# Hazard model changelog

The changelog is code, not prose: `lib/modeling/model-changelog.ts` is the
single source, rendered publicly at `/methodology#changelog`, and
`tests/lib/model-changelog.test.ts` fails when `HAZARD_MODEL_VERSION` in
`lib/constants.ts` is bumped without a matching entry. The model's limits
live beside it in `lib/modeling/model-limits.ts` (rendered at
`/methodology#limits`, returned as `notes` on every EP-curve response).

Bumping the model:

1. Change `HAZARD_MODEL_VERSION` in `lib/constants.ts`.
2. Prepend an entry to `MODEL_CHANGELOG` with the effective date and what
   number moved. Two different answers for the same address never share a
   label.
3. If a limit changed, edit `model-limits.ts` — the methodology page and the
   API response follow.