fix(docs): update quick start guide to reflect correct terminology for voice profiles (#963)

The floating generate box is fixed at the bottom of the viewport, so
all of its Select dropdowns (voice profile, language, engine, effects)
opened downward into — or beyond — the window edge. Add side="top" to
each SelectContent so the menus appear above their trigger instead.

Co-authored-by: Claude Sonnet 4.6 <[email protected]>

.dockerignore

@@ -8,7 +8,8 @@ tauri/
 landing/
 docs/
 mlx-test/
-scripts/
+scripts/*
+!scripts/rocm-entrypoint.sh
 
 # Dependencies & build artifacts (rebuilt in Docker)
 node_modules/

.gitattributes

@@ -0,0 +1,2 @@
+package.json text eol=lf
+scripts/*.sh text eol=lf

CONTRIBUTING.md

@@ -91,7 +91,7 @@ On Windows, to build with CUDA support for local testing:
 just build-local  # Build CPU + CUDA server binaries + Tauri installer
 ```
 
-This builds the CPU sidecar (bundled with the app), the CUDA binary (placed in `%APPDATA%/com.voicebox.app/backends/` for runtime GPU switching), and the installable Tauri app.
+This builds the CPU sidecar (bundled with the app), the CUDA binary (placed in `%APPDATA%/sh.voicebox.app/backends/` for runtime GPU switching), and the installable Tauri app.
 
 Creates platform-specific installers (`.dmg`, `.msi`, `.AppImage`) in `tauri/src-tauri/target/release/bundle/`.
 

Dockerfile

@@ -20,8 +20,11 @@ COPY package.json bun.lock CHANGELOG.md ./
 COPY app/ ./app/
 COPY web/ ./web/
 
-# Strip workspaces not needed for web build, and fix trailing comma
-RUN sed -i '/"tauri"/d; /"landing"/d' package.json && \
+# Normalize line endings first (a Windows CRLF checkout would otherwise
+# defeat the `-z 's/,\n  ]/…/'` match below, since it's LF-anchored), then
+# strip workspaces not needed for web build, and fix trailing comma
+RUN sed -i 's/\r$//' package.json && \
+    sed -i '/"tauri"/d; /"landing"/d' package.json && \
     sed -i -z 's/,\n  ]/\n  ]/' package.json
 RUN bun install --no-save
 # Build frontend (skip tsc — upstream has pre-existing type errors)
@@ -100,7 +103,11 @@ EXPOSE 17493
 HEALTHCHECK --interval=30s --timeout=10s --retries=3 --start-period=60s \
     CMD curl -f http://localhost:17493/health || exit 1
 
-# Entrypoint joins GPU groups then drops to the voicebox user
+# Entrypoint joins GPU groups then drops to the voicebox user.
+# Normalize CRLF (a Windows checkout otherwise leaves the shebang as
+# `#!/bin/sh\r`, which Linux can't resolve — reported as a misleading
+# "no such file or directory" even though the file exists).
 COPY --chmod=755 scripts/rocm-entrypoint.sh /usr/local/bin/entrypoint.sh
+RUN sed -i 's/\r$//' /usr/local/bin/entrypoint.sh
 ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
 CMD ["uvicorn", "backend.main:app", "--host", "0.0.0.0", "--port", "17493"]

app/src/components/Generation/EngineModelSelector.tsx

@@ -139,7 +139,7 @@ export function EngineModelSelector({ form, compact, selectedProfile }: EngineMo
           <SelectValue />
         </SelectTrigger>
       </FormControl>
-      <SelectContent>
+      <SelectContent side={compact ? 'top' : undefined}>
         {availableOptions.map((opt) => (
           <SelectItem key={opt.value} value={opt.value} className={itemClass}>
             {opt.label}

app/src/components/Generation/FloatingGenerateBox.tsx

@@ -555,7 +555,7 @@ export function FloatingGenerateBox({
                         <SelectTrigger className="h-8 text-xs bg-card border-border rounded-full hover:bg-background/50 transition-all w-full">
                           <SelectValue placeholder={t('generation.voiceSelector.placeholder')} />
                         </SelectTrigger>
-                        <SelectContent>
+                        <SelectContent side="top">
                           {profiles?.map((profile) => (
                             <SelectItem key={profile.id} value={profile.id} className="text-xs">
                               {profile.name}
@@ -582,7 +582,7 @@ export function FloatingGenerateBox({
                                 <SelectValue />
                               </SelectTrigger>
                             </FormControl>
-                            <SelectContent>
+                            <SelectContent side="top">
                               {engineLangs.map((lang) => (
                                 <SelectItem key={lang.value} value={lang.value} className="text-xs">
                                   {lang.label}
@@ -610,7 +610,7 @@ export function FloatingGenerateBox({
                       <SelectTrigger className="h-8 text-xs bg-card border-border rounded-full hover:bg-background/50 transition-all">
                         <SelectValue placeholder={t('generation.effects.none')} />
                       </SelectTrigger>
-                      <SelectContent>
+                      <SelectContent side="top">
                         <SelectItem value="none" className="text-xs">
                           {t('generation.effects.none')}
                         </SelectItem>

app/src/lib/hooks/useHistory.ts

@@ -47,12 +47,14 @@ export function useExportGeneration() {
     mutationFn: async ({ generationId, text }: { generationId: string; text: string }) => {
       const blob = await apiClient.exportGeneration(generationId);
 
-      // Create safe filename from text
+      // Create safe filename from text. Append a short id so exports of
+      // similarly-worded generations don't collide on the same filename
+      // (the first 30 chars are frequently identical).
       const safeText = text
         .substring(0, 30)
         .replace(/[^a-z0-9]/gi, '-')
         .toLowerCase();
-      const filename = `generation-${safeText}.voicebox.zip`;
+      const filename = `generation-${safeText}-${generationId.substring(0, 8)}.voicebox.zip`;
 
       await platform.filesystem.saveFile(filename, blob, [
         {
@@ -73,12 +75,14 @@ export function useExportGenerationAudio() {
     mutationFn: async ({ generationId, text }: { generationId: string; text: string }) => {
       const blob = await apiClient.exportGenerationAudio(generationId);
 
-      // Create safe filename from text
+      // Create safe filename from text. Append a short id so exports of
+      // similarly-worded generations don't collide on the same filename
+      // (the first 30 chars are frequently identical).
       const safeText = text
         .substring(0, 30)
         .replace(/[^a-z0-9]/gi, '-')
         .toLowerCase();
-      const filename = `${safeText}.wav`;
+      const filename = `${safeText}-${generationId.substring(0, 8)}.wav`;
 
       await platform.filesystem.saveFile(filename, blob, [
         {

app/src/lib/utils/format.ts

@@ -25,27 +25,28 @@ function getDateLocale() {
   }
 }
 
-export function formatDate(date: string | Date): string {
-  let dateObj: Date;
-  if (typeof date === 'string') {
-    const dateStr = date.trim();
-    if (!dateStr.includes('Z') && !dateStr.match(/[+-]\d{2}:\d{2}$/)) {
-      dateObj = new Date(`${dateStr}Z`);
-    } else {
-      dateObj = new Date(dateStr);
-    }
-  } else {
-    dateObj = date;
+// Backend timestamps are naive UTC — append `Z` so JS doesn't parse a
+// timezone-less date-time string as local time.
+function parseServerDate(date: string | Date): Date {
+  if (typeof date !== 'string') {
+    return date;
   }
+  const dateStr = date.trim();
+  if (!dateStr.includes('Z') && !dateStr.match(/[+-]\d{2}:\d{2}$/)) {
+    return new Date(`${dateStr}Z`);
+  }
+  return new Date(dateStr);
+}
 
-  return formatDistance(dateObj, new Date(), {
+export function formatDate(date: string | Date): string {
+  return formatDistance(parseServerDate(date), new Date(), {
     addSuffix: true,
     locale: getDateLocale(),
   }).replace(/^about /i, '');
 }
 
 export function formatAbsoluteDate(date: string | Date): string {
-  const dateObj = typeof date === 'string' ? new Date(date) : date;
+  const dateObj = parseServerDate(date);
   return dateObj.toLocaleString(i18n.language, {
     month: 'short',
     day: 'numeric',

backend/app.py

@@ -38,6 +38,13 @@ logging.basicConfig(
 
 logger = logging.getLogger(__name__)
 
+# An empty HSA_OVERRIDE_GFX_VERSION poisons the ROCm HSA runtime. It is
+# treated as "force-empty" and no GPU is detected, even natively supported
+# ones (e.g. gfx1201 / RX 9070 on ROCm 7.2). docker-compose can't
+# conditionally omit an env var, so we clean it up here before torch loads.
+if not os.environ.get("HSA_OVERRIDE_GFX_VERSION"):
+    os.environ.pop("HSA_OVERRIDE_GFX_VERSION", None)
+
 # AMD GPU environment variables must be set before torch import
 # Only set HSA_OVERRIDE_GFX_VERSION for older GPUs that need it.
 # RDNA 3+ (gfx1100+) and RDNA 4 (gfx1200+) are natively supported by ROCm

backend/backends/__init__.py

@@ -56,6 +56,7 @@ class ModelConfig:
     model_size: str = "default"
     size_mb: int = 0
     needs_trim: bool = False
+    retries_runaway: bool = False
     supports_instruct: bool = False
