The API Reference tab contains the complete merchant API contract. Use the environment selector in the playground to send requests to Demo or production. The contract is organized around the same resources and lifecycle described in the guides. Before calling an endpoint:
  1. Read Authentication and keep merchant API keys on your server.
  2. Choose the correct environment.
  3. Add an idempotency key to create requests that may be retried.
  4. Treat webhooks as the source of truth for asynchronous state.
Use the reference with the task guides: checkout, payment methods, subscriptions, payment links, refunds, and webhook operations. Each operation describes required fields, response status, retry behavior, and the next step in the lifecycle.