Add configurable indexer name template for external applications

Implements a new IndexerNameTemplateService that allows users to customize how indexer names appear in synced external applications (Sonarr, Radarr, etc.). The template supports {name} and {instance} placeholders, with a default format of "{name} ({instance})".

- Add IndexerNameTemplate configuration setting with UI control
- Create IndexerNameTemplateService with comprehensive test coverage
- Update all application sync classes to use template service
- Add frontend validation warning when {name} placeholder is missing
- Maintain backward compatibility with consistent null handling

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/Settings/General/HostSettings.js

@@ -22,6 +22,7 @@ function HostSettings(props) {
     urlBase,
     instanceName,
     applicationUrl,
+    indexerNameTemplate,
     enableSsl,
     sslPort,
     sslCertPath,
@@ -105,6 +106,25 @@ function HostSettings(props) {
         />
       </FormGroup>
 
+      <FormGroup
+        advancedSettings={advancedSettings}
+        isAdvanced={true}
+      >
+        <FormLabel>{translate('IndexerNameTemplate')}</FormLabel>
+
+        <FormInputGroup
+          type={inputTypes.TEXT}
+          name="indexerNameTemplate"
+          helpText={translate('IndexerNameTemplateHelpText')}
+          helpTextWarning={
+            indexerNameTemplate && indexerNameTemplate.value &&
+            !indexerNameTemplate.value.includes('{name}') ? translate('IndexerNameTemplateHelpTextWarning') : undefined
+          }
+          onChange={onInputChange}
+          {...indexerNameTemplate}
+        />
+      </FormGroup>
+
       <FormGroup
         advancedSettings={advancedSettings}
         isAdvanced={true}

src/NzbDrone.Core.Test/IndexerTests/IndexerNameTemplateServiceFixture.cs

@@ -0,0 +1,78 @@
+using FluentAssertions;
+using Moq;
+using NUnit.Framework;
+using NzbDrone.Core.Applications;
+using NzbDrone.Core.Configuration;
+using NzbDrone.Test.Common;
+using static NzbDrone.Core.Applications.IndexerNameTemplateDefaults;
+
+namespace NzbDrone.Core.Test.IndexerTests
+{
+    [TestFixture]
+    public class IndexerNameTemplateServiceFixture : TestBase<IndexerNameTemplateService>
+    {
+        private Mock<IConfigService> _configService;
+
+        [SetUp]
+        public void Setup()
+        {
+            _configService = Mocker.GetMock<IConfigService>();
+        }
+
+        [TestCase(null)]
+        [TestCase("")]
+        [TestCase("   ")]
+        public void FormatIndexerName_should_return_empty_when_invalid_input(string indexerName)
+        {
+            _configService.Setup(s => s.IndexerNameTemplate).Returns("{name} ({instance})");
+
+            var result = Subject.FormatIndexerName(indexerName, "Prowlarr");
+
+            result.Should().Be("");
+        }
+
+        [Test]
+        public void FormatIndexerName_should_format_with_template()
+        {
+            _configService.Setup(s => s.IndexerNameTemplate).Returns("{name} ({instance})");
+
+            var result = Subject.FormatIndexerName("MyIndexer", "MyProwlarr");
+
+            result.Should().Be("MyIndexer (MyProwlarr)");
+        }
+
+        [TestCase(null)]
+        [TestCase("")]
+        [TestCase("   ")]
+        public void FormatIndexerName_should_use_fallback_instance_name(string instanceName)
+        {
+            _configService.Setup(s => s.IndexerNameTemplate).Returns("{name} ({instance})");
+
+            var result = Subject.FormatIndexerName("MyIndexer", instanceName);
+
+            result.Should().Be($"MyIndexer ({DefaultInstanceName})");
+        }
+
+        [TestCase(null)]
+        [TestCase("")]
+        [TestCase("   ")]
+        public void FormatIndexerName_should_return_original_name_when_no_template(string template)
+        {
+            _configService.Setup(s => s.IndexerNameTemplate).Returns(template);
+
+            var result = Subject.FormatIndexerName("MyIndexer", "MyProwlarr");
+
+            result.Should().Be("MyIndexer");
+        }
+
+        [Test]
+        public void FormatIndexerName_should_handle_custom_template()
+        {
+            _configService.Setup(s => s.IndexerNameTemplate).Returns("[{instance}] {name}");
+
+            var result = Subject.FormatIndexerName("MyIndexer", "MyProwlarr");
+
+            result.Should().Be("[MyProwlarr] MyIndexer");
+        }
+    }
+}

