Stripe

Stripe takes one-time card payments for web-shop orders on its hosted payment page. Each firm holds its own keys; nothing is shared.

Setup

1. In the Stripe dashboard, create a secret API key (sk_live_…, or sk_test_… while trying things out).
2. Add a webhook endpoint pointing at https://your-site/payment/notify/stripe/ and subscribe it to checkout.session.completed (and checkout.session.async_payment_succeeded if you enable payment methods that confirm later). Copy its signing secret (whsec_…).
3. On this screen, enable the gateway and paste the secret key and the webhook signing secret. Both are write-only: the page never shows them back, and saving with them empty keeps what is stored.
4. Set Mode to test or live — it is stamped on every recorded payment, so test money never masquerades as real money.

How it completes

The signed webhook records a completed payment on the order exactly once; the customer's landing back on the order page additionally verifies the session (paid state, amount, currency, order identity).

Refunds

Refund from the document's payment row — Stripe executes immediately, partial amounts included.