Initial commit

backend/routes/__init__.py

@@ -0,0 +1,32 @@
+"""Route registration for the voicebox API."""
+
+from fastapi import FastAPI
+
+
+def register_routers(app: FastAPI) -> None:
+    """Include all domain routers on the application."""
+    from .health import router as health_router
+    from .profiles import router as profiles_router
+    from .channels import router as channels_router
+    from .generations import router as generations_router
+    from .history import router as history_router
+    from .transcription import router as transcription_router
+    from .stories import router as stories_router
+    from .effects import router as effects_router
+    from .audio import router as audio_router
+    from .models import router as models_router
+    from .tasks import router as tasks_router
+    from .cuda import router as cuda_router
+
+    app.include_router(health_router)
+    app.include_router(profiles_router)
+    app.include_router(channels_router)
+    app.include_router(generations_router)
+    app.include_router(history_router)
+    app.include_router(transcription_router)
+    app.include_router(stories_router)
+    app.include_router(effects_router)
+    app.include_router(audio_router)
+    app.include_router(models_router)
+    app.include_router(tasks_router)
+    app.include_router(cuda_router)

backend/routes/audio.py

@@ -0,0 +1,69 @@
+"""Audio file serving endpoints."""
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import FileResponse
+from sqlalchemy.orm import Session
+
+from .. import config, models
+from ..services import history
+from ..database import get_db
+
+router = APIRouter()
+
+
+@router.get("/audio/version/{version_id}")
+async def get_version_audio(version_id: str, db: Session = Depends(get_db)):
+    """Serve audio for a specific version."""
+    from ..services import versions as versions_mod
+
+    version = versions_mod.get_version(version_id, db)
+    if not version:
+        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():
+        raise HTTPException(status_code=404, detail="Audio file not found")
+
+    return FileResponse(
+        audio_path,
+        media_type="audio/wav",
+        filename=f"generation_{version.generation_id}_{version.label}.wav",
+    )
+
+
+@router.get("/audio/{generation_id}")
+async def get_audio(generation_id: str, db: Session = Depends(get_db)):
+    """Serve generated audio file (serves the default version)."""
+    generation = await history.get_generation(generation_id, db)
+    if not generation:
+        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")
+
+    return FileResponse(
+        audio_path,
+        media_type="audio/wav",
+        filename=f"generation_{generation_id}.wav",
+    )
+
+
+@router.get("/samples/{sample_id}")
+async def get_sample_audio(sample_id: str, db: Session = Depends(get_db)):
+    """Serve profile sample audio file."""
+    from ..database import ProfileSample as DBProfileSample
+
+    sample = db.query(DBProfileSample).filter_by(id=sample_id).first()
+    if not sample:
+        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():
+        raise HTTPException(status_code=404, detail="Audio file not found")
+
+    return FileResponse(
+        audio_path,
+        media_type="audio/wav",
+        filename=f"sample_{sample_id}.wav",
+    )

backend/routes/channels.py

@@ -0,0 +1,98 @@
+"""Audio channel endpoints."""
+
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+
+from .. import models
+from ..services import channels
+from ..database import get_db
+
+router = APIRouter()
+
+
+@router.get("/channels", response_model=list[models.AudioChannelResponse])
+async def list_channels(db: Session = Depends(get_db)):
+    """List all audio channels."""
+    return await channels.list_channels(db)
+
+
+@router.post("/channels", response_model=models.AudioChannelResponse)
+async def create_channel(
+    data: models.AudioChannelCreate,
+    db: Session = Depends(get_db),
+):
+    """Create a new audio channel."""
+    try:
+        return await channels.create_channel(data, db)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.get("/channels/{channel_id}", response_model=models.AudioChannelResponse)
+async def get_channel(
+    channel_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get an audio channel by ID."""
+    channel = await channels.get_channel(channel_id, db)
+    if not channel:
+        raise HTTPException(status_code=404, detail="Channel not found")
+    return channel
+
+
+@router.put("/channels/{channel_id}", response_model=models.AudioChannelResponse)
+async def update_channel(
+    channel_id: str,
+    data: models.AudioChannelUpdate,
+    db: Session = Depends(get_db),
+):
+    """Update an audio channel."""
+    try:
+        channel = await channels.update_channel(channel_id, data, db)
+        if not channel:
+            raise HTTPException(status_code=404, detail="Channel not found")
+        return channel
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.delete("/channels/{channel_id}")
+async def delete_channel(
+    channel_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete an audio channel."""
+    try:
+        success = await channels.delete_channel(channel_id, db)
+        if not success:
+            raise HTTPException(status_code=404, detail="Channel not found")
+        return {"message": "Channel deleted successfully"}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.get("/channels/{channel_id}/voices")
+async def get_channel_voices(
+    channel_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get list of profile IDs assigned to a channel."""
+    try:
+        profile_ids = await channels.get_channel_voices(channel_id, db)
+        return {"profile_ids": profile_ids}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.put("/channels/{channel_id}/voices")
+async def set_channel_voices(
+    channel_id: str,
+    data: models.ChannelVoiceAssignment,
+    db: Session = Depends(get_db),
+):
+    """Set which voices are assigned to a channel."""
+    try:
+        await channels.set_channel_voices(channel_id, data, db)
+        return {"message": "Channel voices updated successfully"}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))

backend/routes/cuda.py

@@ -0,0 +1,82 @@
+"""CUDA backend management endpoints."""
+
+import logging
+
+from fastapi import APIRouter, HTTPException
+from fastapi.responses import StreamingResponse
+
+from ..services.task_queue import create_background_task
+from ..utils.progress import get_progress_manager
+
+router = APIRouter()
+
+logger = logging.getLogger(__name__)
+
+
+@router.get("/backend/cuda-status")
+async def get_cuda_status():
+    """Get CUDA backend download/availability status."""
+    from ..services import cuda
+
+    return cuda.get_cuda_status()
+
+
+@router.post("/backend/download-cuda")
+async def download_cuda_backend():
+    """Download the CUDA backend binary."""
+    from ..services import cuda
+
+    if cuda.get_cuda_binary_path() is not None:
+        raise HTTPException(status_code=409, detail="CUDA backend already downloaded")
+
+    progress_manager = get_progress_manager()
+    existing = progress_manager.get_progress(cuda.PROGRESS_KEY)
+    if existing and existing.get("status") == "downloading":
+        raise HTTPException(status_code=409, detail="CUDA backend download already in progress")
+
+    async def _download():
+        try:
+            await cuda.download_cuda_binary()
+        except Exception as e:
+            logger.error("CUDA download failed: %s", e)
+
+    create_background_task(_download())
+    return {"message": "CUDA backend download started", "progress_key": "cuda-backend"}
+
+
+@router.delete("/backend/cuda")
+async def delete_cuda_backend():
+    """Delete the downloaded CUDA backend binary."""
+    from ..services import cuda
+
+    if cuda.is_cuda_active():
+        raise HTTPException(
+            status_code=409,
+            detail="Cannot delete CUDA backend while it is active. Switch to CPU first.",
+        )
+
+    deleted = await cuda.delete_cuda_binary()
+    if not deleted:
+        raise HTTPException(status_code=404, detail="No CUDA backend found to delete")
+
+    return {"message": "CUDA backend deleted"}
+
+
+@router.get("/backend/cuda-progress")
+async def get_cuda_download_progress():
+    """Get CUDA backend download progress via Server-Sent Events."""
+    progress_manager = get_progress_manager()
+
+    async def event_generator():
+        async for event in progress_manager.subscribe("cuda-backend"):
+            yield event
+
+    return StreamingResponse(
+        event_generator(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )

