# Install

Tilelli runs on CPU. You don't need a GPU. The whole install is ~120 MB
(torch + the bundled 39 MB checkpoint).

## CPU-only — recommended for everyone

The default `pip install torch` on Linux pulls the **CUDA** build (2+ GB,
plus matching nvidia-* runtime wheels). On macOS and Windows the default
wheel is already CPU; on Linux it is not. Save yourself the bandwidth:

```bash
# 1. Get CPU torch first (works on Linux, macOS, Windows)
pip install --index-url https://download.pytorch.org/whl/cpu torch

# 2. Then install Tilelli
git clone https://github.com/TilelliLab/Tilelli-llm
cd tilelli
pip install -e .

# 3. Talk to it
python chat.py "Hello, who are you?"
```

## GPU (optional)

If you actually have a GPU and want to run faster:

```bash
# CUDA 12.x build (Linux):
pip install --index-url https://download.pytorch.org/whl/cu121 torch
# or MPS (macOS): the default macOS wheel already includes MPS.
pip install -e .
```

Inference works fine on CPU — the bundled v4 ckpt is 10 M parameters and
the generation loop is single-threaded NumPy-friendly. A GPU buys you
~5–10× faster generation, not a different model.

## Verifying the install

```bash
pip install -e ".[test]"
pytest -q tests/
```

You should see three smoke tests pass (model loads, tokenizer round-trips,
one generation step runs).

## Training your own (out of the box)

The kit ships a ~700 KB TinyStories slice at `data/tinystories_demo/` so
training works without any download:

```bash
# 50 steps on CPU, takes a couple of minutes:
python scripts/train.py --model tilelli-lite-fp32    --data-dir data/tinystories_demo --steps 50 --batch-size 4 --seq-len 64 --device cpu
python scripts/train.py --model tilelli-lite-ternary --data-dir data/tinystories_demo --steps 50 --batch-size 4 --seq-len 64 --device cpu
python scripts/train.py --model vanilla-fp32         --data-dir data/tinystories_demo --steps 50 --batch-size 4 --seq-len 64 --device cpu
```

Each run writes checkpoints + a per-step JSONL log to `runs/<model>_<timestamp>/`.
The README lists the 5 supported `--model` configs.

## Reproducing the claims

The four `reproduce/0N_*.py` scripts are described in the README. Each
exits non-zero if the bundled v4 checkpoint fails to produce the
documented number within ±5 %.

```bash
python reproduce/03_abstain_held_out.py     # held-out IDK gate
python reproduce/04_neo_false_inability.py  # false-inability probe
python reproduce/02_metacog_probe.py        # cross-regime AUROC
```

A fourth script (`01_benchmark.py`) is an architecture-only check: it
loads the bundled v4 checkpoint, prints the 10.18 M parameter count,
and exits PASS. It runs in ~2 s on CPU. The full val-bpc-vs-vanilla
re-run requires the FineWeb-Edu training pipeline, which is NOT bundled;
the documented number lives in `results/claim_01_benchmark.md`.

## Troubleshooting

- **"sequence length N > max_seq_len 256"**: the bundled ckpt has a
  context window of 256 bytes. If `chat.py` hits this, your prompt is
  too long; trim it.
- **"weights_only=True" load error**: the loader passes
  `weights_only=False` because the checkpoint was authored by us. Trust
  the bundled artifact; for any third-party ckpt, verify the SHA first
  (the SHA for v4 is in the README).
- **macOS Apple Silicon**: PyTorch ≥2.1 ships native arm64 wheels; no
  Rosetta needed.
- **Windows**: the runtime helpers in `src/tilelli/utils/runtime.py`
  touch `/sys/class/thermal/` on Linux only; the calls are exception-
  swallowed elsewhere. No action needed.

## License

Apache 2.0. See `LICENSE`. The bundled weights ship under the same
license. The name "Tilelli" is not licensed by this file — fork freely,
rename if you ship a derivative.