     languages: list[str] = field(default_factory=lambda: ["en"])
 
@@ -232,6 +233,10 @@ def _get_qwen_model_configs() -> list[ModelConfig]:
         repo_1_7b = "Qwen/Qwen3-TTS-12Hz-1.7B-Base"
         repo_0_6b = "Qwen/Qwen3-TTS-12Hz-0.6B-Base"
 
+    # mlx-audio can continue after an EOS miss with silence followed by
+    # codec noise. Retry only the affected text as smaller chunks.
+    retries_runaway = backend_type == "mlx"
+
     return [
         ModelConfig(
             model_name="qwen-tts-1.7B",
@@ -240,6 +245,7 @@ def _get_qwen_model_configs() -> list[ModelConfig]:
             hf_repo_id=repo_1_7b,
             model_size="1.7B",
             size_mb=3500,
+            retries_runaway=retries_runaway,
             supports_instruct=False,  # Base model drops instruct silently
             languages=["zh", "en", "ja", "ko", "de", "fr", "ru", "pt", "es", "it"],
         ),
@@ -250,6 +256,7 @@ def _get_qwen_model_configs() -> list[ModelConfig]:
             hf_repo_id=repo_0_6b,
             model_size="0.6B",
             size_mb=1200,
+            retries_runaway=retries_runaway,
             supports_instruct=False,
             languages=["zh", "en", "ja", "ko", "de", "fr", "ru", "pt", "es", "it"],
         ),
@@ -504,6 +511,14 @@ def engine_needs_trim(engine: str) -> bool:
     return False
 
 
+def engine_retries_runaway(engine: str) -> bool:
+    """Whether unstable output should be retried in smaller chunks."""
+    for cfg in get_tts_model_configs():
+        if cfg.engine == engine:
+            return cfg.retries_runaway
+    return False
+
+
 def engine_has_model_sizes(engine: str) -> bool:
     """Whether this engine supports multiple model sizes (only Qwen currently)."""
     configs = [c for c in get_tts_model_configs() if c.engine == engine]

backend/backends/hume_backend.py

@@ -248,9 +248,13 @@ class HumeTadaBackend:
                 audio = audio.T  # (samples, channels) -> (channels, samples)
             audio = audio.to(device)
 
-            # Encode with forced alignment
+            # Encode with forced alignment.
+            # Must run under inference_mode: encoder params still require
+            # grad by default, and an autograd graph across the DAC/Snake
+            # stack can balloon VRAM far past the model footprint (#890).
             text_arg = [reference_text] if reference_text else None
-            prompt = self.encoder(audio, text=text_arg, sample_rate=sr)
+            with torch.inference_mode():
+                prompt = self.encoder(audio, text=text_arg, sample_rate=sr)
 
             # Serialize EncoderOutput to a dict of CPU tensors for caching
             prompt_dict = {}

backend/build_binary.py

@@ -330,6 +330,9 @@ def build_server(cuda=False, rocm=False):
         ]
     )
 
+    if sys.version_info >= (3, 13):
+        args.extend(["--hidden-import", "audioop"])
+
     # Add CUDA/ROCm-specific hidden imports
     if cuda or rocm:
         variant = "ROCm" if rocm else "CUDA"

backend/config.py

@@ -80,6 +80,11 @@ def resolve_storage_path(path: str | Path | None) -> Path | None:
         return None
 
     stored_path = Path(path)
+    # Empty paths (e.g. failed generations) must not resolve to the data
+    # dir itself, which exists and would defeat the callers' 404 guards.
+    # Path("") is truthy, so check parts rather than the raw value.
+    if not stored_path.parts:
+        return None
     if stored_path.is_absolute():
         rebased_path = _path_relative_to_any_data_dir(stored_path)
         if rebased_path is not None:

backend/mcp_server/tools.py

@@ -12,7 +12,7 @@ import base64 as b64
 import logging
 import tempfile
 from pathlib import Path
-from typing import Any
+from typing import Any, Literal
 
 from fastmcp import FastMCP
 
@@ -49,6 +49,7 @@ def register_tools(mcp: FastMCP) -> None:
         engine: str | None = None,
         personality: bool | None = None,
         language: str | None = None,
+        model_size: Literal["1.7B", "0.6B", "1B", "3B"] | None = None,
     ) -> dict[str, Any]:
         """Speak ``text`` in a voice profile.
 
@@ -61,6 +62,12 @@ def register_tools(mcp: FastMCP) -> None:
         LLM before TTS. When omitted, the per-client binding's
         ``default_personality`` flag decides; when that is unset, the
         default is plain TTS.
+
+        ``model_size`` selects a model variant for engines that ship more
+        than one — ``qwen`` and ``qwen_custom_voice`` accept "1.7B" (default)
+        or "0.6B"; ``tada`` accepts "1B" or "3B". Other engines ignore it.
+        Omit to use the engine default. Requesting a smaller variant (e.g.
+        "0.6B") is faster and avoids reloading a heavier model between calls.
         """
         from ..database.models import MCPClientBinding
 
@@ -99,6 +106,7 @@ def register_tools(mcp: FastMCP) -> None:
                 engine=resolved_engine,
                 language=language,
                 personality=use_persona,
+                model_size=model_size,
                 db=db,
             )
         finally:
@@ -228,18 +236,23 @@ async def _speak(
     engine: str | None,
     language: str | None,
     personality: bool,
+    model_size: str | None = None,
     db,
 ) -> dict[str, Any]:
     """Delegate to POST /generate — the route handles personality-rewrite
     internally when ``personality=true`` and the profile has a prompt."""
     from ..routes.generations import generate_speech
 
+    # model_size=None is intentional: generate_speech normalizes it to the
+    # engine default (see routes/generations.py), so an omitted size behaves
+    # exactly like the REST /generate endpoint with no model_size in the body.
     req = models.GenerationRequest(
         profile_id=profile_id,
         text=text,
         language=language or "en",
         engine=engine,
         personality=personality,
+        model_size=model_size,
     )
     generation = await generate_speech(req, db)
     return _speak_response(generation, profile_name, source="mcp")

backend/requirements-mlx.txt

@@ -16,7 +16,8 @@ miniaudio>=1.59
 # mlx_audio.stt.load) works fine on transformers 4.57.x in practice.
 #
 # Install it via `pip install --no-deps mlx-audio==0.4.1` after this file
-# (see .github/workflows/release.yml). Most other mlx-audio runtime deps
+# (see .github/workflows/release.yml and the setup-python recipe in the
+# justfile). Most other mlx-audio runtime deps
 # (huggingface_hub, librosa, mlx-lm, numba, numpy, protobuf, pyloudnorm,
 # sounddevice, tqdm) are already in requirements.txt or pulled in by
 # other engines.

backend/requirements.txt

@@ -53,6 +53,7 @@ en_core_web_sm @ https://github.com/explosion/spacy-models/releases/download/en_
 unidic-lite>=1.0.8
 
 # Audio processing
+audioop-lts>=0.2.1; python_version >= "3.13"
 librosa>=0.10.0
 soundfile>=0.12.0
 numpy>=1.24.0,<2.0

backend/routes/audio.py

@@ -34,7 +34,7 @@ async def get_version_audio(version_id: str, db: Session = Depends(get_db)):
         raise HTTPException(status_code=404, detail="Version not found")
 
     audio_path = config.resolve_storage_path(version.audio_path)
-    if audio_path is None or not audio_path.exists():
+    if audio_path is None or not audio_path.is_file():
         raise HTTPException(status_code=404, detail="Audio file not found")
 
     return FileResponse(
@@ -52,8 +52,13 @@ async def get_audio(generation_id: str, db: Session = Depends(get_db)):
         raise HTTPException(status_code=404, detail="Generation not found")
 
     audio_path = config.resolve_storage_path(generation.audio_path)
-    if audio_path is None or not audio_path.exists():
-        raise HTTPException(status_code=404, detail="Audio file not found")
+    if audio_path is None or not audio_path.is_file():
+        detail = (
+            "Generation failed; no audio available"
+            if generation.status == "failed"
+            else "Audio file not found"
+        )
+        raise HTTPException(status_code=404, detail=detail)
 
     return FileResponse(
         audio_path,
@@ -72,7 +77,7 @@ async def get_sample_audio(sample_id: str, db: Session = Depends(get_db)):
         raise HTTPException(status_code=404, detail="Sample not found")
 
     audio_path = config.resolve_storage_path(sample.audio_path)
-    if audio_path is None or not audio_path.exists():
+    if audio_path is None or not audio_path.is_file():
         raise HTTPException(status_code=404, detail="Audio file not found")
 
     return FileResponse(

backend/routes/generations.py

@@ -321,7 +321,13 @@ async def stream_speech(
     db: Session = Depends(get_db),
 ):
     """Generate speech and stream the WAV audio directly without saving to disk."""
-    from ..backends import get_tts_backend_for_engine, ensure_model_cached_or_raise, load_engine_model, engine_needs_trim
+    from ..backends import (
+        engine_needs_trim,
+        engine_retries_runaway,
+        ensure_model_cached_or_raise,
+        get_tts_backend_for_engine,
+        load_engine_model,
+    )
 