backend/routes/effects.py

@@ -0,0 +1,262 @@
+"""Effects presets and generation version endpoints."""
+
+import asyncio
+import io
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy.orm import Session
+
+from .. import config, models
+from ..services import history
+from ..database import Generation as DBGeneration, get_db
+
+router = APIRouter()
+
+
+@router.post("/effects/preview/{generation_id}")
+async def preview_effects(
+    generation_id: str,
+    data: models.ApplyEffectsRequest,
+    db: Session = Depends(get_db),
+):
+    """Apply effects to a generation's clean audio and stream back without saving."""
+    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") != "completed":
+        raise HTTPException(status_code=400, detail="Generation is not completed")
+
+    from ..services import versions as versions_mod
+    from ..utils.effects import apply_effects, validate_effects_chain
+    from ..utils.audio import load_audio
+
+    chain_dicts = [e.model_dump() for e in data.effects_chain]
+    error = validate_effects_chain(chain_dicts)
+    if error:
+        raise HTTPException(status_code=400, detail=error)
+
+    all_versions = versions_mod.list_versions(generation_id, db)
+    clean_version = next((v for v in all_versions if v.effects_chain is None), None)
+    source_path = clean_version.audio_path if clean_version else gen.audio_path
+    resolved_source_path = config.resolve_storage_path(source_path)
+    if resolved_source_path is None or not resolved_source_path.exists():
+        raise HTTPException(status_code=404, detail="Source audio file not found")
+
+    audio, sample_rate = await asyncio.to_thread(load_audio, str(resolved_source_path))
+    processed = await asyncio.to_thread(apply_effects, audio, sample_rate, chain_dicts)
+
+    import soundfile as sf
+
+    buf = io.BytesIO()
+    await asyncio.to_thread(lambda: sf.write(buf, processed, sample_rate, format="WAV"))
+    buf.seek(0)
+
+    return StreamingResponse(
+        buf,
+        media_type="audio/wav",
+        headers={
+            "Content-Disposition": f'inline; filename="preview_{generation_id}.wav"',
+            "Cache-Control": "no-cache, no-store",
+        },
+    )
+
+
+@router.get("/effects/available", response_model=models.AvailableEffectsResponse)
+async def get_available_effects():
+    """List all available effect types with parameter definitions."""
+    from ..utils.effects import get_available_effects as _get_effects
+
+    return models.AvailableEffectsResponse(effects=[models.AvailableEffect(**e) for e in _get_effects()])
+
+
+@router.get("/effects/presets", response_model=list[models.EffectPresetResponse])
+async def list_effect_presets(db: Session = Depends(get_db)):
+    """List all effect presets (built-in + user-created)."""
+    from ..services import effects as effects_mod
+
+    return effects_mod.list_presets(db)
+
+
+@router.get("/effects/presets/{preset_id}", response_model=models.EffectPresetResponse)
+async def get_effect_preset(preset_id: str, db: Session = Depends(get_db)):
+    """Get a specific effect preset."""
+    from ..services import effects as effects_mod
+
+    preset = effects_mod.get_preset(preset_id, db)
+    if not preset:
+        raise HTTPException(status_code=404, detail="Preset not found")
+    return preset
+
+
+@router.post("/effects/presets", response_model=models.EffectPresetResponse)
+async def create_effect_preset(
+    data: models.EffectPresetCreate,
+    db: Session = Depends(get_db),
+):
+    """Create a new effect preset."""
+    from ..services import effects as effects_mod
+
+    try:
+        return effects_mod.create_preset(data, db)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.put("/effects/presets/{preset_id}", response_model=models.EffectPresetResponse)
+async def update_effect_preset(
+    preset_id: str,
+    data: models.EffectPresetUpdate,
+    db: Session = Depends(get_db),
+):
+    """Update an effect preset."""
+    from ..services import effects as effects_mod
+
+    try:
+        result = effects_mod.update_preset(preset_id, data, db)
+        if not result:
+            raise HTTPException(status_code=404, detail="Preset not found")
+        return result
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.delete("/effects/presets/{preset_id}")
+async def delete_effect_preset(preset_id: str, db: Session = Depends(get_db)):
+    """Delete a user effect preset."""
+    from ..services import effects as effects_mod
+
+    try:
+        if not effects_mod.delete_preset(preset_id, db):
+            raise HTTPException(status_code=404, detail="Preset not found")
+        return {"status": "deleted"}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.get(
+    "/generations/{generation_id}/versions",
+    response_model=list[models.GenerationVersionResponse],
+)
+async def list_generation_versions(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """List all versions for a generation."""
+    gen = await history.get_generation(generation_id, db)
+    if not gen:
+        raise HTTPException(status_code=404, detail="Generation not found")
+
+    from ..services import versions as versions_mod
+
+    return versions_mod.list_versions(generation_id, db)
+
+
+@router.post(
+    "/generations/{generation_id}/versions/apply-effects",
+    response_model=models.GenerationVersionResponse,
+)
+async def apply_effects_to_generation(
+    generation_id: str,
+    data: models.ApplyEffectsRequest,
+    db: Session = Depends(get_db),
+):
+    """Apply an effects chain to an existing generation, creating a new version."""
+    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") != "completed":
+        raise HTTPException(status_code=400, detail="Generation is not completed")
+
+    from ..services import versions as versions_mod
+    from ..utils.effects import apply_effects, validate_effects_chain
+    from ..utils.audio import load_audio, save_audio
+
+    chain_dicts = [e.model_dump() for e in data.effects_chain]
+    error = validate_effects_chain(chain_dicts)
+    if error:
+        raise HTTPException(status_code=400, detail=error)
+
+    all_versions = versions_mod.list_versions(generation_id, db)
+    source_version_id = data.source_version_id
+    if source_version_id:
+        source_version = next((v for v in all_versions if v.id == source_version_id), None)
+        if not source_version:
+            raise HTTPException(status_code=404, detail="Source version not found")
+        source_path = source_version.audio_path
+    else:
+        clean_version = next((v for v in all_versions if v.effects_chain is None), None)
+        if not clean_version:
+            source_path = gen.audio_path
+        else:
+            source_path = clean_version.audio_path
+            source_version_id = clean_version.id
+
+    resolved_source_path = config.resolve_storage_path(source_path)
+    if resolved_source_path is None or not resolved_source_path.exists():
+        raise HTTPException(status_code=404, detail="Source audio file not found")
+
+    audio, sample_rate = await asyncio.to_thread(load_audio, str(resolved_source_path))
+    processed_audio = await asyncio.to_thread(apply_effects, audio, sample_rate, chain_dicts)
+
+    version_id = str(uuid.uuid4())
+    processed_path = config.get_generations_dir() / f"{generation_id}_{version_id[:8]}.wav"
+    await asyncio.to_thread(save_audio, processed_audio, str(processed_path), sample_rate)
+
+    label = data.label or f"version-{len(all_versions) + 1}"
+
+    version = versions_mod.create_version(
+        generation_id=generation_id,
+        label=label,
+        audio_path=config.to_storage_path(processed_path),
+        db=db,
+        effects_chain=chain_dicts,
+        is_default=data.set_as_default,
+        source_version_id=source_version_id,
+    )
+
+    return version
+
+
+@router.put(
+    "/generations/{generation_id}/versions/{version_id}/set-default",
+    response_model=models.GenerationVersionResponse,
+)
+async def set_default_version(
+    generation_id: str,
+    version_id: str,
+    db: Session = Depends(get_db),
+):
+    """Set a specific version as the default for a generation."""
+    from ..services import versions as versions_mod
+
+    version = versions_mod.get_version(version_id, db)
+    if not version or version.generation_id != generation_id:
+        raise HTTPException(status_code=404, detail="Version not found")
+
+    result = versions_mod.set_default_version(version_id, db)
+    if not result:
+        raise HTTPException(status_code=404, detail="Version not found")
+    return result
+
+
+@router.delete("/generations/{generation_id}/versions/{version_id}")
+async def delete_generation_version(
+    generation_id: str,
+    version_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete a version. Cannot delete the last remaining version."""
+    from ..services import versions as versions_mod
+
+    version = versions_mod.get_version(version_id, db)
+    if not version or version.generation_id != generation_id:
+        raise HTTPException(status_code=404, detail="Version not found")
+
+    if not versions_mod.delete_version(version_id, db):
+        raise HTTPException(
+            status_code=400,
+            detail="Cannot delete the last remaining version",
+        )
+    return {"status": "deleted"}

