feat: async generation queue with serial execution

Generations now return immediately with a 'generating' status and appear in history right away. TTS runs in a serial background queue to avoid GPU contention. Users can kick off multiple generations without blocking. - Async POST /generate creates DB record immediately, queues TTS work - Serial generation queue prevents concurrent GPU access (Metal/CUDA/CPU) - SSE endpoint GET /generate/{id}/status for real-time completion tracking - Retry endpoint POST /generate/{id}/retry for failed generations - Store engine and model_size on generation records for retry support - History cards show animated loader (react-loaders) for generating/playing - Failed generations show retry button instead of actions menu - Model downloads happen inline in the queue instead of rejecting with 202 - Stale 'generating' records marked as failed on server startup - Autoplay on generate setting (default: on) - Show engine name on generation cards - Remove sidebar generation spinner - Checkbox alignment fix in settings
2026-09-17 22:00:40 -07:00 · 2026-03-13 10:02:41 -07:00
parent 52285362ce
commit 655a60ca81
22 changed files with 755 additions and 315 deletions
@@ -1,13 +1,15 @@
+import { useQueryClient } from '@tanstack/react-query';
 import {
-  AudioWaveform,
  Download,
  FileArchive,
  Loader2,
  MoreHorizontal,
  Play,
+  RotateCcw,
  Trash2,
 } from 'lucide-react';
 import { useEffect, useRef, useState } from 'react';
+import Loader from 'react-loaders';
 import { Button } from '@/components/ui/button';
 import {
  Dialog,
@@ -36,7 +38,8 @@ import {
  useImportGeneration,
 } from '@/lib/hooks/useHistory';
 import { cn } from '@/lib/utils/cn';
-import { formatDate, formatDuration } from '@/lib/utils/format';
+import { formatDate, formatDuration, formatEngineName } from '@/lib/utils/format';
+import { useGenerationStore } from '@/stores/generationStore';
 import { usePlayerStore } from '@/stores/playerStore';

 // OLD TABLE-BASED COMPONENT - REMOVED (can be found in git history)
@@ -54,9 +57,12 @@ export function HistoryTable() {
  const [importDialogOpen, setImportDialogOpen] = useState(false);
  const [selectedFile, setSelectedFile] = useState<File | null>(null);
  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false);
-  const [generationToDelete, setGenerationToDelete] = useState<{ id: string; name: string } | null>(null);
+  const [generationToDelete, setGenerationToDelete] = useState<{ id: string; name: string } | null>(
+    null,
+  );
  const limit = 20;
  const { toast } = useToast();
+  const queryClient = useQueryClient();

  const {
    data: historyData,
@@ -71,6 +77,7 @@ export function HistoryTable() {
  const exportGeneration = useExportGeneration();
  const exportGenerationAudio = useExportGenerationAudio();
  const importGeneration = useImportGeneration();
+  const addPendingGeneration = useGenerationStore((state) => state.addPendingGeneration);
  const setAudioWithAutoPlay = usePlayerStore((state) => state.setAudioWithAutoPlay);
  const restartCurrentAudio = usePlayerStore((state) => state.restartCurrentAudio);
  const currentAudioId = usePlayerStore((state) => state.audioId);
@@ -194,6 +201,20 @@ export function HistoryTable() {
    }
  };

+  const handleRetry = async (generationId: string) => {
+    try {
+      const result = await apiClient.retryGeneration(generationId);
+      addPendingGeneration(result.id);
+      queryClient.invalidateQueries({ queryKey: ['history'] });
+    } catch (error) {
+      toast({
+        title: 'Retry failed',
+        description: error instanceof Error ? error.message : 'Could not retry generation',
+        variant: 'destructive',
+      });
+    }
+  };
+
  const handleImportConfirm = () => {
    if (selectedFile) {
      importGeneration.mutate(selectedFile, {
@@ -250,22 +271,30 @@ export function HistoryTable() {
          >
            {history.map((gen) => {
              const isCurrentlyPlaying = currentAudioId === gen.id && isPlaying;
+              const isGenerating = gen.status === 'generating';
+              const isFailed = gen.status === 'failed';
+              const isPlayable = !isGenerating && !isFailed;
              return (
                <div
                  key={gen.id}
-                  role="button"
-                  tabIndex={0}
+                  role={isPlayable ? 'button' : undefined}
+                  tabIndex={isPlayable ? 0 : undefined}
                  className={cn(
-                    'flex items-stretch gap-4 h-26 border rounded-md p-3 bg-card hover:bg-muted/70 transition-colors text-left w-full',
+                    'flex items-stretch gap-4 h-26 border rounded-md p-3 bg-card transition-colors text-left w-full',
+                    isPlayable && 'hover:bg-muted/70 cursor-pointer',
                    isCurrentlyPlaying && 'bg-muted/70',
                  )}
                  aria-label={
-                    isCurrentlyPlaying
-                      ? `Sample from ${gen.profile_name}, ${formatDuration(gen.duration)}, ${formatDate(gen.created_at)}. Playing. Press Enter to restart.`
-                      : `Sample from ${gen.profile_name}, ${formatDuration(gen.duration)}, ${formatDate(gen.created_at)}. Press Enter to play.`
+                    isGenerating
+                      ? `Generating speech for ${gen.profile_name}...`
+                      : isFailed
+                        ? `Generation failed for ${gen.profile_name}`
+                        : isCurrentlyPlaying
+                          ? `Sample from ${gen.profile_name}, ${formatDuration(gen.duration ?? 0)}, ${formatDate(gen.created_at)}. Playing. Press Enter to restart.`
+                          : `Sample from ${gen.profile_name}, ${formatDuration(gen.duration ?? 0)}, ${formatDate(gen.created_at)}. Press Enter to play.`
                  }
                  onMouseDown={(e) => {
-                    // Don't trigger play if clicking on textarea or if text is selected
+                    if (!isPlayable) return;
                    const target = e.target as HTMLElement;
                    if (target.closest('textarea') || window.getSelection()?.toString()) {
                      return;
@@ -273,6 +302,7 @@ export function HistoryTable() {
                    handlePlay(gen.id, gen.text, gen.profile_id);
                  }}
                  onKeyDown={(e) => {
+                    if (!isPlayable) return;
                    const target = e.target as HTMLElement;
                    if (target.closest('textarea') || target.closest('button')) return;
                    if (e.key === 'Enter' || e.key === ' ') {
@@ -281,9 +311,14 @@ export function HistoryTable() {
                    }
                  }}
                >
-                  {/* Waveform icon */}
-                  <div className="flex items-center shrink-0">
-                    <AudioWaveform className="h-5 w-5 text-muted-foreground" />
+                  {/* Status icon */}
+                  <div className="flex items-center shrink-0 w-10 justify-center overflow-hidden">
+                    <div className="scale-50">
+                      <Loader
+                        type={isGenerating ? 'line-scale' : 'line-scale-pulse-out-rapid'}
+                        active={isGenerating || isCurrentlyPlaying}
+                      />
+                    </div>
                  </div>

