Your PHP app proxies read-only searches to Colorado's public ArcGIS parcel layer.
GET /api/search.php?address=Pearl&city=Boulder GET /api/search.php?county=Boulder&owner=SMITH GET /api/search.php?parcel=123456789
Parameters: address, city, zip, county, owner, parcel, account.
Responses are JSON and include up to 50 matching parcel features plus GeoJSON geometry for the map.