,9 @@ function BlocklistDetailsModal(props: BlocklistDetailsModalProps) {
                 data={message}
               />
             ) : null}
+            {source ? (
+              <DescriptionListItem title={translate('Source')} data={source} />
+            ) : null}
           </DescriptionList>
         </ModalBody>
 
diff --git a/frontend/src/Activity/Blocklist/BlocklistRow.tsx b/frontend/src/Activity/Blocklist/BlocklistRow.tsx
index c7410320d..8db01a1e0 100644
--- a/frontend/src/Activity/Blocklist/BlocklistRow.tsx
+++ b/frontend/src/Activity/Blocklist/BlocklistRow.tsx
@@ -37,6 +37,7 @@ function BlocklistRow(props: BlocklistRowProps) {
     protocol,
     indexer,
     message,
+    source,
     isSelected,
     columns,
     onSelectedChange,
@@ -154,6 +155,7 @@ function BlocklistRow(props: BlocklistRowProps) {
         protocol={protocol}
         indexer={indexer}
         message={message}
+        source={source}
         onModalClose={handleDetailsModalClose}
       />
     </TableRow>
diff --git a/frontend/src/Activity/History/Details/HistoryDetails.tsx b/frontend/src/Activity/History/Details/HistoryDetails.tsx
index 588bd7482..c3c3ea7f9 100644
--- a/frontend/src/Activity/History/Details/HistoryDetails.tsx
+++ b/frontend/src/Activity/History/Details/HistoryDetails.tsx
@@ -174,7 +174,7 @@ function HistoryDetails(props: HistoryDetailsProps) {
   }
 
   if (eventType === 'downloadFailed') {
-    const { message, indexer } = data as DownloadFailedHistory;
+    const { indexer, message, source } = data as DownloadFailedHistory;
 
     return (
       <DescriptionList>
@@ -195,6 +195,10 @@ function HistoryDetails(props: HistoryDetailsProps) {
         {message ? (
           <DescriptionListItem title={translate('Message')} data={message} />
         ) : null}
+
+        {source ? (
+          <DescriptionListItem title={translate('Source')} data={source} />
+        ) : null}
       </DescriptionList>
     );
   }
diff --git a/frontend/src/Helpers/Hooks/useApiMutation.ts b/frontend/src/Helpers/Hooks/useApiMutation.ts
index f3aeb0d01..c3fe85958 100644
--- a/frontend/src/Helpers/Hooks/useApiMutation.ts
+++ b/frontend/src/Helpers/Hooks/useApiMutation.ts
@@ -20,6 +20,7 @@ function useApiMutation<T, TData>(options: MutationOptions<T, TData>) {
       headers: {
         ...options.headers,
         'X-Api-Key': window.Sonarr.apiKey,
+        'X-Sonarr-Client': 'Sonarr',
       },
     };
   }, [options]);
diff --git a/frontend/src/Helpers/Hooks/useApiQuery.ts b/frontend/src/Helpers/Hooks/useApiQuery.ts
index ec4304627..bdeab78bf 100644
--- a/frontend/src/Helpers/Hooks/useApiQuery.ts
+++ b/frontend/src/Helpers/Hooks/useApiQuery.ts
@@ -26,6 +26,7 @@ const useApiQuery = <T>(options: QueryOptions<T>) => {
         headers: {
           ...options.headers,
           'X-Api-Key': window.Sonarr.apiKey,
+          'X-Sonarr-Client': 'Sonarr',
         },
       },
     };
diff --git a/frontend/src/Helpers/Hooks/usePagedApiQuery.ts b/frontend/src/Helpers/Hooks/usePagedApiQuery.ts
index a1ce29470..5fceedbb1 100644
--- a/frontend/src/Helpers/Hooks/usePagedApiQuery.ts
+++ b/frontend/src/Helpers/Hooks/usePagedApiQuery.ts
@@ -64,6 +64,7 @@ const usePagedApiQuery = <T>(options: PagedQueryOptions<T>) => {
         headers: {
           ...options.headers,
           'X-Api-Key': window.Sonarr.apiKey,
+          'X-Sonarr-Client': 'Sonarr',
         },
       },
     };
diff --git a/frontend/src/typings/Blocklist.ts b/frontend/src/typings/Blocklist.ts
index bbf4cacae..b0b0e8d9e 100644
--- a/frontend/src/typings/Blocklist.ts
+++ b/frontend/src/typings/Blocklist.ts
@@ -15,6 +15,7 @@ interface Blocklist extends ModelBase {
   seriesId?: number;
   indexer?: string;
   message?: string;
+  source?: string;
 }
 
