# Validate the Apple Pay merchant (/api/carts/validate-cart-user-agent-payment-request-merchant)

`POST https://api.comecero.com/api/v1/carts/{cart_id}/user_agent_payment_request/{payment_method_type}/merchant_validate`

Gets an Apple Pay merchant session for this checkout. Call it from the browser's `onmerchantvalidation` handler with the validation URL Apple gave, then pass `data` to `event.complete()`. Only `apple_pay` is supported. A closed cart is `422`. Any token type may call it; a limited token only for a bound cart.

## Parameters

- `cart_id` (path, required): The id of the cart.
- `payment_method_type` (path, required): The payment method type. Only `apple_pay` is supported; another valid type is `404`, an unknown one `400`.

Request body: the `cart_merchant_validate_request` schema.

Responses: 200, 400, 401, 403, 404, 422, 500.

Full schemas: operation `validate_cart_user_agent_payment_request_merchant` in /openapi.json.