PlateQuery API

A pay-per-query, read-only API for license plate lookups — messages posted about a plate, plus ALPR (automated license plate reader) search history where publicly available. 1 query = 1 credit. Built for AI agents first (MCP), with a plain REST API underneath.

Pricing

First 10 credits are free — confirm your email after signup to get them. After that, buy a package below — bulk costs less per credit. 1 credit = 1 query, MCP or REST.

Buying requires an account. Confirm your email (check the activation link we send on signup) to get 10 free credits automatically. The button takes you to your account settings to check out via Stripe.

Need more than 8,000 lookups a month? Contact us for volume pricing.

Connect an agent (MCP)

There's no API key to create or copy. Add the server below to Claude, ChatGPT, Grok, or any other MCP-compatible client — it discovers everything else itself (that this server needs an account, where to log in or sign up, how to get a token) via standard OAuth 2.1. You'll be prompted to log in or create a free PlateQuery account right in the connection flow, and that's it.

Exact menu names shift between app versions — look for "Connectors," "Custom connector," "Tools," or "MCP servers" in that app's settings if a label below doesn't quite match what you see.

Claude (Desktop & Code)

Claude Desktop: Settings → Connectors → Add custom connector → paste the Server URL above. Claude detects that sign-in is required and opens the login/signup page for you.

Claude Code: claude mcp add --transport http platequery https://api.platequery.com/mcp — the OAuth flow runs the first time a tool from it is used.

ChatGPT

Settings → Connectors → Create (or "Advanced" / Developer mode, depending on your plan) → add a custom connector with the Server URL above. ChatGPT will walk you through signing in the first time it needs to.

Grok

In Grok's settings (grok.com or the X app), look for Connectors / Tools / MCP servers, and add a custom server with the Server URL above.

What your agent can do

Once connected, you can just ask in plain language — the agent picks the right tool and query for you:

• "Look up California plate 7ABC123 — has anyone reported anything about it?"
• "Has Texas plate JKL9021 shown up in any license-plate-reader searches recently?"
• "I'm about to buy a used car, Ohio plate DEF456 — anything on record before I commit?"
• "Pull the last 20 messages posted about my plate, MYPLATE1 in California."

REST API

The same account, same credits, same OAuth token work as a plain REST API too — for a script, a backend, or anything that isn't an MCP client. Every request costs 1 credit and returns your remaining balance in the X-Credits-Remaining header.

curl "https://api.platequery.com/v1/plates/lookup?plate=ABC123&region=California" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

{
  "plate": "ABC123",
  "region": "California",
  "private": false,
  "is_owner": false,
  "messages": [
    {"author": "3b12b2b...", "text": "Left their lights on in the lot!", "created_on": "2026-08-02T14:03:00Z"}
  ],
  "messages_total": 7,
  "flock_mentions_total": 3,
  "flock_mentions_source": "Flock Safety"
}

/v1/plates/lookup is a quick summary only — the latest 3 messages plus a total count, and just the ALPR-mention total (no rows). For the full history, paginated, use the two endpoints below.

Message history

Paginated. Also 1 credit per call, regardless of page. Default page size is 10, max 15.

curl "https://api.platequery.com/v1/plates/messages?plate=ABC123&region=California&page=1&page_size=10" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

{
  "plate": "ABC123",
  "region": "California",
  "private": false,
  "is_owner": false,
  "page": 1,
  "page_size": 10,
  "total": 7,
  "has_next": false,
  "results": [
    {"author": "3b12b2b...", "text": "Left their lights on in the lot!", "created_on": "2026-08-02T14:03:00Z"}
  ]
}

ALPR mention history

Automated license plate reader search history, where publicly available. Same shape and pricing as message history above.

curl "https://api.platequery.com/v1/plates/alpr-mentions?plate=ABC123&region=California&page=1&page_size=10" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

{
  "plate": "ABC123",
  "region": "California",
  "private": false,
  "is_owner": false,
  "page": 1,
  "page_size": 10,
  "total": 3,
  "has_next": false,
  "results": [
    {"agency": "Example PD", "searched_at": "2026-07-30T09:12:00Z", "source": "Flock Safety"}
  ]
}

Authentication (OAuth 2.1)

MCP and REST are both OAuth-only — there's no separate API key to manage. platequery.com is the authorization server; api.platequery.com only ever validates the tokens it issues.

Writing your own client instead of using an off-the-shelf MCP host? Any standard OAuth 2.1 library that supports PKCE and RFC 7591 registration will work against the endpoints above.

Errors