backend/routes/generations.py

@@ -0,0 +1,345 @@
+"""TTS generation endpoints."""
+
+import asyncio
+import logging
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy.orm import Session
+
+logger = logging.getLogger(__name__)
+
+from .. import models
+from ..services import history, profiles, tts
+from ..database import Generation as DBGeneration, VoiceProfile as DBVoiceProfile, get_db
+from ..services.generation import run_generation
+from ..services.task_queue import cancel_generation as cancel_generation_job, enqueue_generation
+from ..utils.tasks import get_task_manager
+
+router = APIRouter()
+
+
+def _resolve_generation_engine(data: models.GenerationRequest, profile) -> str:
+    return data.engine or getattr(profile, "default_engine", None) or getattr(profile, "preset_engine", None) or "qwen"
+
+
+@router.post("/generate", response_model=models.GenerationResponse)
+async def generate_speech(
+    data: models.GenerationRequest,
+    db: Session = Depends(get_db),
+):
+    """Generate speech from text using a voice profile."""
+    task_manager = get_task_manager()
+    generation_id = str(uuid.uuid4())
+
+    profile = await profiles.get_profile(data.profile_id, db)
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")
+
+    from ..backends import engine_has_model_sizes
+
+    engine = _resolve_generation_engine(data, profile)
+    try:
+        profiles.validate_profile_engine(profile, engine)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+    model_size = (data.model_size or "1.7B") if engine_has_model_sizes(engine) else None
+
+    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_has_model_sizes(engine) else None,
+    )
+
+    task_manager.start_generation(
+        task_id=generation_id,
+        profile_id=data.profile_id,
+        text=data.text,
+    )
+
+    effects_chain_config = None
+    if data.effects_chain is not None:
+        effects_chain_config = [e.model_dump() for e in data.effects_chain]
+    else:
+        import json as _json
+
+        profile_obj = db.query(DBVoiceProfile).filter_by(id=data.profile_id).first()
+        if profile_obj and profile_obj.effects_chain:
+            try:
+                effects_chain_config = _json.loads(profile_obj.effects_chain)
+            except Exception:
+                pass
+
+    enqueue_generation(
+        generation_id,
+        run_generation(
+            generation_id=generation_id,
+            profile_id=data.profile_id,
+            text=data.text,
+            language=data.language,
+            engine=engine,
+            model_size=model_size,
+            seed=data.seed,
+            normalize=data.normalize,
+            effects_chain=effects_chain_config,
+            instruct=data.instruct,
+            mode="generate",
+            max_chunk_chars=data.max_chunk_chars,
+            crossfade_ms=data.crossfade_ms,
+        )
+    )
+
+    return generation
+
+
+@router.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")
+
+    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,
+    )
+
+    enqueue_generation(
+        generation_id,
+        run_generation(
+            generation_id=generation_id,
+            profile_id=gen.profile_id,
+            text=gen.text,
+            language=gen.language,
+            engine=gen.engine or "qwen",
+            model_size=gen.model_size or "1.7B",
+            seed=gen.seed,
+            instruct=gen.instruct,
+            mode="retry",
+        )
+    )
+
+    return models.GenerationResponse.model_validate(gen)
+
+
+@router.post(
+    "/generate/{generation_id}/regenerate",
+    response_model=models.GenerationResponse,
+)
+async def regenerate_generation(generation_id: str, db: Session = Depends(get_db)):
+    """Re-run TTS with the same parameters and save the result as a new version."""
+    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") != "completed":
+        raise HTTPException(status_code=400, detail="Generation must be completed to regenerate")
+
+    gen.status = "generating"
+    gen.error = None
+    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,
+    )
+
+    version_id = str(uuid.uuid4())
+
+    enqueue_generation(
+        generation_id,
+        run_generation(
+            generation_id=generation_id,
+            profile_id=gen.profile_id,
+            text=gen.text,
+            language=gen.language,
+            engine=gen.engine or "qwen",
+            model_size=gen.model_size or "1.7B",
+            seed=gen.seed,
+            instruct=gen.instruct,
+            mode="regenerate",
+            version_id=version_id,
+        )
+    )
+
+    return models.GenerationResponse.model_validate(gen)
+
+
+@router.post("/generate/{generation_id}/cancel")
+async def cancel_generation(generation_id: str, db: Session = Depends(get_db)):
+    """Cancel a queued or running generation."""
+    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") not in ("loading_model", "generating"):
+        raise HTTPException(status_code=400, detail="Only active generations can be cancelled")
+
+    cancellation_state = cancel_generation_job(generation_id)
+    if cancellation_state is None:
+        raise HTTPException(status_code=409, detail="Generation is no longer cancellable")
+
+    if cancellation_state == "queued":
+        task_manager = get_task_manager()
+        task_manager.complete_generation(generation_id)
+        await history.update_generation_status(
+            generation_id=generation_id,
+            status="failed",
+            db=db,
+            error="Generation cancelled",
+        )
+        return {"message": "Queued generation cancelled"}
+
+    return {"message": "Generation cancellation requested"}
+
+
+@router.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."""
+    import json
+
+    async def event_stream():
+        try:
+            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)
+        except (BrokenPipeError, ConnectionResetError, asyncio.CancelledError):
+            logger.debug("SSE client disconnected for generation %s", generation_id)
+
+    return StreamingResponse(
+        event_stream(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )
+
+
+@router.post("/generate/stream")
+async def stream_speech(
+    data: models.GenerationRequest,
+    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
+
+    profile = await profiles.get_profile(data.profile_id, db)
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")
+
+    engine = _resolve_generation_engine(data, profile)
+    try:
+        profiles.validate_profile_engine(profile, engine)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    tts_model = get_tts_backend_for_engine(engine)
+    model_size = data.model_size or "1.7B"
+
+    await ensure_model_cached_or_raise(engine, model_size)
+    await load_engine_model(engine, model_size)
+
+    voice_prompt = await profiles.create_voice_prompt_for_profile(
+        data.profile_id,
+        db,
+        engine=engine,
+    )
+
+    from ..utils.chunked_tts import generate_chunked
+
+    trim_fn = None
+    if engine_needs_trim(engine):
+        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,
+    )
+
+    effects_chain_config = None
+    if data.effects_chain is not None:
+        effects_chain_config = [e.model_dump() for e in data.effects_chain]
+    elif profile.effects_chain:
+        import json as _json
+
+        try:
+            effects_chain_config = _json.loads(profile.effects_chain)
+        except Exception:
+            effects_chain_config = None
+
+    if effects_chain_config:
+        from ..utils.effects import apply_effects
+
+        audio = apply_effects(audio, sample_rate, effects_chain_config)
+
+    if data.normalize:
+        from ..utils.audio import normalize_audio
+
+        audio = normalize_audio(audio)
+
+    wav_bytes = tts.audio_to_wav_bytes(audio, sample_rate)
+
+    async def _wav_stream():
+        try:
+            chunk_size = 64 * 1024
+            for i in range(0, len(wav_bytes), chunk_size):
+                yield wav_bytes[i : i + chunk_size]
+        except (BrokenPipeError, ConnectionResetError, asyncio.CancelledError):
+            logger.debug("Client disconnected during audio stream")
+
+    return StreamingResponse(
+        _wav_stream(),
+        media_type="audio/wav",
+        headers={"Content-Disposition": 'attachment; filename="speech.wav"'},
+    )

backend/routes/health.py

@@ -0,0 +1,248 @@
+"""Health and infrastructure endpoints."""
+
+import asyncio
+import os
+import signal
+from pathlib import Path
+
+import torch
+from fastapi import APIRouter, Depends
+from fastapi.responses import FileResponse
+from sqlalchemy.orm import Session
+
+from .. import config, models
+from ..services import tts
+from ..database import get_db
+from ..utils.platform_detect import get_backend_type
+
+router = APIRouter()
+
+# Frontend build directory — present in Docker, absent in dev/API-only mode
+_frontend_dir = Path(__file__).resolve().parent.parent.parent / "frontend"
+
+
+@router.get("/")
+async def root():
+    """Root endpoint — serves SPA index.html in Docker, JSON otherwise."""
+    from .. import __version__
+
+    index = _frontend_dir / "index.html"
+    if index.is_file():
+        return FileResponse(index, media_type="text/html")
+    return {"message": "voicebox API", "version": __version__}
+
+
+@router.post("/shutdown")
+async def shutdown():
+    """Gracefully shutdown the server."""
+
+    async def shutdown_async():
+        await asyncio.sleep(0.1)
+        os.kill(os.getpid(), signal.SIGTERM)
+
+    asyncio.create_task(shutdown_async())
+    return {"message": "Shutting down..."}
+
+
+@router.post("/watchdog/disable")
+async def watchdog_disable():
+    """Disable the parent process watchdog so the server keeps running."""
+    from backend.server import disable_watchdog
+
+    disable_watchdog()
+    return {"message": "Watchdog disabled"}
+
+
+@router.get("/health", response_model=models.HealthResponse)
+async def health():
+    """Health check endpoint."""
+    from huggingface_hub import constants as hf_constants
+    from pathlib import Path
+
+    tts_model = tts.get_tts_model()
+    backend_type = get_backend_type()
+
+    has_cuda = torch.cuda.is_available()
+    has_mps = hasattr(torch.backends, "mps") and torch.backends.mps.is_available()
+
+    has_xpu = False
+    xpu_name = None
+    try:
+        import intel_extension_for_pytorch as ipex  # noqa: F401 -- side-effect import enables XPU
+
+        if hasattr(torch, "xpu") and torch.xpu.is_available():
+            has_xpu = True
+            try:
+                xpu_name = torch.xpu.get_device_name(0)
+            except Exception:
+                xpu_name = "Intel GPU"
+    except ImportError:
+        pass
+
+    has_directml = False
+    directml_name = None
+    try:
+        import torch_directml
+
+        if torch_directml.device_count() > 0:
+            has_directml = True
+            try:
+                directml_name = torch_directml.device_name(0)
+            except Exception:
+                directml_name = "DirectML GPU"
+    except ImportError:
+        pass
+
+    gpu_compat_warning = None
+    if has_cuda:
+        from ..backends.base import check_cuda_compatibility
+
+        _compatible, gpu_compat_warning = check_cuda_compatibility()
+
+    gpu_available = has_cuda or has_mps or has_xpu or has_directml or backend_type == "mlx"
+
+    gpu_type = None
+    if has_cuda:
+        gpu_type = f"CUDA ({torch.cuda.get_device_name(0)})"
+    elif has_mps:
+        gpu_type = "MPS (Apple Silicon)"
+    elif backend_type == "mlx":
+        gpu_type = "Metal (Apple Silicon via MLX)"
+    elif has_xpu:
+        gpu_type = f"XPU ({xpu_name})"
+    elif has_directml:
+        gpu_type = f"DirectML ({directml_name})"
+
+    vram_used = None
+    if has_cuda:
+        vram_used = torch.cuda.memory_allocated() / 1024 / 1024
+    elif has_xpu:
+        try:
+            vram_used = torch.xpu.memory_allocated() / 1024 / 1024
+        except Exception:
+            pass  # memory_allocated() may not be available on all IPEX versions
+
+    model_loaded = False
+    model_size = None
+    try:
+        if tts_model.is_loaded():
+            model_loaded = True
+            model_size = getattr(tts_model, "_current_model_size", None)
+            if not model_size:
+                model_size = getattr(tts_model, "model_size", None)
+    except Exception:
+        model_loaded = False
+        model_size = None
+
+    model_downloaded = None
+    try:
+        from ..backends import get_model_config
+
+        default_config = get_model_config("qwen-tts-1.7B")
+        default_model_id = default_config.hf_repo_id if default_config else "Qwen/Qwen3-TTS-12Hz-1.7B-Base"
+
+        try:
+            from huggingface_hub import scan_cache_dir
+
+            cache_info = scan_cache_dir()
+            for repo in cache_info.repos:
+                if repo.repo_id == default_model_id:
+                    model_downloaded = True
+                    break
+        except (ImportError, Exception):
+            cache_dir = hf_constants.HF_HUB_CACHE
+            repo_cache = Path(cache_dir) / ("models--" + default_model_id.replace("/", "--"))
+            if repo_cache.exists():
+                has_model_files = (
+                    any(repo_cache.rglob("*.bin"))
+                    or any(repo_cache.rglob("*.safetensors"))
+                    or any(repo_cache.rglob("*.pt"))
+                    or any(repo_cache.rglob("*.pth"))
+                    or any(repo_cache.rglob("*.npz"))
+                )
+                model_downloaded = has_model_files
+    except Exception:
+        pass
+
+    return models.HealthResponse(
+        status="healthy",
+        model_loaded=model_loaded,
+        model_downloaded=model_downloaded,
+        model_size=model_size,
+        gpu_available=gpu_available,
+        gpu_type=gpu_type,
+        vram_used_mb=vram_used,
+        backend_type=backend_type,
+        backend_variant=os.environ.get(
+            "VOICEBOX_BACKEND_VARIANT",
+            "cuda" if torch.cuda.is_available() else ("xpu" if has_xpu else "cpu"),
+        ),
+        gpu_compatibility_warning=gpu_compat_warning,
+    )
+
+
+@router.get("/health/filesystem", response_model=models.FilesystemHealthResponse)
+async def filesystem_health():
+    """Check filesystem health: directory existence, write permissions, and disk space."""
+    import shutil
+
+    dirs_to_check = {
+        "generations": config.get_generations_dir(),
+        "profiles": config.get_profiles_dir(),
+        "data": config.get_data_dir(),
+    }
+
+    checks: list[models.DirectoryCheck] = []
+    all_ok = True
+
+    for _label, dir_path in dirs_to_check.items():
+        exists = dir_path.exists()
+        writable = False
+        error = None
+        if exists:
+            probe = dir_path / ".voicebox_probe"
+            try:
+                probe.write_text("ok")
+                probe.unlink()
+                writable = True
+            except PermissionError:
+                error = "Permission denied"
+            except OSError as e:
+                error = str(e)
+            finally:
+                try:
+                    probe.unlink(missing_ok=True)
+                except Exception:
+                    pass
+        else:
+            error = "Directory does not exist"
+
+        if not exists or not writable:
+            all_ok = False
+
+        checks.append(
+            models.DirectoryCheck(
+                path=str(dir_path.resolve()),
+                exists=exists,
+                writable=writable,
+                error=error,
+            )
+        )
+
+    disk_free_mb = None
+    disk_total_mb = None
+    try:
+        usage = shutil.disk_usage(str(config.get_data_dir()))
+        disk_free_mb = round(usage.free / (1024 * 1024), 1)
+        disk_total_mb = round(usage.total / (1024 * 1024), 1)
+        if disk_free_mb < 500:
+            all_ok = False
+    except OSError:
+        all_ok = False
+
+    return models.FilesystemHealthResponse(
+        healthy=all_ok,
+        disk_free_mb=disk_free_mb,
+        disk_total_mb=disk_total_mb,
+        directories=checks,
+    )

