# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project

`ai_mouse` is an ONNX-Runtime SDK that generates human-like mouse trajectories
and scroll wheel events. Runtime dependencies are `numpy + onnxruntime` only;
training and the FastAPI web UI live under `tools/` and are not packaged.

Package manager: **uv**, Python 3.12-3.13.

## Library vs tools — hard boundary

- **`src/ai_mouse/`** — wheel content. NEVER add `import torch` /
  `import fastapi` / `import scipy` / `import matplotlib` here. CI's
  `library` job installs only runtime deps and would break.
- **`tools/`** — repo-only dev code (training, server, collector, eval,
  data adapters, ONNX export). May `import` library private modules
  (`ai_mouse._coord`, `ai_mouse._postprocess`) freely — they co-evolve.
- **Bundled assets**: `src/ai_mouse/assets/{flow_model,scroll_decoder}.onnx`
  plus four JSON metadata files. Re-generated by
  `tools/export_onnx.py` after retraining.

## Commands

```bash
# Web UI (collect + train + verify in browser)
uv run python tools/serve.py

# Tools CLI dispatch
uv run python -m tools train --data data/traces.jsonl --output data/models_v2
uv run python -m tools eval --model-dir data/models_v2 \
    --reference data/pretrain_traces.jsonl --output data/eval_reports/r.md
uv run python -m tools balabit-adapter --input data/balabit_raw \
    --output data/pretrain_traces.jsonl

# Re-export ONNX (after retraining)
uv run python -m tools.export_onnx --flow-ckpt data/models_v2 \
    --scroll-ckpt data/scroll_models --output src/ai_mouse/assets/

# Tests
uv run pytest tests/unit            # library-only (no torch)
uv run pytest tests/tools           # full dev suite (needs [dev] group)
uv run pytest tests/unit/test_mouse.py::test_mouse_model_seed_reproducibility

# Dependency sync
uv sync                              # runtime only
uv sync --group dev                  # dev-everything
```

## Architecture

Two parallel ML subsystems share a **collect → train → export → serve** flow.

### Mouse trajectories (`src/ai_mouse/mouse.py` library; `tools/trainer.py` training)

- **Model**: `TrajectoryFlowModel` (Conditional Flow Matching with 4-layer
  pre-norm Transformer, d_model=128, defined in `tools/models.py`)
- **Inference**: 10-step Euler ODE in Python; each step runs
  `session.run(...)` on `src/ai_mouse/assets/flow_model.onnx`. Followed by
  numpy post-processing in `_postprocess.py` (endpoint snapping, forward
  monotonicity, gaussian smoothing, log_dt → cumulative timestamps,
  truncated-normal click duration).
- **Rotated coordinate frame** (`_coord.py`): trajectories normalised so
  `start → (0, 0)`, `end → (1, 0)`. Makes the model angle/distance invariant.

### Scroll wheel (`src/ai_mouse/scroll.py`; `tools/scroll/trainer.py`)

- **Model**: `ScrollCVAE` (bidirectional-GRU encoder + GRU decoder VAE,
  `tools/scroll/models.py`). Only the **decoder** is exported to ONNX
  (`scroll_decoder.onnx`); encoder is training-only.
- **Inference**: sample `z ~ N(0, 1)` in numpy → one `session.run(...)` →
  softmax-normalise deltas → quantise (40 px precise / 120 px otherwise) →
  scale to target distance → cumulative timestamps.

### Server (`tools/server/`) and frontend (`static/`)

App factory `create_app()` mounts four routers under `/api`. Frontend is
vanilla Vue 3 + axios + ECharts via CDN. Note: the `/api/verify` and
`/api/scroll/verify` endpoints always use the **bundled** ONNX weights
(via `from ai_mouse import generate / generate_scroll`). If you retrain
and want the Web UI to reflect new weights, re-run `tools.export_onnx` and
restart the server.

## Config

`tools/config.py` holds the training-side dataclasses (`TrainConfig`,
`ScrollTrainConfig`, etc.). The library does NOT use these — its only
"configuration" is what's embedded in `src/ai_mouse/assets/train_config.json`
(architecture params needed to know `seq_len` etc. at inference time).

## Tests

- `tests/unit/conftest.py` — fixtures for library-only tests, no torch.
- `tests/tools/conftest.py` — `model_dir` and `scroll_model_dir` fixtures
  that produce **untrained** torch weights in a temp dir. Used by training-
  /server-side tests.
- `tests/unit/test_golden.py` — regression suite that pins library output
  against `tests/unit/data/golden_{mouse,scroll}.npz` captured before the
  ONNX migration. Tolerance is distance-scaled: mouse allows ±max(30 px, 20%
  of move distance) and ±700 ms; scroll requires exact total deltaY match
  and ±2 quanta per event.

Server tests use `httpx.ASGITransport(app=create_app())` with
`pytest-asyncio` — no live socket.
