Pay
Not available yet. This page says what is planned, not what you can call today: there is no route for it in the API reference, and the platform follows its measured velocity rather than a calendar.
Planned. Payment intents through a redirect or hosted elements (the platform never holds funds nor card data: PCI-DSS SAQ A), providers PayDunya, Wave, Stripe and PayPal, then FedaPay and direct rails, a double-entry ledger, refunds, disputes and payouts. Each product stays the merchant on its own provider accounts.
What you can do today. Build against the parts that already exist, because they are the ones Pay will use: authentication, idempotency, webhooks, the sandbox conventions and the error contract.
When Pay ships it will arrive with its own guide here, its routes in the reference, its deterministic sandbox scenarios, and its place in the erasure call.