feat: implement tweakable utility workers concurrency, instead of hard-coded value set to 5

app.py

@@ -51,7 +51,6 @@ if _umask_value:
         # Defer logging setup; avoid failing on invalid UMASK
         pass
 
-
 # Import and initialize routes (this will start the watch manager)
 from routes.auth.credentials import router as credentials_router  # noqa: E402
 from routes.auth.auth import router as auth_router  # noqa: E402
@@ -65,14 +64,8 @@ from routes.core.history import router as history_router  # noqa: E402
 from routes.system.progress import router as prgs_router  # noqa: E402
 from routes.system.config import router as config_router  # noqa: E402
 
-
-# Import Celery configuration and manager
 from routes.utils.celery_config import REDIS_URL  # noqa: E402
 
-# Import authentication system
-
-# Import watch manager controls (start/stop) without triggering side effects
-
 
 # Configure application-wide logging
 def setup_logging():

spotizerr-ui/src/components/config/ServerTab.tsx

@@ -110,6 +110,76 @@ function SpotifyApiForm() {
   );
 }
 
+function UtilityConcurrencyForm() {
+  const queryClient = useQueryClient();
+  const { data: configData, isLoading } = useQuery({
+    queryKey: ["config"],
+    queryFn: () => authApiClient.getConfig<any>(),
+  });
+
+  const { register, handleSubmit, reset, formState: { isDirty } } = useForm<{ utilityConcurrency: number }>();
+
+  useEffect(() => {
+    if (configData) {
+      reset({ utilityConcurrency: Number(configData.utilityConcurrency ?? 1) });
+    }
+  }, [configData, reset]);
+
+  const mutation = useMutation({
+    mutationFn: (payload: { utilityConcurrency: number }) => authApiClient.updateConfig(payload),
+    onSuccess: () => {
+      toast.success("Utility worker concurrency saved!");
+      queryClient.invalidateQueries({ queryKey: ["config"] });
+    },
+    onError: (e) => {
+      toast.error(`Failed to save: ${(e as any).message}`);
+    },
+  });
+
+  const onSubmit = (values: { utilityConcurrency: number }) => {
+    const value = Math.max(1, Number(values.utilityConcurrency || 1));
+    mutation.mutate({ utilityConcurrency: value });
+  };
+
+  if (isLoading) return <p className="text-content-muted dark:text-content-muted-dark">Loading server settings...</p>;
+
+  return (
+    <form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
+      <div className="flex items-center justify-end mb-2">
+        <div className="flex items-center gap-3">
+          <button
+            type="submit"
+            disabled={mutation.isPending || !isDirty}
+            className="px-4 py-2 bg-button-primary hover:bg-button-primary-hover text-button-primary-text rounded-md disabled:opacity-50"
+            title="Save Utility Concurrency"
+          >
+            {mutation.isPending ? (
+              <img src="/spinner.svg" alt="Saving" className="w-5 h-5 animate-spin logo" />
+            ) : (
+              <img src="/save.svg" alt="Save" className="w-5 h-5 logo" />
+            )}
+          </button>
+        </div>
+      </div>
+
+      <div className="flex flex-col gap-2">
+        <label htmlFor="utilityConcurrency" className="text-content-primary dark:text-content-primary-dark">Utility Worker Concurrency</label>
+        <input
+          id="utilityConcurrency"
+          type="number"
+          min={1}
+          step={1}
+          {...register("utilityConcurrency", { valueAsNumber: true })}
+          className="block w-full p-2 border bg-input-background dark:bg-input-background-dark border-input-border dark:border-input-border-dark rounded-md focus:outline-none focus:ring-2 focus:ring-input-focus"
+          placeholder="1"
+        />
+        <p className="text-xs text-content-secondary dark:text-content-secondary-dark">Controls concurrency of the utility Celery worker. Minimum 1.</p>
+      </div>
+    </form>
+  );
+}
+
+// --- Components ---
 function WebhookForm() {
   const queryClient = useQueryClient();
   const { data, isLoading } = useQuery({ queryKey: ["webhookConfig"], queryFn: fetchWebhookConfig });
@@ -223,6 +293,12 @@ export function ServerTab() {
         <SpotifyApiForm />
       </div>
       <hr className="border-border dark:border-border-dark" />
+      <div>
+        <h3 className="text-xl font-semibold text-content-primary dark:text-content-primary-dark">Utility Worker</h3>
+        <p className="text-sm text-content-muted dark:text-content-muted-dark mt-1">Tune background utility worker concurrency for low-powered systems.</p>
+        <UtilityConcurrencyForm />
+      </div>
+      <hr className="border-border dark:border-border-dark" />
       <div>
         <h3 className="text-xl font-semibold text-content-primary dark:text-content-primary-dark">Webhooks</h3>
         <p className="text-sm text-content-muted dark:text-content-muted-dark mt-1">

spotizerr-ui/src/contexts/SettingsProvider.tsx

@@ -32,6 +32,7 @@ export type FlatAppSettings = {
 	deezer: string;
 	deezerQuality: "MP3_128" | "MP3_320" | "FLAC";
 	maxConcurrentDownloads: number;
+	utilityConcurrency: number;
 	realTime: boolean;
 	fallback: boolean;
 	convertTo: "MP3" | "AAC" | "OGG" | "OPUS" | "FLAC" | "WAV" | "ALAC" | "";
@@ -72,6 +73,7 @@ const defaultSettings: FlatAppSettings = {
 	deezer: "",
 	deezerQuality: "MP3_128",
 	maxConcurrentDownloads: 3,
+	utilityConcurrency: 1,
 	realTime: false,
 	fallback: false,
 	convertTo: "",
@@ -135,6 +137,7 @@ const fetchSettings = async (): Promise<FlatAppSettings> => {
 			// Ensure required frontend-only fields exist
 			recursiveQuality: Boolean((camelData as any).recursiveQuality ?? false),
 			realTimeMultiplier: Number((camelData as any).realTimeMultiplier ?? 0),
+			utilityConcurrency: Number((camelData as any).utilityConcurrency ?? 1),
 			// Ensure watch subkeys default if missing
 			watch: {
 				...(camelData.watch as any),

spotizerr-ui/src/contexts/settings-context.ts

@@ -8,6 +8,7 @@ export interface AppSettings {
   deezer: string;
   deezerQuality: "MP3_128" | "MP3_320" | "FLAC";
   maxConcurrentDownloads: number;
+  utilityConcurrency: number;
   realTime: boolean;
   fallback: boolean;
   convertTo: "MP3" | "AAC" | "OGG" | "OPUS" | "FLAC" | "WAV" | "ALAC" | "";

spotizerr-ui/src/lib/api-client.ts

@@ -369,6 +369,17 @@ class AuthApiClient {
   get client() {
     return this.apiClient;
   }
+
+  // General config helpers
+  async getConfig<T = any>(): Promise<T> {
+    const response = await this.apiClient.get<T>("/config");
+    return response.data;
+    }
+
+  async updateConfig<T = any>(partial: Record<string, unknown>): Promise<T> {
+    const response = await this.apiClient.put<T>("/config", partial);
+    return response.data;
+  }
 }
 
 // Create and export a singleton instance