Developer API — Massachusetts property data
The tract.earth developer API serves the same Massachusetts data the platform runs on: parcels, assessor records, owner and entity intelligence, comparable sales, and distress signals. It is read-only JSON over HTTPS, authenticated with a single X-API-Key header and metered by plan, and keys can be scoped to one product or to the whole catalog.
What the API serves
- Parcels — look up a parcel by id, search a municipality, or resolve an address to the parcel it sits on.
- Owner and entity intelligence — the owner of record, and the filing record behind an LLC or trust.
- Comparable sales — nearby sales for a subject parcel, with the assessed-to-sale ratio where both exist.
- Distress signals — tax delinquency and lis pendens status for a parcel or municipality.
- Reference data — the municipality, neighborhood and ZIP lists the other endpoints key against.
Authentication and plans
Every request carries an X-API-Key header. Keys are minted per product or across the whole catalog, are revocable, and are metered against your plan; each product page ships an OpenAPI schema and an interactive sandbox you can call without writing a client.
Skip trace and direct mail are deliberately not in the public API — they are billable third-party actions, so they stay behind the authenticated app.
Parcel identity
A Massachusetts parcel id is unique only within its town — Wellesley and Winchester both mint a parcel numbered 17-115. Parcels are therefore identified by state, municipality and parcel id together, and any client that keys on the parcel id alone will collide across town lines.
Frequently asked questions
Is there an API?
Yes. The same Massachusetts parcel intelligence is available as a read-only, stateless REST API — pass an API key, get JSON. It is useful for PropTech apps, CRM enrichment, lender/insurance underwriting, lead generation, and market dashboards.
What is the difference between tract.earth and engine.earth?
tract.earth is the real-estate product: research plus the Deal Desk CRM, built for operators. engine.earth is the developer playground for the same underlying APIs across all data products. Same data, two front doors.
Are skip trace and direct mail in the public API?
No. Read-only data endpoints (parcels, owners, comps, signals, geocoding) are part of the API. Skip trace, direct mail, and saved-list endpoints remain user-only and are not exposed on the public API surface.
Where does this data come from?
- MassGIS Data: Property Tax Parcels — The state-standardized Level 3 parcel layer that is our canonical parcel backbone.
- Massachusetts Secretary of the Commonwealth — Corporations Division — The filing record behind LLC and trust ownership: managers, officers, and registered agents.