Post a street address or an APN with county FIPS — whatever you have.
Property Data API
Submit an address or APN and get property data back for your real estate workflow: owners, taxes, deeds, mortgages, permits, and comps. Not an API expert? Paste our docs into your AI tool of choice and ask it to build the request.
Example response
GET /v1/properties/{property_id}{ "property_id": "14D3EB7", "apn": "135-310-008-000", "fips": "06107", "property_address": "1842 W Sample Ct, Exeter, CA 93221", "owner_1_full_name": "Morgan Family Trust", "assessed_value": 509811, "annual_tax_amount": 5735.48, "last_sale_date": "2018-05-01", "estimated_market_value": 584205, "combined_estimated_loan_balance": 320668}
How it works
Three steps from address to record
The API takes a property you identify and returns the public-record data for it.
Every response includes a match status. Misses and uncertain matches don't use credits.
Owner, tax, value, and property facts come back as JSON, with a property ID for deeds, permits, and comps if you need them.
Use cases
What teams build with it
Four common places the API replaces manual county lookups.
Fill in owner, tax, and property details automatically when an address comes in.
Let your users look up a property by address or APN inside your product.
Check names, mailing addresses, and assessed values against county records.
Give agents and back-office jobs structured property data to work with.
Data coverage
What's in the record
The core record covers owner, tax, value, and property facts. Deeds, mortgages, permits, and comps are separate endpoints when you need more.
Property ID, APN, FIPS, county, situs address, latitude, longitude, and source update dates help you tie the record back to the right parcel.
Owner names, owner mailing address, and occupancy signals from indexed public property records.
Assessed value, market value, annual tax amount, tax year, tax rate, and exemption indicators when assessor records include them.
Land use, year built, beds, baths, square footage, lot size, legal description, subdivision, HOA, and building features.
Sale comps, rental comps, estimated market value, estimated rent, gross yield, cap rate, estimated equity, and LTV fields when present.
Pull deed transactions, mortgage and lien rows, building permits, sale comps, and rental comps when the core record is not enough.
Endpoints
Public API endpoints and credits
Start with an address or APN, then use the returned property ID for the core record or deeper history endpoints. Detail endpoints charge only when they return rows.
| Endpoint | Credits | Use case |
|---|---|---|
GET/v1/properties | 1 | Resolve address or APN input. Charges only when status is matched and the core property record is returned. |
GET/v1/properties/{property_id} | 1 | Fetch the core parcel, owner, tax, valuation, facts, location, and mortgage summary fields for a known property ID. |
GET/v1/properties/{property_id}/mortgages | 3 | Retrieve mortgage and lien rows, including lender, amount, rate, recording date, term, payment, and lien position when available. |
GET/v1/properties/{property_id}/transactions | 3 | Retrieve recorded deed and transaction rows with buyer, seller, document, title-company, lender, and amount fields when available. |
GET/v1/properties/{property_id}/permits | 3 | Retrieve permit rows where county coverage is available, including type, status, permit number, date, contractor, fees, and description. |
GET/v1/properties/{property_id}/comparable-sales | 3 | Retrieve comparable sale rows with address, price, date, facts, distance, rank, similarity score, and comparable property ID. |
GET/v1/properties/{property_id}/comparable-rentals | 3 | Retrieve comparable rental rows with rent, effective date, facts, distance, rank, adjusted rent, AVM value, and comparable property ID. |
API vs bulk data
Use the API when your product needs answers one property at a time
If a user submits an address, calls up a record, or asks an AI agent to check a property, use the API. If you need to refresh a whole county, state, or national database on a schedule, use bulk files instead.
Pricing
API plans
Pick a monthly credit allowance for the number of property records you expect to pull. Address and APN searches are free, core property records are 1 credit, and add-on history endpoints are 3 credits when they return rows.
Pro + API
Unlimited web views plus starter API access for AI tools and light workflows.
- Monthly credits
- 500/month
- Effective rate
- $0.10/core record
- Core lookup
- 1 credit each
API Growth
Small production integrations, internal review tools, and appraisal QA pilots.
- Monthly credits
- 2,000/month
- Effective rate
- $0.075/core record
- Core lookup
- 1 credit each
Great value$500/month
API Scale
Higher-volume validation, enrichment, and workflow automation.
- Monthly credits
- 10,000/month
- Effective rate
- $0.05/core record
- Core lookup
- 1 credit each
API Enterprise
Large-volume API access with room for procurement and custom support.
- Monthly credits
- 100,000/month
- Effective rate
- $0.03/core record
- Core lookup
- 1 credit each
All API plans use hard included-credit limits at launch. Higher volume and overage terms can be handled by agreement once usage is established.
Usage and billing
Pay for records, not dead ends
Address and APN matching is part of the lookup flow. You spend credits when a core property record comes back, or when an add-on endpoint returns real rows for mortgages, deeds, permits, or comps.
- Lookups that do not return a property record do not spend credits.
- Empty detail collections also return 0 charged credits.
- Rate limits apply per account across API keys on a rolling 60-second window; all API requests count toward the limit.
- Included API credits reset monthly. Standard launch plans use a hard limit rather than automatic overage billing.
- Requests over the limit return 429 with a Retry-After header. Queue large jobs and retry with backoff.
Data limits
Public records vary by county
County records are not identical everywhere. Some counties publish richer owner, tax, deed, permit, or comp history than others. Contact us to confirm field coverage for your target counties.
- Verify with the county assessor or recorder when a decision needs certified records.
- AssessorSearch is not a consumer reporting agency. Do not use API data for FCRA-governed decisions such as credit, employment, housing, or tenant screening.
- The API is not a title search, legal opinion, tax service, or appraisal certification.
FAQ
Questions before you build
The practical things teams usually need to know before wiring property records into a product, workflow, or AI tool.
Yes. Send a street address when that is all you have, or send APN plus county FIPS when your workflow already stores parcel numbers.
The core record includes the fields most teams need first: parcel identity, address, owner and mailing details, assessor and tax fields, property facts, source dates, and mortgage summary fields when available.
Yes. Use the add-on endpoints when you need deeper history for a matched property: deed transactions, mortgage and lien rows, building permits, comparable sales, and comparable rentals.
Start with the developer docs and sample responses. You can paste the docs into ChatGPT, Claude, Cursor, or another AI coding tool and ask it to write the request for your stack.
Use the API when your app needs one property at a time from an address or APN. Use bulk files when you need recurring county, state, or nationwide refreshes for a database or warehouse.
Address and APN searches are 0 credits. A matched core property record is 1 credit. Add-on endpoints are 3 credits only when rows are returned.
Next step
Start building with the API
Open the docs, copy the endpoint you need, and test it against an address or APN. If you are building with AI, paste the docs and ask it to generate the request for your app.