backend/routes/history.py

@@ -0,0 +1,189 @@
+"""Generation history endpoints."""
+
+import io
+
+from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
+from fastapi.responses import FileResponse, StreamingResponse
+from sqlalchemy.orm import Session
+
+from .. import config, models
+from ..services import export_import, history
+from ..app import safe_content_disposition
+from ..database import Generation as DBGeneration, VoiceProfile as DBVoiceProfile, get_db
+
+router = APIRouter()
+
+
+@router.get("/history", response_model=models.HistoryListResponse)
+async def list_history(
+    profile_id: str | None = None,
+    search: str | None = None,
+    limit: int = 50,
+    offset: int = 0,
+    db: Session = Depends(get_db),
+):
+    """List generation history with optional filters."""
+    query = models.HistoryQuery(
+        profile_id=profile_id,
+        search=search,
+        limit=limit,
+        offset=offset,
+    )
+    return await history.list_generations(query, db)
+
+
+@router.get("/history/stats")
+async def get_stats(db: Session = Depends(get_db)):
+    """Get generation statistics."""
+    return await history.get_generation_stats(db)
+
+
+@router.post("/history/import")
+async def import_generation(
+    file: UploadFile = File(...),
+    db: Session = Depends(get_db),
+):
+    """Import a generation from a ZIP archive."""
+    MAX_FILE_SIZE = 50 * 1024 * 1024
+
+    content = await file.read()
+
+    if len(content) > MAX_FILE_SIZE:
+        raise HTTPException(
+            status_code=400, detail=f"File too large. Maximum size is {MAX_FILE_SIZE / (1024 * 1024)}MB"
+        )
+
+    try:
+        result = await export_import.import_generation_from_zip(content, db)
+        return result
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.delete("/history/failed")
+async def clear_failed_generations(db: Session = Depends(get_db)):
+    """Delete every generation with status='failed'. Used by the UI's 'Clear failed' button (#410)."""
+    count = await history.delete_failed_generations(db)
+    return {"deleted": count}
+
+
+@router.get("/history/{generation_id}", response_model=models.HistoryResponse)
+async def get_generation(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get a generation by ID."""
+    result = (
+        db.query(DBGeneration, DBVoiceProfile.name.label("profile_name"))
+        .join(DBVoiceProfile, DBGeneration.profile_id == DBVoiceProfile.id)
+        .filter(DBGeneration.id == generation_id)
+        .first()
+    )
+
+    if not result:
+        raise HTTPException(status_code=404, detail="Generation not found")
+
+    gen, profile_name = result
+    return models.HistoryResponse(
+        id=gen.id,
+        profile_id=gen.profile_id,
+        profile_name=profile_name,
+        text=gen.text,
+        language=gen.language,
+        audio_path=gen.audio_path,
+        duration=gen.duration,
+        seed=gen.seed,
+        instruct=gen.instruct,
+        engine=gen.engine or "qwen",
+        model_size=gen.model_size,
+        status=gen.status or "completed",
+        error=gen.error,
+        is_favorited=bool(gen.is_favorited),
+        created_at=gen.created_at,
+    )
+
+
+@router.post("/history/{generation_id}/favorite")
+async def toggle_favorite(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """Toggle the favorite status of a generation."""
+    gen = db.query(DBGeneration).filter_by(id=generation_id).first()
+    if not gen:
+        raise HTTPException(status_code=404, detail="Generation not found")
+    gen.is_favorited = not gen.is_favorited
+    db.commit()
+    return {"is_favorited": gen.is_favorited}
+
+
+@router.delete("/history/{generation_id}")
+async def delete_generation(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete a generation."""
+    success = await history.delete_generation(generation_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Generation not found")
+    return {"message": "Generation deleted successfully"}
+
+
+@router.get("/history/{generation_id}/export")
+async def export_generation(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """Export a generation as a ZIP archive."""
+    generation = db.query(DBGeneration).filter_by(id=generation_id).first()
+    if not generation:
+        raise HTTPException(status_code=404, detail="Generation not found")
+
+    try:
+        zip_bytes = export_import.export_generation_to_zip(generation_id, db)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+    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"
+
+    return StreamingResponse(
+        io.BytesIO(zip_bytes),
+        media_type="application/zip",
+        headers={"Content-Disposition": safe_content_disposition("attachment", filename)},
+    )
+
+
+@router.get("/history/{generation_id}/export-audio")
+async def export_generation_audio(
+    generation_id: str,
+    db: Session = Depends(get_db),
+):
+    """Export only the audio file from a generation."""
+    generation = db.query(DBGeneration).filter_by(id=generation_id).first()
+    if not generation:
+        raise HTTPException(status_code=404, detail="Generation not found")
+
+    if not generation.audio_path:
+        raise HTTPException(status_code=404, detail="Generation has no audio file")
+
+    audio_path = config.resolve_storage_path(generation.audio_path)
+    if audio_path is None or not audio_path.is_file():
+        raise HTTPException(status_code=404, detail="Audio file not found")
+
+    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"
+
+    return FileResponse(
+        audio_path,
+        media_type="audio/wav",
+        headers={"Content-Disposition": safe_content_disposition("attachment", filename)},
+    )

