Card Validator API

About the Card Validator API

Card Validator works by validating the card number against the Luhn algorithm and the brand's prefix and length rules. It identifies the card scheme, extracts the BIN and last four digits, checks the number against a list of known published test cards, and returns a risk score summarizing how safe the number is to trust.

What people use it for

Dynamic Checkout Formatting

When shoppers type card numbers during checkout, frontend forms inspect partial validity to display matching brand icons and security code hints immediately.

Test Card Interception

Flag published processor test numbers in production checkouts before sending them to gateways, preventing failed authorization attempts or merchant penalty fees.

Payment Method Tokenization

Subscription billing services verify Luhn checksums and separate the bank identification number and last four digits before storing masked records in customer vaults.

Account Signup Screening

To block automated trial abuse, fraud prevention systems score incoming payment details and reject generated numbers that fail mathematical card validity checks.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON

Default REST response

XML

Markup format

YAML

Human-readable

CSV

Tabular export

Beta

GraphQL

Query language

New

MCP

For AI agents

Request parameters — GET /v1/cardvalidator

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

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curl "https://api.apiverve.com/v1/cardvalidator?number=4900264223817524" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Response — GET /v1/cardvalidator

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

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{
  "status": "ok",
  "error": null,
  "data": {
    "card": {
      "niceType": "Visa",
      "type": "visa",
      "patterns": [
        4
      ],
      "gaps": [
        4,
        8,
        12
      ],
      "lengths": [
        16,
        18,
        19
      ],
      "code": {
        "name": "CVV",
        "size": 3
      },
      "matchStrength": 1
    },
    "brand": "Visa",
    "cardNumber": "4900264223817524",
    "bin": "490026",
    "last4": "7524",
    "isValid": true,
    "isPotentiallyValid": true,
    "isTestCard": false,
    "riskScore": 0,
    "riskLevel": "low"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Zero-code embed — one snippet, no backend

Drop an interactive Card Validator form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.

Changelog — Card Validator API

Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.

Currently v1