src/NzbDrone.Core/Applications/IndexerNameTemplateService.cs

@@ -0,0 +1,46 @@
+using NzbDrone.Core.Configuration;
+
+namespace NzbDrone.Core.Applications
+{
+    public static class IndexerNameTemplateDefaults
+    {
+        public const string DefaultTemplate = "{name} ({instance})";
+        public const string DefaultInstanceName = "Prowlarr";
+    }
+
+    public interface IIndexerNameTemplateService
+    {
+        string FormatIndexerName(string indexerName, string instanceName);
+    }
+
+    public class IndexerNameTemplateService : IIndexerNameTemplateService
+    {
+        private readonly IConfigService _configService;
+
+        public IndexerNameTemplateService(IConfigService configService)
+        {
+            _configService = configService;
+        }
+
+        public string FormatIndexerName(string indexerName, string instanceName)
+        {
+            if (string.IsNullOrWhiteSpace(indexerName))
+            {
+                return string.Empty;
+            }
+
+            var template = _configService.IndexerNameTemplate;
+
+            if (string.IsNullOrWhiteSpace(template))
+            {
+                return indexerName;
+            }
+
+            var finalInstanceName = !string.IsNullOrWhiteSpace(instanceName) ? instanceName : IndexerNameTemplateDefaults.DefaultInstanceName;
+
+            return template
+                .Replace("{name}", indexerName)
+                .Replace("{instance}", finalInstanceName);
+        }
+    }
+}

src/NzbDrone.Core/Applications/LazyLibrarian/LazyLibrarian.cs

@@ -15,12 +15,14 @@ public class LazyLibrarian : ApplicationBase<LazyLibrarianSettings>
 
         private readonly ILazyLibrarianV1Proxy _lazyLibrarianV1Proxy;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public LazyLibrarian(ILazyLibrarianV1Proxy lazyLibrarianV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public LazyLibrarian(ILazyLibrarianV1Proxy lazyLibrarianV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _lazyLibrarianV1Proxy = lazyLibrarianV1Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -155,8 +157,8 @@ private LazyLibrarianIndexer BuildLazyLibrarianIndexer(IndexerDefinition indexer
 
             var lazyLibrarianIndexer = new LazyLibrarianIndexer
             {
-                Name = originalName ?? $"{indexer.Name} (Prowlarr)",
-                Altername = $"{indexer.Name} (Prowlarr)",
+                Name = originalName ?? _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
+                Altername = originalName ?? _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 Host = $"{Settings.ProwlarrUrl.TrimEnd('/')}/{indexer.Id}/api",
                 Apikey = _configFileProvider.ApiKey,
                 Categories = string.Join(",", indexerCapabilities.Categories.SupportedCategories(Settings.SyncCategories.ToArray())),

src/NzbDrone.Core/Applications/Lidarr/Lidarr.cs

@@ -21,13 +21,15 @@ public class Lidarr : ApplicationBase<LidarrSettings>
         private readonly ILidarrV1Proxy _lidarrV1Proxy;
         private readonly ICached<List<LidarrIndexer>> _schemaCache;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Lidarr(ICacheManager cacheManager, ILidarrV1Proxy lidarrV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Lidarr(ICacheManager cacheManager, ILidarrV1Proxy lidarrV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _schemaCache = cacheManager.GetCache<List<LidarrIndexer>>(GetType());
             _lidarrV1Proxy = lidarrV1Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -247,7 +249,7 @@ private LidarrIndexer BuildLidarrIndexer(IndexerDefinition indexer, IndexerCapab
             var lidarrIndexer = new LidarrIndexer
             {
                 Id = id,
-                Name = $"{indexer.Name} (Prowlarr)",
+                Name = _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 EnableRss = indexer.Enable && indexer.AppProfile.Value.EnableRss,
                 EnableAutomaticSearch = indexer.Enable && indexer.AppProfile.Value.EnableAutomaticSearch,
                 EnableInteractiveSearch = indexer.Enable && indexer.AppProfile.Value.EnableInteractiveSearch,

src/NzbDrone.Core/Applications/Mylar/Mylar.cs

@@ -15,12 +15,14 @@ public class Mylar : ApplicationBase<MylarSettings>
 
         private readonly IMylarV3Proxy _mylarV3Proxy;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Mylar(IMylarV3Proxy mylarV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Mylar(IMylarV3Proxy mylarV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _mylarV3Proxy = mylarV3Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -155,8 +157,8 @@ private MylarIndexer BuildMylarIndexer(IndexerDefinition indexer, IndexerCapabil
 
