README

Introduction

This application is a simple payment gateway implementing a JSON API via the Rails 5 API mode. Usually merchants with online businesses integrate with payment gateways in order to offer electronic payments to their customers. The API allows you to trigger Sale and Void transactions and receive the transaction's status and unique identifier.

Supported transaction types:

Sale

A Sale transaction allows the merchant to bill directly the customer's credit card.

Void

A Sale transaction can be reversed with a Void transaction and this way it will not show up on the customer's credit card statement. Real world Void transactions can be triggered only on the same day the corresponding Sale transaction took place.

Setup

Ubuntu set up

• Update ubuntu -> 5 minutes

sudo apt-get update

• Install required dependencies -> 3 min

sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev

• install RVM -> 10 minutes Ruby Rails

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
curl -sSL https://get.rvm.io | bash -s stable
source ~/.rvm/scripts/rvm
rvm install 2.2.2
rvm use 2.2.2 --default
ruby -v

gem install bundler

• Configure Git -> 2 min optional

git config --global color.ui true
git config --global user.name "YOUR NAME"
git config --global user.email "[email protected]"
ssh-keygen -t rsa -b 4096 -C "[email protected]"

cat ~/.ssh/id_rsa.pub

ssh -T [email protected]

• Clone the repository and issue the following commands:

$ bundle install
$ bundel exec rake db:create:all
$ bundle exec rake db:schema:load
$ bundle exec rails s -p 3001

Minutes per module

1. PaymentTransactionsController -> 15/20 minutes

   1. expalin routes.rb - 2 min
   2. strong params
   3. make 'create' action - 15 min

2. PaymentTransaction model -> 25/30 minutes

   1. factory! method - 10 min
   2. process! - 10 min

3. Gateway model -> 15/25 minutes

   1. process method - 5 min
   2. process_transaction method - 15

Authentication

To interact with the gateway API, you need to provide login credentials using standard HTTP Basic Authentication. Credentials can be set in your config file.

Root API endpoint

http://localhost:3001

Create a Sale transaction

POST /payment_transactions

Parameters

name	description
card_number	Card Number
cvv	Three digit number printed on the back of the card
expiration_date	Card's expiration date
amount	Amount to be charged
usage	Reason for the payment
transaction_type	sale
card_holder	Card holder's name
email	Customer's email address
address	Customer's address

Example request

$ curl http://localhost:3001/payment_transactions \
    -H "Content-Type: application/json;charset=UTF-8" \
    -H "Authorization: Basic cGFuZGFoYXB2YTprYWNoYW1haw==" \
    -d '{
    "payment_transaction": {
      "card_number": "4200000000000000",
      "cvv": "123",
      "expiration_date": "06/2019",
      "amount": "500",
      "usage": "Coffeemaker",
      "transaction_type": "sale",
      "card_holder": "Panda Panda",
      "email": "[email protected]",
      "address": "Panda Street, China"
    }
}'

Example success response

HTTP/1.1 200 OK
Content-Type:application/json;charset=UTF-8

{
  "unique_id": "0e08644635ccb520c2eeb54f33865660",
  "status": "approved",
  "usage": "Coffeemaker",
  "amount": 500,
  "transaction_time": "2016-11-11T15:32:01.368Z",
  "message": "Your transaction has been approved."
}

Create a Void transaction

POST /payment_transactions

Parameters

name	description
reference_id	Sale transaction unique_id
transaction_type	void

Example request

$ curl http://localhost:3001/payment_transactions \
    -H "Content-Type: application/json;charset=UTF-8" \
    -H "Authorization: Basic cGFuZGFoYXB2YTprYWNoYW1haw==" \
    -d '{
    "payment_transaction": {
      "reference_id": "0e08644635ccb520c2eeb54f33865660",
      "transaction_type": "void"
    }
}'

HTTP/1.1 200 OK
Content-Type:application/json;charset=UTF-8

{
  "unique_id": "7e59f0116b74d62e3980ee0231b02dc4",
  "status": "approved",
  "usage": "Coffeemaker",
  "amount": 500,
  "transaction_time": "2016-11-11T15:25:38.817Z",
  "message": "Your transaction has been voided successfully"
}

Errors

HTTP Status Codes

Status Code	Description
200	OK
401	Access denied
422	Unprocessable entity

Example Sale error response

HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8

{
  "unique_id": "2f256d59ce3472459704dc43040f0788",
  "status": "declined",
  "usage": "Coffeemaker",
  "amount": 500,
  "transaction_time": "2016-11-11T15:32:34.913Z",
  "message": "Your transaction has been declined!"
}

Example Void error response

HTTP/1.1 422 Unprocessable entity
Content-Type: application/json;charset=UTF-8

{
  "reference_id": ["Invalid reference transaction!"]
}