                  {/* Left side - Meta information */}
@@ -294,11 +329,22 @@ export function HistoryTable() {
                    <div className="flex items-center gap-2">
                      <span className="text-xs text-muted-foreground">{gen.language}</span>
                      <span className="text-xs text-muted-foreground">
-                        {formatDuration(gen.duration)}
+                        {formatEngineName(gen.engine, gen.model_size)}
                      </span>
+                      {isFailed ? (
+                        <span className="text-xs text-destructive">Failed</span>
+                      ) : !isGenerating ? (
+                        <span className="text-xs text-muted-foreground">
+                          {formatDuration(gen.duration ?? 0)}
+                        </span>
+                      ) : null}
                    </div>
                    <div className="text-xs text-muted-foreground">
-                      {formatDate(gen.created_at)}
+                      {isGenerating ? (
+                        <span className="text-accent">Generating...</span>
+                      ) : (
+                        formatDate(gen.created_at)
+                      )}
                    </div>
                  </div>

@@ -308,58 +354,70 @@ export function HistoryTable() {
                      value={gen.text}
                      className="flex-1 resize-none text-sm text-muted-foreground select-text"
                      readOnly
-                      aria-label={`Transcript for sample from ${gen.profile_name}, ${formatDuration(gen.duration)}`}
+                      aria-label={`Transcript for sample from ${gen.profile_name}, ${formatDuration(gen.duration ?? 0)}`}
                    />
                  </div>

-                  {/* Far right - Ellipsis actions */}
+                  {/* Far right - Actions */}
                  <div
-                    className="w-10 shrink-0 flex justify-end"
+                    className="w-10 shrink-0 flex justify-end items-center"
                    onMouseDown={(e) => e.stopPropagation()}
                    onClick={(e) => e.stopPropagation()}
                  >
-                    <DropdownMenu>
-                      <DropdownMenuTrigger asChild>
-                        <Button
-                          variant="ghost"
-                          size="icon"
-                          className="h-8 w-8"
-                          aria-label="Actions"
-                        >
-                          <MoreHorizontal className="h-4 w-4" />
-                        </Button>
-                      </DropdownMenuTrigger>
-                      <DropdownMenuContent align="end">
-                        <DropdownMenuItem
-                          onClick={() => handlePlay(gen.id, gen.text, gen.profile_id)}
-                        >
-                          <Play className="mr-2 h-4 w-4" />
-                          Play
-                        </DropdownMenuItem>
-                        <DropdownMenuItem
-                          onClick={() => handleDownloadAudio(gen.id, gen.text)}
-                          disabled={exportGenerationAudio.isPending}
-                        >
-                          <Download className="mr-2 h-4 w-4" />
-                          Export Audio
-                        </DropdownMenuItem>
-                        <DropdownMenuItem
-                          onClick={() => handleExportPackage(gen.id, gen.text)}
-                          disabled={exportGeneration.isPending}
-                        >
-                          <FileArchive className="mr-2 h-4 w-4" />
-                          Export Package
-                        </DropdownMenuItem>
-                        <DropdownMenuItem
-                          onClick={() => handleDeleteClick(gen.id, gen.profile_name)}
-                          disabled={deleteGeneration.isPending}
-                          className="text-destructive focus:text-destructive"
-                        >
-                          <Trash2 className="mr-2 h-4 w-4" />
-                          Delete
-                        </DropdownMenuItem>
-                      </DropdownMenuContent>
-                    </DropdownMenu>
+                    {isFailed ? (
+                      <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-8 w-8"
+                        aria-label="Retry generation"
+                        onClick={() => handleRetry(gen.id)}
+                      >
+                        <RotateCcw className="h-4 w-4" />
+                      </Button>
+                    ) : isPlayable ? (
+                      <DropdownMenu>
+                        <DropdownMenuTrigger asChild>
+                          <Button
+                            variant="ghost"
+                            size="icon"
+                            className="h-8 w-8"
+                            aria-label="Actions"
+                          >
+                            <MoreHorizontal className="h-4 w-4" />
+                          </Button>
+                        </DropdownMenuTrigger>
+                        <DropdownMenuContent align="end">
+                          <DropdownMenuItem
+                            onClick={() => handlePlay(gen.id, gen.text, gen.profile_id)}
+                          >
+                            <Play className="mr-2 h-4 w-4" />
+                            Play
+                          </DropdownMenuItem>
+                          <DropdownMenuItem
+                            onClick={() => handleDownloadAudio(gen.id, gen.text)}
+                            disabled={exportGenerationAudio.isPending}
+                          >
+                            <Download className="mr-2 h-4 w-4" />
+                            Export Audio
+                          </DropdownMenuItem>
+                          <DropdownMenuItem
+                            onClick={() => handleExportPackage(gen.id, gen.text)}
+                            disabled={exportGeneration.isPending}
+                          >
+                            <FileArchive className="mr-2 h-4 w-4" />
+                            Export Package
+                          </DropdownMenuItem>
+                          <DropdownMenuItem
+                            onClick={() => handleDeleteClick(gen.id, gen.profile_name)}
+                            disabled={deleteGeneration.isPending}
+                            className="text-destructive focus:text-destructive"
+                          >
+                            <Trash2 className="mr-2 h-4 w-4" />
+                            Delete
+                          </DropdownMenuItem>
+                        </DropdownMenuContent>
+                      </DropdownMenu>
+                    ) : null}
                  </div>
                </div>
              );
@@ -387,7 +445,8 @@ export function HistoryTable() {
          <DialogHeader>
            <DialogTitle>Delete Generation</DialogTitle>
            <DialogDescription>
-              Are you sure you want to delete this generation from "{generationToDelete?.name}"? This action cannot be undone.
+              Are you sure you want to delete this generation from "{generationToDelete?.name}"?
+              This action cannot be undone.
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
@@ -124,6 +124,7 @@ export function ConnectionForm() {
          <div className="flex items-start space-x-3">
            <Checkbox
              id="keepServerRunning"
+              className="mt-[6px]"
              checked={keepServerRunningOnClose}
              onCheckedChange={(checked: boolean) => {
                setKeepServerRunningOnClose(checked);
@@ -158,6 +159,7 @@ export function ConnectionForm() {
            <div className="flex items-start space-x-3">
              <Checkbox
                id="allowNetworkAccess"
+                className="mt-[6px]"
                checked={mode === 'remote'}
                onCheckedChange={(checked: boolean) => {
                  setMode(checked ? 'remote' : 'local');
@@ -10,6 +10,8 @@ export function GenerationSettings() {
  const setCrossfadeMs = useServerStore((state) => state.setCrossfadeMs);
  const normalizeAudio = useServerStore((state) => state.normalizeAudio);
  const setNormalizeAudio = useServerStore((state) => state.setNormalizeAudio);
+  const autoplayOnGenerate = useServerStore((state) => state.autoplayOnGenerate);
+  const setAutoplayOnGenerate = useServerStore((state) => state.setAutoplayOnGenerate);