backend/routes/models.py

@@ -0,0 +1,475 @@
+"""Model management endpoints."""
+
+import asyncio
+import shutil
+from pathlib import Path
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy.orm import Session
+
+from .. import models
+from ..utils.platform_detect import get_backend_type
+from ..services.task_queue import create_background_task
+from ..utils.progress import get_progress_manager
+from ..utils.tasks import get_task_manager
+
+router = APIRouter()
+
+
+def _get_dir_size(path: Path) -> int:
+    """Get total size of a directory in bytes."""
+    total = 0
+    for f in path.rglob("*"):
+        if f.is_file():
+            total += f.stat().st_size
+    return total
+
+
+def _copy_with_progress(src: Path, dst: Path, progress_manager, copied_so_far: int, total_bytes: int) -> int:
+    """Copy a directory tree with byte-level progress tracking."""
+    dst.mkdir(parents=True, exist_ok=True)
+    for item in src.iterdir():
+        dest_item = dst / item.name
+        if item.is_dir():
+            copied_so_far = _copy_with_progress(item, dest_item, progress_manager, copied_so_far, total_bytes)
+        else:
+            size = item.stat().st_size
+            shutil.copy2(str(item), str(dest_item))
+            copied_so_far += size
+            progress_manager.update_progress(
+                "migration",
+                copied_so_far,
+                total_bytes,
+                filename=item.name,
+                status="downloading",
+            )
+    return copied_so_far
+
+
+@router.post("/models/load")
+async def load_model(model_size: str = "1.7B"):
+    """Manually load TTS model."""
+    from ..services import tts
+
+    try:
+        tts_model = tts.get_tts_model()
+        await tts_model.load_model_async(model_size)
+        return {"message": f"Model {model_size} loaded successfully"}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/models/unload")
+async def unload_model():
+    """Unload the default Qwen TTS model to free memory."""
+    from ..services import tts
+
+    try:
+        tts.unload_tts_model()
+        return {"message": "Model unloaded successfully"}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/models/{model_name}/unload")
+async def unload_model_by_name(model_name: str):
+    """Unload a specific model from memory without deleting it from disk."""
+    from ..backends import get_model_config, unload_model_by_config
+
+    config = get_model_config(model_name)
+    if not config:
+        raise HTTPException(status_code=400, detail=f"Unknown model: {model_name}")
+
+    try:
+        was_loaded = unload_model_by_config(config)
+        if not was_loaded:
+            return {"message": f"Model {model_name} is not loaded"}
+        return {"message": f"Model {model_name} unloaded successfully"}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e)) from e
+
+
+@router.get("/models/progress/{model_name}")
+async def get_model_progress(model_name: str):
+    """Get model download progress via Server-Sent Events."""
+    progress_manager = get_progress_manager()
+
+    async def event_generator():
+        async for event in progress_manager.subscribe(model_name):
+            yield event
+
+    return StreamingResponse(
+        event_generator(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )
+
+
+@router.get("/models/cache-dir")
+async def get_models_cache_dir():
+    """Get the path to the HuggingFace model cache directory."""
+    from huggingface_hub import constants as hf_constants
+
+    return {"path": str(Path(hf_constants.HF_HUB_CACHE))}
+
+
+@router.post("/models/migrate")
+async def migrate_models(request: models.ModelMigrateRequest):
+    """Move all downloaded models to a new directory with byte-level progress via SSE."""
+    from huggingface_hub import constants as hf_constants
+
+    source = Path(hf_constants.HF_HUB_CACHE)
+    destination = Path(request.destination)
+
+    if not source.exists():
+        raise HTTPException(status_code=404, detail="Current model cache directory not found")
+
+    if source.resolve() == destination.resolve():
+        raise HTTPException(status_code=400, detail="Source and destination are the same directory")
+
+    if destination.resolve().is_relative_to(source.resolve()):
+        raise HTTPException(status_code=400, detail="Destination cannot be inside the current cache directory")
+
+    progress_manager = get_progress_manager()
+    model_dirs = [d for d in source.iterdir() if d.name.startswith("models--") and d.is_dir()]
+    if not model_dirs:
+        progress_manager.update_progress("migration", 1, 1, status="complete")
+        progress_manager.mark_complete("migration")
+        return {"moved": 0, "errors": [], "source": str(source), "destination": str(destination)}
+
+    destination.mkdir(parents=True, exist_ok=True)
+
+    same_fs = False
+    try:
+        same_fs = source.stat().st_dev == destination.stat().st_dev
+    except OSError:
+        pass
+
+    async def migrate_background():
+        moved = 0
+        errors = []
+        try:
+            if same_fs:
+                total = len(model_dirs)
+                for i, item in enumerate(model_dirs):
+                    dest_item = destination / item.name
+                    try:
+                        if dest_item.exists():
+                            shutil.rmtree(dest_item)
+                        shutil.move(str(item), str(dest_item))
+                        moved += 1
+                        progress_manager.update_progress(
+                            "migration",
+                            i + 1,
+                            total,
+                            filename=item.name,
+                            status="downloading",
+                        )
+                    except Exception as e:
+                        errors.append(f"{item.name}: {str(e)}")
+            else:
+                total_bytes = sum(_get_dir_size(d) for d in model_dirs)
+                progress_manager.update_progress(
+                    "migration", 0, total_bytes, filename="Calculating...", status="downloading"
+                )
+
+                copied = 0
+                for item in model_dirs:
+                    dest_item = destination / item.name
+                    try:
+                        if dest_item.exists():
+                            shutil.rmtree(dest_item)
+                        copied = await asyncio.to_thread(
+                            _copy_with_progress, item, dest_item, progress_manager, copied, total_bytes
+                        )
+                        await asyncio.to_thread(shutil.rmtree, str(item))
+                        moved += 1
+                    except Exception as e:
+                        errors.append(f"{item.name}: {str(e)}")
+
+            progress_manager.update_progress("migration", 1, 1, status="complete")
+            progress_manager.mark_complete("migration")
+        except Exception as e:
+            progress_manager.update_progress("migration", 0, 0, status="error")
+            progress_manager.mark_error("migration", str(e))
+
+    create_background_task(migrate_background())
+
+    return {"source": str(source), "destination": str(destination)}
+
+
+@router.get("/models/migrate/progress")
+async def get_migration_progress():
+    """Get model migration progress via Server-Sent Events."""
+    progress_manager = get_progress_manager()
+
+    async def event_generator():
+        async for event in progress_manager.subscribe("migration"):
+            yield event
+
+    return StreamingResponse(
+        event_generator(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )
+
+
+@router.get("/models/status", response_model=models.ModelStatusListResponse)
+async def get_model_status():
+    """Get status of all available models."""
+    from huggingface_hub import constants as hf_constants
+
+    backend_type = get_backend_type()
+    task_manager = get_task_manager()
+
+    active_download_names = {task.model_name for task in task_manager.get_active_downloads()}
+
+    try:
+        from huggingface_hub import scan_cache_dir
+
+        use_scan_cache = True
+    except ImportError:
+        use_scan_cache = False
+
+    from ..backends import get_all_model_configs, check_model_loaded
+
+    registry_configs = get_all_model_configs()
+    model_configs = [
+        {
+            "model_name": cfg.model_name,
+            "display_name": cfg.display_name,
+            "hf_repo_id": cfg.hf_repo_id,
+            "model_size": cfg.model_size,
+            "check_loaded": lambda c=cfg: check_model_loaded(c),
+        }
+        for cfg in registry_configs
+    ]
+
+    model_to_repo = {cfg["model_name"]: cfg["hf_repo_id"] for cfg in model_configs}
+    active_download_repos = {model_to_repo.get(name) for name in active_download_names if name in model_to_repo}
+
+    cache_info = None
+    if use_scan_cache:
+        try:
+            cache_info = scan_cache_dir()
+        except Exception:
+            pass
+
+    statuses = []
+
+    for config in model_configs:
+        try:
+            downloaded = False
+            size_mb = None
+            loaded = False
+
+            if cache_info:
+                repo_id = config["hf_repo_id"]
+                for repo in cache_info.repos:
+                    if repo.repo_id == repo_id:
+                        has_model_weights = False
+                        for rev in repo.revisions:
+                            for f in rev.files:
+                                fname = f.file_name.lower()
+                                if fname.endswith((".safetensors", ".bin", ".pt", ".pth", ".npz")):
+                                    has_model_weights = True
+                                    break
+                            if has_model_weights:
+                                break
+
+                        has_incomplete = False
+                        try:
+                            cache_dir = hf_constants.HF_HUB_CACHE
+                            blobs_dir = Path(cache_dir) / ("models--" + repo_id.replace("/", "--")) / "blobs"
+                            if blobs_dir.exists():
+                                has_incomplete = any(blobs_dir.glob("*.incomplete"))
+                        except Exception:
+                            pass
+
+                        if has_model_weights and not has_incomplete:
+                            downloaded = True
+                            try:
+                                total_size = sum(revision.size_on_disk for revision in repo.revisions)
+                                size_mb = total_size / (1024 * 1024)
+                            except Exception:
+                                pass
+                        break
+
+            if not downloaded:
+                try:
+                    cache_dir = hf_constants.HF_HUB_CACHE
+                    repo_cache = Path(cache_dir) / ("models--" + config["hf_repo_id"].replace("/", "--"))
+
+                    if repo_cache.exists():
+                        blobs_dir = repo_cache / "blobs"
+                        has_incomplete = blobs_dir.exists() and any(blobs_dir.glob("*.incomplete"))
+
+                        if not has_incomplete:
+                            snapshots_dir = repo_cache / "snapshots"
+                            has_model_files = False
+                            if snapshots_dir.exists():
+                                has_model_files = (
+                                    any(snapshots_dir.rglob("*.bin"))
+                                    or any(snapshots_dir.rglob("*.safetensors"))
+                                    or any(snapshots_dir.rglob("*.pt"))
+                                    or any(snapshots_dir.rglob("*.pth"))
+                                    or any(snapshots_dir.rglob("*.npz"))
+                                )
+
+                            if has_model_files:
+                                downloaded = True
+                                try:
+                                    total_size = sum(
+                                        f.stat().st_size
+                                        for f in repo_cache.rglob("*")
+                                        if f.is_file() and not f.name.endswith(".incomplete")
+                                    )
+                                    size_mb = total_size / (1024 * 1024)
+                                except Exception:
+                                    pass
+                except Exception:
+                    pass
+
+            try:
+                loaded = config["check_loaded"]()
+            except Exception:
+                loaded = False
+
+            is_downloading = config["hf_repo_id"] in active_download_repos
+
+            if is_downloading:
+                downloaded = False
+                size_mb = None
+
+            statuses.append(
+                models.ModelStatus(
+                    model_name=config["model_name"],
+                    display_name=config["display_name"],
+                    hf_repo_id=config["hf_repo_id"],
+                    downloaded=downloaded,
+                    downloading=is_downloading,
+                    size_mb=size_mb,
+                    loaded=loaded,
+                )
+            )
+        except Exception:
+            try:
+                loaded = config["check_loaded"]()
+            except Exception:
+                loaded = False
+
+            is_downloading = config["hf_repo_id"] in active_download_repos
+
+            statuses.append(
+                models.ModelStatus(
+                    model_name=config["model_name"],
+                    display_name=config["display_name"],
+                    hf_repo_id=config["hf_repo_id"],
+                    downloaded=False,
+                    downloading=is_downloading,
+                    size_mb=None,
+                    loaded=loaded,
+                )
+            )
+
+    return models.ModelStatusListResponse(models=statuses)
+
+
+@router.post("/models/download")
+async def trigger_model_download(request: models.ModelDownloadRequest):
+    """Trigger download of a specific model."""
+    from ..backends import get_model_config, get_model_load_func
+
+    task_manager = get_task_manager()
+    progress_manager = get_progress_manager()
+
+    config = get_model_config(request.model_name)
+    if not config:
+        raise HTTPException(status_code=400, detail=f"Unknown model: {request.model_name}")
+
+    load_func = get_model_load_func(config)
+
+    async def download_in_background():
+        try:
+            result = load_func()
+            if asyncio.iscoroutine(result):
+                await result
+            task_manager.complete_download(request.model_name)
+        except Exception as e:
+            task_manager.error_download(request.model_name, str(e))
+
+    task_manager.start_download(request.model_name)
+
+    progress_manager.update_progress(
+        model_name=request.model_name,
+        current=0,
+        total=0,
+        filename="Connecting to HuggingFace...",
+        status="downloading",
+    )
+
+    create_background_task(download_in_background())
+
+    return {"message": f"Model {request.model_name} download started"}
+
+
+@router.post("/models/download/cancel")
+async def cancel_model_download(request: models.ModelDownloadRequest):
+    """Cancel or dismiss an errored/stale download task."""
+    task_manager = get_task_manager()
+    progress_manager = get_progress_manager()
+
+    removed = task_manager.cancel_download(request.model_name)
+
+    progress_removed = False
+    with progress_manager._lock:
+        if request.model_name in progress_manager._progress:
+            del progress_manager._progress[request.model_name]
+            progress_removed = True
+
+    if removed or progress_removed:
+        return {"message": f"Download task for {request.model_name} cancelled"}
+    return {"message": f"No active task found for {request.model_name}"}
+
+
+@router.delete("/models/{model_name}")
+async def delete_model(model_name: str):
+    """Delete a downloaded model from the HuggingFace cache."""
+    from huggingface_hub import constants as hf_constants
+    from ..backends import get_model_config, unload_model_by_config
+
+    config = get_model_config(model_name)
+    if not config:
+        raise HTTPException(status_code=400, detail=f"Unknown model: {model_name}")
+
+    hf_repo_id = config.hf_repo_id
+
+    try:
+        unload_model_by_config(config)
+
+        cache_dir = hf_constants.HF_HUB_CACHE
+        repo_cache_dir = Path(cache_dir) / ("models--" + hf_repo_id.replace("/", "--"))
+
+        if not repo_cache_dir.exists():
+            raise HTTPException(status_code=404, detail=f"Model {model_name} not found in cache")
+
+        try:
+            shutil.rmtree(repo_cache_dir)
+        except OSError as e:
+            raise HTTPException(status_code=500, detail=f"Failed to delete model cache directory: {str(e)}")
+
+        return {"message": f"Model {model_name} deleted successfully"}
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to delete model: {str(e)}")

