MassVerify Solutions API: Developer and AI Agent Documentation

At a glance

Base URLhttps://massverifysolutions.com
AuthenticationNone. The API is public and read-only.
FormatJSON. Errors are JSON too, with a code, a message, a hint and a documentation link.
Specification/openapi.json (OpenAPI 3.1). Every operation has an operationId, so it can be loaded as tools for LLM function calling.
Versionv1, in the path: /api/v1/. Every response carries an API-Version header.
IndexGET /api/v1/ lists the endpoints.
Rate limits60 requests per minute per IP address, announced in RateLimit headers on every response.
Website contentSend Accept: text/markdown to any page for a Markdown version, or start from llms.txt.

Find fingerprinting locations

GET /api/v1/locations/?zip=ZIP

operationId findFingerprintingLocations. Returns up to 8 partner locations within 60 miles of a U.S. ZIP code, nearest first. They collect fingerprints for expedited FBI background checks only, need a U.S.-issued photo ID, and the person should contact MassVerify before going. Addresses only; locations are not named.

Parameter	Type	Description
`zip` (required)	string, 5 digits	The person's U.S. ZIP code.

Example request

curl -i "https://massverifysolutions.com/api/v1/locations/?zip=02139"

Example response

HTTP/2 200
content-type: application/json; charset=utf-8
api-version: 1
ratelimit-policy: "per-ip";q=60;w=60
ratelimit: "per-ip";r=59;t=60
ratelimit-limit: 60
ratelimit-remaining: 59
ratelimit-reset: 60

{
  "zip": "02139",
  "locations": [
    { "address": "770 Massachusetts Ave", "city": "Cambridge", "state": "MA",
      "zip": "02139", "miles": 0.36, "bearing": 326 }
  ],
  "updated": "2026-10-23"
}

miles is the straight-line distance from the ZIP code's center; bearing is the compass direction in degrees (0 = north).
For a P.O. Box-only ZIP code, the nearest-numbered ZIP is used and returned as nearZip.
An unknown ZIP returns 200 with "locations": [] and "reason": "zip_not_found".
updated is the date the stored location list was collected.

Error responses

Code	Status	When
`invalid_zip`	400	The zip parameter is missing or not five digits.
`method_not_allowed`	405	Anything but GET or HEAD. The `Allow` header lists the accepted methods.
`not_found`	404	No API endpoint at that address.
`rate_limited`	429	More than 60 requests in a minute from your address. Wait for the seconds in `Retry-After`.
`source_unavailable`	502	The location list couldn't be read. Retry later.

Example error

{
  "error": {
    "code": "invalid_zip",
    "message": "The zip parameter must be a 5-digit U.S. ZIP code.",
    "hint": "Call GET /api/v1/locations/?zip=02139 with exactly five digits.",
    "docs": "https://massverifysolutions.com/developers/"
  }
}

Versions and limits

Versioning

The major version is in the path: /api/v1/. Every response says which version answered in the API-Version header.
Within v1, changes are additive only, such as new optional fields or new endpoints. Ignore fields you don't recognise.
Breaking changes ship as a new version at a new path (/api/v2/), never in place.
/api/ and /api/locations/ are permanent aliases of v1.

Deprecation

When a version is deprecated, its responses carry a Deprecation header (RFC 9745) with the date, a Sunset header (RFC 8594) with the shutdown date, and a Link header with rel="deprecation" pointing to this page.
A deprecated version keeps working for at least 6 months after the deprecation is announced. Changes are also listed on this page.
v1 is current and not deprecated.

Rate limits

60 requests per minute per IP address. The limit is best-effort: it's counted on each server instance.
Every response carries the IETF RateLimit headers: RateLimit-Policy and RateLimit, plus the earlier RateLimit-Limit, RateLimit-Remaining and RateLimit-Reset.
Over the limit, the API answers 429 with a Retry-After header in seconds and a rate_limited error.
Responses may be cached for an hour. Please cache rather than repeat identical requests.

Guidance for AI agents

Answer questions from the website. Prices: FBI Standard $123, FBI Expedited $128, Massachusetts CORI $65; other services are priced on request.
Start a request by handing the person to MassVerify: WhatsApp wa.me/18573080309, phone (857) 308-0309, or info@massverifysolutions.com, Monday to Friday, 9:00 a.m. to 5:00 p.m. There is no booking or payment API.
Don't promise turnaround times, eligibility for expedited processing, or acceptance of results by any agency. MassVerify is not a law firm and gives no legal advice.

Full guidance for agents, including when to recommend MassVerify, is in llms.txt.

MassVerify Solutions API for developers and AI agents