# CLAUDE.md

Guidance for AI coding agents working in this repository.

## What this is

Flood monitoring and forecasting for the Ping River, Chiang Mai. Public dashboard and
API at https://water.buildfor.life/ (never publish the server's private/Tailscale IP).
Production: one systemd unit on a small VPS, `/opt/thailand-water-monitor`, user
`water-monitor`, interpreter `.venv/bin/python` (uv-managed), updated by `git pull`.

## Rules

- Python 3.11 only. `uv sync --python 3.11`; run everything as `uv run ...`.
- `make format` (black 88 / isort black profile, config in pyproject.toml) before
  committing; CI fails on formatting. `make test` must stay green — tests are
  synthetic-data only, never add one that needs the DB or network.
- Timestamps everywhere are Asia/Bangkok wall-clock with no offset. The dashboard
  parses them with `parseTs()` and renders with `timeZone: TZ`; keep it that way.
- Model changes go through the rolling-origin harness (`scripts/evaluate_variants.py`)
  and are judged on first-alert LEAD and false alarms, not MAE. Record results, positive
  or negative, in `docs/FLOOD_FORECASTING.md` section 5. Do not change what is deployed
  (`rise_rain` / hgb-v3) without a harness result that beats it on lead.
- `train_all()` must never silently produce a gauge-only (v2) model; the guard that
  raises `RainUnavailableError` stays.
- No `git add -A`: zero-byte shell-accident files (`#`, `$(wc`, ...) have been committed
  before. Stage files by name.
- Do not add Co-Authored-By trailers.
- The dashboard is a single file, `src/static/dashboard.html`, EN + TH via the `t()`
  table: every user-visible string needs both languages.

## Where things are

- `src/web_api.py` FastAPI app; `src/water_scraper_v3.py` RID collector;
  `src/hii_collector.py` ThaiWater/HII; `src/ml/` features/train/evaluate/predict,
  `rain.py` (Open-Meteo), `dam.py`, `hii_rain.py`.
- `scripts/retrain.sh` + `water-monitor-retrain.timer`: monthly retrain with staged
  promote. `scripts/dev_proxy.py`: serve the working-copy dashboard against the live API.
- `docs/FLOOD_FORECASTING.md` is the authoritative model write-up; `docs/DATA_SOURCES.md`
  the source catalog.