     profile = await profiles.get_profile(data.profile_id, db)
     if not profile:
@@ -347,10 +353,15 @@ async def stream_speech(
     from ..utils.chunked_tts import generate_chunked
 
     trim_fn = None
+    runaway_detector = None
     if engine_needs_trim(engine):
         from ..utils.audio import trim_tts_output
 
         trim_fn = trim_tts_output
+    if engine_retries_runaway(engine):
+        from ..utils.audio import has_tts_runaway
+
+        runaway_detector = has_tts_runaway
 
     audio, sample_rate = await generate_chunked(
         tts_model,
@@ -362,6 +373,7 @@ async def stream_speech(
         max_chunk_chars=data.max_chunk_chars,
         crossfade_ms=data.crossfade_ms,
         trim_fn=trim_fn,
+        runaway_detector=runaway_detector,
     )
 
     effects_chain_config = None

backend/routes/history.py

@@ -151,7 +151,9 @@ async def export_generation(
     safe_text = "".join(c for c in generation.text[:30] if c.isalnum() or c in (" ", "-", "_")).strip()
     if not safe_text:
         safe_text = "generation"
-    filename = f"generation-{safe_text}.voicebox.zip"
+    # Append a short id so exports of similarly-worded generations don't collide
+    # on the same filename (the first 30 chars are frequently identical).
+    filename = f"generation-{safe_text}-{generation_id[:8]}.voicebox.zip"
 
     return StreamingResponse(
         io.BytesIO(zip_bytes),
@@ -180,7 +182,9 @@ async def export_generation_audio(
     safe_text = "".join(c for c in generation.text[:30] if c.isalnum() or c in (" ", "-", "_")).strip()
     if not safe_text:
         safe_text = "generation"
-    filename = f"{safe_text}.wav"
+    # Append a short id so exports of similarly-worded generations don't collide
+    # on the same filename (the first 30 chars are frequently identical).
+    filename = f"{safe_text}-{generation_id[:8]}.wav"
 
     return FileResponse(
         audio_path,

backend/routes/profiles.py

@@ -232,7 +232,7 @@ async def upload_profile_avatar(
     db: Session = Depends(get_db),
 ):
     """Upload or update avatar image for a profile."""
-    with tempfile.NamedTemporaryFile(delete=False, suffix=Path(file.filename).suffix) as tmp:
+    with tempfile.NamedTemporaryFile(delete=False, suffix=Path(file.filename or "").suffix) as tmp:
         content = await file.read()
         tmp.write(content)
         tmp_path = tmp.name

backend/routes/transcription.py

@@ -35,13 +35,25 @@ async def transcribe_audio(
             tmp.write(chunk)
         tmp_path = tmp.name
 
+    stt_path = tmp_path
     try:
-        from ..utils.audio import load_audio
+        from ..utils.audio import load_audio, save_audio
         from ..backends import WHISPER_HF_REPOS
 
         audio, sr = await asyncio.to_thread(load_audio, tmp_path)
         duration = len(audio) / sr
 
+        # The STT backend (mlx_audio.stt -> miniaudio) only decodes
+        # WAV/FLAC/MP3/Vorbis, so browser recordings uploaded as WebM/Opus
+        # fail with "unsupported file format" (issue: web-mode dictation).
+        # librosa already decoded the file above (it falls back to
+        # audioread/ffmpeg for exotic containers), so re-encode that PCM to a
+        # temp WAV and hand *that* to Whisper. WAV inputs pass through
+        # unchanged.
+        if file_suffix != ".wav":
+            stt_path = f"{tmp_path}.stt.wav"
+            await asyncio.to_thread(save_audio, audio, stt_path, sr)
+
         whisper_model = transcribe.get_whisper_model()
         model_size = model if model else whisper_model.model_size
 
@@ -76,7 +88,7 @@ async def transcribe_audio(
                 },
             )
 
-        text = await whisper_model.transcribe(tmp_path, language, model_size)
+        text = await whisper_model.transcribe(stt_path, language, model_size)
 
         return models.TranscriptionResponse(
             text=text,
@@ -89,3 +101,5 @@ async def transcribe_audio(
         raise HTTPException(status_code=500, detail=str(e))
     finally:
         Path(tmp_path).unlink(missing_ok=True)
+        if stt_path != tmp_path:
+            Path(stt_path).unlink(missing_ok=True)

backend/services/generation.py

@@ -48,9 +48,14 @@ async def run_generation(
     This is the single entry point for all background generation work.
     It is designed to be enqueued via ``services.task_queue.enqueue_generation``.
     """
-    from ..backends import load_engine_model, get_tts_backend_for_engine, engine_needs_trim
+    from ..backends import (
+        engine_needs_trim,
+        engine_retries_runaway,
+        get_tts_backend_for_engine,
+        load_engine_model,
+    )
     from ..utils.chunked_tts import generate_chunked
-    from ..utils.audio import normalize_audio, save_audio, trim_tts_output
+    from ..utils.audio import has_tts_runaway, normalize_audio, save_audio, trim_tts_output
 
     task_manager = get_task_manager()
     bg_db = next(get_db())
@@ -72,12 +77,14 @@ async def run_generation(
 
         await history.update_generation_status(generation_id, "generating", bg_db)
         trim_fn = trim_tts_output if engine_needs_trim(engine) else None
+        runaway_detector = has_tts_runaway if engine_retries_runaway(engine) else None
 
         gen_kwargs: dict = dict(
             language=language,
             seed=seed if mode != "regenerate" else None,
             instruct=instruct,
             trim_fn=trim_fn,
+            runaway_detector=runaway_detector,
         )
         if max_chunk_chars is not None:
             gen_kwargs["max_chunk_chars"] = max_chunk_chars
@@ -267,9 +274,14 @@ async def generate_audio_sync(
     normalize, then encodes in-memory via :func:`tts.audio_to_wav_bytes`
     (same helper ``/generate/stream`` uses).
     """
-    from ..backends import load_engine_model, get_tts_backend_for_engine, engine_needs_trim
+    from ..backends import (
+        engine_needs_trim,
+        engine_retries_runaway,
+        get_tts_backend_for_engine,
+        load_engine_model,
+    )
     from ..utils.chunked_tts import generate_chunked
-    from ..utils.audio import normalize_audio, trim_tts_output
+    from ..utils.audio import has_tts_runaway, normalize_audio, trim_tts_output
     from . import tts
 
     bg_db = next(get_db())
@@ -287,12 +299,14 @@ async def generate_audio_sync(
         bg_db.close()
 
     trim_fn = trim_tts_output if engine_needs_trim(engine) else None
+    runaway_detector = has_tts_runaway if engine_retries_runaway(engine) else None
 
     gen_kwargs: dict = dict(
         language=language,
         seed=seed,
         instruct=instruct,
         trim_fn=trim_fn,
+        runaway_detector=runaway_detector,
     )
     if max_chunk_chars is not None:
         gen_kwargs["max_chunk_chars"] = max_chunk_chars

backend/services/stories.py

@@ -125,12 +125,24 @@ async def list_stories(
     """
     stories = db.query(DBStory).order_by(DBStory.updated_at.desc()).all()
 
+    if not stories:
+        return []
+
+    # Batch-fetch all story item counts in one query to avoid an N+1 pattern
+    # (previously there was one COUNT query per story in the loop below).
+    story_ids = [s.id for s in stories]
+    count_rows = (
+        db.query(DBStoryItem.story_id, func.count(DBStoryItem.id).label("cnt"))
+        .filter(DBStoryItem.story_id.in_(story_ids))
+        .group_by(DBStoryItem.story_id)
+        .all()
+    )
+    item_counts = {row.story_id: row.cnt for row in count_rows}
+
     result = []
     for story in stories:
-        item_count = db.query(func.count(DBStoryItem.id)).filter(DBStoryItem.story_id == story.id).scalar()
-
         response = StoryResponse.model_validate(story)
-        response.item_count = item_count
+        response.item_count = item_counts.get(story.id, 0)
         result.append(response)
 
     return result

backend/tests/test_audio_failed_generation.py

@@ -0,0 +1,164 @@
+"""
+Regression tests for GET /audio/{generation_id} on failed generations.
+
+A failed generation stores an empty ``audio_path``. Previously,
+``config.resolve_storage_path("")`` resolved to the data directory itself,
+which exists, so the route's 404 guard passed and ``FileResponse`` raised
+``RuntimeError: File at path .../data is not a file`` — a 500 instead of
+a clean 404.
+
+Usage:
+    python -m pytest backend/tests/test_audio_failed_generation.py -v
+"""
+
+import sys
+from pathlib import Path
+
+import pytest
+from fastapi import FastAPI
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from starlette.testclient import TestClient
+
+# Repo root on sys.path so ``backend`` imports as a package (the audio
+# routes use package-relative imports).
+sys.path.insert(0, str(Path(__file__).parent.parent.parent))
+
+from backend import config
+from backend.database import (
+    Base,
+    Generation,
+    GenerationVersion,
+    ProfileSample,
+    VoiceProfile,
+    get_db,
+)
+from backend.routes.audio import router as audio_router
+
+
+def test_resolve_storage_path_empty_returns_none():