 export default Blocklist;
diff --git a/frontend/src/typings/History.ts b/frontend/src/typings/History.ts
index c4d7f7644..cdd1ae9f1 100644
--- a/frontend/src/typings/History.ts
+++ b/frontend/src/typings/History.ts
@@ -37,6 +37,7 @@ export interface GrabbedHistoryData {
 export interface DownloadFailedHistory {
   message: string;
   indexer?: string;
+  source?: string;
 }
 
 export interface DownloadFolderImportedHistory {
diff --git a/src/NzbDrone.Common.Test/Http/UserAgentParserFixture.cs b/src/NzbDrone.Common.Test/Http/UserAgentParserFixture.cs
new file mode 100644
index 000000000..161f7b7c8
--- /dev/null
+++ b/src/NzbDrone.Common.Test/Http/UserAgentParserFixture.cs
@@ -0,0 +1,23 @@
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common.Http;
+using NzbDrone.Test.Common;
+
+namespace NzbDrone.Common.Test.Http;
+
+[TestFixture]
+public class UserAgentParserFixture : TestBase
+{
+    // Ref *Arr `_userAgent = $"{BuildInfo.AppName}/{BuildInfo.Version} ({osName} {osVersion})";`
+    // Ref Mylar `Mylar3/' +str(hash) +'(' +vers +') +http://www.github.com/mylar3/mylar3/`
+    [TestCase("Mylar3/ 3ee23rh23irqfq (13123123) http://www.github.com/mylar3/mylar3/", "Mylar3")]
+    [TestCase("Lidarr/1.0.0.2300 (ubuntu 20.04)", "Lidarr")]
+    [TestCase("Radarr/1.0.0.2300 (ubuntu 20.04)", "Radarr")]
+    [TestCase("Readarr/1.0.0.2300 (ubuntu 20.04)", "Readarr")]
+    [TestCase("Sonarr/3.0.6.9999 (ubuntu 20.04)", "Sonarr")]
+    [TestCase("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36", "Other")]
+    public void should_parse_user_agent(string userAgent, string parsedAgent)
+    {
+        UserAgentParser.ParseSource(userAgent).Should().Be(parsedAgent);
+    }
+}
diff --git a/src/NzbDrone.Common/Http/UserAgentParser.cs b/src/NzbDrone.Common/Http/UserAgentParser.cs
index 0a31410f2..6a481a5dd 100644
--- a/src/NzbDrone.Common/Http/UserAgentParser.cs
+++ b/src/NzbDrone.Common/Http/UserAgentParser.cs
@@ -1,7 +1,12 @@
+using System.Text.RegularExpressions;
+
 namespace NzbDrone.Common.Http
 {
     public static class UserAgentParser
     {
+        private static readonly Regex AppSourceRegex = new(@"(?<agent>[a-z0-9]*)\/.*(?:\(.*\))?",
+            RegexOptions.IgnoreCase | RegexOptions.Compiled);
+
         public static string SimplifyUserAgent(string userAgent)
         {
             if (userAgent == null || userAgent.StartsWith("Mozilla/5.0"))
@@ -11,5 +16,17 @@ namespace NzbDrone.Common.Http
 