  return (
    <Card role="region" aria-label="Generation Settings" tabIndex={0}>
@@ -35,7 +37,7 @@ export function GenerationSettings() {
              value={[maxChunkChars]}
              onValueChange={([value]) => setMaxChunkChars(value)}
              min={100}
-              max={2000}
+              max={5000}
              step={50}
              aria-label="Auto-chunking character limit"
            />
@@ -73,6 +75,7 @@ export function GenerationSettings() {
              id="normalizeAudio"
              checked={normalizeAudio}
              onCheckedChange={setNormalizeAudio}
+              className="mt-[6px]"
            />
            <div className="space-y-1">
              <label
@@ -86,6 +89,26 @@ export function GenerationSettings() {
              </p>
            </div>
          </div>
+
+          <div className="flex items-start gap-3">
+            <Checkbox
+              id="autoplayOnGenerate"
+              checked={autoplayOnGenerate}
+              onCheckedChange={setAutoplayOnGenerate}
+              className="mt-[6px]"
+            />
+            <div className="space-y-1">
+              <label
+                htmlFor="autoplayOnGenerate"
+                className="text-sm font-medium leading-none cursor-pointer"
+              >
+                Autoplay on generate
+              </label>
+              <p className="text-sm text-muted-foreground">
+                Automatically play audio when a generation completes.
+              </p>
+            </div>
+          </div>
        </div>
      </CardContent>
    </Card>
@@ -1,9 +1,7 @@
 import { Link, useMatchRoute } from '@tanstack/react-router';
-import { Box, BookOpen, Loader2, Mic, Server, Speaker, Volume2 } from 'lucide-react';
+import { BookOpen, Box, Mic, Server, Speaker, Volume2 } from 'lucide-react';
 import voiceboxLogo from '@/assets/voicebox-logo.png';
 import { cn } from '@/lib/utils/cn';
-import { useGenerationStore } from '@/stores/generationStore';
-import { usePlayerStore } from '@/stores/playerStore';

 interface SidebarProps {
  isMacOS?: boolean;
@@ -19,9 +17,6 @@ const tabs = [
 ];

 export function Sidebar({ isMacOS }: SidebarProps) {
-  const isGenerating = useGenerationStore((state) => state.isGenerating);
-  const audioUrl = usePlayerStore((state) => state.audioUrl);
-  const isPlayerVisible = !!audioUrl;
  const matchRoute = useMatchRoute();

  return (
@@ -42,9 +37,7 @@ export function Sidebar({ isMacOS }: SidebarProps) {
          const Icon = tab.icon;
          // For index route, use exact match; for others, use default matching
          const isActive =
-            tab.path === '/'
-              ? matchRoute({ to: '/', exact: true })
-              : matchRoute({ to: tab.path });
+            tab.path === '/' ? matchRoute({ to: '/', exact: true }) : matchRoute({ to: tab.path });

          return (
            <Link
@@ -63,21 +56,6 @@ export function Sidebar({ isMacOS }: SidebarProps) {
          );
        })}
      </div>
-
-      {/* Spacer to push loader to bottom */}
-      <div className="flex-1" />
-
-      {/* Generation Loader */}
-      {isGenerating && (
-        <div
-          className={cn(
-            'w-full flex items-center justify-center transition-all duration-200',
-            isPlayerVisible ? 'mb-[120px]' : 'mb-0',
-          )}
-        >
-          <Loader2 className="h-6 w-6 text-accent animate-spin" />
-        </div>
-      )}
    </div>
  );
 }
@@ -1,5 +1,5 @@
-import * as React from 'react';
 import { Check } from 'lucide-react';
+import * as React from 'react';
 import { cn } from '@/lib/utils/cn';

 export interface CheckboxProps {
@@ -1,4 +1,5 @@
@import "tailwindcss" source(".");
+@import "loaders.css/loaders.min.css";

@theme {
  --radius-sm: calc(var(--radius) - 4px);
@@ -155,3 +156,18 @@
  animation: fadeIn 0.5s ease-out 0.15s forwards;
  opacity: 0;
 }
+
+/* react-loaders */
+.line-scale-pulse-out-rapid > div,
+.line-scale > div {
+  background-color: hsl(var(--accent)) !important;
+}
+
+.loader-hidden {
+  display: block;
+}
+
+.loader-hidden > div > div {
+  animation-play-state: paused !important;
+  background-color: hsl(var(--muted-foreground)) !important;
+}
@@ -200,6 +200,12 @@ class ApiClient {
    });
  }

+  async retryGeneration(generationId: string): Promise<GenerationResponse> {
+    return this.request<GenerationResponse>(`/generate/${generationId}/retry`, {
+      method: 'POST',
+    });
+  }
+
  // History
  async listHistory(query?: HistoryQuery): Promise<HistoryListResponse> {
    const params = new URLSearchParams();
@@ -278,6 +284,11 @@ class ApiClient {
    return response.json();
  }

+  // Generation status SSE
+  getGenerationStatusUrl(generationId: string): string {
+    return `${this.getBaseUrl()}/generate/${generationId}/status`;
+  }
+
  // Audio
  getAudioUrl(audioId: string): string {
    return `${this.getBaseUrl()}/audio/${audioId}`;
@@ -46,9 +46,14 @@ export interface GenerationResponse {
  profile_id: string;
  text: string;
  language: string;
-  audio_path: string;
-  duration: number;
+  audio_path?: string;
+  duration?: number;
  seed?: number;
+  instruct?: string;
+  engine?: string;
+  model_size?: string;
+  status: 'generating' | 'completed' | 'failed';
+  error?: string;
  created_at: string;
 }

@@ -8,7 +8,6 @@ import { LANGUAGE_CODES, type LanguageCode } from '@/lib/constants/languages';
 import { useGeneration } from '@/lib/hooks/useGeneration';
 import { useModelDownloadToast } from '@/lib/hooks/useModelDownloadToast';
 import { useGenerationStore } from '@/stores/generationStore';
-import { usePlayerStore } from '@/stores/playerStore';
 import { useServerStore } from '@/stores/serverStore';

 const generationSchema = z.object({
@@ -30,8 +29,7 @@ interface UseGenerationFormOptions {
 export function useGenerationForm(options: UseGenerationFormOptions = {}) {
  const { toast } = useToast();
  const generation = useGeneration();
-  const setAudioWithAutoPlay = usePlayerStore((state) => state.setAudioWithAutoPlay);
-  const setIsGenerating = useGenerationStore((state) => state.setIsGenerating);
+  const addPendingGeneration = useGenerationStore((state) => state.addPendingGeneration);
  const maxChunkChars = useServerStore((state) => state.maxChunkChars);
  const crossfadeMs = useServerStore((state) => state.crossfadeMs);
  const normalizeAudio = useServerStore((state) => state.normalizeAudio);
@@ -71,8 +69,6 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
    }

    try {
-      setIsGenerating(true);
-
      const engine = data.engine || 'qwen';
      const modelName =
        engine === 'luxtts'
@@ -93,6 +89,7 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
                ? 'Qwen TTS 1.7B'
                : 'Qwen TTS 0.6B';

+      // Check if model needs downloading
      try {
        const modelStatus = await apiClient.getModelStatus();
        const model = modelStatus.models.find((m) => m.model_name === modelName);
@@ -106,6 +103,7 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
      }

      const isQwen = engine === 'qwen';
+      // This now returns immediately with status="generating"
      const result = await generation.mutateAsync({
        profile_id: selectedProfileId,
        text: data.text,
@@ -119,14 +117,10 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
        normalize: normalizeAudio,
      });

-      toast({
-        title: 'Generation complete!',
-        description: `Audio generated (${result.duration.toFixed(2)}s)`,
-      });
-
-      const audioUrl = apiClient.getAudioUrl(result.id);
-      setAudioWithAutoPlay(audioUrl, result.id, selectedProfileId, data.text.substring(0, 50));
+      // Track this generation for SSE status updates
+      addPendingGeneration(result.id);