+    """An empty stored path must not resolve to the data dir itself."""
+    assert config.resolve_storage_path("") is None
+    assert config.resolve_storage_path(None) is None
+    # Path("") is truthy, so it must be rejected via its (empty) parts.
+    assert config.resolve_storage_path(Path("")) is None
+
+
+@pytest.fixture
+def client(tmp_path, monkeypatch):
+    """Minimal app with only the audio routes and a temp sqlite DB."""
+    monkeypatch.setattr(config, "_data_dir", tmp_path)
+    # An existing directory that a stored audio_path may wrongly point to.
+    (tmp_path / "somedir").mkdir()
+
+    engine = create_engine(
+        f"sqlite:///{tmp_path / 'test.db'}",
+        connect_args={"check_same_thread": False},
+    )
+    Base.metadata.create_all(bind=engine)
+    testing_session_local = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+    session = testing_session_local()
+    profile = VoiceProfile(id="profile-1", name="Test Profile")
+    session.add(profile)
+
+    session.add_all(
+        [
+            Generation(
+                id="gen-failed-empty",
+                profile_id="profile-1",
+                text="failed generation",
+                audio_path="",
+                status="failed",
+                error="engine exploded",
+            ),
+            Generation(
+                id="gen-failed-null",
+                profile_id="profile-1",
+                text="failed generation",
+                audio_path=None,
+                status="failed",
+            ),
+            Generation(
+                id="gen-missing-file",
+                profile_id="profile-1",
+                text="completed but file deleted",
+                audio_path="generations/does-not-exist.wav",
+                status="completed",
+            ),
+            Generation(
+                id="gen-with-version",
+                profile_id="profile-1",
+                text="generation with a broken version",
+                audio_path="somedir",
+                status="completed",
+            ),
+            GenerationVersion(
+                id="version-dir",
+                generation_id="gen-with-version",
+                label="original",
+                audio_path="somedir",
+            ),
+            ProfileSample(
+                id="sample-dir",
+                profile_id="profile-1",
+                audio_path="somedir",
+                reference_text="sample pointing at a directory",
+            ),
+        ]
+    )
+    session.commit()
+    session.close()
+
+    app = FastAPI()
+    app.include_router(audio_router)
+
+    def override_get_db():
+        db = testing_session_local()
+        try:
+            yield db
+        finally:
+            db.close()
+
+    app.dependency_overrides[get_db] = override_get_db
+    return TestClient(app)
+
+
+@pytest.mark.parametrize("generation_id", ["gen-failed-empty", "gen-failed-null"])
+def test_failed_generation_returns_404(client, generation_id):
+    """Failed generations (empty/null audio_path) get a clean 404, not a 500."""
+    response = client.get(f"/audio/{generation_id}")
+    assert response.status_code == 404
+    assert response.json()["detail"] == "Generation failed; no audio available"
+
+
+def test_missing_audio_file_returns_404(client):
+    """A completed generation whose file vanished still 404s."""
+    response = client.get("/audio/gen-missing-file")
+    assert response.status_code == 404
+    assert response.json()["detail"] == "Audio file not found"
+
+
+def test_unknown_generation_returns_404(client):
+    response = client.get("/audio/no-such-generation")
+    assert response.status_code == 404
+    assert response.json()["detail"] == "Generation not found"
+
+
+@pytest.mark.parametrize(
+    "url",
+    [
+        "/audio/gen-with-version",
+        "/audio/version/version-dir",
+        "/samples/sample-dir",
+    ],
+)
+def test_audio_path_pointing_at_directory_returns_404(client, url):
+    """A stored path resolving to an existing directory must 404, not 500.
+
+    Guards the is_file() checks: a directory passes exists() and would
+    crash FileResponse.
+    """
+    response = client.get(url)
+    assert response.status_code == 404
+    assert response.json()["detail"] == "Audio file not found"

backend/tests/test_audioop_python313.py

@@ -0,0 +1,123 @@
+"""
+Regression tests for issue #852: audioop removed from Python 3.13 stdlib.
+
+Voice sample validation imports audioop transitively (librosa → audioread).
+The audioop-lts backport must be declared in requirements and bundled in
+PyInstaller builds on 3.13+.
+"""
+
+import re
+import sys
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from build_binary import build_server
+
+
+@pytest.fixture
+def backend_dir():
+    return Path(__file__).parent.parent
+
+
+class TestAudioopRequirements:
+    def test_requirements_declare_audioop_lts_for_python_313(self, backend_dir):
+        content = (backend_dir / "requirements.txt").read_text()
+        assert re.search(
+            r"^audioop-lts.*python_version\s*>=\s*['\"]3\.13['\"]",
+            content,
+            re.MULTILINE,
+        ), "requirements.txt must pin audioop-lts for Python 3.13+"
+
+
+@pytest.mark.skipif(sys.version_info < (3, 13), reason="Python 3.13+ only")
+class TestAudioopRuntime:
+    def test_audioop_importable(self):
+        import audioop  # noqa: F401
+
+    def test_validate_reference_wav_does_not_fail_on_missing_audioop(self, tmp_path):
+        import numpy as np
+        import soundfile as sf
+        from utils.audio import validate_and_load_reference_audio
+
+        sr = 24000
+        t = np.arange(int(sr * 3), dtype=np.float32) / sr
+        audio = (0.3 * np.sin(2 * np.pi * 220 * t)).astype(np.float32)
+        path = tmp_path / "reference.wav"
+        sf.write(str(path), audio, sr)
+
+        ok, err, out_audio, out_sr = validate_and_load_reference_audio(str(path))
+
+        assert ok, err
+        assert out_audio is not None
+        assert out_sr == sr
+        assert "audioop" not in (err or "").lower()
+
+
+class TestAudioopBuildArgs:
+    @staticmethod
+    def _hidden_imports(args):
+        imports = []
+        for i, arg in enumerate(args):
+            if arg == "--hidden-import" and i + 1 < len(args):
+                imports.append(args[i + 1])
+        return imports
+
+    def test_pyinstaller_includes_audioop_on_python_313(self):
+        class FakeVersionInfo(tuple):
+            @property
+            def major(self):
+                return self[0]
+
+            @property
+            def minor(self):
+                return self[1]
+
+            @property
+            def micro(self):
+                return self[2]
+
+        fake_313 = FakeVersionInfo((3, 13, 0, "final", 0))
+
+        with (
+            patch("build_binary.PyInstaller.__main__.run") as mock_run,
+            patch("build_binary.platform.system", return_value="Linux"),
+            patch("build_binary.is_apple_silicon", return_value=False),
+            patch("build_binary.os.chdir"),
+            patch("build_binary.sys.version_info", fake_313),
+        ):
+            build_server()
+            args = mock_run.call_args[0][0]
+
+        assert "audioop" in self._hidden_imports(args)
+
+    def test_pyinstaller_omits_audioop_on_python_312(self):
+        class FakeVersionInfo(tuple):
+            @property
+            def major(self):
+                return self[0]
+
+            @property
+            def minor(self):
+                return self[1]
+
+            @property
+            def micro(self):
+                return self[2]
+
+        fake_312 = FakeVersionInfo((3, 12, 0, "final", 0))
+
+        with (
+            patch("build_binary.PyInstaller.__main__.run") as mock_run,
+            patch("build_binary.platform.system", return_value="Linux"),
+            patch("build_binary.is_apple_silicon", return_value=False),
+            patch("build_binary.os.chdir"),
+            patch("build_binary.sys.version_info", fake_312),
+        ):
+            build_server()
+            args = mock_run.call_args[0][0]
+
+        assert "audioop" not in self._hidden_imports(args)

backend/tests/test_hume_encode_inference_mode.py

@@ -0,0 +1,68 @@
+"""Ensure TADA voice-prompt encoding disables autograd (#890)."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from unittest.mock import AsyncMock
+
+import numpy as np
+import pytest
+import soundfile as sf
+import torch
+
+from backend.backends.hume_backend import HumeTadaBackend
+
+
+@dataclass
+class _FakeEncoderOutput:
+    emb: torch.Tensor
+
+
+class _GradTrackingEncoder:
+    """Raises unless called under torch.inference_mode()."""
+
+    def __init__(self) -> None:
+        self.called_under_inference_mode = False
+
+    def __call__(self, audio, text=None, sample_rate=None):
+        self.called_under_inference_mode = torch.is_inference_mode_enabled()
+        if not self.called_under_inference_mode:
