pay-rails / Pay

Pay - Payments engine for Ruby on Rails

Pay is a payments engine for Ruby on Rails 4.2 and higher.

Current Payment Providers

• Stripe (SCA Compatible using API version 2020-08-27)
• Paddle (SCA Compatible & supports PayPal)
• Braintree (supports PayPal)
• Fake Processor

Want to add a new payment provider? Contributions are welcome and the instructions are here.

Check the CHANGELOG for any required migrations or changes needed if you're upgrading from a previous version of Pay.

Tutorial

Want to see how Pay works? Check out our video getting started guide.

Installation

Add these lines to your application's Gemfile:

gem 'pay', '~> 2.0'

# To use Stripe, also include:
gem 'stripe', '< 6.0', '>= 2.8'

# To use Braintree + PayPal, also include:
gem 'braintree', '< 3.0', '>= 2.92.0'

# To use Paddle, also include:
gem 'paddle_pay', '~> 0.1'

# To use Receipts
gem 'receipts', '~> 1.0.0'

And then execute:

bundle

Make sure you've configured your ActionMailer default_url_options so Pay can generate links to for features like Stripe Checkout.

# config/application.rb
config.action_mailer.default_url_options = { host: "example.com" }

Migrations

To add the migrations to your application, run the following migration:

bin/rails pay:install:migrations

We also need to run migrations to add Pay to the User, Account, Team, etc models that we want to make payments in our app.

bin/rails g pay User

This will generate a migration to add Pay fields to our User model and automatically includes the Pay::Billable module in our User model. Repeat this for all the models you want to make payments in your app.

Finally, run the migrations

rake db:migrate

Getting NoMethodError?

NoMethodError (undefined method 'stripe_customer' for #<User:0x00007fbc34b9bf20>)

Fully restart your Rails application bin/spring stop && rails s

Usage

The Pay::Billable module should be included in the models you want to make payments and subscriptions.

# app/models/user.rb
class User < ActiveRecord::Base
  include Pay::Billable
end

An email attribute or method on your Billable model is required.

To sync over customer names, your Billable model should respond to the first_name and last_name methods. Pay will sync these over to your Customer objects in Stripe and Braintree.

Configuration

Need to make some changes to how Pay is used? You can create an initializer config/initializers/pay.rb

Pay.setup do |config|
  config.chargeable_class = 'Pay::Charge'
  config.chargeable_table = 'pay_charges'

  # For use in the receipt/refund/renewal mailers
  config.business_name = "Business Name"
  config.business_address = "1600 Pennsylvania Avenue NW"
  config.application_name = "My App"
  config.support_email = "[email protected]"

  config.send_emails = true

  config.default_product_name = "default"
  config.default_plan_name = "default"

  config.automount_routes = true
  config.routes_path = "/pay" # Only when automount_routes is true
end

This allows you to create your own Charge class for instance, which could add receipt functionality:

class Charge < Pay::Charge
  def receipts
    # do some receipts stuff using the https://github.com/excid3/receipts gem
  end
end

Pay.setup do |config|
  config.chargeable_class = 'Charge'
end

Credentials

You'll need to add your private Stripe API key to your Rails secrets config/secrets.yml, credentials rails credentials:edit

development:
  stripe:
    private_key: xxxx
    public_key: yyyy
    signing_secret: zzzz
  braintree:
    private_key: xxxx
    public_key: yyyy
    merchant_id: aaaa
    environment: sandbox
  paddle:
    vendor_id: xxxx
    vendor_auth_code: yyyy
    public_key_base64: MII...==
    environment: sandbox

For Stripe, you can also use the STRIPE_PUBLIC_KEY, STRIPE_PRIVATE_KEY and STRIPE_SIGNING_SECRET environment variables. For Braintree, you can also use BRAINTREE_MERCHANT_ID, BRAINTREE_PUBLIC_KEY, BRAINTREE_PRIVATE_KEY, and BRAINTREE_ENVIRONMENT environment variables. For Paddle, you can also use PADDLE_VENDOR_ID, PADDLE_VENDOR_AUTH_CODE, PADDLE_PUBLIC_KEY_BASE64 and PADDLE_ENVIRONMENT environment variables.

