API documentation

One base URL, three REST endpoints, and an MCP server — all pure compute. Authenticate with ?key= or an Authorization: Bearer header. Get a free key →

BIN / IIN lookup

Returns the scheme, valid lengths, and CVV length for a BIN. Issuer/country are returned for known sample BINs only — this is a QA helper, not a comprehensive BIN database.

GET /api/v1/bin?bin=424242&key=YOUR_KEY

{
  "bin": "424242",
  "scheme": "visa",
  "brand": "Visa",
  "type": "credit",
  "bank": "Stripe test",
  "country": "US",
  "lengths": [13, 16, 19],
  "cvvLength": 3
}

Luhn validation

Checks the mod-10 checksum and detects the scheme.

GET /api/v1/luhn?number=4242424242424242&key=YOUR_KEY

{ "number": "4242424242424242", "luhnValid": true, "scheme": "visa", "brand": "Visa", "lengthValid": true }

Generate test cards

Returns Luhn-valid, non-functional QA fixtures. These are declined by real processors.

GET /api/v1/generate?network=visa&count=5&key=YOUR_KEY

MCP server (for AI agents)

Streamable-HTTP MCP endpoint exposing the validate_card, lookup_bin, and generate_test_cards tools. Add it to Claude / Cursor / any MCP client; pass your key via the Authorization header, ?key=, or an apiKey tool argument.

MCP endpoint:  https://www.testcards.io/mcp   (POST, JSON-RPC 2.0)

{ "mcpServers": {
    "testcards": {
      "url": "https://www.testcards.io/mcp?key=YOUR_KEY"
    }
} }

Parameters

Param	Applies to	Description
key	required	Your API key (or send as Authorization: Bearer <key>).
bin	required for /bin	A BIN/IIN or full card number. Scheme & length are computed; issuer fields fill in for known sample BINs.
number	required for /luhn	The card number to validate against the Luhn checksum.
network	for /generate	visa \| mastercard \| amex \| discover \| diners \| jcb \| unionpay \| maestro. Default visa.
count	for /generate	How many numbers to generate, 1–50. Default 1.

Errors

401 invalid/missing key · 429 monthly limit reached · 400 bad parameter · 422 unrecognized card number.