backend/routes/profiles.py

@@ -0,0 +1,363 @@
+"""Voice profile endpoints."""
+
+import io
+import json as _json
+import logging
+import tempfile
+from datetime import datetime
+from pathlib import Path
+
+from fastapi import APIRouter, Depends, File, Form, HTTPException, UploadFile
+from fastapi.responses import FileResponse, StreamingResponse
+from sqlalchemy.orm import Session
+
+from .. import config, models
+from ..app import safe_content_disposition
+from ..database import VoiceProfile as DBVoiceProfile, get_db
+from ..services import channels, export_import, profiles
+from ..services.profiles import _profile_to_response
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+@router.post("/profiles", response_model=models.VoiceProfileResponse)
+async def create_profile(
+    data: models.VoiceProfileCreate,
+    db: Session = Depends(get_db),
+):
+    """Create a new voice profile."""
+    try:
+        return await profiles.create_profile(data, db)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.get("/profiles", response_model=list[models.VoiceProfileResponse])
+async def list_profiles(db: Session = Depends(get_db)):
+    """List all voice profiles."""
+    return await profiles.list_profiles(db)
+
+
+@router.post("/profiles/import", response_model=models.VoiceProfileResponse)
+async def import_profile(
+    file: UploadFile = File(...),
+    db: Session = Depends(get_db),
+):
+    """Import a voice profile from a ZIP archive."""
+    MAX_FILE_SIZE = 100 * 1024 * 1024
+
+    content = await file.read()
+
+    if len(content) > MAX_FILE_SIZE:
+        raise HTTPException(
+            status_code=400, detail=f"File too large. Maximum size is {MAX_FILE_SIZE / (1024 * 1024)}MB"
+        )
+
+    try:
+        profile = await export_import.import_profile_from_zip(content, db)
+        return profile
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+# ── Preset Voice Endpoints ───────────────────────────────────────────
+# These MUST be declared before /profiles/{profile_id} to avoid the
+# wildcard swallowing "presets" as a profile_id.
+
+
+@router.get("/profiles/presets/{engine}")
+async def list_preset_voices(engine: str):
+    """List available preset voices for an engine."""
+    if engine == "kokoro":
+        from ..backends.kokoro_backend import KOKORO_VOICES
+
+        return {
+            "engine": engine,
+            "voices": [
+                {
+                    "voice_id": vid,
+                    "name": name,
+                    "gender": gender,
+                    "language": lang,
+                }
+                for vid, name, gender, lang in KOKORO_VOICES
+            ],
+        }
+    if engine == "qwen_custom_voice":
+        from ..backends.qwen_custom_voice_backend import QWEN_CUSTOM_VOICES
+
+        return {
+            "engine": engine,
+            "voices": [
+                {
+                    "voice_id": speaker_id,
+                    "name": display_name,
+                    "gender": gender,
+                    "language": lang,
+                }
+                for speaker_id, display_name, gender, lang, _desc in QWEN_CUSTOM_VOICES
+            ],
+        }
+    return {"engine": engine, "voices": []}
+
+@router.get("/profiles/{profile_id}", response_model=models.VoiceProfileResponse)
+async def get_profile(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get a voice profile by ID."""
+    profile = await profiles.get_profile(profile_id, db)
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")
+    return profile
+
+
+@router.put("/profiles/{profile_id}", response_model=models.VoiceProfileResponse)
+async def update_profile(
+    profile_id: str,
+    data: models.VoiceProfileCreate,
+    db: Session = Depends(get_db),
+):
+    """Update a voice profile."""
+    try:
+        profile = await profiles.update_profile(profile_id, data, db)
+        if not profile:
+            raise HTTPException(status_code=404, detail="Profile not found")
+        return profile
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.delete("/profiles/{profile_id}")
+async def delete_profile(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete a voice profile."""
+    success = await profiles.delete_profile(profile_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Profile not found")
+    return {"message": "Profile deleted successfully"}
+
+
+SAMPLE_MAX_FILE_SIZE = 50 * 1024 * 1024  # 50 MB
+SAMPLE_UPLOAD_CHUNK_SIZE = 1024 * 1024  # 1 MB
+
+
+@router.post("/profiles/{profile_id}/samples", response_model=models.ProfileSampleResponse)
+async def add_profile_sample(
+    profile_id: str,
+    file: UploadFile = File(...),
+    reference_text: str = Form(...),
+    db: Session = Depends(get_db),
+):
+    """Add a sample to a voice profile."""
+    _allowed_audio_exts = {".wav", ".mp3", ".m4a", ".ogg", ".flac", ".aac", ".webm", ".opus"}
+    _uploaded_ext = Path(file.filename or "").suffix.lower()
+    file_suffix = _uploaded_ext if _uploaded_ext in _allowed_audio_exts else ".wav"
+
+    with tempfile.NamedTemporaryFile(suffix=file_suffix, delete=False) as tmp:
+        total_size = 0
+        while chunk := await file.read(SAMPLE_UPLOAD_CHUNK_SIZE):
+            total_size += len(chunk)
+            if total_size > SAMPLE_MAX_FILE_SIZE:
+                Path(tmp.name).unlink(missing_ok=True)
+                raise HTTPException(
+                    status_code=413,
+                    detail=f"File too large (max {SAMPLE_MAX_FILE_SIZE // (1024 * 1024)} MB)",
+                )
+            tmp.write(chunk)
+        tmp_path = tmp.name
+
+    try:
+        sample = await profiles.add_profile_sample(
+            profile_id,
+            tmp_path,
+            reference_text,
+            db,
+        )
+        return sample
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to process audio file: {str(e)}")
+    finally:
+        Path(tmp_path).unlink(missing_ok=True)
+
+
+@router.get("/profiles/{profile_id}/samples", response_model=list[models.ProfileSampleResponse])
+async def get_profile_samples(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get all samples for a profile."""
+    return await profiles.get_profile_samples(profile_id, db)
+
+
+@router.delete("/profiles/samples/{sample_id}")
+async def delete_profile_sample(
+    sample_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete a profile sample."""
+    success = await profiles.delete_profile_sample(sample_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Sample not found")
+    return {"message": "Sample deleted successfully"}
+
+
+@router.put("/profiles/samples/{sample_id}", response_model=models.ProfileSampleResponse)
+async def update_profile_sample(
+    sample_id: str,
+    data: models.ProfileSampleUpdate,
+    db: Session = Depends(get_db),
+):
+    """Update a profile sample's reference text."""
+    sample = await profiles.update_profile_sample(sample_id, data.reference_text, db)
+    if not sample:
+        raise HTTPException(status_code=404, detail="Sample not found")
+    return sample
+
+
+@router.post("/profiles/{profile_id}/avatar", response_model=models.VoiceProfileResponse)
+async def upload_profile_avatar(
+    profile_id: str,
+    file: UploadFile = File(...),
+    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:
+        content = await file.read()
+        tmp.write(content)
+        tmp_path = tmp.name
+
+    try:
+        profile = await profiles.upload_avatar(profile_id, tmp_path, db)
+        return profile
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    finally:
+        Path(tmp_path).unlink(missing_ok=True)
+
+
+@router.get("/profiles/{profile_id}/avatar")
+async def get_profile_avatar(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get avatar image for a profile."""
+    profile = await profiles.get_profile(profile_id, db)
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")
+
+    if not profile.avatar_path:
+        raise HTTPException(status_code=404, detail="No avatar found for this profile")
+
+    avatar_path = config.resolve_storage_path(profile.avatar_path)
+    if avatar_path is None or not avatar_path.exists():
+        raise HTTPException(status_code=404, detail="Avatar file not found")
+
+    return FileResponse(avatar_path)
+
+
+@router.delete("/profiles/{profile_id}/avatar")
+async def delete_profile_avatar(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete avatar image for a profile."""
+    success = await profiles.delete_avatar(profile_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Profile not found or no avatar to delete")
+    return {"message": "Avatar deleted successfully"}
+
+
+@router.get("/profiles/{profile_id}/export")
+async def export_profile(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Export a voice profile as a ZIP archive."""
+    try:
+        profile = await profiles.get_profile(profile_id, db)
+        if not profile:
+            raise HTTPException(status_code=404, detail="Profile not found")
+
+        zip_bytes = export_import.export_profile_to_zip(profile_id, db)
+
+        safe_name = "".join(c for c in profile.name if c.isalnum() or c in (" ", "-", "_")).strip()
+        if not safe_name:
+            safe_name = "profile"