Generators

If you want to modify the Stripe SCA template or any other views, you can copy over the view files using:

bin/rails generate pay:views

If you want to modify the email templates, you can copy over the view files using:

bin/rails generate pay:email_views

Emails

Emails can be enabled/disabled using the send_emails configuration option (enabled per default). When enabled, the following emails will be sent:

• When a charge succeeded
• When a charge was refunded
• When a subscription is about to renew

Billable API

Trials

You can check if the user is on a trial by simply asking:

user = User.find_by(email: '[email protected]')

user.on_trial? #=> true or false

The on_trial? method has two optional arguments with default values.

user = User.find_by(email: '[email protected]')

user.on_trial?(name: 'default', plan: 'plan') #=> true or false

Generic Trials

For trials that don't require cards upfront:

user = User.create(
  email: '[email protected]',
  trial_ends_at: 30.days.from_now
)

user.on_generic_trial? #=> true

Creating a Charge

Stripe and Braintree

user = User.find_by(email: '[email protected]')

user.processor = 'stripe'
user.card_token = 'payment_method_id'
user.charge(1500) # $15.00 USD

user = User.find_by(email: '[email protected]')

user.processor = 'braintree'
user.card_token = 'nonce'
user.charge(1500) # $15.00 USD

The charge method takes the amount in cents as the primary argument.

You may pass optional arguments that will be directly passed on to either Stripe or Braintree. You can use these options to charge different currencies, etc.

On failure, a Pay::Error will be raised with details about the payment failure.

Paddle

It is only possible to create immediate one-time charges on top of an existing subscription.

user = User.find_by(email: '[email protected]')

user.processor = 'paddle'
user.charge(1500, {charge_name: "Test"}) # $15.00 USD

An existing subscription and a charge name are required.

Creating a Subscription

Stripe and Braintree

user = User.find_by(email: '[email protected]')

user.processor = 'stripe'
user.card_token = 'payment_method_id'
user.subscribe

A card_token must be provided as an attribute.

The subscribe method has three optional arguments with default values.

def subscribe(name: Pay.default_product_name, plan: Pay.default_plan_name, **options)
  ...
end

For example, you can pass the quantity option to subscribe to a plan with for per-seat pricing.

user.subscribe(name: Pay.default_product_name, plan: Pay.default_plan_name, quantity: 3)

Name

Name is an internally used name for the subscription.

Plan

Plan is the plan ID or price ID from the payment processor. For example: plan_xxxxx or price_xxxxx

Options

By default, the trial specified on the subscription will be used.

trial_period_days: 30 can be set to override and a trial to the subscription. This works the same for Braintree and Stripe.

Paddle

It is currently not possible to create a subscription through the API. Instead the subscription in Pay is created by the Paddle Subscription Webhook. In order to be able to assign the subcription to the correct owner, the Paddle passthrough parameter has to be used for checkout.

To ensure that the owner cannot be tampered with, Pay uses a Signed Global ID with a purpose. The purpose string consists of "paddle_" and the subscription plan id (or product id respectively).

Javascript Checkout:

Paddle.Checkout.open({
	product: 12345,
	passthrough: "<%= Pay::Paddle.passthrough(owner: current_user) %>"
});

Paddle Button Checkout:

<a href="#!" class="paddle_button" data-product="12345" data-email="<%= current_user.email %>" data-passthrough="<%= Pay::Paddle.passthrough(owner: current_user) %>"

Passthrough

Pay providers a helper method for generating the passthrough JSON object to associate the purchase with the correct Rails model.

Pay::Paddle.passthrough(owner: current_user, foo: :bar)
#=> { owner_sgid: "xxxxxxxx", foo: "bar" }

# To generate manually without the helper
#=> { owner_sgid: current_user.to_sgid.to_s, foo: "bar" }.to_json

Pay parses the passthrough JSON string and verifies the owner_sgid hash to match the webhook with the correct billable record. The passthrough parameter owner_sgid is only required for creating a subscription.