             var mylarIndexer = new MylarIndexer
             {
-                Name = originalName ?? $"{indexer.Name} (Prowlarr)",
-                Altername = $"{indexer.Name} (Prowlarr)",
+                Name = originalName ?? _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
+                Altername = originalName ?? _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 Host = $"{Settings.ProwlarrUrl.TrimEnd('/')}/{indexer.Id}/api",
                 Apikey = _configFileProvider.ApiKey,
                 Categories = string.Join(",", indexerCapabilities.Categories.SupportedCategories(Settings.SyncCategories.ToArray())),

src/NzbDrone.Core/Applications/Radarr/Radarr.cs

@@ -21,13 +21,15 @@ public class Radarr : ApplicationBase<RadarrSettings>
         private readonly IRadarrV3Proxy _radarrV3Proxy;
         private readonly ICached<List<RadarrIndexer>> _schemaCache;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Radarr(ICacheManager cacheManager, IRadarrV3Proxy radarrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Radarr(ICacheManager cacheManager, IRadarrV3Proxy radarrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _schemaCache = cacheManager.GetCache<List<RadarrIndexer>>(GetType());
             _radarrV3Proxy = radarrV3Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -245,7 +247,7 @@ private RadarrIndexer BuildRadarrIndexer(IndexerDefinition indexer, IndexerCapab
             var radarrIndexer = new RadarrIndexer
             {
                 Id = id,
-                Name = $"{indexer.Name} (Prowlarr)",
+                Name = _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 EnableRss = indexer.Enable && indexer.AppProfile.Value.EnableRss,
                 EnableAutomaticSearch = indexer.Enable && indexer.AppProfile.Value.EnableAutomaticSearch,
                 EnableInteractiveSearch = indexer.Enable && indexer.AppProfile.Value.EnableInteractiveSearch,

src/NzbDrone.Core/Applications/Readarr/Readarr.cs

@@ -21,13 +21,15 @@ public class Readarr : ApplicationBase<ReadarrSettings>
         private readonly ICached<List<ReadarrIndexer>> _schemaCache;
         private readonly IReadarrV1Proxy _readarrV1Proxy;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Readarr(ICacheManager cacheManager, IReadarrV1Proxy readarrV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Readarr(ICacheManager cacheManager, IReadarrV1Proxy readarrV1Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _schemaCache = cacheManager.GetCache<List<ReadarrIndexer>>(GetType());
             _readarrV1Proxy = readarrV1Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -241,7 +243,7 @@ private ReadarrIndexer BuildReadarrIndexer(IndexerDefinition indexer, IndexerCap
             var readarrIndexer = new ReadarrIndexer
             {
                 Id = id,
-                Name = $"{indexer.Name} (Prowlarr)",
+                Name = _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 EnableRss = indexer.Enable && indexer.AppProfile.Value.EnableRss,
                 EnableAutomaticSearch = indexer.Enable && indexer.AppProfile.Value.EnableAutomaticSearch,
                 EnableInteractiveSearch = indexer.Enable && indexer.AppProfile.Value.EnableInteractiveSearch,

src/NzbDrone.Core/Applications/Sonarr/Sonarr.cs

@@ -21,13 +21,15 @@ public class Sonarr : ApplicationBase<SonarrSettings>
         private readonly ICached<List<SonarrIndexer>> _schemaCache;
         private readonly ISonarrV3Proxy _sonarrV3Proxy;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Sonarr(ICacheManager cacheManager, ISonarrV3Proxy sonarrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Sonarr(ICacheManager cacheManager, ISonarrV3Proxy sonarrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _schemaCache = cacheManager.GetCache<List<SonarrIndexer>>(GetType());
             _sonarrV3Proxy = sonarrV3Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -253,7 +255,7 @@ private SonarrIndexer BuildSonarrIndexer(IndexerDefinition indexer, IndexerCapab
             var sonarrIndexer = new SonarrIndexer
             {
                 Id = id,
-                Name = $"{indexer.Name} (Prowlarr)",
+                Name = _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 EnableRss = indexer.Enable && indexer.AppProfile.Value.EnableRss,
                 EnableAutomaticSearch = indexer.Enable && indexer.AppProfile.Value.EnableAutomaticSearch,
                 EnableInteractiveSearch = indexer.Enable && indexer.AppProfile.Value.EnableInteractiveSearch,

src/NzbDrone.Core/Applications/Whisparr/Whisparr.cs

@@ -21,13 +21,15 @@ public class Whisparr : ApplicationBase<WhisparrSettings>
         private readonly IWhisparrV3Proxy _whisparrV3Proxy;
         private readonly ICached<List<WhisparrIndexer>> _schemaCache;
         private readonly IConfigFileProvider _configFileProvider;
+        private readonly IIndexerNameTemplateService _indexerNameTemplateService;
 