+            raise AssertionError("encoder forward must run under inference_mode")
+        # Touch a requires_grad tensor the way Snake1d alpha would.
+        alpha = torch.nn.Parameter(torch.ones(1, device=audio.device))
+        _ = audio.mean() * alpha
+        return _FakeEncoderOutput(emb=torch.zeros(1, 4, device=audio.device))
+
+
+@pytest.mark.asyncio
+async def test_create_voice_prompt_runs_encoder_under_inference_mode(tmp_path, monkeypatch):
+    wav = tmp_path / "ref.wav"
+    sf.write(str(wav), np.zeros(24000, dtype=np.float32), 24000)
+
+    backend = HumeTadaBackend()
+    backend.model = object()  # mark loaded
+    backend.model_size = "1B"
+    backend._device = "cpu"
+    encoder = _GradTrackingEncoder()
+    backend.encoder = encoder
+
+    monkeypatch.setattr(backend, "load_model", AsyncMock(return_value=None))
+    monkeypatch.setattr(
+        "backend.backends.hume_backend.get_cached_voice_prompt",
+        lambda key: None,
+    )
+    monkeypatch.setattr(
+        "backend.backends.hume_backend.cache_voice_prompt",
+        lambda key, value: None,
+    )
+
+    prompt, from_cache = await backend.create_voice_prompt(
+        str(wav),
+        reference_text="hello world",
+        use_cache=False,
+    )
+
+    assert from_cache is False
+    assert encoder.called_under_inference_mode is True
+    assert isinstance(prompt["emb"], torch.Tensor)
+    assert prompt["emb"].device.type == "cpu"

backend/tests/test_mcp_speak.py

@@ -0,0 +1,91 @@
+"""Tests for the voicebox.speak MCP tool's ``model_size`` plumbing (issue #884).
+
+The MCP speak path used to build its ``GenerationRequest`` without a
+``model_size``, so every agent-triggered generation silently fell back to the
+schema default ("1.7B") — there was no way to reach 0.6B (or TADA's 1B/3B)
+through MCP. These tests pin the fix: ``_speak`` now forwards ``model_size``
+straight into the request, matching the REST ``/generate`` surface.
+"""
+
+import pytest
+from pydantic import ValidationError
+
+import backend.routes.generations as generations
+from backend.mcp_server import tools
+
+
+class _FakeGeneration:
+    """Minimal stand-in for GenerationResponse consumed by ``_speak_response``."""
+
+    def model_dump(self, mode="json"):
+        return {"id": "gen-test", "status": "generating"}
+
+
+@pytest.fixture
+def captured_request(monkeypatch):
+    """Replace the real (torch-backed) generate_speech with a capturing stub.
+
+    ``_speak`` imports ``generate_speech`` lazily from ``routes.generations``,
+    so patching the attribute on that module intercepts the call and lets us
+    inspect the ``GenerationRequest`` it would have run.
+    """
+    captured = {}
+
+    async def fake_generate_speech(req, db):
+        captured["req"] = req
+        return _FakeGeneration()
+
+    monkeypatch.setattr(generations, "generate_speech", fake_generate_speech)
+    # Isolate the unit from the MCP event bus — _speak_response fires a
+    # speak-start event we don't care about here.
+    monkeypatch.setattr(tools.mcp_events, "publish", lambda *a, **k: None)
+    return captured
+
+
+@pytest.mark.asyncio
+async def test_speak_forwards_explicit_model_size(captured_request):
+    await tools._speak(
+        profile_id="p1",
+        profile_name="Morgan",
+        text="hello",
+        engine="qwen",
+        language="en",
+        personality=False,
+        model_size="0.6B",
+        db=None,
+    )
+    assert captured_request["req"].model_size == "0.6B"
+
+
+@pytest.mark.asyncio
+async def test_speak_omitted_model_size_is_none(captured_request):
+    # Omitted → None; generate_speech normalizes None to the engine default,
+    # so this reproduces the pre-fix behaviour for callers that don't ask.
+    await tools._speak(
+        profile_id="p1",
+        profile_name="Morgan",
+        text="hello",
+        engine="qwen",
+        language="en",
+        personality=False,
+        db=None,
+    )
+    assert captured_request["req"].model_size is None
+
+
+@pytest.mark.asyncio
+async def test_speak_rejects_invalid_model_size(captured_request):
+    # The GenerationRequest schema pattern is the single source of truth for
+    # valid sizes; a bad value is rejected before any generation runs.
+    with pytest.raises(ValidationError):
+        await tools._speak(
+            profile_id="p1",
+            profile_name="Morgan",
+            text="hello",
+            engine="qwen",
+            language="en",
+            personality=False,
+            model_size="9B",
+            db=None,
+        )
+    assert "req" not in captured_request

backend/tests/test_mlx_smoke.py

@@ -0,0 +1,55 @@
+"""
+Smoke test for the MLX backend dependencies on Apple Silicon.
+
+Guards the `--no-deps` install of mlx-audio/mlx-lm done by `just setup-python`
+and release.yml: those packages skip their declared dependencies (transformers
+>=5.x conflict), so a missing transitive dep only surfaces at import time.
+This test fails fast if the MLX STT/TTS entry points the backend uses stop
+importing (e.g. the `miniaudio` regression from issue #505).
+
+Usage:
+    python -m pytest backend/tests/test_mlx_smoke.py -v
+"""
+
+import platform
+import sys
+
+import pytest
+
+pytestmark = pytest.mark.skipif(
+    not (sys.platform == "darwin" and platform.machine() == "arm64"),
+    reason="MLX packages are only installed on Apple Silicon macOS",
+)
+
+
+def test_mlx_core_runs():
+    """The MLX runtime itself works (Metal array op)."""
+    import mlx.core as mx
+
+    assert mx.array([1, 2]).sum().item() == 3
+
+
+def test_mlx_audio_tts_entry_point():
+    """`from mlx_audio.tts import load` — used by MLXBackend.load_model_async."""
+    from mlx_audio.tts import load
+
+    assert callable(load)
+
+
+def test_mlx_audio_stt_entry_point():
+    """`from mlx_audio.stt import load` — used by the Whisper MLX STT path.
+
+    Importing mlx_audio.stt also pulls in miniaudio, so this catches the
+    ModuleNotFoundError from issue #505 on fresh installs.
+    """
+    from mlx_audio.stt import load
+
+    assert callable(load)
+
+
+def test_mlx_lm_entry_points():
+    """`mlx_lm.load` / `mlx_lm.generate` — used by qwen_llm_backend."""
+    from mlx_lm import generate, load
+
+    assert callable(load)
+    assert callable(generate)

backend/tests/test_qwen_runaway_retry.py

@@ -0,0 +1,117 @@
+"""Regression coverage for runaway MLX Qwen TTS output."""
+
+from unittest.mock import patch
+
+import numpy as np
+import pytest
+
+from backend.backends import engine_needs_trim, engine_retries_runaway
+from backend.utils.audio import has_tts_runaway
+from backend.utils.chunked_tts import generate_chunked
+
+SAMPLE_RATE = 1000
+
+
+def test_mlx_qwen_enables_runaway_retry_without_aggressive_trim():
+    with patch("backend.backends.get_backend_type", return_value="mlx"):
+        assert engine_needs_trim("qwen") is False
+        assert engine_retries_runaway("qwen") is True
+
+
+def test_pytorch_qwen_keeps_runaway_retry_disabled():
+    with patch("backend.backends.get_backend_type", return_value="pytorch"):
+        assert engine_needs_trim("qwen") is False
+        assert engine_retries_runaway("qwen") is False
+
+
+def test_detector_flags_long_internal_silence():
+    speech = np.full(2 * SAMPLE_RATE, 0.2, dtype=np.float32)
+    runaway_gap = np.zeros(2500, dtype=np.float32)
+    hallucinated_noise = np.full(2 * SAMPLE_RATE, 0.8, dtype=np.float32)
+    audio = np.concatenate([speech, runaway_gap, hallucinated_noise])
+
+    assert has_tts_runaway(audio, SAMPLE_RATE) is True
+
+
+def test_detector_ignores_normal_internal_pause():
+    speech = np.full(SAMPLE_RATE, 0.2, dtype=np.float32)
+    normal_pause = np.zeros(1200, dtype=np.float32)
+    audio = np.concatenate([speech, normal_pause, speech])
+
+    assert has_tts_runaway(audio, SAMPLE_RATE) is False
+
+
+def test_trailing_silence_is_not_a_runaway():
+    speech = np.full(SAMPLE_RATE, 0.2, dtype=np.float32)
+    trailing_silence = np.zeros(2 * SAMPLE_RATE, dtype=np.float32)
+
+    assert (
+        has_tts_runaway(
+            np.concatenate([speech, trailing_silence]),
+            SAMPLE_RATE,
+        )
+        is False
+    )
+
+
+@pytest.mark.asyncio
+async def test_runaway_chunk_is_retried_as_smaller_chunks():
+    class FakeBackend:
+        def __init__(self):
+            self.calls = []
+
+        async def generate(self, text, *_args):
+            self.calls.append(text)
+            if len(text) > 200:
+                speech = np.full(SAMPLE_RATE, 0.2, dtype=np.float32)
+                silence = np.zeros(2500, dtype=np.float32)
+                noise = np.full(SAMPLE_RATE, 0.8, dtype=np.float32)
+                return np.concatenate([speech, silence, noise]), SAMPLE_RATE
+            return np.full(SAMPLE_RATE, 0.2, dtype=np.float32), SAMPLE_RATE
+
+    backend = FakeBackend()
+    text = f"{'A' * 119}. {'B' * 119}."
+
+    audio, sample_rate = await generate_chunked(
+        backend,
+        text,
+        {},
+        max_chunk_chars=800,
