## Content-addressed store of source-form surfaces

The *Original* representation of each distribution model — raster sources at
their own resolution as COGs (`am/`: AquaMaps at 0.5°; `ax/`: AquaX as
delivered), vector ranges as PMTiles (`bl/`, `rng_iucn/`, `rng_fws/`,
`ch_*/` …) — named by a hash of their contents, so a model unchanged between
releases is stored once. The gridded *Interpolated* surface scoring used lives
in `cog/`. Subfolders are source datasets (`ds_key`).

Find the asset for a species via a release's `tables/native_asset.parquet`
(`asset_url`, with `representation` = `native` or `model`), or search spatially
with the STAC API rather than guessing filenames. Releases before 2026-10
carried their own copies under `{ver}/native/`; those were retired once every
release pointed here.