# Bulk Download — Petrel Karst & Depressions Layer v0.1

The bundle endpoint returns a manifest of **per-file signed URLs**, valid for
one hour. There is no S3 path to sync against: `aws s3 sync` will not work, and
a signed URL cannot carry an `X-API-Key` header (the signature IS the auth).

## Whole layer

```bash
export PETREL_API_KEY=tlk.<uuid>.<secret>

curl -s -H "X-API-Key: $PETREL_API_KEY" \
  https://api.petreldata.io/v1/layer/karst_depressions/v0.1/bundle > bundle.json

jq -r '.files[] | "\(.url)\t\(.name)"' bundle.json | \
  while IFS=$'\t' read -r url name; do
      echo "fetching $name"
      curl -s -o "$name" "$url"
  done
```

## Size

Two global 3-arcsec bands (432000 x 216000 land-masked) plus docs and the STAC
item. Depth compresses well because most land drains and reads exactly zero;
solubility is uint8 and small.

## Re-download

Signed URLs expire after an hour. Re-request the manifest; the underlying
objects are immutable for a given vintage, so a partial download can simply be
resumed with a fresh URL.

## Verify before you use it

```bash
python3 - <<'PY'
import rasterio
with rasterio.open("karst_depression_depth_90m.tif") as s:
    print(s.width, s.height, s.dtypes[0], s.tags().get("SCALE"))
    print("coast clip:", s.tags().get("PETREL_COAST_CLIP"))
PY
```

If `PETREL_COAST_CLIP` is absent the file is not a shipped Petrel product —
re-download rather than use it.