Retrieving a Subscription from the Database

user = User.find_by(email: '[email protected]')

user.subscription

A subscription can be retrieved by name, too.

user = User.find_by(email: '[email protected]')

user.subscription(name: 'bananastand+')

Checking a User's Trial/Subscription Status

user = User.find_by(email: '[email protected]')
user.on_trial_or_subscribed?

The on_trial_or_subscribed? method has two optional arguments with default values.

def on_trial_or_subscribed?(name: 'default', plan: nil)
  ...
end

Checking a User's Subscription Status

user = User.find_by(email: '[email protected]')
user.subscribed?

The subscribed? method has two optional arguments with default values.

def subscribed?(name: 'default', plan: nil)
  ...
end

Name

Name is an internally used name for the subscription.

Plan

Plan is the plan ID from the payment processor.

Retrieving a Payment Processor Account

Stripe and Braintree

user = User.find_by(email: '[email protected]')

user.customer #> Stripe or Braintree customer account

Paddle

It is currently not possible to retrieve a payment processor account through the API.

Updating a Customer's Credit Card

Stripe and Braintree

user = User.find_by(email: '[email protected]')

user.update_card('payment_method_id')

Paddle

Paddle provides a unique Update URL for each user, which allows them to update the payment method.

user = User.find_by(email: '[email protected]')

user.subscription.paddle_update_url

Retrieving a Customer's Subscription from the Processor

user = User.find_by(email: '[email protected]')

user.processor_subscription(subscription_id) #=> Stripe, Braintree or Paddle Subscription

Subscription API

Checking a Subscription's Trial Status

user = User.find_by(email: '[email protected]')

user.subscription.on_trial? #=> true or false

Checking a Subscription's Cancellation Status

user = User.find_by(email: '[email protected]')

user.subscription.cancelled? #=> true or false

Checking a Subscription's Grace Period Status

user = User.find_by(email: '[email protected]')

user.subscription.on_grace_period? #=> true or false

Checking to See If a Subscription Is Active

user = User.find_by(email: '[email protected]')

user.subscription.active? #=> true or false

Checking to See If a Subscription Is Paused

user = User.find_by(email: '[email protected]')

user.subscription.paused? #=> true or false

Cancel a Subscription (At End of Billing Cycle)

Stripe, Braintree and Paddle

user = User.find_by(email: '[email protected]')

user.subscription.cancel

Paddle

In addition to the API, Paddle provides a subscription Cancel URL that you can redirect customers to cancel their subscription.

user.subscription.paddle_cancel_url

Cancel a Subscription Immediately

user = User.find_by(email: '[email protected]')

user.subscription.cancel_now!

Pause a Subscription

Paddle

user = User.find_by(email: '[email protected]')

user.subscription.pause

Swap a Subscription to another Plan

user = User.find_by(email: '[email protected]')

user.subscription.swap("yearly")

Resume a Subscription

Stripe or Braintree Subscription (on Grace Period)

user = User.find_by(email: '[email protected]')

user.subscription.resume

Paddle (Paused)

user = User.find_by(email: '[email protected]')

user.subscription.resume

Retrieving the Subscription from the Processor

user = User.find_by(email: '[email protected]')

user.subscription.processor_subscription

Customizing Pay Models

Want to add methods to Pay::Subscription or Pay::Charge? You can define a concern and simply include it in the model when Rails loads the code.

Pay uses the to_prepare method to allow concerns to be included every time Rails reloads the models in development as well.

# app/models/concerns/subscription_extensions.rb
module SubscriptionExtensions
  extend ActiveSupport::Concern

  included do
    # associations and other class level things go here
  end

  # instance methods and code go here
end

# config/initializers/subscription_extensions.rb

# Re-include the SubscriptionExtensions every time Rails reloads
Rails.application.config.to_prepare do
  Pay.subscription_model.include SubscriptionExtensions
end

Routes & Webhooks

Routes are automatically mounted to /pay by default.

We provide a route for confirming SCA payments at /pay/payments/:payment_intent_id

Webhooks are automatically mounted at /pay/webhooks/{provider}

Customizing webhook mount path

If you have a catch all route (for 404s etc) and need to control where/when the webhook endpoints mount, you will need to disable automatic mounting and mount the engine above your catch all route.