+        crossfade_ms=50,
+        runaway_detector=has_tts_runaway,
+    )
+
+    assert sample_rate == SAMPLE_RATE
+    assert backend.calls == [text, f"{'A' * 119}.", f"{'B' * 119}."]
+    assert len(audio) == 1950
+
+
+@pytest.mark.asyncio
+async def test_persistent_runaway_fails_instead_of_returning_corrupt_audio():
+    class AlwaysRunawayBackend:
+        def __init__(self):
+            self.calls = []
+
+        async def generate(self, text, *_args):
+            self.calls.append(text)
+            speech = np.full(SAMPLE_RATE, 0.2, dtype=np.float32)
+            silence = np.zeros(2500, dtype=np.float32)
+            noise = np.full(SAMPLE_RATE, 0.8, dtype=np.float32)
+            return np.concatenate([speech, silence, noise]), SAMPLE_RATE
+
+    backend = AlwaysRunawayBackend()
+    text = f"{'A' * 119}. {'B' * 119}."
+
+    with pytest.raises(
+        RuntimeError,
+        match="remained unstable after retrying smaller text chunks",
+    ):
+        await generate_chunked(
+            backend,
+            text,
+            {},
+            max_chunk_chars=800,
+            runaway_detector=has_tts_runaway,
+        )
+
+    assert [len(call) for call in backend.calls] == [241, 120, 100]

backend/utils/audio.py

@@ -110,6 +110,43 @@ def save_audio(
         raise OSError(f"Failed to save audio to {path}: {e}") from e
 
 
+def has_tts_runaway(
+    audio: np.ndarray,
+    sample_rate: int = 24000,
+    frame_ms: int = 20,
+    silence_threshold_db: float = -40.0,
+    max_internal_silence_ms: int = 2000,
+) -> bool:
+    """Detect speech followed by a long silence and then more output.
+
+    This shape is a reliable signal that a TTS model missed EOS and resumed
+    with hallucinated speech or codec noise. Leading and trailing silence do
+    not count because they are not bounded by non-silent audio.
+    """
+    frame_len = int(sample_rate * frame_ms / 1000)
+    if frame_len == 0 or len(audio) < frame_len:
+        return False
+
+    n_frames = len(audio) // frame_len
+    threshold_linear = 10 ** (silence_threshold_db / 20)
+    max_silence_frames = int(max_internal_silence_ms / frame_ms)
+    seen_speech = False
+    consecutive_silence = 0
+
+    for i in range(n_frames):
+        frame = audio[i * frame_len : (i + 1) * frame_len]
+        is_speech = np.sqrt(np.mean(frame**2)) >= threshold_linear
+        if is_speech:
+            if seen_speech and consecutive_silence >= max_silence_frames:
+                return True
+            seen_speech = True
+            consecutive_silence = 0
+        elif seen_speech:
+            consecutive_silence += 1
+
+    return False
+
+
 def trim_tts_output(
     audio: np.ndarray,
     sample_rate: int = 24000,

backend/utils/chunked_tts.py

@@ -20,6 +20,8 @@ logger = logging.getLogger("voicebox.chunked-tts")
 # Default chunk size in characters.  Can be overridden per-request via
 # the ``max_chunk_chars`` field on GenerationRequest.
 DEFAULT_MAX_CHUNK_CHARS = 800
+MAX_RUNAWAY_RETRIES = 2
+MIN_RUNAWAY_RETRY_CHARS = 100
 
 # Common abbreviations that should NOT be treated as sentence endings.
 # Lowercase for case-insensitive matching.
@@ -211,6 +213,7 @@ async def generate_chunked(
     max_chunk_chars: int = DEFAULT_MAX_CHUNK_CHARS,
     crossfade_ms: int = 50,
     trim_fn=None,
+    runaway_detector=None,
 ) -> Tuple[np.ndarray, int]:
     """Generate audio with automatic chunking for long text.
 
@@ -239,25 +242,75 @@ async def generate_chunked(
         Optional ``(audio, sample_rate) -> audio`` post-processing
         function applied to each chunk before concatenation (e.g.
         ``trim_tts_output`` for Chatterbox engines).
+    runaway_detector : callable | None
+        Optional ``(audio, sample_rate) -> bool`` detector. When it flags
+        unstable output, the affected text is split in half and retried.
 
     Returns
     -------
     (audio, sample_rate) : Tuple[np.ndarray, int]
     """
+    async def generate_one(
+        chunk_text: str,
+        chunk_seed: int | None,
+        retry_depth: int = 0,
+    ) -> tuple[np.ndarray, int]:
+        chunk_audio, chunk_sr = await backend.generate(
+            chunk_text,
+            voice_prompt,
+            language,
+            chunk_seed,
+            instruct,
+        )
+
+        if runaway_detector is not None and runaway_detector(chunk_audio, chunk_sr):
+            if retry_depth >= MAX_RUNAWAY_RETRIES or len(chunk_text) <= MIN_RUNAWAY_RETRY_CHARS:
+                raise RuntimeError(
+                    "TTS output remained unstable after retrying smaller text chunks"
+                )
+
+            retry_max_chars = max(MIN_RUNAWAY_RETRY_CHARS, len(chunk_text) // 2)
+            retry_chunks = split_text_into_chunks(chunk_text, retry_max_chars)
+            if len(retry_chunks) <= 1:
+                raise RuntimeError("Unable to split unstable TTS output for retry")
+
+            logger.warning(
+                "Detected unstable TTS output for %d chars; retrying as %d smaller chunks",
+                len(chunk_text),
+                len(retry_chunks),
+            )
+            retry_audio: list[np.ndarray] = []
+            for i, retry_text in enumerate(retry_chunks):
+                retry_seed = (
+                    chunk_seed + ((retry_depth + 1) * 1000) + i
+                    if chunk_seed is not None
+                    else None
+                )
+                audio, sample_rate = await generate_one(
+                    retry_text,
+                    retry_seed,
+                    retry_depth + 1,
+                )
+                retry_audio.append(np.asarray(audio, dtype=np.float32))
+
+            return (
+                concatenate_audio_chunks(
+                    retry_audio,
+                    sample_rate,
+                    crossfade_ms=crossfade_ms,
+                ),
+                sample_rate,
+            )
+
+        if trim_fn is not None:
+            chunk_audio = trim_fn(chunk_audio, chunk_sr)
+        return np.asarray(chunk_audio, dtype=np.float32), chunk_sr
+
     chunks = split_text_into_chunks(text, max_chunk_chars)
 
     if len(chunks) <= 1:
         # Short text — single-shot fast path
-        audio, sample_rate = await backend.generate(
-            text,
-            voice_prompt,
-            language,
-            seed,
-            instruct,
-        )
-        if trim_fn is not None:
-            audio = trim_fn(audio, sample_rate)
-        return audio, sample_rate
+        return await generate_one(text, seed)
 
     # Long text — chunked generation
     logger.info(
@@ -281,17 +334,12 @@ async def generate_chunked(
         # always produces the same output.
         chunk_seed = (seed + i) if seed is not None else None
 
-        chunk_audio, chunk_sr = await backend.generate(
+        chunk_audio, chunk_sr = await generate_one(
             chunk_text,
-            voice_prompt,
-            language,
             chunk_seed,
-            instruct,
         )
-        if trim_fn is not None:
-            chunk_audio = trim_fn(chunk_audio, chunk_sr)
 
-        audio_chunks.append(np.asarray(chunk_audio, dtype=np.float32))
+        audio_chunks.append(chunk_audio)
         if sample_rate is None:
             sample_rate = chunk_sr
 

docker-compose.rocm.yml

@@ -34,3 +34,15 @@ services:
 
       # Tune the ROCm memory allocator
       - PYTORCH_HIP_ALLOC_CONF=garbage_collection_threshold:0.8,max_split_size_mb:512
+
+      # Redirect MIOpen kernel cache to a writable, persistent directory.
+      # Without this, MIOpen may fail to write its cache and throw
+      # miopenStatusUnknownError on fresh containers.
+      - MIOPEN_USER_DB_PATH=/app/data/cache/miopen_db
+      - MIOPEN_CUSTOM_CACHE_DIR=/app/data/cache/miopen_cache
+
+      # Use fast heuristics for kernel selection instead of exhaustive
+      # benchmarking. On RDNA4, exhaustive mode tries kernels that fail to
+      # allocate workspace memory (ptr: 0 size: 0), causing system stuttering
+      # on every generation even when the cache is present.
+      - MIOPEN_FIND_MODE=FAST

docs/content/docs/developer/tts-generation.mdx

@@ -49,6 +49,7 @@ class ModelConfig:
     model_size: str = "default"
     size_mb: int = 0
     needs_trim: bool = False
+    retries_runaway: bool = False
     supports_instruct: bool = False
     languages: list[str] = field(default_factory=lambda: ["en"])
 ```
@@ -59,6 +60,7 @@ Registry helpers in `backends/__init__.py` replace what used to be per-engine `i
 - `get_tts_model_configs()` — only TTS variants
 - `get_model_config(model_name)` — lookup by name
 - `engine_needs_trim(engine)` — whether output should run through `trim_tts_output()`
+- `engine_retries_runaway(engine)` — whether unstable output should be retried as smaller chunks
 - `load_engine_model(engine, model_size)` — downloads + loads, handles engines with multiple sizes
 - `get_tts_backend_for_engine(engine)` — thread-safe backend factory with double-checked locking
 
