# Veena3 → Modal Migration - COMPLETE

**Status**: ✅ Complete (Dec 25, 2025)

This document records the completed migration from Django (`veena3srv/`) to Modal-native (`veena3modal/`).

---

## Migration Summary

### What Was Done

1. **Moved core inference code** from `veena3srv/apps/inference/` to `veena3modal/core/` and `veena3modal/processing/`
2. **Created FastAPI endpoints** replacing Django REST Framework views
3. **Configured Modal autoscaling** with L40S GPU, memory snapshots, and input concurrency
4. **Preserved all features**:
   - True streaming TTS with BiCodec
   - Indic text normalization
   - Emotion tag support
   - Super-resolution (16kHz → 48kHz)
   - Long text chunking with voice consistency

### Final Architecture

```
veena3modal/
├── app.py                    # Modal entrypoint
├── api/                      # FastAPI endpoints
├── core/                     # Model loading, pipelines, decoders
├── processing/               # Text normalization, chunking
├── audio/                    # WAV headers, crossfade, encoding
├── services/                 # Runtime singleton, Supabase
└── tests/                    # Unit, integration, modal_live
```

### Autoscaling Configuration

See `scaling.md` for detailed analysis. Summary:

```python
@app.cls(
    gpu="L40S",
    min_containers=0,
    buffer_containers=1,
    scaledown_window=300,
    enable_memory_snapshot=True,
)
@modal.concurrent(max_inputs=16, target_inputs=8)
```

### Test Results

| Suite | Passed | Notes |
|-------|--------|-------|
| Unit tests | 267 | All passing |
| Edge case tests | 32 | All passing |
| Modal Live | 37 | 14 skipped (need credentials) |
| Load tests | 100% success | Up to 32 concurrent |

### Performance

| Metric | Value |
|--------|-------|
| Max RPS per container | 20.35 |
| p50 latency (short text) | 580-830ms |
| TTFB | ~450-520ms |
| RTF | 0.19-0.30 |

---

## Legacy Files (Removed)

- `veena3srv/` - Django application (removed)
- `CLEANUP_PLAN.md` - Migration checklist (completed, removed)

## Current Documentation

- `README.md` - Quick start and API reference
- `scaling.md` - Autoscaling analysis and configuration
- `PROGRESS.md` - Development history