+      // Reset form immediately — user can start typing again
      form.reset({
        text: '',
        language: data.language,
@@ -143,7 +137,6 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
        variant: 'destructive',
      });
    } finally {
-      setIsGenerating(false);
      setDownloadingModelName(null);
      setDownloadingDisplayName(null);
    }
@@ -0,0 +1,118 @@
+import { useQueryClient } from '@tanstack/react-query';
+import { useEffect, useRef } from 'react';
+import { useToast } from '@/components/ui/use-toast';
+import { apiClient } from '@/lib/api/client';
+import { useGenerationStore } from '@/stores/generationStore';
+import { usePlayerStore } from '@/stores/playerStore';
+import { useServerStore } from '@/stores/serverStore';
+
+interface GenerationStatusEvent {
+  id: string;
+  status: 'generating' | 'completed' | 'failed';
+  duration?: number;
+  error?: string;
+}
+
+/**
+ * Subscribes to SSE for all pending generations. When a generation completes,
+ * invalidates the history query, removes it from pending, and auto-plays
+ * if the player is idle.
+ */
+export function useGenerationProgress() {
+  const queryClient = useQueryClient();
+  const { toast } = useToast();
+  const pendingIds = useGenerationStore((s) => s.pendingGenerationIds);
+  const removePendingGeneration = useGenerationStore((s) => s.removePendingGeneration);
+  const isPlaying = usePlayerStore((s) => s.isPlaying);
+  const setAudioWithAutoPlay = usePlayerStore((s) => s.setAudioWithAutoPlay);
+  const autoplayOnGenerate = useServerStore((s) => s.autoplayOnGenerate);
+
+  // Keep refs to avoid stale closures in EventSource handlers
+  const isPlayingRef = useRef(isPlaying);
+  const autoplayRef = useRef(autoplayOnGenerate);
+  isPlayingRef.current = isPlaying;
+  autoplayRef.current = autoplayOnGenerate;
+
+  // Track active EventSource instances
+  const eventSourcesRef = useRef<Map<string, EventSource>>(new Map());
+
+  useEffect(() => {
+    const currentSources = eventSourcesRef.current;
+
+    // Close SSE connections for IDs no longer pending
+    for (const [id, source] of currentSources.entries()) {
+      if (!pendingIds.has(id)) {
+        source.close();
+        currentSources.delete(id);
+      }
+    }
+
+    // Open SSE connections for new pending IDs
+    for (const id of pendingIds) {
+      if (currentSources.has(id)) continue;
+
+      const url = apiClient.getGenerationStatusUrl(id);
+      const source = new EventSource(url);
+
+      source.onmessage = (event) => {
+        try {
+          const data: GenerationStatusEvent = JSON.parse(event.data);
+
+          if (data.status === 'completed') {
+            source.close();
+            currentSources.delete(id);
+            removePendingGeneration(id);
+
+            // Refresh history to pick up the completed generation
+            queryClient.invalidateQueries({ queryKey: ['history'] });
+
+            toast({
+              title: 'Generation complete!',
+              description: data.duration
+                ? `Audio generated (${data.duration.toFixed(2)}s)`
+                : 'Audio generated',
+            });
+
+            // Auto-play if enabled and nothing is currently playing
+            if (autoplayRef.current && !isPlayingRef.current) {
+              const genAudioUrl = apiClient.getAudioUrl(id);
+              setAudioWithAutoPlay(genAudioUrl, id, '', '');
+            }
+          } else if (data.status === 'failed') {
+            source.close();
+            currentSources.delete(id);
+            removePendingGeneration(id);
+
+            queryClient.invalidateQueries({ queryKey: ['history'] });
+
+            toast({
+              title: 'Generation failed',
+              description: data.error || 'An error occurred during generation',
+              variant: 'destructive',
+            });
+          }
+        } catch {
+          // Ignore parse errors from heartbeats etc
+        }
+      };
+
+      source.onerror = () => {
+        // EventSource auto-reconnects, but if we get repeated errors
+        // just clean up
+        source.close();
+        currentSources.delete(id);
+        removePendingGeneration(id);
+      };
+
+      currentSources.set(id, source);
+    }
+
+    return () => {
+      // Cleanup on unmount
+      for (const source of currentSources.values()) {
+        source.close();
+      }
+      currentSources.clear();
+    };
+  }, [pendingIds, removePendingGeneration, queryClient, toast, setAudioWithAutoPlay]);
+}
@@ -17,6 +17,7 @@ export function useRestoreActiveTasks() {
  const [activeDownloads, setActiveDownloads] = useState<ActiveDownloadTask[]>([]);
  const setIsGenerating = useGenerationStore((state) => state.setIsGenerating);
  const setActiveGenerationId = useGenerationStore((state) => state.setActiveGenerationId);
+  const addPendingGeneration = useGenerationStore((state) => state.addPendingGeneration);

  // Track which downloads we've seen to detect new ones
  const seenDownloadsRef = useRef<Set<string>>(new Set());
@@ -25,10 +26,13 @@ export function useRestoreActiveTasks() {
    try {
      const tasks = await apiClient.getActiveTasks();

-      // Update generation state
+      // Update generation state — restore pending generations (e.g., after page refresh)
      if (tasks.generations.length > 0) {
        setIsGenerating(true);
        setActiveGenerationId(tasks.generations[0].task_id);
+        for (const gen of tasks.generations) {
+          addPendingGeneration(gen.task_id);
+        }
      } else {
        // Only clear if we were tracking a generation
        const currentId = useGenerationStore.getState().activeGenerationId;
@@ -21,10 +21,25 @@ export function formatDate(date: string | Date): string {
  } else {
    dateObj = date;
  }
-  
+
  return formatDistance(dateObj, new Date(), { addSuffix: true }).replace(/^about /i, '');
 }

+const ENGINE_DISPLAY_NAMES: Record<string, string> = {
+  qwen: 'Qwen',
+  luxtts: 'LuxTTS',
+  chatterbox: 'Chatterbox',
+  chatterbox_turbo: 'Chatterbox Turbo',
+};
+
+export function formatEngineName(engine?: string, modelSize?: string): string {
+  const name = ENGINE_DISPLAY_NAMES[engine ?? 'qwen'] ?? engine ?? 'Qwen';
+  if (engine === 'qwen' && modelSize) {
+    return `${name} ${modelSize}`;
+  }
+  return name;
+}
+
 export function formatFileSize(bytes: number): string {
  if (bytes === 0) return '0 Bytes';
  const k = 1024;
@@ -8,8 +8,10 @@ import { Sidebar } from '@/components/Sidebar';
 import { StoriesTab } from '@/components/StoriesTab/StoriesTab';
 import { Toaster } from '@/components/ui/toaster';
 import { VoicesTab } from '@/components/VoicesTab/VoicesTab';
+import { useGenerationProgress } from '@/lib/hooks/useGenerationProgress';
 import { useModelDownloadToast } from '@/lib/hooks/useModelDownloadToast';
 import { MODEL_DISPLAY_NAMES, useRestoreActiveTasks } from '@/lib/hooks/useRestoreActiveTasks';
+
 // Simple platform check that works in both web and Tauri
 const isMacOS = () => navigator.platform.toLowerCase().includes('mac');

@@ -18,6 +20,9 @@ function RootLayout() {
  // Monitor active downloads/generations and show toasts for them
  const activeDownloads = useRestoreActiveTasks();