@@ -152,7 +154,7 @@ The request path from frontend to audio file:
 
 6. **Inference** — the engine's `generate()` returns `(audio_array, sample_rate)`.
 
-7. **Post-process** — if `engine_needs_trim(engine)` is True, `trim_tts_output()` strips trailing silence. Effects chains (if any) are applied per generation version, not the clean version.
+7. **Validate and post-process** — engines with `retries_runaway=True` retry unstable output as smaller chunks. If `engine_needs_trim(engine)` is True, `trim_tts_output()` strips trailing silence. Effects chains (if any) are applied per generation version, not the clean version.
 
 8. **Persist** — audio is written to the generations directory, a row is inserted into the `generations` table, and the response includes the generation metadata.
 

docs/content/docs/overview/quick-start.mdx

@@ -14,12 +14,12 @@ Make sure you have [installed Voicebox](/overview/installation) and launched the
 Voice profiles are the foundation of Voicebox. Each profile contains voice samples that the AI uses to clone the voice.
 
 <Steps>
-  <Step title="Navigate to Profiles">
-    Click the **Profiles** tab in the sidebar
+  <Step title="Navigate to Voices">
+    Click the **Voices** tab in the sidebar
   </Step>
 
-  <Step title="Create New Profile">
-    Click the **+ New Profile** button
+  <Step title="Create New Voice">
+    Click the **+ New Voice** button
 
     Fill in the details:
     - **Name:** A descriptive name (e.g., "John Smith")

justfile

@@ -72,6 +72,12 @@ setup-python:
     if [ "$(uname -m)" = "arm64" ] && [ "$(uname)" = "Darwin" ]; then
         echo "Detected Apple Silicon — installing MLX dependencies..."
         {{ pip }} install -r {{ backend_dir }}/requirements-mlx.txt
+        # mlx-lm and mlx-audio declare transformers>=5.x, which conflicts with
+        # our transformers<=4.57.x cap, so install them --no-deps (their other
+        # runtime deps are covered by requirements.txt / requirements-mlx.txt —
+        # see the note in requirements-mlx.txt and .github/workflows/release.yml)
+        {{ pip }} install --no-deps mlx-lm==0.31.1
+        {{ pip }} install --no-deps mlx-audio==0.4.1
     fi
     {{ pip }} install git+https://github.com/QwenLM/Qwen3-TTS.git
     {{ pip }} install pyinstaller ruff pytest pytest-asyncio -q
@@ -89,10 +95,10 @@ setup-python:
     }
     Write-Host "Installing Python dependencies..."
     & "{{ python }}" -m pip install --upgrade pip -q
-    $gpus = Get-CimInstance Win32_VideoController | Select-Object -ExpandProperty Name
-    Write-Host "Detected GPUs: $($gpus -join ', ')"
-    $hasNvidia = ($gpus | Where-Object { $_ -match 'NVIDIA' }).Count -gt 0
-    $hasIntelArc = ($gpus | Where-Object { $_ -match 'Arc' }).Count -gt 0
+    $gpus = Get-CimInstance Win32_VideoController | Select-Object -ExpandProperty Name; \
+    Write-Host "Detected GPUs: $($gpus -join ', ')"; \
+    $hasNvidia = ($gpus | Where-Object { $_ -match 'NVIDIA' }).Count -gt 0; \
+    $hasIntelArc = ($gpus | Where-Object { $_ -match 'Arc' }).Count -gt 0; \
     if ($hasNvidia) { \
         Write-Host "NVIDIA GPU detected — installing PyTorch with CUDA support..."; \
         & "{{ pip }}" install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu128; \
@@ -226,12 +232,16 @@ build-server: _ensure-venv
 build-server: _ensure-venv
     $ErrorActionPreference = "Stop"; \
     $env:PATH = "{{ venv_bin }};$env:PATH"; \
-    & "{{ python }}" backend/build_binary.py; \
-    if ($LASTEXITCODE -ne 0) { throw "build_binary.py failed with exit code $LASTEXITCODE" }; \
     $triple = (rustc --print host-tuple); \
     New-Item -ItemType Directory -Path "{{ tauri_dir }}/src-tauri/binaries" -Force | Out-Null; \
+    & "{{ python }}" backend/build_binary.py; \
+    if ($LASTEXITCODE -ne 0) { throw "build_binary.py failed with exit code $LASTEXITCODE" }; \
     Copy-Item "backend/dist/voicebox-server.exe" "{{ tauri_dir }}/src-tauri/binaries/voicebox-server-$triple.exe" -Force; \
-    Write-Host "Copied sidecar: voicebox-server-$triple.exe"
+    Write-Host "Copied sidecar: voicebox-server-$triple.exe"; \
+    & "{{ python }}" backend/build_binary.py --shim; \
+    if ($LASTEXITCODE -ne 0) { throw "build_binary.py --shim failed with exit code $LASTEXITCODE" }; \
+    Copy-Item "backend/dist/voicebox-mcp.exe" "{{ tauri_dir }}/src-tauri/binaries/voicebox-mcp-$triple.exe" -Force; \
+    Write-Host "Copied sidecar: voicebox-mcp-$triple.exe"
 
 # Build CUDA server binary and place in app data dir for local testing
 [windows]

tauri/src-tauri/src/audio_capture/linux.rs

@@ -66,13 +66,46 @@ fn find_monitor_source_via_pactl() -> Option<String> {
     None
 }
 
