Enable Stripe Billing on a Shopify storefront using Stripe.js and a custom payment element for subscription checkout

In-depth guide

Steps

1. Create a Stripe Customer with POST /v1/customers on your server, storing the Stripe customer_id alongside your Shopify customer record
2. Create a SetupIntent with POST /v1/setup_intents (usage=off_session) to collect and save a payment method before charging
3. On the storefront, initialize Stripe.js and mount the Payment Element to a div; confirm setup with stripe.confirmSetup() passing the client_secret from the SetupIntent
4. On the setup_intent.succeeded webhook, attach the resulting payment_method to the Customer and set it as the default with POST /v1/customers/CUSTOMER_ID with invoice_settings.default_payment_method
5. Create the subscription server-side with POST /v1/subscriptions using the Stripe customer_id, price ID, and payment_settings.payment_method_types; set collection_method=charge_automatically
6. Handle customer.subscription.trial_will_end (fires 3 days before trial ends by default) to prompt payment method confirmation if none is on file