+  // Subscribe to SSE for pending generations — handles completion, auto-play, and history refresh
+  useGenerationProgress();
+
  return (
    <AppFrame>
      <div className="flex flex-1 min-h-0 overflow-hidden">
@@ -1,15 +1,37 @@
 import { create } from 'zustand';

 interface GenerationState {
+  /** IDs of generations currently in progress */
+  pendingGenerationIds: Set<string>;
+  /** Whether any generation is in progress (derived convenience) */
  isGenerating: boolean;
-  activeGenerationId: string | null;
+  addPendingGeneration: (id: string) => void;
+  removePendingGeneration: (id: string) => void;
+  /** Legacy setter for backward compat with useRestoreActiveTasks */
  setIsGenerating: (generating: boolean) => void;
  setActiveGenerationId: (id: string | null) => void;
+  activeGenerationId: string | null;
 }

 export const useGenerationStore = create<GenerationState>((set) => ({
+  pendingGenerationIds: new Set(),
  isGenerating: false,
  activeGenerationId: null,
+
+  addPendingGeneration: (id) =>
+    set((state) => {
+      const next = new Set(state.pendingGenerationIds);
+      next.add(id);
+      return { pendingGenerationIds: next, isGenerating: true };
+    }),
+
+  removePendingGeneration: (id) =>
+    set((state) => {
+      const next = new Set(state.pendingGenerationIds);
+      next.delete(id);
+      return { pendingGenerationIds: next, isGenerating: next.size > 0 };
+    }),
+
  setIsGenerating: (generating) => set({ isGenerating: generating }),
  setActiveGenerationId: (id) => set({ activeGenerationId: id }),
 }));
@@ -23,6 +23,9 @@ interface ServerStore {
  normalizeAudio: boolean;
  setNormalizeAudio: (value: boolean) => void;

+  autoplayOnGenerate: boolean;
+  setAutoplayOnGenerate: (value: boolean) => void;
+
  customModelsDir: string | null;
  setCustomModelsDir: (dir: string | null) => void;
 }
@@ -51,6 +54,9 @@ export const useServerStore = create<ServerStore>()(
      normalizeAudio: true,
      setNormalizeAudio: (value) => set({ normalizeAudio: value }),

+      autoplayOnGenerate: true,
+      setAutoplayOnGenerate: (value) => set({ autoplayOnGenerate: value }),
+
      customModelsDir: null,
      setCustomModelsDir: (dir) => set({ customModelsDir: dir }),
    }),
@@ -45,10 +45,14 @@ class Generation(Base):
    profile_id = Column(String, ForeignKey("profiles.id"), nullable=False)
    text = Column(Text, nullable=False)
    language = Column(String, default="en")
-    audio_path = Column(String, nullable=False)
-    duration = Column(Float, nullable=False)
+    audio_path = Column(String, nullable=True)
+    duration = Column(Float, nullable=True)
    seed = Column(Integer)
    instruct = Column(Text)
+    engine = Column(String, default="qwen")
+    model_size = Column(String, nullable=True)
+    status = Column(String, default="completed")  # generating, completed, failed
+    error = Column(Text, nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow)


@@ -288,6 +292,36 @@ def _run_migrations(engine):
                conn.commit()
                print("Added avatar_path column to profiles")

+    # Migration: Add status and error columns to generations table
+    if 'generations' in inspector.get_table_names():
+        columns = {col['name'] for col in inspector.get_columns('generations')}
+        if 'status' not in columns:
+            print("Migrating generations: adding status column")
+            with engine.connect() as conn:
+                conn.execute(text("ALTER TABLE generations ADD COLUMN status VARCHAR DEFAULT 'completed'"))
+                conn.commit()
+                print("Added status column to generations")
+        if 'error' not in columns:
+            print("Migrating generations: adding error column")
+            with engine.connect() as conn:
+                conn.execute(text("ALTER TABLE generations ADD COLUMN error TEXT"))
+                conn.commit()
+                print("Added error column to generations")
+        if 'engine' not in columns:
+            print("Migrating generations: adding engine column")
+            with engine.connect() as conn:
+                conn.execute(text("ALTER TABLE generations ADD COLUMN engine VARCHAR DEFAULT 'qwen'"))
+                conn.commit()
+                print("Added engine column to generations")
+        # Re-read columns after engine migration (variable name shadows outer `engine`)
+        columns = {col['name'] for col in inspector.get_columns('generations')}
+        if 'model_size' not in columns:
+            print("Migrating generations: adding model_size column")
+            with engine.connect() as conn:
+                conn.execute(text("ALTER TABLE generations ADD COLUMN model_size VARCHAR"))
+                conn.commit()
+                print("Added model_size column to generations")
+

 def get_db():
    """Get database session (generator for dependency injection)."""
@@ -29,6 +29,10 @@ async def create_generation(
    seed: Optional[int],
    db: Session,
    instruct: Optional[str] = None,
+    generation_id: Optional[str] = None,
+    status: str = "completed",
+    engine: Optional[str] = "qwen",
+    model_size: Optional[str] = None,
 ) -> GenerationResponse:
    """
    Create a new generation history entry.
@@ -42,12 +46,16 @@ async def create_generation(
        seed: Random seed used (if any)
        db: Database session
        instruct: Natural language instruction used (if any)
+        generation_id: Pre-assigned ID (for async generation flow)
+        status: Generation status (generating, completed, failed)
+        engine: TTS engine used (qwen, luxtts, chatterbox, chatterbox_turbo)
+        model_size: Model size variant (1.7B, 0.6B) — only relevant for qwen

    Returns:
        Created generation entry
    """
    db_generation = DBGeneration(
-        id=str(uuid.uuid4()),
+        id=generation_id or str(uuid.uuid4()),
        profile_id=profile_id,
        text=text,
        language=language,
@@ -55,6 +63,9 @@ async def create_generation(
        duration=duration,
        seed=seed,
        instruct=instruct,
+        engine=engine,
+        model_size=model_size,
+        status=status,
        created_at=datetime.utcnow(),
    )

@@ -65,6 +76,32 @@ async def create_generation(
    return GenerationResponse.model_validate(db_generation)


+async def update_generation_status(
+    generation_id: str,
+    status: str,
+    db: Session,
+    audio_path: Optional[str] = None,
+    duration: Optional[float] = None,
+    error: Optional[str] = None,
+) -> Optional[GenerationResponse]:
+    """Update the status of a generation (used by async generation flow)."""
+    generation = db.query(DBGeneration).filter_by(id=generation_id).first()
+    if not generation:
+        return None
+
+    generation.status = status
+    if audio_path is not None:
+        generation.audio_path = audio_path
+    if duration is not None:
+        generation.duration = duration
+    if error is not None:
+        generation.error = error
+
+    db.commit()
+    db.refresh(generation)
+    return GenerationResponse.model_validate(generation)
+
+
 async def get_generation(
    generation_id: str,
    db: Session,
@@ -143,6 +180,10 @@ async def list_generations(
            duration=generation.duration,
            seed=generation.seed,
            instruct=generation.instruct,
+            engine=generation.engine or "qwen",
+            model_size=generation.model_size,
+            status=generation.status or "completed",
+            error=generation.error,
            created_at=generation.created_at,
        ))
    
@@ -62,6 +62,9 @@ from .platform_detect import get_backend_type
 # Keep references to fire-and-forget background tasks to prevent GC
 _background_tasks: set = set()

+# Generation queue — serializes TTS inference to avoid GPU contention
+_generation_queue: asyncio.Queue = None  # type: ignore  # initialized at startup
+

 def _create_background_task(coro) -> asyncio.Task:
    """Create a background task and prevent it from being garbage collected."""
@@ -71,6 +74,24 @@ def _create_background_task(coro) -> asyncio.Task:
    return task