+/// Select the capture device: prefer an exact match against the monitor
+/// source name reported by `pactl`, then fall back to any device whose name
+/// contains "monitor", then the host's default input device.
+fn select_capture_device(host: &cpal::Host, monitor_source: Option<&str>) -> Option<cpal::Device> {
+    let devices: Vec<cpal::Device> = host.input_devices().ok()?.collect();
+
+    if let Some(target) = monitor_source {
+        if let Some(pos) = devices
+            .iter()
+            .position(|d| d.name().map(|n| n == target).unwrap_or(false))
+        {
+            eprintln!(
+                "Linux audio capture: Using pactl monitor device: {}",
+                target
+            );
+            return devices.into_iter().nth(pos);
+        }
+    }
+
+    if let Some(pos) = devices.iter().position(|d| {
+        d.name()
+            .map(|n| n.to_lowercase().contains("monitor"))
+            .unwrap_or(false)
+    }) {
+        let name = devices[pos].name().unwrap_or_default();
+        eprintln!("Linux audio capture: Found monitor device by name: {}", name);
+        return devices.into_iter().nth(pos);
+    }
+
+    eprintln!("Linux audio capture: No monitor device found, falling back to default input");
+    host.default_input_device()
+}
+
 /// Start capturing system audio on Linux using PulseAudio monitor sources.
 ///
 /// On modern Linux with PulseAudio or PipeWire, we first try to detect the
-/// monitor source via `pactl` and set the `PULSE_SOURCE` environment variable.
-/// This tells PulseAudio's ALSA plugin to use the monitor as the default input
-/// source for this process. If `pactl` is unavailable, we fall back to searching
-/// cpal device names for "monitor".
+/// monitor source via `pactl`, then select the matching cpal input device by
+/// name. This avoids mutating the process environment (`PULSE_SOURCE`), which
+/// is not thread-safe and would affect every thread in the process. If `pactl`
+/// is unavailable, we fall back to searching cpal device names for "monitor".
 pub async fn start_capture(
     state: &AudioCaptureState,
     max_duration_secs: u32,
@@ -101,73 +134,16 @@ pub async fn start_capture(
 
     // Spawn capture on a dedicated thread
     thread::spawn(move || {
-        // Try to set PULSE_SOURCE to a monitor before initializing cpal.
-        // This tells PulseAudio/PipeWire's ALSA plugin to use the monitor
-        // as the default input source for this process.
-        let monitor_source = find_monitor_source_via_pactl();
-        if let Some(ref source_name) = monitor_source {
-            eprintln!(
-                "Linux audio capture: Setting PULSE_SOURCE={}",
-                source_name
-            );
-            std::env::set_var("PULSE_SOURCE", source_name);
-        }
-
         let host = cpal::default_host();
+        let monitor_source = find_monitor_source_via_pactl();
 
-        // Select the capture device.
-        // If PULSE_SOURCE was set, the default input device IS the monitor.
-        // Otherwise, fall back to searching device names for "monitor".
-        let device = if monitor_source.is_some() {
-            // PULSE_SOURCE was set — default input IS the monitor now
-            match host.default_input_device() {
-                Some(d) => {
-                    let name = d.name().unwrap_or_default();
-                    eprintln!(
-                        "Linux audio capture: Using PULSE_SOURCE monitor device: {}",
-                        name
-                    );
-                    d
-                }
-                None => {
-                    let error_msg = "No audio input device available".to_string();
-                    eprintln!("{}", error_msg);
-                    *error_arc.lock().unwrap() = Some(error_msg);
-                    return;
-                }
-            }
-        } else {
-            // pactl not available — try to find monitor by name (original approach)
-            let mut monitor_device = None;
-            if let Ok(devices) = host.input_devices() {
-                for d in devices {
-                    if let Ok(name) = d.name() {
-                        let name_lower = name.to_lowercase();
-                        if name_lower.contains("monitor") {
-                            eprintln!(
-                                "Linux audio capture: Found monitor device by name: {}",
-                                name
-                            );
-                            monitor_device = Some(d);
-                            break;
-                        }
-                    }
-                }
-            }
-            match monitor_device {
-                Some(d) => d,
-                None => {
-                    eprintln!("Linux audio capture: No monitor device found, falling back to default input");
-                    match host.default_input_device() {
-                        Some(d) => d,
-                        None => {
-                            let error_msg = "No audio input device available".to_string();
-                            eprintln!("{}", error_msg);
-                            *error_arc.lock().unwrap() = Some(error_msg);
-                            return;
-                        }
-                    }
-                }
+        let device = match select_capture_device(&host, monitor_source.as_deref()) {
+            Some(d) => d,
+            None => {
+                let error_msg = "No audio input device available".to_string();
+                eprintln!("{}", error_msg);
+                *error_arc.lock().unwrap() = Some(error_msg);
+                return;
             }
         };
 

tauri/src-tauri/src/key_codes.rs

@@ -30,6 +30,7 @@ pub fn key_from_str(name: &str) -> Option<Key> {
         "ShiftLeft" => Key::ShiftLeft,
         "ShiftRight" => Key::ShiftRight,
         "CapsLock" => Key::CapsLock,
+        "Function" => Key::Function,
 
         // Whitespace / navigation
         "Space" => Key::Space,

tauri/src-tauri/src/keyboard_layout.rs

@@ -19,19 +19,23 @@
 //! regardless of the active layout — most Windows apps treat that as
 //! Ctrl+V. AutoHotkey relies on the same behaviour.
 
+#[cfg(target_os = "macos")]
 use std::sync::atomic::{AtomicU16, Ordering};
 
 /// `kVK_ANSI_V` — the keycode for the physical V key on a US QWERTY
 /// layout. Used as the fallback whenever live resolution can't produce a
 /// better answer (no Unicode key layout data, lookup failure, non-macOS).
+#[cfg(target_os = "macos")]
 const FALLBACK_V_KEYCODE: u16 = 9;
 
+#[cfg(target_os = "macos")]
 static V_KEYCODE: AtomicU16 = AtomicU16::new(FALLBACK_V_KEYCODE);
 
 /// Returns the keycode whose current-layout translation is `'v'`. Falls
 /// back to `kVK_ANSI_V` when resolution hasn't run, the active input
 /// source carries no Unicode key layout data, or no keycode in the layout
 /// produces `v`.
+#[cfg(target_os = "macos")]
 pub fn paste_keycode_v() -> u16 {
     V_KEYCODE.load(Ordering::Relaxed)
 }

tauri/src-tauri/src/synthetic_keys.rs

@@ -4,10 +4,14 @@
 //! pipeline so the focused app performs its native paste action against
 //! whatever the clipboard module has just staged.
 //!
-//! - **macOS** — Cmd down, V down with Cmd flag, V up with Cmd flag, Cmd
-//!   up via `CGEventPost` at `kCGHIDEventTap`. Accessibility permission is
-//!   load-bearing: without it the system swallows the events silently, so
-//!   callers must gate on [`crate::accessibility::is_trusted`].
+//! - **macOS** — Cmd down with Cmd flag, V down with Cmd flag, V up with
+//!   Cmd flag, Cmd up via `CGEventPost` at `kCGHIDEventTap`. The Cmd-down
+//!   event carries the Command flag so its `flagsChanged` representation
+//!   matches hardware — Electron/Chromium tracks modifier state from that
+//!   flag and drops the paste otherwise (see the note on the event table).
+//!   Accessibility permission is load-bearing: without it the system
+//!   swallows the events silently, so callers must gate on
+//!   [`crate::accessibility::is_trusted`].
 //! - **Windows** — Ctrl down, V down, V up, Ctrl up via `SendInput`. No
 //!   permission gate, but UAC/UIPI blocks delivery into elevated target
 //!   windows when we run non-elevated — nothing we can do short of also
@@ -101,7 +105,18 @@ pub fn send_paste() -> Result<(), String> {
         let _source_guard = scopeguard::guard(source, |s| CFRelease(s as *const c_void));
 
         let events = [
-            (KEYCODE_LEFT_CMD, true, 0),
+            // The Cmd-down event must carry the Command flag itself. On real
+            // hardware the Cmd keyDown is a flagsChanged event whose flags
+            // already include Command; Chromium/Electron builds its tracked
+            // modifier state from that flag. Posting Cmd-down with flags = 0
+            // leaves that tracker showing "Command up", so the following V —
+            // even though its own flags carry Command — matches neither the
+            // Cmd+V accelerator (tracker says no modifier) nor plain-text
+            // insertion (event flags say Command), and Electron drops it
+            // silently. AppKit reads the V event's own flags and pastes
+            // regardless, which is why native apps worked but Electron
+            // targets (Slack, VS Code) silently no-op'd.
+            (KEYCODE_LEFT_CMD, true, K_CG_EVENT_FLAG_MASK_COMMAND),
             (v_keycode, true, K_CG_EVENT_FLAG_MASK_COMMAND),
             (v_keycode, false, K_CG_EVENT_FLAG_MASK_COMMAND),
             (KEYCODE_LEFT_CMD, false, 0),