# LFM2.5-1.2B System One LoRA

Promoted run: seed-only teacher aliases (not grown templates).

- Base: `models/LFM2.5-1.2B-Instruct-8bit` (QLoRA on the same 8-bit MLX checkpoint we serve)
- Adapter: `adapters/lfm25-1.2b-systemone`
- Rank 16, scale 2.0, AdamW 5e-5, batch 4, 2 epochs / 64 iters, ~131s
- Targets: attn q/k/v/o + MLP w1/w2/w3, all 16 layers
- Data: 78 train items / 126 examples; frozen holdout 17 items / 29 examples (`evals/splits.json`)
- Completions match serve-time scoring: option keys, yes/no, level digits. Prompt masked.

## Serve (T=1, no calibration.json)

```sh
JEVONS_ADAPTER=adapters/lfm25-1.2b-systemone \
JEVONS_TEMPERATURE=1 \
JEVONS_CALIBRATION=off \
JEVONS_MODEL=models/LFM2.5-1.2B-Instruct-8bit \
uv run jevons serve
```

Or: `uv run jevons serve --adapter adapters/lfm25-1.2b-systemone --temperature 1 --calibration off`

Disable: `--adapter off`

## T=1 vs previous baseline

| split | run | modal | choice / noul / score | ECE | Brier | acc@≥0.8 | schema |
| --- | --- | --- | --- | --- | --- | --- | --- |
| full n=155 | base | 69.7% | 78.6 / 68.2 / 56.1 | 0.107 | 0.387 | 92.1% (n=63) | 100% |
| full n=155 | LoRA | 83.9% | 85.7 / 95.5 / 68.3 | 0.077 | 0.193 | 95.9% (n=97) | 100% |
| holdout n=29 | base | 72.4% | 76.9 / 87.5 / 50.0 | 0.122 | 0.390 | 100% (n=11) | 100% |
| holdout n=29 | LoRA | 72.4% | 69.2 / 75.0 / 75.0 | 0.248 | 0.303 | 100% (n=14) | 100% |

Full-set 83.9% includes the 78 train items. Honest ship metric is holdout modal, still 72.4% vs a 90% bar.

## Failed grown run (do not serve)

`adapters/lfm25-1.2b-systemone-grown`: 200 official-Jev labels on `grow.py` templates + LoRA scale 20. Holdout modal 38%. Choice collapsed to `sales` / `transfer` / `weather`.