California contractor license API

A free, read-only API for California CSLB contractor records. Look up a license by number, or search by name, city, county, or classification. Responses are JSON (or CSV), sourced from public records, no key required.

Base URL

https://www.prelien.co/api/v1

All endpoints accept GET, return JSON by default, and allow cross-origin requests. They are rate-limited per IP; a 429 response means slow down.

Get a license

GET /api/v1/license/{number}

Returns the public CSLB record for one license number.

curl https://www.prelien.co/api/v1/license/1116193

Response

{
  "data": {
    "license_number": 1116193,
    "business_name": "Howes & Electrical",
    "business_type": "Sole Owner",
    "city": "Fresno",
    "county": "Fresno",
    "state": "CA",
    "license_status": "CLEAR",
    "issue_date": "2010-04-18",
    "expiration_date": "2026-04-30",
    "classifications": ["C10"],
    "bond_on_file": true,
    "wc_status": "Exempt",
    "profile_url": "https://www.prelien.co/contractor/howes-electrical-1116193",
    "verify_url": "https://www.cslb.ca.gov/onlineservices/checklicenseII/checklicense.aspx"
  },
  "meta": {
    "source": "California CSLB public records via Prelien",
    "as_of": "2026-06-12",
    "terms": "https://www.prelien.co/developers",
    "notice": "An automated summary of public CSLB records, not a rating or endorsement. Verify current status on the official CSLB website."
  }
}

Search contractors

GET /api/v1/contractors

Search and page through records. Add format=csv to download the current page as CSV.

Parameter	Description
q	Full-text search across name, city, and license number
city	Exact city match (e.g. Fresno)
county	Exact county match (e.g. Los Angeles)
classification	CSLB class in display form (e.g. C-10, B)
page	Page number, default 1
page_size	Records per page, default 25, max 100
format	json (default) or csv

curl "https://www.prelien.co/api/v1/contractors?classification=C-10&county=Fresno&page_size=50"

Response

{
  "data": [ /* array of records, same shape as above */ ],
  "pagination": { "page": 1, "page_size": 25, "total": 1240, "max_page_size": 100 },
  "meta": { "source": "California CSLB public records via Prelien", "as_of": "2026-06-12" }
}

Usage & attribution

• The data is public California CSLB record information, presented as an automated summary, not a rating, score, or endorsement.
• When you display a record, link users to its profile or the official CSLB record so they can confirm current status.
• Endpoints are rate-limited per IP. For higher volume, contact us for a keyed plan.
• Honor the as_of date; bond and workers' comp status are point-in-time.

Frequently asked questions

Do I need an API key?

No. The endpoints are open and read-only, rate-limited per IP. If you need higher volume or a stable SLA for production use, get in touch and we'll set up a keyed plan.

Can I use this commercially?

Yes, within the rate limits and attribution below. The data is public CSLB record information; you must present it as an automated summary of public records, not a rating or endorsement, and link users to the official CSLB record to confirm currency.

How fresh is the data?

Records mirror the public CSLB dataset, which refreshes roughly monthly. Each response includes an as_of date. Always treat bond and workers' comp status as point-in-time and verify on CSLB before transacting.