ccvapi

Credit Card Number verifier API

https://ccvapi.cleverapps.io/card/api/verify

This is a RESTful API that verifies credit card numbers (Issuers and Checksum) via Luhn Algorithm.

Card Types

All Card Types are located in the included card_types.json:

[
  {
    "name": "Visa",
    "patterns": [
      4
    ],
    "lengths": [16, 18, 19]
  },
  {
    "name": "MasterCard",
    "patterns": [
      [51, 55],
      [2221, 2229],
      [223, 229],
      [23, 26],
      [270, 271],
      2720
    ],
    "lengths": [16]
  }
]

Adding a card Issuer can be done only via this file. The "patterns" field is an array of homogenous type that can either be an int (e.g. Visa has one pattern to follow, and that is all numbers would start in 4) or an array of [min, max], (e.g., MasterCard uses multiple of these ranges).

The lengths field is where the usual length of digits that is used by the specific Issuer on their Customer's Account Numbers. (This is not range, as you can see well that Visa uses 16, 18 or 19 digits long for their Account Numbers, skipping 17)

HTTP Config

HTTP configuration is in the included config.toml file. At the very least, you would set the path for both error.log and access.log in here, the port to use, and where the card types json file would be fetched from.

All default values are filled in.

Command Line

Alternatively, you can also set them through commandline flags. All you have to do is run it as follows:

go get github.com/jtejido/ccvapi
go build
./ccvapi -h
  -access-log string
        Location of the logfile. (default "access.log")
  -card-path string
        Location of the card types json file. (default "card_types.json")
  -error-log string
        Location of the logfile. (default "error.log")
  -host int
        The local port to listen to. (default 8080)

Request

Once ran, it will listen on the 8080 port of the localhost, (http://localhost:8080/card/api/verify).

Verifying a PAN can be done via POST:

curl --header "Content-Type: application/json" --request POST --data '{ "PAN": "2222400050000009" }' http://localhost:8080/card/api/verify

A demo app is hosted at https://ccvapi.cleverapps.io/card/api/verify, you can try and send a POST request!

Response

The response is sent as a json data as well.

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   110  100    81  100    29   4764   1705 --:--:-- --:--:-- --:--:--

{"Valid":true,"Issuer":"MasterCard","Error":{"ErrorNo":0,"Message":"Success"},"PatternMatch":4,"LengthMatch":16}

Error field is composed of Error # and a message.

  SUCCS  // Success (Valid is true, and the top Issuer match is given)
  UKNWN  // General failure, unknown issuer, failed match and length (Valid is false)
  INVDN  // Failed verification, but given with a possible Issuer/Bank match (Valid is false)

PatternMatch is how much a pattern matches the card's pattern, it sends out the Issuer with the largest pattern match (e.g. Visa matches at the first digit, which is 4, but an Elo matches a number with 401178 more than a Visa)

The top result is based on PatternMatch, LengthMatch is used to describe which length pattern have passed from the given number, say, an Elo-like number that starts with 401178 will not match Elo if it's 19-digit long (as Elo is 16-digit long, unless changed from the json file), but Visa would, hence it'll be considered Visa.

Built-in Card Issuers

See this json file

Brand
Visa
Mastercard
American Express
Diners Club
Discover
JCB
UnionPay
Maestro
Mir
Elo
Hiper
Hipercard