Public ArcGIS FeatureServer endpoint for Sonoma County parcel data. URL, supported fields, and a working sample query — copy it, or open it directly in the UrbanKit parcel lookup tool.
https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0APNAssessor's Parcel NumberSitusFormatted1Situs Address (line 1)SitusStreetNameSitus Street NameSitusCitySitus Citycurl -s 'https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0/query?where=APN%3D%27029-201-001%27&outFields=APN,SitusFormatted1,SitusStreetName,SitusCity&f=json'
https://socogis.sonomacounty.ca.gov/map/rest/services/OWTSPublic/Cities_GIS_Parcel_Base/FeatureServer/0/query?where=APN='029-201-001'&outFields=APN,SitusFormatted1,SitusStreetName,SitusCity&f=jsonOpen this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| APN | Assessor's Parcel Number | YES |
| SitusFormatted1 | Situs Address (line 1) | YES |
| SitusStreetName | Situs Street Name | YES |
| SitusCity | Situs City | YES |
Sonoma County (county seat Santa Rosa, pop. 490,000) publishes parcels through the OWTSPublic Cities_GIS_Parcel_Base FeatureServer. APN format is XXX-XXX-XXX with hyphens (e.g. '029-201-001'). Owner name is NOT exposed on this public layer — California Government Code §7928.205 restricts owner and mailing-address data from public REST endpoints. For ownership data, use the Sonoma County Assessor's parcel search at sonomacounty.ca.gov/assessor. The address schema on this layer was refactored in 2026: the prior single SitusAddress string field was replaced by two formatted address lines (SitusFormatted1, SitusFormatted2) plus fully structured components — SitusStreetNo, SitusDirection, SitusStreetName, SitusStreetType, SitusUnitNumber, SitusCity, SitusState, SitusZip. Queries on the old SitusAddress field name will fail against the current layer; use SitusFormatted1 or SitusStreetName instead. The endpoint is hosted on the county's own ArcGIS server (socogis.sonomacounty.ca.gov). The Sonoma County GIS open-data hub is at gis-sonomacounty.hub.arcgis.com.
Sonoma County GIS — https://gis-sonomacounty.hub.arcgis.com/
Sonoma County's Cities GIS Parcel Base layer exposes a parcel identifier (Assessor's Parcel Number) and address fields (Situs Address (line 1), Situs Street Name, Situs City). Use it for address-to-PIN lookups and identifier queries. All 4 listed fields accept queries. Served as an ArcGIS FeatureServer layer, so edits and applyEdits operations are technically exposed (read access only is published here); last verified 2026-05-15.
/query?where=…&outFields=*&f=jsonto the URL. The sample query above is a working example you can paste into a browser tab to see the raw JSON response.Counties publish parcel data through their own ArcGIS Server installations, each with its own schema. One county uses APN, another uses PIN, a third uses PARCEL_ID. Some expose owner names; others keep them on a separate assessor's portal. The searchable fields list above reflects what Sonoma County actually publishes — not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
Many county servers allow public reads but block browser cross-origin requests. The UrbanKit parcel lookup tool fetches directly from your browser; if it works there, the layer is technically public. For your own integration, you may need a same-origin proxy or server-side fetch.
Possibly — counties move services without warning. We re-verify entries weekly and flag stale ones. If you're seeing a fresh 404, please let us know and we'll update the listing.
Most are. Public ArcGIS layers don't typically rate-limit individual reads, but heavy programmatic use can trigger throttling at the host level. Be respectful — query what you need.