-        public Whisparr(ICacheManager cacheManager, IWhisparrV3Proxy whisparrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, Logger logger)
+        public Whisparr(ICacheManager cacheManager, IWhisparrV3Proxy whisparrV3Proxy, IConfigFileProvider configFileProvider, IAppIndexerMapService appIndexerMapService, IIndexerFactory indexerFactory, IIndexerNameTemplateService indexerNameTemplateService, Logger logger)
             : base(appIndexerMapService, indexerFactory, logger)
         {
             _schemaCache = cacheManager.GetCache<List<WhisparrIndexer>>(GetType());
             _whisparrV3Proxy = whisparrV3Proxy;
             _configFileProvider = configFileProvider;
+            _indexerNameTemplateService = indexerNameTemplateService;
         }
 
         public override ValidationResult Test()
@@ -232,7 +234,7 @@ private WhisparrIndexer BuildWhisparrIndexer(IndexerDefinition indexer, IndexerC
             var whisparrIndexer = new WhisparrIndexer
             {
                 Id = id,
-                Name = $"{indexer.Name} (Prowlarr)",
+                Name = _indexerNameTemplateService.FormatIndexerName(indexer.Name, _configFileProvider.InstanceName),
                 EnableRss = indexer.Enable && indexer.AppProfile.Value.EnableRss,
                 EnableAutomaticSearch = indexer.Enable && indexer.AppProfile.Value.EnableAutomaticSearch,
                 EnableInteractiveSearch = indexer.Enable && indexer.AppProfile.Value.EnableInteractiveSearch,

src/NzbDrone.Core/Configuration/ConfigService.cs

@@ -88,6 +88,12 @@ public bool LogIndexerResponse
             set { SetValue("LogIndexerResponse", value); }
         }
 
+        public string IndexerNameTemplate
+        {
+            get { return GetValue("indexernametemplate", Applications.IndexerNameTemplateDefaults.DefaultTemplate); }
+            set { SetValue("indexernametemplate", value); }
+        }
+
         public int FirstDayOfWeek
         {
             get { return GetValueInt("FirstDayOfWeek", (int)CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek); }

src/NzbDrone.Core/Configuration/IConfigService.cs

@@ -53,6 +53,7 @@ public interface IConfigService
 
         // Indexers
         bool LogIndexerResponse { get; set; }
+        string IndexerNameTemplate { get; set; }
 
         CertificateValidationType CertificateValidation { get; }
         string ApplicationUrl { get; }

src/NzbDrone.Core/Localization/Core/en.json

@@ -384,6 +384,9 @@
   "IndexerMTeamTpSettingsApiKeyHelpText": "API Key from the Site (Found in User Control Panel => Security => Laboratory)",
   "IndexerMTeamTpSettingsFreeleechOnlyHelpText": "Search freeleech releases only",
   "IndexerName": "Indexer Name",
+  "IndexerNameTemplate": "Indexer Name Template",
+  "IndexerNameTemplateHelpText": "Template to customize how indexer names appear in external applications. Use {name} for the indexer name and {instance} for the instance name. Default: {name} ({instance})",
+  "IndexerNameTemplateHelpTextWarning": "Template does not contain {name} - indexer names may not be distinguishable",
   "IndexerNebulanceSettingsApiKeyHelpText": "API Key from User Settings > Api Keys. Key must have List and Download permissions",
   "IndexerNewznabSettingsAdditionalParametersHelpText": "Additional Newznab parameters",
   "IndexerNewznabSettingsApiKeyHelpText": "Site API Key",

src/Prowlarr.Api.V1/Config/HostConfigResource.cs

@@ -47,6 +47,7 @@ public class HostConfigResource : RestResource
         public int BackupRetention { get; set; }
         public int HistoryCleanupDays { get; set; }
         public bool TrustCgnatIpAddresses { get; set; }
+        public string IndexerNameTemplate { get; set; }
     }
 
     public static class HostConfigResourceMapper
@@ -92,7 +93,8 @@ public static HostConfigResource ToResource(this IConfigFileProvider model, ICon
                 BackupInterval = configService.BackupInterval,
                 BackupRetention = configService.BackupRetention,
                 ApplicationUrl = configService.ApplicationUrl,
-                HistoryCleanupDays = configService.HistoryCleanupDays
+                HistoryCleanupDays = configService.HistoryCleanupDays,
+                IndexerNameTemplate = configService.IndexerNameTemplate
             };
         }
     }