             return userAgent;
         }
+
+        public static string ParseSource(string userAgent)
+        {
+            var match = AppSourceRegex.Match(SimplifyUserAgent(userAgent) ?? string.Empty);
+
+            if (match.Groups["agent"].Success)
+            {
+                return match.Groups["agent"].Value;
+            }
+
+            return "Other";
+        }
     }
 }
diff --git a/src/NzbDrone.Core/Blocklisting/Blocklist.cs b/src/NzbDrone.Core/Blocklisting/Blocklist.cs
index 8941f42fd..f26d980a0 100644
--- a/src/NzbDrone.Core/Blocklisting/Blocklist.cs
+++ b/src/NzbDrone.Core/Blocklisting/Blocklist.cs
@@ -24,6 +24,7 @@ namespace NzbDrone.Core.Blocklisting
         public IndexerFlags IndexerFlags { get; set; }
         public ReleaseType ReleaseType { get; set; }
         public string Message { get; set; }
+        public string Source { get; set; }
         public string TorrentInfoHash { get; set; }
         public List<Language> Languages { get; set; }
     }
diff --git a/src/NzbDrone.Core/Blocklisting/BlocklistService.cs b/src/NzbDrone.Core/Blocklisting/BlocklistService.cs
index f6aa6ceef..52ad1f8a5 100644
--- a/src/NzbDrone.Core/Blocklisting/BlocklistService.cs
+++ b/src/NzbDrone.Core/Blocklisting/BlocklistService.cs
@@ -17,7 +17,7 @@ namespace NzbDrone.Core.Blocklisting
         bool Blocklisted(int seriesId, ReleaseInfo release);
         bool BlocklistedTorrentHash(int seriesId, string hash);
         PagingSpec<Blocklist> Paged(PagingSpec<Blocklist> pagingSpec);
-        void Block(RemoteEpisode remoteEpisode, string message);
+        void Block(RemoteEpisode remoteEpisode, string message, string source);
         void Delete(int id);
         void Delete(List<int> ids);
     }
@@ -71,7 +71,7 @@ namespace NzbDrone.Core.Blocklisting
             return _blocklistRepository.GetPaged(pagingSpec);
         }
 
-        public void Block(RemoteEpisode remoteEpisode, string message)
+        public void Block(RemoteEpisode remoteEpisode, string message, string source)
         {
             var blocklist = new Blocklist
                             {
@@ -85,6 +85,7 @@ namespace NzbDrone.Core.Blocklisting
                                 Indexer = remoteEpisode.Release.Indexer,
                                 Protocol = remoteEpisode.Release.DownloadProtocol,
                                 Message = message,
+                                Source = source,
                                 Languages = remoteEpisode.ParsedEpisodeInfo.Languages
                             };
 
@@ -185,6 +186,7 @@ namespace NzbDrone.Core.Blocklisting
                 Indexer = message.Data.GetValueOrDefault("indexer"),
                 Protocol = (DownloadProtocol)Convert.ToInt32(message.Data.GetValueOrDefault("protocol")),
                 Message = message.Message,
+                Source = message.Source,
                 Languages = message.Languages,
                 TorrentInfoHash = message.TrackedDownload?.Protocol == DownloadProtocol.Torrent
                     ? message.TrackedDownload.DownloadItem.DownloadId
diff --git a/src/NzbDrone.Core/Datastore/Migration/223_add_source_to_blocklist.cs b/src/NzbDrone.Core/Datastore/Migration/223_add_source_to_blocklist.cs
new file mode 100644
index 000000000..39e63425f
--- /dev/null
+++ b/src/NzbDrone.Core/Datastore/Migration/223_add_source_to_blocklist.cs
@@ -0,0 +1,14 @@
+using FluentMigrator;
+using NzbDrone.Core.Datastore.Migration.Framework;
+
+namespace NzbDrone.Core.Datastore.Migration
+{
+    [Migration(223)]
+    public class add_source_to_blocklist : NzbDroneMigrationBase
+    {
+        protected override void MainDbUpgrade()
+        {
+            Alter.Table("Blocklist").AddColumn("Source").AsString().Nullable();
+        }
+    }
+}
diff --git a/src/NzbDrone.Core/Download/DownloadFailedEvent.cs b/src/NzbDrone.Core/Download/DownloadFailedEvent.cs
index 7a42b7e18..c6e0bd7e8 100644
--- a/src/NzbDrone.Core/Download/DownloadFailedEvent.cs
+++ b/src/NzbDrone.Core/Download/DownloadFailedEvent.cs
@@ -21,6 +21,7 @@ namespace NzbDrone.Core.Download
         public string DownloadClient { get; set; }
         public string DownloadId { get; set; }
         public string Message { get; set; }
+        public string Source { get; set; }
         public Dictionary<string, string> Data { get; set; }
         public TrackedDownload TrackedDownload { get; set; }
         public List<Language> Languages { get; set; }
diff --git a/src/NzbDrone.Core/Download/FailedDownloadService.cs b/src/NzbDrone.Core/Download/FailedDownloadService.cs
index 0851ae794..37e05e099 100644
--- a/src/NzbDrone.Core/Download/FailedDownloadService.cs
+++ b/src/NzbDrone.Core/Download/FailedDownloadService.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using NzbDrone.Common.EnvironmentInfo;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Download.TrackedDownloads;
 using NzbDrone.Core.History;
@@ -11,8 +12,8 @@ namespace NzbDrone.Core.Download
 {
     public interface IFailedDownloadService
     {
-        void MarkAsFailed(int historyId, bool skipRedownload = false);
-        void MarkAsFailed(TrackedDownload trackedDownload, bool skipRedownload = false);
+        void MarkAsFailed(int historyId, string message = null, string source = null, bool skipRedownload = false);
+        void MarkAsFailed(TrackedDownload trackedDownload, string message = null, string source = null, bool skipRedownload = false);
         void Check(TrackedDownload trackedDownload);
         void ProcessFailed(TrackedDownload trackedDownload);
     }
@@ -30,15 +31,16 @@ namespace NzbDrone.Core.Download
             _eventAggregator = eventAggregator;
         }
 
