diff --git a/allstarr/Controllers/AdminController.cs b/allstarr/Controllers/AdminController.cs
index f0cf7a1..f54c0ea 100644
--- a/allstarr/Controllers/AdminController.cs
+++ b/allstarr/Controllers/AdminController.cs
@@ -986,14 +986,15 @@ public class AdminController : ControllerBase
             {
                 // Store external mapping in cache (NO EXPIRATION - manual mappings are permanent)
                 var externalMappingKey = $"spotify:external-map:{decodedName}:{request.SpotifyId}";
-                var externalMapping = new { provider = request.ExternalProvider, id = request.ExternalId };
+                var normalizedProvider = request.ExternalProvider!.ToLowerInvariant(); // Normalize to lowercase
+                var externalMapping = new { provider = normalizedProvider, id = request.ExternalId };
                 await _cache.SetAsync(externalMappingKey, externalMapping);
                 
                 // Also save to file for persistence across restarts
-                await SaveManualMappingToFileAsync(decodedName, request.SpotifyId, null, request.ExternalProvider!, request.ExternalId!);
+                await SaveManualMappingToFileAsync(decodedName, request.SpotifyId, null, normalizedProvider, request.ExternalId!);
                 
                 _logger.LogInformation("Manual external mapping saved: {Playlist} - Spotify {SpotifyId} → {Provider} {ExternalId}", 
-                    decodedName, request.SpotifyId, request.ExternalProvider, request.ExternalId);
+                    decodedName, request.SpotifyId, normalizedProvider, request.ExternalId);
             }
             
             // Clear all related caches to force rebuild
@@ -1083,7 +1084,8 @@ public class AdminController : ControllerBase
                 try
                 {
                     var metadataService = HttpContext.RequestServices.GetRequiredService<IMusicMetadataService>();
-                    var externalSong = await metadataService.GetSongAsync(request.ExternalProvider!, request.ExternalId!);
+                    var normalizedProvider = request.ExternalProvider!.ToLowerInvariant(); // Normalize to lowercase
+                    var externalSong = await metadataService.GetSongAsync(normalizedProvider, request.ExternalId!);
                     
                     if (externalSong != null)
                     {
@@ -1095,7 +1097,7 @@ public class AdminController : ControllerBase
                     else
                     {
                         _logger.LogWarning("Failed to fetch external track metadata for {Provider} ID {Id}", 
-                            request.ExternalProvider, request.ExternalId);
+                            normalizedProvider, request.ExternalId);
                     }
                 }
                 catch (Exception ex)
@@ -1141,7 +1143,7 @@ public class AdminController : ControllerBase
                 artist = trackArtist ?? "Unknown",
                 album = trackAlbum ?? "Unknown",
                 isLocal = isLocalMapping,
-                externalProvider = hasExternalMapping ? request.ExternalProvider : null
+                externalProvider = hasExternalMapping ? request.ExternalProvider!.ToLowerInvariant() : null
             };
             
             return Ok(new