# config/initializers/pay.rb
config.automount_routes = false

# config/routes.rb
mount Pay::Engine, at: '/secret-webhook-path'

If you just want to modify where the engine mounts it's routes then you can change the path.

# config/initializers/pay.rb

config.routes_path = '/secret-webhook-path'

Payment Providers

We support Stripe, Braintree and Paddle and make our best attempt to standardize the three. They function differently so keep that in mind if you plan on doing more complex payments. It would be best to stick with a single payment provider in that case so you don't run into discrepancies.

Braintree

development:
  braintree:
    private_key: xxxx
    public_key: yyyy
    merchant_id: zzzz
    environment: sandbox

Paddle

  paddle:
    vendor_id: xxxx
    vendor_auth_code: yyyy
    public_key_base64: MII...==
    environment: sandbox

Paddle receipts can be retrieved by a charge receipt URL.

user = User.find_by(email: '[email protected]')

charge = user.charges.first
charge.paddle_receipt_url

Stripe

You'll need to add your private Stripe API key to your Rails secrets config/secrets.yml, credentials rails credentials:edit

development:
  stripe:
    private_key: xxxx
    public_key: yyyy
    signing_secret: zzzz

You can also use the STRIPE_PRIVATE_KEY and STRIPE_SIGNING_SECRET environment variables.

To see how to use Stripe Elements JS & Devise, click here.

You need the following event types to trigger the webhook:

customer.subscription.updated
customer.subscription.deleted
customer.subscription.created
payment_method.updated
invoice.payment_action_required
customer.updated
customer.deleted
charge.succeeded
charge.refunded

Strong Customer Authentication (SCA)

Our Stripe integration requires the use of Payment Method objects to correctly support Strong Customer Authentication with Stripe. If you've previously been using card tokens, you'll need to upgrade your Javascript integration.

Subscriptions that require SCA are marked as incomplete by default. Once payment is authenticated, Stripe will send a webhook updating the status of the subscription. You'll need to use the Stripe CLI to forward webhooks to your application to make sure your subscriptions work correctly for SCA payments.

stripe listen --forward-to localhost:3000/pay/webhooks/stripe

You should use stripe.confirmCardSetup on the client to collect card information anytime you want to save the card and charge them later (adding a card, then charging them on the next page for example). Use stripe.confirmCardPayment if you'd like to charge the customer immediately (think checking out of a shopping cart).

The Javascript also needs to have a PaymentIntent or SetupIntent created server-side and the ID passed into the Javascript to do this. That way it knows how to safely handle the card tokenization if it meets the SCA requirements.

Payment Confirmations

Sometimes you'll have a payment that requires extra authentication. In this case, Pay provides a webhook and action for handling these payments. It will automatically email the customer and provide a link with the PaymentIntent ID in the url where the customer will be asked to fill out their name and card number to confirm the payment. Once done, they'll be redirected back to your application.

If you'd like to change the views of the payment confirmation page, you can install the views using the generator and modify the template.

If you use the default views for payment confirmations, and also have a Content Security Policy in place for your application, make sure to add the following domains to their respective configurations in your content_security_policy.rb (otherwise these views won't load properly):

• style_src: https://unpkg.com
• script_src: https://cdn.jsdelivr.net and https://js.stripe.com
• frame_src: https://js.stripe.com

Background jobs

If a user's email is updated and they have a processor_id set, Pay will enqueue a background job (EmailSyncJob) to sync the email with the payment processor.

It's important you set a queue_adapter for this to happen. If you don't, the code will be executed immediately upon user update. More information here

Contributors

• Jason Charnes
• Chris Oliver

Contributing

👋 Thanks for your interest in contributing. Feel free to fork this repo.

If you have an issue you'd like to submit, please do so using the issue tracker in GitHub. In order for us to help you in the best way possible, please be as detailed as you can.

If you'd like to open a PR please make sure the following things pass:

bin/rails db:test:prepare
bin/rails test

License

The gem is available as open source under the terms of the MIT License.