-        public void MarkAsFailed(int historyId, bool skipRedownload = false)
+        public void MarkAsFailed(int historyId, string message, string source = null, bool skipRedownload = false)
         {
-            var history = _historyService.Get(historyId);
+            message ??= "Manually marked as failed";
 
+            var history = _historyService.Get(historyId);
             var downloadId = history.DownloadId;
 
             if (downloadId.IsNullOrWhiteSpace())
             {
-                PublishDownloadFailedEvent(history, new List<int> { history.EpisodeId }, "Manually marked as failed", skipRedownload: skipRedownload);
+                PublishDownloadFailedEvent(history, new List<int> { history.EpisodeId }, message, source, skipRedownload: skipRedownload);
 
                 return;
             }
@@ -55,16 +57,16 @@ namespace NzbDrone.Core.Download
             grabbedHistory.AddRange(GetGrabbedHistory(downloadId));
             grabbedHistory = grabbedHistory.DistinctBy(h => h.Id).ToList();
 
-            PublishDownloadFailedEvent(history, GetEpisodeIds(grabbedHistory), "Manually marked as failed");
+            PublishDownloadFailedEvent(history, GetEpisodeIds(grabbedHistory), message, source);
         }
 
-        public void MarkAsFailed(TrackedDownload trackedDownload, bool skipRedownload = false)
+        public void MarkAsFailed(TrackedDownload trackedDownload, string message, string source = null, bool skipRedownload = false)
         {
             var history = GetGrabbedHistory(trackedDownload.DownloadItem.DownloadId);
 
             if (history.Any())
             {
-                PublishDownloadFailedEvent(history.First(), GetEpisodeIds(history), "Manually marked as failed", trackedDownload, skipRedownload: skipRedownload);
+                PublishDownloadFailedEvent(history.First(), GetEpisodeIds(history), message ?? "Manually marked as failed", source, trackedDownload, skipRedownload: skipRedownload);
             }
         }
 
@@ -117,10 +119,10 @@ namespace NzbDrone.Core.Download
             }
 
             trackedDownload.State = TrackedDownloadState.Failed;
-            PublishDownloadFailedEvent(grabbedItems.First(), GetEpisodeIds(grabbedItems), failure, trackedDownload);
+            PublishDownloadFailedEvent(grabbedItems.First(), GetEpisodeIds(grabbedItems), failure, $"{BuildInfo.AppName} Failed Download Handling", trackedDownload);
         }
 
-        private void PublishDownloadFailedEvent(EpisodeHistory historyItem, List<int> episodeIds, string message, TrackedDownload trackedDownload = null, bool skipRedownload = false)
+        private void PublishDownloadFailedEvent(EpisodeHistory historyItem, List<int> episodeIds, string message, string source, TrackedDownload trackedDownload = null, bool skipRedownload = false)
         {
             Enum.TryParse(historyItem.Data.GetValueOrDefault(EpisodeHistory.RELEASE_SOURCE, ReleaseSourceType.Unknown.ToString()), out ReleaseSourceType releaseSource);
 