+        filename = f"profile-{safe_name}.voicebox.zip"
+
+        return StreamingResponse(
+            io.BytesIO(zip_bytes),
+            media_type="application/zip",
+            headers={"Content-Disposition": safe_content_disposition("attachment", filename)},
+        )
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/profiles/{profile_id}/channels")
+async def get_profile_channels(
+    profile_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get list of channel IDs assigned to a profile."""
+    try:
+        channel_ids = await channels.get_profile_channels(profile_id, db)
+        return {"channel_ids": channel_ids}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.put("/profiles/{profile_id}/channels")
+async def set_profile_channels(
+    profile_id: str,
+    data: models.ProfileChannelAssignment,
+    db: Session = Depends(get_db),
+):
+    """Set which channels a profile is assigned to."""
+    try:
+        await channels.set_profile_channels(profile_id, data, db)
+        return {"message": "Profile channels updated successfully"}
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.put("/profiles/{profile_id}/effects", response_model=models.VoiceProfileResponse)
+async def update_profile_effects(
+    profile_id: str,
+    data: models.ProfileEffectsUpdate,
+    db: Session = Depends(get_db),
+):
+    """Set or clear the default effects chain for a voice profile."""
+    profile = db.query(DBVoiceProfile).filter_by(id=profile_id).first()
+    if not profile:
+        raise HTTPException(status_code=404, detail="Profile not found")
+
+    if data.effects_chain is not None:
+        from ..utils.effects import validate_effects_chain
+
+        chain_dicts = [e.model_dump() for e in data.effects_chain]
+        error = validate_effects_chain(chain_dicts)
+        if error:
+            raise HTTPException(status_code=400, detail=error)
+        profile.effects_chain = _json.dumps(chain_dicts)
+    else:
+        profile.effects_chain = None
+
+    profile.updated_at = datetime.utcnow()
+    db.commit()
+    db.refresh(profile)
+
+    return _profile_to_response(profile)

backend/routes/stories.py

@@ -0,0 +1,223 @@
+"""Story endpoints."""
+
+import io
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy.orm import Session
+
+from .. import database, models
+from ..services import stories
+from ..app import safe_content_disposition
+from ..database import get_db
+
+router = APIRouter()
+
+
+@router.get("/stories", response_model=list[models.StoryResponse])
+async def list_stories(db: Session = Depends(get_db)):
+    """List all stories."""
+    return await stories.list_stories(db)
+
+
+@router.post("/stories", response_model=models.StoryResponse)
+async def create_story(
+    data: models.StoryCreate,
+    db: Session = Depends(get_db),
+):
+    """Create a new story."""
+    try:
+        return await stories.create_story(data, db)
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
+@router.get("/stories/{story_id}", response_model=models.StoryDetailResponse)
+async def get_story(
+    story_id: str,
+    db: Session = Depends(get_db),
+):
+    """Get a story with all its items."""
+    story = await stories.get_story(story_id, db)
+    if not story:
+        raise HTTPException(status_code=404, detail="Story not found")
+    return story
+
+
+@router.put("/stories/{story_id}", response_model=models.StoryResponse)
+async def update_story(
+    story_id: str,
+    data: models.StoryCreate,
+    db: Session = Depends(get_db),
+):
+    """Update a story."""
+    story = await stories.update_story(story_id, data, db)
+    if not story:
+        raise HTTPException(status_code=404, detail="Story not found")
+    return story
+
+
+@router.delete("/stories/{story_id}")
+async def delete_story(
+    story_id: str,
+    db: Session = Depends(get_db),
+):
+    """Delete a story."""
+    success = await stories.delete_story(story_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Story not found")
+    return {"message": "Story deleted successfully"}
+
+
+@router.post("/stories/{story_id}/items", response_model=models.StoryItemDetail)
+async def add_story_item(
+    story_id: str,
+    data: models.StoryItemCreate,
+    db: Session = Depends(get_db),
+):
+    """Add a generation to a story."""
+    item = await stories.add_item_to_story(story_id, data, db)
+    if not item:
+        raise HTTPException(status_code=404, detail="Story or generation not found")
+    return item
+
+
+@router.delete("/stories/{story_id}/items/{item_id}")
+async def remove_story_item(
+    story_id: str,
+    item_id: str,
+    db: Session = Depends(get_db),
+):
+    """Remove a story item from a story."""
+    success = await stories.remove_item_from_story(story_id, item_id, db)
+    if not success:
+        raise HTTPException(status_code=404, detail="Story item not found")
+    return {"message": "Item removed successfully"}
+
+
+@router.put("/stories/{story_id}/items/times")
+async def update_story_item_times(
+    story_id: str,
+    data: models.StoryItemBatchUpdate,
+    db: Session = Depends(get_db),
+):
+    """Update story item timecodes."""
+    success = await stories.update_story_item_times(story_id, data, db)
+    if not success:
+        raise HTTPException(status_code=400, detail="Invalid timecode update request")
+    return {"message": "Item timecodes updated successfully"}
+
+
+@router.put("/stories/{story_id}/items/reorder", response_model=list[models.StoryItemDetail])
+async def reorder_story_items(
+    story_id: str,
+    data: models.StoryItemReorder,
+    db: Session = Depends(get_db),
+):
+    """Reorder story items and recalculate timecodes."""
+    items = await stories.reorder_story_items(story_id, data.generation_ids, db)
+    if items is None:
+        raise HTTPException(
+            status_code=400, detail="Invalid reorder request - ensure all generation IDs belong to this story"
+        )
+    return items
+
+
+@router.put("/stories/{story_id}/items/{item_id}/move", response_model=models.StoryItemDetail)
+async def move_story_item(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemMove,
+    db: Session = Depends(get_db),
+):
+    """Move a story item (update position and/or track)."""
+    item = await stories.move_story_item(story_id, item_id, data, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item not found")
+    return item
+
+
+@router.put("/stories/{story_id}/items/{item_id}/trim", response_model=models.StoryItemDetail)
+async def trim_story_item(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemTrim,
+    db: Session = Depends(get_db),
+):
+    """Trim a story item."""
+    item = await stories.trim_story_item(story_id, item_id, data, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item not found or invalid trim values")
+    return item
+
+
+@router.post("/stories/{story_id}/items/{item_id}/split", response_model=list[models.StoryItemDetail])
+async def split_story_item(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemSplit,
+    db: Session = Depends(get_db),
+):
+    """Split a story item at a given time, creating two clips."""
+    items = await stories.split_story_item(story_id, item_id, data, db)
+    if items is None:
+        raise HTTPException(status_code=404, detail="Story item not found or invalid split point")
+    return items
+
+
+@router.post("/stories/{story_id}/items/{item_id}/duplicate", response_model=models.StoryItemDetail)
+async def duplicate_story_item(
+    story_id: str,
+    item_id: str,
+    db: Session = Depends(get_db),
+):
+    """Duplicate a story item."""
+    item = await stories.duplicate_story_item(story_id, item_id, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item not found")
+    return item
+
+
+@router.put("/stories/{story_id}/items/{item_id}/version", response_model=models.StoryItemDetail)
+async def set_story_item_version(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemVersionUpdate,
+    db: Session = Depends(get_db),
+):
+    """Pin a story item to a specific generation version."""
+    item = await stories.set_story_item_version(story_id, item_id, data, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item or version not found")
+    return item
+
+
+@router.get("/stories/{story_id}/export-audio")
+async def export_story_audio(
+    story_id: str,
+    db: Session = Depends(get_db),
+):
+    """Export story as single mixed audio file."""
+    try:
+        story = db.query(database.Story).filter_by(id=story_id).first()
+        if not story:
+            raise HTTPException(status_code=404, detail="Story not found")
+
+        audio_bytes = await stories.export_story_audio(story_id, db)
+        if not audio_bytes:
+            raise HTTPException(status_code=400, detail="Story has no audio items")
+
+        safe_name = "".join(c for c in story.name if c.isalnum() or c in (" ", "-", "_")).strip()
+        if not safe_name:
+            safe_name = "story"
+        filename = f"{safe_name}.wav"
+
+        return StreamingResponse(
+            io.BytesIO(audio_bytes),
+            media_type="audio/wav",
+            headers={"Content-Disposition": safe_content_disposition("attachment", filename)},
+        )
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))

