# Deploying V6 Production Model

## Quick Deploy (zero code changes)

The V6 model uses the **exact same 37-feature schema** as your existing `app/recommend/reranker.py`. To deploy:

### Option 1: Replace the model file

```bash
# In your ResearchIT Space repo:
cp production_model/reranker_v6_production.txt models/reranker-phase6/production_model/reranker_v1.txt
```

The reranker code searches for `reranker_v1.txt` — replacing it with V6 makes it active immediately.

### Option 2: Add as a new path (safer)

In `app/recommend/reranker.py`, add V6 to the search paths (it's checked first):

```python
_MODEL_SEARCH_PATHS = [
    os.environ.get("RERANKER_MODEL_PATH", ""),
    "models/reranker-phase6/production_model/reranker_v6_production.txt",  # ← ADD THIS
    "models/reranker-phase6/production_model/reranker_v1.txt",
    "production_model/reranker_v1.txt",
    ...
]
```

### Option 3: Use environment variable

```bash
export RERANKER_MODEL_PATH="models/reranker-phase6/production_model/reranker_v6_production.txt"
```

## What Changed (V1 → V6)

| Aspect | V1 | V6 |
|--------|-----|-----|
| Feature schema | 37 features | 37 features (identical) |
| Training labels | cited=2, co-cited=1, not=0 | 5-tier expert authority |
| Hard Neg AUC | ~0.63 | **0.758** (+20.7%) |
| Trees | 141 | 32 (faster inference) |
| Model size | 948 KB | 219 KB (77% smaller) |
| Latency | 0.37ms/100 candidates | ~0.2ms/100 candidates (fewer trees) |

## What This Means for Users

V6 will:
- Rank papers from the right field higher (category matching learned)
- Give recency a proper weight (not just citation count)
- Better balance between highly-cited classics and newer relevant work
- Suppress papers that experts consistently exclude from reading lists

## Verification

After deploying, check the health endpoint:
```
GET /healthz/reranker
```

Should return:
```json
{"model_loaded": true, "num_trees": 32, "num_features": 37}
```

## Rollback

If anything goes wrong, revert to V1:
```bash
export RERANKER_MODEL_PATH="models/reranker-phase6/production_model/reranker_v1.txt"
```