@@ -133,6 +135,7 @@ namespace NzbDrone.Core.Download
                 DownloadClient = historyItem.Data.GetValueOrDefault(EpisodeHistory.DOWNLOAD_CLIENT),
                 DownloadId = historyItem.DownloadId,
                 Message = message,
+                Source = source,
                 Data = historyItem.Data,
                 TrackedDownload = trackedDownload,
                 Languages = historyItem.Languages,
diff --git a/src/NzbDrone.Core/History/HistoryService.cs b/src/NzbDrone.Core/History/HistoryService.cs
index 6bef7b722..65a64852f 100644
--- a/src/NzbDrone.Core/History/HistoryService.cs
+++ b/src/NzbDrone.Core/History/HistoryService.cs
@@ -249,6 +249,7 @@ namespace NzbDrone.Core.History
                 history.Data.Add("DownloadClient", message.DownloadClient);
                 history.Data.Add("DownloadClientName", message.TrackedDownload?.DownloadItem.DownloadClientInfo.Name);
                 history.Data.Add("Message", message.Message);
+                history.Data.Add("Source", message.Source);
                 history.Data.Add("ReleaseGroup", message.TrackedDownload?.RemoteEpisode?.ParsedEpisodeInfo?.ReleaseGroup ?? message.Data.GetValueOrDefault(EpisodeHistory.RELEASE_GROUP));
                 history.Data.Add("Size", message.TrackedDownload?.DownloadItem.TotalSize.ToString() ?? message.Data.GetValueOrDefault(EpisodeHistory.SIZE));
                 history.Data.Add("Indexer", message.TrackedDownload?.RemoteEpisode?.Release?.Indexer ?? message.Data.GetValueOrDefault(EpisodeHistory.INDEXER));
diff --git a/src/Sonarr.Api.V3/Queue/QueueController.cs b/src/Sonarr.Api.V3/Queue/QueueController.cs
index 633424fda..454b497fc 100644
--- a/src/Sonarr.Api.V3/Queue/QueueController.cs
+++ b/src/Sonarr.Api.V3/Queue/QueueController.cs
@@ -323,7 +323,7 @@ namespace Sonarr.Api.V3.Queue
         {
             if (blocklist)
             {
-                _blocklistService.Block(pendingRelease.RemoteEpisode, "Pending release manually blocklisted");
+                _blocklistService.Block(pendingRelease.RemoteEpisode, "Pending release manually blocklisted", null);
             }
 
             _pendingReleaseService.RemovePendingQueueItemsObsolete(pendingRelease.Id);
@@ -356,7 +356,7 @@ namespace Sonarr.Api.V3.Queue
 
             if (blocklist)
             {
-                _failedDownloadService.MarkAsFailed(trackedDownload, skipRedownload);
+                _failedDownloadService.MarkAsFailed(trackedDownload, null, null, skipRedownload);
             }
 
             if (!removeFromClient && !blocklist && !changeCategory)
diff --git a/src/Sonarr.Api.V5/Queue/QueueController.cs b/src/Sonarr.Api.V5/Queue/QueueController.cs
index 67bdca9b6..784f3b121 100644
--- a/src/Sonarr.Api.V5/Queue/QueueController.cs
+++ b/src/Sonarr.Api.V5/Queue/QueueController.cs
@@ -68,13 +68,13 @@ namespace Sonarr.Api.V5.Queue
         }
 
         [RestDeleteById]
-        public ActionResult RemoveAction(int id, bool removeFromClient = true, bool blocklist = false, bool skipRedownload = false, bool changeCategory = false)
+        public ActionResult RemoveAction(int id, string? message = null, bool removeFromClient = true, bool blocklist = false, bool skipRedownload = false, bool changeCategory = false)
         {
             var pendingRelease = _pendingReleaseService.FindPendingQueueItem(id);
 
             if (pendingRelease != null)
             {
-                Remove(pendingRelease, blocklist);
+                Remove(pendingRelease, message, blocklist);
 
                 return Deleted();
             }
@@ -86,14 +86,14 @@ namespace Sonarr.Api.V5.Queue
                 throw new NotFoundException();
             }
 