backend/routes/tasks.py

@@ -0,0 +1,125 @@
+"""Task and cache management endpoints."""
+
+from datetime import datetime
+
+from fastapi import APIRouter
+
+from .. import models
+from ..utils.cache import clear_voice_prompt_cache
+from ..utils.progress import get_progress_manager
+from ..utils.tasks import get_task_manager
+from fastapi import HTTPException
+
+router = APIRouter()
+
+
+@router.post("/tasks/clear")
+async def clear_all_tasks():
+    """Clear all download tasks and progress state."""
+    task_manager = get_task_manager()
+    progress_manager = get_progress_manager()
+
+    task_manager.clear_all()
+
+    with progress_manager._lock:
+        progress_manager._progress.clear()
+        progress_manager._last_notify_time.clear()
+        progress_manager._last_notify_progress.clear()
+
+    return {"message": "All task state cleared"}
+
+
+@router.post("/cache/clear")
+async def clear_cache():
+    """Clear all voice prompt caches (memory and disk)."""
+    try:
+        deleted_count = clear_voice_prompt_cache()
+        return {
+            "message": "Voice prompt cache cleared successfully",
+            "files_deleted": deleted_count,
+        }
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to clear cache: {str(e)}")
+
+
+@router.get("/tasks/active", response_model=models.ActiveTasksResponse)
+async def get_active_tasks():
+    """Return all currently active downloads and generations."""
+    task_manager = get_task_manager()
+    progress_manager = get_progress_manager()
+
+    active_downloads = []
+    task_manager_downloads = task_manager.get_active_downloads()
+    progress_active = progress_manager.get_all_active()
+
+    download_map = {task.model_name: task for task in task_manager_downloads}
+    progress_map = {p["model_name"]: p for p in progress_active}
+
+    all_model_names = set(download_map.keys()) | set(progress_map.keys())
+    for model_name in all_model_names:
+        task = download_map.get(model_name)
+        progress = progress_map.get(model_name)
+
+        if task:
+            error = task.error
+            if not error:
+                with progress_manager._lock:
+                    pm_data = progress_manager._progress.get(model_name)
+                    if pm_data:
+                        error = pm_data.get("error")
+            prog = progress or {}
+            if not prog:
+                with progress_manager._lock:
+                    pm_data = progress_manager._progress.get(model_name)
+                    if pm_data:
+                        prog = pm_data
+            active_downloads.append(
+                models.ActiveDownloadTask(
+                    model_name=model_name,
+                    status=task.status,
+                    started_at=task.started_at,
+                    error=error,
+                    progress=prog.get("progress"),
+                    current=prog.get("current"),
+                    total=prog.get("total"),
+                    filename=prog.get("filename"),
+                )
+            )
+        elif progress:
+            timestamp_str = progress.get("timestamp")
+            if timestamp_str:
+                try:
+                    started_at = datetime.fromisoformat(timestamp_str.replace("Z", "+00:00"))
+                except (ValueError, AttributeError):
+                    started_at = datetime.utcnow()
+            else:
+                started_at = datetime.utcnow()
+
+            active_downloads.append(
+                models.ActiveDownloadTask(
+                    model_name=model_name,
+                    status=progress.get("status", "downloading"),
+                    started_at=started_at,
+                    error=progress.get("error"),
+                    progress=progress.get("progress"),
+                    current=progress.get("current"),
+                    total=progress.get("total"),
+                    filename=progress.get("filename"),
+                )
+            )
+
+    active_generations = []
+    for gen_task in task_manager.get_active_generations():
+        active_generations.append(
+            models.ActiveGenerationTask(
+                task_id=gen_task.task_id,
+                profile_id=gen_task.profile_id,
+                text_preview=gen_task.text_preview,
+                started_at=gen_task.started_at,
+            )
+        )
+
+    return models.ActiveTasksResponse(
+        downloads=active_downloads,
+        generations=active_generations,
+    )

backend/routes/transcription.py

@@ -0,0 +1,84 @@
+"""Transcription endpoints."""
+
+import asyncio
+import tempfile
+from pathlib import Path
+
+from fastapi import APIRouter, File, Form, HTTPException, UploadFile
+
+from .. import models
+from ..services import transcribe
+from ..services.task_queue import create_background_task
+from ..utils.tasks import get_task_manager
+
+router = APIRouter()
+
+UPLOAD_CHUNK_SIZE = 1024 * 1024  # 1MB
+
+
+@router.post("/transcribe", response_model=models.TranscriptionResponse)
+async def transcribe_audio(
+    file: UploadFile = File(...),
+    language: str | None = Form(None),
+    model: str | None = Form(None),
+):
+    """Transcribe audio file to text."""
+    with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp:
+        while chunk := await file.read(UPLOAD_CHUNK_SIZE):
+            tmp.write(chunk)
+        tmp_path = tmp.name
+
+    try:
+        from ..utils.audio import load_audio
+        from ..backends import WHISPER_HF_REPOS
+
+        audio, sr = await asyncio.to_thread(load_audio, tmp_path)
+        duration = len(audio) / sr
+
+        whisper_model = transcribe.get_whisper_model()
+        model_size = model if model else whisper_model.model_size
+
+        valid_sizes = list(WHISPER_HF_REPOS.keys())
+        if model_size not in valid_sizes:
+            raise HTTPException(
+                status_code=400,
+                detail=f"Invalid model size '{model_size}'. Must be one of: {', '.join(valid_sizes)}",
+            )
+
+        already_loaded = whisper_model.is_loaded() and whisper_model.model_size == model_size
+        if not already_loaded and not whisper_model._is_model_cached(model_size):
+            progress_model_name = f"whisper-{model_size}"
+            task_manager = get_task_manager()
+
+            async def download_whisper_background():
+                try:
+                    await whisper_model.load_model_async(model_size)
+                    task_manager.complete_download(progress_model_name)
+                except Exception as e:
+                    task_manager.error_download(progress_model_name, str(e))
+
+            task_manager.start_download(progress_model_name)
+            create_background_task(download_whisper_background())
+
+            raise HTTPException(
+                status_code=202,
+                detail={
+                    "message": f"Whisper model {model_size} is being downloaded. Please wait and try again.",
+                    "model_name": progress_model_name,
+                    "downloading": True,
+                },
+            )
+
+        text = await whisper_model.transcribe(tmp_path, language, model_size)
+
+        return models.TranscriptionResponse(
+            text=text,
+            duration=duration,
+        )
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+    finally:
+        Path(tmp_path).unlink(missing_ok=True)