Stripe Checkout Beta: Avoid creating new customer for every payment

Question

I'm building a Rails application using Stripe Checkout Beta. For this, I'm creating a Stripe::Checkout::Session on the server, use redirectToCheckout on the frontend and then wait for the webhook coming in with the type checkout_beta.session_succeeded telling me that the payment was fulfilled. This works fine, but:

For every payment, Stripe creates a new customer - which is not what I want. If an existing customer pays a second time, Stripe should not create a new customer, the new payment should be linked to the existing customer.

How can I set the customer id before I redirect to Checkout?

Here is my Ruby controller code:

# app/controllers/payments_controller.rb

def new
  @session = Stripe::Checkout::Session.create(
    success_url: "https://shop.example.test/success",
    cancel_url: "https://shop.example.test/cancelled",
    payment_method_types: ["card"],
    line_items: cart_items.map do |cart_item|
      {
        name: cart_item.name,
        quantity: 1,
        amount: cart_item.name.price.cents,
        currency: 'eur'
      }
    end,
    customer_email: current_user.email
  )
end

The HTML code (using Slim):

# app/views/payments/new.html.slim

= content_tag :div, nil, data: { \
    controller: 'stripe',
    stripe_public_key: ENV['STRIPE_PUBLIC_KEY'],
    stripe_session_id: @session.id }

The JavaScript code (using Stimulus.js):

// app/javascripts/controllers/stripe_controller.js

import { Controller } from 'stimulus'

export default class extends Controller {
  connect() {
    this.stripe = window.Stripe(this.data.get('public-key'), {
      betas: ['checkout_beta_4']
    })

    this.stripe.redirectToCheckout({
      paymentIntentId: this.data.get('session-id')
    }).then((result) => {
      console.log(result)
    })
  }
}

The Ruby webhook code (using the gem stripe_event):

# config/initializer/stripe.rb

Stripe.api_key = Rails.configuration.x.stripe.private_key
Stripe.api_version = '2019-02-19; checkout_sessions_beta=v4'
StripeEvent.signing_secret = Rails.configuration.x.stripe.webhook_secret

class RecordSessions
  def call(event)
    session = event.data.object

    Payment.create!(
      stripe_charge_token: session.payment_intent
    )
  end
end

StripeEvent.configure do |events|
  events.subscribe 'checkout_beta.session_succeeded', RecordSessions.new
end

Right now this isn't possible, by design the session always creates a new customer, but that will likely change very soon as the beta progresses and Stripe adds new features. — karllekko

Laszlo Schürg Laszlo Schürg · Accepted Answer · 2019-08-19T20:55:31

The API of Stripe::Checkout::Session.create allows to add a customer key which references to a Stripe customer id. This way the payment is added to your existing customer.

You may specify an existing Customer object for Checkout to use when making one-time payments or subscriptions. If you do so, any Stripe objects that Checkout creates are associated with that Customer.
session = Stripe::Checkout::Session.create(
  customer: 'cus_123',
  payment_method_types: ['card'],
  line_items: [{
    name: 'T-shirt',
    description: 'Comfortable cotton t-shirt',
    images: ['https://example.com/t-shirt.png'],
    amount: 500,
    currency: 'eur',
    quantity: 1,
  }],
  success_url: 'https://example.com/success',
  cancel_url: 'https://example.com/cancel',
)

See: https://stripe.com/docs/payments/checkout/server#using-existing-customers

Stripe Checkout Beta: Avoid creating new customer for every payment

1 Answers