-            Remove(trackedDownload, removeFromClient, blocklist, skipRedownload, changeCategory);
+            Remove(trackedDownload, message, removeFromClient, blocklist, skipRedownload, changeCategory);
             _trackedDownloadService.StopTracking(trackedDownload.DownloadItem.DownloadId);
 
             return Deleted();
         }
 
         [HttpDelete("bulk")]
-        public object RemoveMany([FromBody] QueueBulkResource resource, [FromQuery] bool removeFromClient = true, [FromQuery] bool blocklist = false, [FromQuery] bool skipRedownload = false, [FromQuery] bool changeCategory = false)
+        public object RemoveMany([FromBody] QueueBulkResource resource, [FromQuery] string? message, [FromQuery] bool removeFromClient = true, [FromQuery] bool blocklist = false, [FromQuery] bool skipRedownload = false, [FromQuery] bool changeCategory = false)
         {
             var trackedDownloadIds = new List<string>();
             var pendingToRemove = new List<NzbDrone.Core.Queue.Queue>();
@@ -119,12 +119,12 @@ namespace Sonarr.Api.V5.Queue
 
             foreach (var pendingRelease in pendingToRemove.DistinctBy(p => p.Id))
             {
-                Remove(pendingRelease, blocklist);
+                Remove(pendingRelease, message, blocklist);
             }
 
             foreach (var trackedDownload in trackedToRemove.DistinctBy(t => t.DownloadItem.DownloadId))
             {
-                Remove(trackedDownload, removeFromClient, blocklist, skipRedownload, changeCategory);
+                Remove(trackedDownload, message, removeFromClient, blocklist, skipRedownload, changeCategory);
                 trackedDownloadIds.Add(trackedDownload.DownloadItem.DownloadId);
             }
 
@@ -314,17 +314,17 @@ namespace Sonarr.Api.V5.Queue
             }
         }
 
-        private void Remove(NzbDrone.Core.Queue.Queue pendingRelease, bool blocklist)
+        private void Remove(NzbDrone.Core.Queue.Queue pendingRelease, string? message, bool blocklist)
         {
             if (blocklist)
             {
-                _blocklistService.Block(pendingRelease.RemoteEpisode, "Pending release manually blocklisted");
+                _blocklistService.Block(pendingRelease.RemoteEpisode, message ?? "Pending release manually blocklisted", Request.GetSource());
             }
 
             _pendingReleaseService.RemovePendingQueueItems(pendingRelease.Id);
         }
 
-        private TrackedDownload? Remove(TrackedDownload trackedDownload, bool removeFromClient, bool blocklist, bool skipRedownload, bool changeCategory)
+        private TrackedDownload? Remove(TrackedDownload trackedDownload, string? message, bool removeFromClient, bool blocklist, bool skipRedownload, bool changeCategory)
         {
             if (removeFromClient)
             {
@@ -351,7 +351,7 @@ namespace Sonarr.Api.V5.Queue
 
             if (blocklist)
             {
-                _failedDownloadService.MarkAsFailed(trackedDownload, skipRedownload);
+                _failedDownloadService.MarkAsFailed(trackedDownload, message, Request.GetSource(), skipRedownload);
             }
 
             if (!removeFromClient && !blocklist && !changeCategory)
diff --git a/src/Sonarr.Http/Extensions/RequestExtensions.cs b/src/Sonarr.Http/Extensions/RequestExtensions.cs
index 772264dfb..4689e40a0 100644
--- a/src/Sonarr.Http/Extensions/RequestExtensions.cs
+++ b/src/Sonarr.Http/Extensions/RequestExtensions.cs
@@ -97,6 +97,16 @@ namespace Sonarr.Http.Extensions
             return remoteIP.ToString();
         }
 
+        public static string GetSource(this HttpRequest request)
+        {
+            if (request.Headers.TryGetValue("X-Sonarr-Client", out var source))
+            {
+                return source;
+            }
+
+            return NzbDrone.Common.Http.UserAgentParser.ParseSource(request.Headers["User-Agent"]);
+        }
+
         public static void DisableCache(this IHeaderDictionary headers)
         {
             headers.Remove("Last-Modified");