ArcGIS Hub → PortalJS
Overview
Migrate an entire ArcGIS Hub open-data site into a PortalJS Arc portal in one pass.
Every Hub site is machine-readable — a DCAT-US catalog at /data.json, with every dataset
backed by an ArcGIS REST FeatureService — so migration is a harvest → export → convert →
publish → verify pipeline that runs almost fully automated on the operator's machine, no
server-side compute. The tooling is the reusable arcgis-to-portaljs migrator: input is one
Hub URL, output is a ready-to-deploy PortalJS catalog plus a parity report.
The skill is an orchestrator: it reuses the DCAT-US harvest from portaljs-migrate, the
ogr2ogr/tippecanoe/duckdb dual-tier conversion from portaljs-add-geo, and the bulk
Git-LFS → R2 push from portaljs-migrate. Its novel parts are the FeatureService REST export
loop (paged features, not just a link) and the source-vs-derived parity report.
Prerequisites
- A scaffolded PortalJS portal whose template ships
components/MapPreview.tsx and
components/GeoQuery.tsx (PR #1647 or later). Run portaljs-new-portal first if none.
- Native CLIs: GDAL (
ogr2ogr, ogrinfo), tippecanoe, duckdb (with spatial),
and jq. macOS: brew install gdal tippecanoe duckdb jq; Debian/Ubuntu:
apt-get install gdal-bin duckdb jq plus tippecanoe (apt or build from source); Windows via
WSL. The skill hard-stops with the install hint if any is missing.
- Arc credentials for the Git-LFS → R2 push (the token
portaljs-deploy resolves), or an OSS
self-hosted Giftless.
Instructions
The canonical, full step-by-step workflow is
.claude/commands/arcgis-to-portaljs.md
— the single source of truth. Read and follow it when executing. Summary:
- Gather input — Hub URL, portal directory, project slug, optional flags (
--limit,
--only, --dry-run, --namespace-mode). Interview if missing; never dead-end.
- Check native tools (
ogr2ogr, tippecanoe, duckdb + spatial, jq). Any missing →
print the per-OS install and stop.
- Validate the portal directory and confirm the geo showcase components exist.
- Harvest the Hub
/data.json (reuse the portaljs-migrate DCAT-US map) and classify each
item: vector (FeatureService), table, or non-data (web map / 3D / imagery → skipped).
- Export each vector layer through the ArcGIS REST
query API with resultOffset paging
(f=geojson, outSR=4326); fall back to keyset paging on transfer limits; accept a
customer File Geodatabase dump for very large layers.
- Convert each layer to the dual tier via the
portaljs-add-geo recipe (PMTiles +
GeoParquet); tabular items to Parquet. Preserve the native-CRS original.
- Publish — bulk Git-LFS track + one push to R2 through Giftless, then append dual-tier
datasets.json entries (upsert on (namespace, slug)).
- Write
arcgis-parity-report.md — record count, extent, attribute schema, and geometry
validity, source vs derived, per dataset, plus the migrated/skipped/failed accounting.
- Report the inventory, migrated datasets, R2 push, and parity summary.
Output
- Created:
data/<namespace>/<slug>.pmtiles, .parquet, and the original per vector
dataset (all LFS-tracked → R2); Parquet + original per table; arcgis-parity-report.md.
- Modified:
datasets.json (one dual-tier entry per vector dataset, one resource entry
per table); .gitattributes (LFS tracking).
- Verified: the parity report compares each derived artifact to the live FeatureService.
- Result:
/@<namespace>/<slug> renders <MapPreview> + <GeoQuery> for each vector
dataset with no page edits; the catalog lists everything migrated.
Error Handling
| Symptom | Cause | Fix |
|---|
MISSING_INPUT | No Hub URL provided | Pass the site root (e.g. https://hub-lewisville.opendata.arcgis.com) and retry. |
MISSING_TOOLS | ogr2ogr/tippecanoe/duckdb/jq (or duckdb spatial) absent | Print the per-OS install line and stop; re-run after installing. |
NOT_A_PORTAL | Target dir has no datasets.json / geo components | Run portaljs-new-portal first, then re-run. |
HARVEST_FAILED | /data.json unreachable or not DCAT-US | Confirm the site is an ArcGIS Hub and the feed loads in a browser. |
EXPORT_FAILED | One FeatureService layer errored or hit a hard transfer cap | Logged and skipped; try keyset paging or a customer FGDB dump for that layer. |
LFS_PUSH_FAILED | Missing/expired Arc token or unset lfs.url | Re-mint the JWT (see portaljs-deploy); confirm git config lfs.url. |
Examples
Example 1 — Migrate a City Hub (Lewisville)
/arcgis-to-portaljs https://hub-lewisville.opendata.arcgis.com slug=lewisville
Example 2 — Dry-run inventory + plan only (no writes)
/arcgis-to-portaljs https://streamwaterdata.co.uk --dry-run
Example 3 — Migrate a subset, one namespace per publisher
/arcgis-to-portaljs https://streamwaterdata.co.uk --only sewer-catchments,water-boundaries --namespace-mode owner
Resources
