# Documentation

- [Overview](/docs): Accept card payments with Sites Way.
- [Quickstart](/docs/quickstart): Take your first test payment with the hosted payment page.
- [Authentication](/docs/authentication): API keys, environments and permissions.
- [Testing](/docs/testing): Test mode, test cards and what to check before going live.

- **Building**
- [Webhooks](/docs/webhooks): Learn of every change on your server, signed.
- [Idempotency](/docs/idempotency): Retry safely — a payment or a refund is never made twice.
- [Limits](/docs/limits): Request rates, sizes and lifetimes.

- **Reference**
- API reference
  - [API reference](/docs/api-reference): Every endpoint of the merchant API, generated from the API itself.
  - [Merchant](/docs/api-reference/merchant): The account behind the API key.
  - [Payments](/docs/api-reference/payments): Create payments and send customers to pay them.
  - [Refunds](/docs/api-reference/refunds): Give money back, fully or in part.
  - [Webhook endpoints](/docs/api-reference/webhook-endpoints): Where we send events, signed, so your server learns of every change.
  - [Finance](/docs/api-reference/finance): Balance, settlements, payouts, fees and statements.
- Reference
  - [Errors](/docs/reference/errors): Every error code the API returns, with its HTTP status.
  - [Webhook events](/docs/reference/webhook-events): The events you can subscribe to.
  - [Test cards](/docs/reference/test-cards): Card numbers for the test environment and what each one does.