API
Search US building permits over an API
One JSON API over permits from 1,500+ building departments in all 50 states and DC. Every record traces back to the office that issued it.
What it offers
You can search by state, county or city, by an area drawn on a map or by a radius around a point, and narrow the results by the date a permit was filed, issued or last updated, by permit type, by declared value and by the owners, applicants and contractors named on it.
Every permit has a stable ID that stays the same from one day to the next, and the permits for one building are grouped into a project. You can move from a state down to a metro area, a county and a single jurisdiction, and look up a contractor to see the work on record under its name. To stay current, ask for the permits added or changed since your last check.
Address lookup is coming. It will return every permit on record at a given address, so you can see the history of one property in a single request.
Example
Ask for permits declaring $50M or more in Arizona that mention a data center, newest first. One result looks like this:
{
"permit_number": "BLD-2026-04187",
"city": "Example City",
"state": "AZ",
"address": "4100 S Industrial Pkwy",
"description": "New 2-story data center shell building, 240,000 sq ft",
"date_applied": "2026-10-06",
"value_usd": 182000000,
"owner_name": "Example Data Centers LLC",
"contractor_name": "Example Builders Inc",
"source_url": "https://permits.example.gov/record/BLD-2026-04187"
}This is a made-up example, shortened.
Signals and projects
On top of permits, the API can return projects: one timeline per project that links early signals to the permits that follow, with the project's stage, the parties involved and a record of what changed. These come with the Signals add-on and Projects and Signals Pro. Read more about signals and projects.
Delivery options
Besides the API, you can receive new and changed records as signed webhooks, or load bulk downloads into your own systems as Parquet snapshots plus a file of each day's changes. Pro customers can also keep a streaming connection open and receive each update the moment we record it.
An AI assistant server (MCP) lets AI assistants search the data on your behalf, and a command-line tool (CLI) gives you the same searches from a terminal.
Access
Access is by API key, and the free tier includes 1,000 permits a month, counted by distinct permits returned, so reading a permit again is free. Paid tiers, area feeds and the projects and signals packages are on the pricing page. Self-serve keys are coming soon, and the full reference comes with your key.