+async def _generation_worker():
+    """Worker that processes generation tasks one at a time."""
+    while True:
+        coro = await _generation_queue.get()
+        try:
+            await coro
+        except Exception:
+            import traceback
+            traceback.print_exc()
+        finally:
+            _generation_queue.task_done()
+
+
+def _enqueue_generation(coro):
+    """Add a generation coroutine to the serial queue."""
+    _generation_queue.put_nowait(coro)
+
+
 app = FastAPI(
    title="voicebox API",
    description="Production-quality Qwen3-TTS voice cloning API",
@@ -695,214 +716,255 @@ async def generate_speech(
    data: models.GenerationRequest,
    db: Session = Depends(get_db),
 ):
-    """Generate speech from text using a voice profile."""
+    """Generate speech from text using a voice profile.
+    
+    Creates a history entry immediately with status='generating' and kicks off
+    TTS in the background. The frontend can poll or use SSE to detect completion.
+    """
    task_manager = get_task_manager()
    generation_id = str(uuid.uuid4())
-    
-    try:
-        # Start tracking generation
-        task_manager.start_generation(
-            task_id=generation_id,
-            profile_id=data.profile_id,
-            text=data.text,
-        )
-        
-        # Get profile
-        profile = await profiles.get_profile(data.profile_id, db)
-        if not profile:
-            raise HTTPException(status_code=404, detail="Profile not found")
-        
-        # Generate audio
-        from .backends import get_tts_backend_for_engine

-        engine = data.engine or "qwen"
-        tts_model = get_tts_backend_for_engine(engine)
+    # Validate profile exists before creating the record
+    profile = await profiles.get_profile(data.profile_id, db)
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")

-        # Resolve model size (only relevant for Qwen engine)
-        model_size = data.model_size or "1.7B"
+    from .backends import get_tts_backend_for_engine
+    engine = data.engine or "qwen"
+    tts_model = get_tts_backend_for_engine(engine)
+    model_size = data.model_size or "1.7B"

-        # Check if model needs to be downloaded first
-        if engine == "qwen":
-            if not tts_model._is_model_cached(model_size):
-                model_name = f"qwen-tts-{model_size}"
+    # Create the history entry immediately with status="generating"
+    generation = await history.create_generation(
+        profile_id=data.profile_id,
+        text=data.text,
+        language=data.language,
+        audio_path="",
+        duration=0,
+        seed=data.seed,
+        db=db,
+        instruct=data.instruct,
+        generation_id=generation_id,
+        status="generating",
+        engine=engine,
+        model_size=model_size if engine == "qwen" else None,
+    )

-                async def download_model_background():
-                    try:
-                        await tts_model.load_model_async(model_size)
-                    except Exception as e:
-                        task_manager.error_download(model_name, str(e))
-
-                task_manager.start_download(model_name)
-                _create_background_task(download_model_background())
-
-                raise HTTPException(
-                    status_code=202,
-                    detail={
-                        "message": f"Model {model_size} is being downloaded. Please wait and try again.",
-                        "model_name": model_name,
-                        "downloading": True,
-                    },
-                )
-
-            # Load (or switch to) the requested model
-            await tts_model.load_model_async(model_size)
-        elif engine == "luxtts":
-            if not tts_model._is_model_cached():
-                model_name = "luxtts"
-
-                async def download_luxtts_background():
-                    try:
-                        await tts_model.load_model()
-                    except Exception as e:
-                        task_manager.error_download(model_name, str(e))
-
-                task_manager.start_download(model_name)
-                _create_background_task(download_luxtts_background())
-
-                raise HTTPException(
-                    status_code=202,
-                    detail={
-                        "message": "LuxTTS model is being downloaded. Please wait and try again.",
-                        "model_name": model_name,
-                        "downloading": True,
-                    },
-                )
-
-            await tts_model.load_model()
-        elif engine == "chatterbox":
-            if not tts_model._is_model_cached():
-                model_name = "chatterbox-tts"
-
-                async def download_chatterbox_background():
-                    try:
-                        await tts_model.load_model()
-                    except Exception as e:
-                        task_manager.error_download(model_name, str(e))
-
-                task_manager.start_download(model_name)
-                asyncio.create_task(download_chatterbox_background())
-
-                raise HTTPException(
-                    status_code=202,
-                    detail={
-                        "message": "Chatterbox model is being downloaded. Please wait and try again.",
-                        "model_name": model_name,
-                        "downloading": True,
-                    },
-                )
-
-            await tts_model.load_model()
-        elif engine == "chatterbox_turbo":
-            if not tts_model._is_model_cached():
-                model_name = "chatterbox-turbo"
-
-                async def download_chatterbox_turbo_background():
-                    try:
-                        await tts_model.load_model()
-                    except Exception as e:
-                        task_manager.error_download(model_name, str(e))
-
-                task_manager.start_download(model_name)
-                asyncio.create_task(download_chatterbox_turbo_background())
-
-                raise HTTPException(
-                    status_code=202,
-                    detail={
-                        "message": "Chatterbox Turbo model is being downloaded. Please wait and try again.",
-                        "model_name": model_name,
-                        "downloading": True,
-                    },
-                )
-
-            await tts_model.load_model()
-
-        # Create voice prompt from profile
-        voice_prompt = await profiles.create_voice_prompt_for_profile(
-            data.profile_id,
-            db,
-            use_cache=True,
-            engine=engine,
-        )
-
-        from .utils.chunked_tts import generate_chunked
-
-        # Resolve per-chunk trim function for engines that need it
-        trim_fn = None
-        if engine in ("chatterbox", "chatterbox_turbo"):
-            from .utils.audio import trim_tts_output
-            trim_fn = trim_tts_output
-
-        audio, sample_rate = await generate_chunked(
-            tts_model,
-            data.text,
-            voice_prompt,
-            language=data.language,
-            seed=data.seed,
-            instruct=data.instruct,
-            max_chunk_chars=data.max_chunk_chars,
-            crossfade_ms=data.crossfade_ms,
-            trim_fn=trim_fn,
-        )
-
-        if data.normalize:
-            from .utils.audio import normalize_audio
-            audio = normalize_audio(audio)
-
-        # Calculate duration
-        duration = len(audio) / sample_rate
-
-        # Save audio
-        audio_path = config.get_generations_dir() / f"{generation_id}.wav"
-
-        from .utils.audio import save_audio
-        import errno
+    # Track in task manager
+    task_manager.start_generation(
+        task_id=generation_id,
+        profile_id=data.profile_id,
+        text=data.text,
+    )

+    # Kick off TTS in background
+    async def _run_generation():
+        bg_db = next(get_db())
        try:
-            save_audio(audio, str(audio_path), sample_rate)
-        except BrokenPipeError:
-            raise HTTPException(
-                status_code=500,
-                detail="Audio save failed: broken pipe (the output stream was closed unexpectedly)",
-            )
-        except OSError as save_err:
-            err_no = getattr(save_err, "errno", None) or (
-                getattr(save_err.__cause__, "errno", None)
-                if save_err.__cause__
-                else None
-            )
-            if err_no == errno.ENOENT:
-                msg = f"Audio save failed: directory not found — {audio_path.parent}"
-            elif err_no == errno.EACCES:
-                msg = f"Audio save failed: permission denied — {audio_path.parent}"
-            elif err_no == errno.ENOSPC:
-                msg = "Audio save failed: no disk space remaining"
+            # Load model
+            if engine == "qwen":
+                await tts_model.load_model_async(model_size)
            else:
-                msg = f"Audio save failed: {save_err}"
-            raise HTTPException(status_code=500, detail=msg)
+                await tts_model.load_model()

