Customers and saved cards

Customers

• POST /api/v1/customers {name, email?, phone?} (phone in E.164, e.g. +15555550123)
• GET /api/v1/customers, GET /api/v1/customers/:id

Saving a card

A card can be kept on file only with the customer's agreement:

• Checkout / API: confirm a payment intent that has a customer with save_payment_method: true (secret key).
• Virtual terminal: tick "Save this card on file" when the customer agrees on the phone.
• Subscriptions: the signup page saves the card as part of agreeing to the terms.

The consent (who, when, how) is stored with the card.

Using saved cards

• GET /api/v1/customers/:id/payment_methods — brand, last 4, expiry, funding.
• Charge: create a payment intent for the customer, then confirm with payment_method: "pm_<id>", off_session: true if the customer isn't present, and expected_total to make sure the price you quoted is the price charged.
• DELETE /api/v1/payment_methods/:id — remove (also detached at the gateway).