Open-Data-Wächter

The twin is built from open data that changes under it: Saxony replaces tiles as it flies them again, the statewide Basis-DLM every quarter, OSM every minute; services go down for days (GeoSN's in 2026-10). This skill says what changed since the committed data was fetched and reports it for the maintainer.

Run the check

bun scripts/open-data-watch.ts            # every committed site
bun scripts/open-data-watch.ts dresden    # one
bun scripts/open-data-watch.ts --json     # for a script

It downloads no data. Its report has two parts: Zu tun (a service that does not answer, a newer Stand than provenance.json records, a newer Basis-DLM, OSM data older than 60 days) and Stand (what answered, and editions no record holds yet). Only a recorded edition can be outdone: bun scripts/open-data-watch.ts <site> --record writes the current ones into the tiles that record none, right after a fetch.

Act on it

1. Nothing under „Zu tun“: stop. Write nothing.
2. A service down: say which, since when (look at the last comment on the issue: was it down last week too?), and whether a re-bake is blocked by it. Three weeks in a row is worth a line to the maintainer.
3. A new edition of a committed tile (DGM1, LoD2, DOM1, DOP): report it for the maintainer, with the tiles, the old and new Stand and what a re-bake touches; do not re-bake here. A re-bake needs the whole site's raw inputs, which a fresh container lacks: the OSM extract (Geofabrik does not answer from it), the Mapillary caches (no MAPILLARY_TOKEN; without them the facade, window and lamp steps write empty files over the committed ones), gigabytes of scan and orthophoto. A bake on less rewrites committed outputs with less, and no check in the run reliably tells. Record nothing in provenance.json either: the record names what was baked.
4. A newer Basis-DLM, OSM older than 60 days: these re-bake every tile of every site of that Land (hours, gigabytes). Do not start it: report it with what it would touch, for the maintainer to schedule. The maintainer's rule: bake from fresh OSM extracts (BBBike works from the container, Geofabrik does not), never dodge a re-bake — so say plainly when one is due.
5. Editions no record holds: list them once (they stay until someone records them); recording them (--record) is the maintainer's, after a fetch.
6. Report in German as one comment on the open issue labelled open-data in mdugue/bridge (create it, titled „Open-Data-Wächter“, only if none is open): the „Zu tun“ lines with what each needs from the maintainer, and the report's „Stand“ folded under <details>.

Never

• commit raw downloads (data/_raw/ is gitignored for a reason) or another site's data folder that is not committed yet (ADR 0037);
• merge, push, or open a PR (the report is the whole output);
• re-bake a whole Land on your own initiative.