-        # Create history entry
-        generation = await history.create_generation(
-            profile_id=data.profile_id,
-            text=data.text,
-            language=data.language,
-            audio_path=str(audio_path),
-            duration=duration,
-            seed=data.seed,
-            db=db,
-            instruct=data.instruct,
-        )
-        
-        # Mark generation as complete
-        task_manager.complete_generation(generation_id)
-        
-        return generation
-        
-    except ValueError as e:
-        task_manager.complete_generation(generation_id)
-        raise HTTPException(status_code=400, detail=str(e))
-    except Exception as e:
-        task_manager.complete_generation(generation_id)
-        raise HTTPException(status_code=500, detail=str(e))
+            # Create voice prompt
+            voice_prompt = await profiles.create_voice_prompt_for_profile(
+                data.profile_id,
+                bg_db,
+                use_cache=True,
+                engine=engine,
+            )
+
+            from .utils.chunked_tts import generate_chunked
+
+            trim_fn = None
+            if engine in ("chatterbox", "chatterbox_turbo"):
+                from .utils.audio import trim_tts_output
+                trim_fn = trim_tts_output
+
+            audio, sample_rate = await generate_chunked(
+                tts_model,
+                data.text,
+                voice_prompt,
+                language=data.language,
+                seed=data.seed,
+                instruct=data.instruct,
+                max_chunk_chars=data.max_chunk_chars,
+                crossfade_ms=data.crossfade_ms,
+                trim_fn=trim_fn,
+            )
+
+            if data.normalize:
+                from .utils.audio import normalize_audio
+                audio = normalize_audio(audio)
+
+            duration = len(audio) / sample_rate
+            audio_path = config.get_generations_dir() / f"{generation_id}.wav"
+
+            from .utils.audio import save_audio
+            save_audio(audio, str(audio_path), sample_rate)
+
+            # Update the record to completed
+            await history.update_generation_status(
+                generation_id=generation_id,
+                status="completed",
+                db=bg_db,
+                audio_path=str(audio_path),
+                duration=duration,
+            )
+
+        except Exception as e:
+            import traceback
+            traceback.print_exc()
+            await history.update_generation_status(
+                generation_id=generation_id,
+                status="failed",
+                db=bg_db,
+                error=str(e),
+            )
+        finally:
+            task_manager.complete_generation(generation_id)
+            bg_db.close()
+
+    _enqueue_generation(_run_generation())
+
+    return generation
+
+
+@app.post("/generate/{generation_id}/retry", response_model=models.GenerationResponse)
+async def retry_generation(generation_id: str, db: Session = Depends(get_db)):
+    """Retry a failed generation using the same parameters."""
+    gen = db.query(DBGeneration).filter_by(id=generation_id).first()
+    if not gen:
+        raise HTTPException(status_code=404, detail="Generation not found")
+
+    if (gen.status or "completed") != "failed":
+        raise HTTPException(status_code=400, detail="Only failed generations can be retried")
+
+    # Reset the record to generating
+    gen.status = "generating"
+    gen.error = None
+    gen.audio_path = ""
+    gen.duration = 0
+    db.commit()
+    db.refresh(gen)
+
+    task_manager = get_task_manager()
+    task_manager.start_generation(
+        task_id=generation_id,
+        profile_id=gen.profile_id,
+        text=gen.text,
+    )
+
+    # Resolve engine/model from stored values
+    retry_engine = gen.engine or "qwen"
+    retry_model_size = gen.model_size or "1.7B"
+
+    from .backends import get_tts_backend_for_engine
+    tts_model = get_tts_backend_for_engine(retry_engine)
+
+    async def _run_retry():
+        bg_db = next(get_db())
+        try:
+            if retry_engine == "qwen":
+                await tts_model.load_model_async(retry_model_size)
+            else:
+                await tts_model.load_model()
+
+            voice_prompt = await profiles.create_voice_prompt_for_profile(
+                gen.profile_id,
+                bg_db,
+                use_cache=True,
+                engine=retry_engine,
+            )
+
+            from .utils.chunked_tts import generate_chunked
+
+            trim_fn = None
+            if retry_engine in ("chatterbox", "chatterbox_turbo"):
+                from .utils.audio import trim_tts_output
+                trim_fn = trim_tts_output
+
+            audio, sample_rate = await generate_chunked(
+                tts_model,
+                gen.text,
+                voice_prompt,
+                language=gen.language,
+                seed=gen.seed,
+                instruct=gen.instruct,
+                trim_fn=trim_fn,
+            )
+
+            duration = len(audio) / sample_rate
+            audio_path = config.get_generations_dir() / f"{generation_id}.wav"
+
+            from .utils.audio import save_audio
+            save_audio(audio, str(audio_path), sample_rate)
+
+            await history.update_generation_status(
+                generation_id=generation_id,
+                status="completed",
+                db=bg_db,
+                audio_path=str(audio_path),
+                duration=duration,
+            )
+        except Exception as e:
+            import traceback
+            traceback.print_exc()
+            await history.update_generation_status(
+                generation_id=generation_id,
+                status="failed",
+                db=bg_db,
+                error=str(e),
+            )
+        finally:
+            task_manager.complete_generation(generation_id)
+            bg_db.close()
+
+    _enqueue_generation(_run_retry())
+
+    return models.GenerationResponse.model_validate(gen)
+
+
+@app.get("/generate/{generation_id}/status")
+async def get_generation_status(generation_id: str, db: Session = Depends(get_db)):
+    """SSE endpoint that streams generation status updates.
+    
+    Polls the DB every second and yields the current status. Closes when
+    the generation reaches 'completed' or 'failed'.
+    """
+    import json
+
+    async def event_stream():
+        while True:
+            db.expire_all()
+            gen = db.query(DBGeneration).filter_by(id=generation_id).first()
+            if not gen:
+                yield f"data: {json.dumps({'status': 'not_found', 'id': generation_id})}\n\n"
+                return
+
+            payload = {
+                "id": gen.id,
+                "status": gen.status or "completed",
+                "duration": gen.duration,
+                "error": gen.error,
+            }
+            yield f"data: {json.dumps(payload)}\n\n"
+
+            if (gen.status or "completed") in ("completed", "failed"):
+                return
+
+            await asyncio.sleep(1)
+
+    return StreamingResponse(
+        event_stream(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )


