Feature service to data layer

Move an ArcGIS Online hosted feature service into a GratisGIS data layer. Schema, symbology, and features all come over.

intermediate

A hosted feature service can become a portal data layer. That copy is a separate step from importing a web map. A WebMap JSON import that only keeps the FeatureServer URL still draws from ArcGIS Online.

Admins can run the copy from Admin, Migrations, From ArcGIS Online. When the preview marks a hosted feature service for import, the commit copies schema and features into PostGIS and, if a web map in the same run referenced that service, rewrites the map onto the new data layer. Referenced services that are not hosted stay as live pointers.

The manual export below is the same cutover when you would rather move a file than use that importer.

Two paths

Pick one based on whether you want a copy or a live reference.

Path A: copy the data over

You're cutting the dependency. Use this when GratisGIS will own the data from here on.

Export from AGO. From the feature service's item page in AGO, click Export Data → File geodatabase or Shapefile. (GeoPackage is also fine if you have a tool that produces one.) Wait for the export item.
Download the resulting file.
Create a data layer in GratisGIS. From the new-item wizard, pick Data layer, upload the exported file. The portal ingests the schema and features into PostGIS.
Restore symbology if needed (see "Symbology" below).
Tell anyone referencing the AGO service to switch their map layer to the new data layer item.
Retire the AGO service when the cutover is done.

Path B: reference it in place

You're keeping AGO as the source of truth. Use this when you want to consume the data here without moving it (the AGO portal is authoritative, or other teams still publish to it).

Create an ArcGIS service item in GratisGIS pointing at the feature service URL.
Add it to maps as you would a data layer.

This isn't migration; it's hybrid mode. The data stays at AGO. See ArcGIS service under Items for the full surface.

What carries over (Path A)

Schema. Field names, types, length, nullable. Coded-value domains come in as inline pick lists; if you have one domain shared across many feature services, convert it to a Pick list item first and re-bind on the GratisGIS side.
Features. Geometry, attribute values, attachments (if the export format carried them, File Geodatabase does; Shapefile doesn't carry attachments).
Spatial reference. Reprojected to EPSG:4326 on ingest (PostGIS stores everything geographic; per-map rendering projection is independent).

What does NOT carry over automatically

Symbology and labels. AGO stores these on the web map layer reference, not on the feature service itself. After Path A, the new data layer comes in with default symbology. You'll set styles on the GratisGIS side either at the layer level (where every map referencing it sees the same default) or per-map.
Pop-up config. Same reasoning. Set on the GratisGIS map layer reference.
Edits-in-flight. If someone is editing the AGO service while you export, that edit won't be in your export. Pick a cutover window or freeze the source first.
Sharing. AGO group memberships, organization-level permissions, and item-level overrides don't translate. Set sharing fresh on the GratisGIS item.

Symbology

If you want to bring symbology over too, the path is:

From AGO, get the web map JSON for a web map that uses your feature service.
On the GratisGIS side, after creating the data layer, open the map you want to add it to.
Use Import web map JSON in the map builder; the importer maps AGO renderer types (simple, unique value, class breaks) onto GratisGIS symbology types.

See Web map to map for the full importer surface.

Verifying the copy

Before you cut anyone over:

Feature count. Compare AGO's count to the new data layer's row count. They should match exactly.
Spot-check geometry. Open the new data layer on a map and verify a known feature is in the right place.
Spot-check attributes. Open a row in the feature browser, confirm field values match AGO.