@app.post("/generate/stream")
@@ -2480,9 +2542,29 @@ def _get_gpu_status() -> str:
@app.on_event("startup")
 async def startup_event():
    """Run on application startup."""
+    global _generation_queue
    print("voicebox API starting up...")
    database.init_db()
    print(f"Database initialized at {database._db_path}")
+
+    # Start the serial generation worker
+    _generation_queue = asyncio.Queue()
+    _create_background_task(_generation_worker())
+
+    # Mark any stale "generating" records as failed — these are leftovers
+    # from a previous process that was killed mid-generation
+    try:
+        from sqlalchemy import text as sa_text
+        db = next(get_db())
+        result = db.execute(
+            sa_text("UPDATE generations SET status = 'failed', error = 'Server was shut down during generation' WHERE status = 'generating'")
+        )
+        if result.rowcount > 0:
+            print(f"Marked {result.rowcount} stale generation(s) as failed")
+        db.commit()
+        db.close()
+    except Exception as e:
+        print(f"Warning: Could not clean up stale generations: {e}")
    backend_type = get_backend_type()
    print(f"Backend: {backend_type.upper()}")
    print(f"GPU available: {_get_gpu_status()}")
@@ -69,10 +69,14 @@ class GenerationResponse(BaseModel):
    profile_id: str
    text: str
    language: str
-    audio_path: str
-    duration: float
-    seed: Optional[int]
-    instruct: Optional[str]
+    audio_path: Optional[str] = None
+    duration: Optional[float] = None
+    seed: Optional[int] = None
+    instruct: Optional[str] = None
+    engine: Optional[str] = "qwen"
+    model_size: Optional[str] = None
+    status: str = "completed"
+    error: Optional[str] = None
    created_at: datetime

    class Config:
@@ -94,10 +98,14 @@ class HistoryResponse(BaseModel):
    profile_name: str
    text: str
    language: str
-    audio_path: str
-    duration: float
-    seed: Optional[int]
-    instruct: Optional[str]
+    audio_path: Optional[str] = None
+    duration: Optional[float] = None
+    seed: Optional[int] = None
+    instruct: Optional[str] = None
+    engine: Optional[str] = "qwen"
+    model_size: Optional[str] = None
+    status: str = "completed"
+    error: Optional[str] = None
    created_at: datetime

    class Config:
@@ -4,6 +4,10 @@
  "workspaces": {
    "": {
      "name": "voicebox",
+      "dependencies": {
+        "loaders.css": "^0.1.2",
+        "react-loaders": "^3.0.1",
+      },
      "devDependencies": {
        "@biomejs/biome": "2.3.12",
        "@types/node": "^20.0.0",
@@ -678,6 +682,8 @@

    "class-variance-authority": ["[email protected]", "", { "dependencies": { "clsx": "^2.1.1" } }, "sha512-Ka+9Trutv7G8M6WT6SeiRWz792K5qEqIGEGzXKhAE6xOWAY6pPH8U+9IY3oCMv6kqTmLsv7Xh/2w2RigkePMsg=="],

+    "classnames": ["[email protected]", "", {}, "sha512-saHYOzhIQs6wy2sVxTM6bUDsQO4F50V9RQ22qBpEdCW+I+/Wmke2HOl6lS6dTpdxVhb88/I6+Hs+438c3lfUow=="],
+
    "client-only": ["[email protected]", "", {}, "sha512-IV3Ou0jSMzZrd3pZ48nLkT9DA7Ag1pnPzaiQhpW7c3RbcqqzvzzVu+L8gfqMp/8IM2MQtSiqaCxrrcfu8I8rMA=="],

    "clsx": ["[email protected]", "", {}, "sha512-eYm0QWBtUrBWZWG0d386OGAw16Z995PiOVo2B7bjWSbHedGl5e0ZWaq65kOGgUSNesEIDkB9ISbTg/JK9dhCZA=="],
@@ -874,6 +880,8 @@

    "lines-and-columns": ["[email protected]", "", {}, "sha512-7ylylesZQ/PV29jhEDl3Ufjo6ZX7gCqJr5F7PKrqc93v7fzSymt1BpwEU8nAUXs8qzzvqhbjhK5QZg6Mt/HkBg=="],

+    "loaders.css": ["[email protected]", "", {}, "sha512-Rhowlq24ey1VOeor+3wYOt9+MjaxBOJm1u4KlQgNC3+0xJ0LS4wq4iG57D/BPzvuD/7HHDGQOWJ+81oR2EI9bQ=="],
+
    "locate-path": ["[email protected]", "", { "dependencies": { "p-locate": "^5.0.0" } }, "sha512-iPZK6eYjbxRu3uB4/WZ3EsEIMJFMqAoopl3R+zuq0UjcAm/MO6KCweDgPfP3elTztoKP3KtnVHxTn2NHBSDVUw=="],

    "lodash.merge": ["[email protected]", "", {}, "sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ=="],
@@ -960,6 +968,8 @@

    "prelude-ls": ["[email protected]", "", {}, "sha512-vkcDPrRZo1QZLbn5RLGPpg/WmIQ65qoWWhcGKf/b5eplkkarX0m9z8ppCat4mlOqUsWpyNuYgO3VRyrYHSzX5g=="],

+    "prop-types": ["[email protected]", "", { "dependencies": { "loose-envify": "^1.4.0", "object-assign": "^4.1.1", "react-is": "^16.13.1" } }, "sha512-oj87CgZICdulUohogVAR7AjlC0327U4el4L6eAvOqCeudMDVU0NThNaV+b9Df4dXgSP1gXMTnPdhfe/2qDH5cg=="],
+
    "punycode": ["[email protected]", "", {}, "sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg=="],

    "queue-microtask": ["[email protected]", "", {}, "sha512-NuaNSa6flKT5JaSYQzJok04JzTL1CA6aGhv5rfLW3PgqA+M2ChpZQnAC8h8i4ZFkBS8X5RqkDBHA7r4hej3K9A=="],
@@ -970,6 +980,10 @@

    "react-hook-form": ["[email protected]", "", { "peerDependencies": { "react": "^16.8.0 || ^17 || ^18 || ^19" } }, "sha512-9SUJKCGKo8HUSsCO+y0CtqkqI5nNuaDqTxyqPsZPqIwudpj4rCrAz/jZV+jn57bx5gtZKOh3neQu94DXMc+w5w=="],

+    "react-is": ["[email protected]", "", {}, "sha512-24e6ynE2H+OKt4kqsOvNd8kBpV65zoxbA4BVsEOB3ARVWQki/DHzaUoC5KuON/BiccDaCCTZBuOcfZs70kR8bQ=="],
+
+    "react-loaders": ["[email protected]", "", { "dependencies": { "classnames": "^2.2.3" }, "peerDependencies": { "prop-types": ">=15.6.0", "react": ">=15" } }, "sha512-4igMNqs9Fb3d4Z+0UHIGQNJsw/37gX0nUO8QxupnEKRn1dtyYC1LGwk5GuaoDciMQCQc/MmPwb4Fn6ZfdoX1FQ=="],
+
    "react-refresh": ["[email protected]", "", {}, "sha512-z6F7K9bV85EfseRCp2bzrpyQ0Gkw1uLoCel9XBVWPg/TjRj94SkJzUTGfOa4bs7iJvBWtQG0Wq7wnI0syw3EBQ=="],

    "react-remove-scroll": ["[email protected]", "", { "dependencies": { "react-remove-scroll-bar": "^2.3.7", "react-style-singleton": "^2.2.3", "tslib": "^2.1.0", "use-callback-ref": "^1.3.3", "use-sidecar": "^1.1.3" }, "peerDependencies": { "@types/react": "*", "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0 || ^19.0.0-rc" }, "optionalPeers": ["@types/react"] }, "sha512-Iqb9NjCCTt6Hf+vOdNIZGdTiH1QSqr27H/Ek9sv/a97gfueI/5h1s3yRi1nngzMUaOOToin5dI1dXKdXiF+u0Q=="],
@@ -40,5 +40,9 @@
  "engines": {
    "bun": ">=1.0.0"
  },
-  "packageManager": "[email protected]"
+  "packageManager": "[email protected]",
+  "dependencies": {
+    "loaders.css": "^0.1.2",
+    "react-loaders": "^3.0.1"
+  }
 }