Checkout SDK reference

import { Checkout, ConfigError, MountError } from "@lynqpay/checkout-sdk";

Method	Description
`mount(selectorOrElement)`	Mount hosted Checkout.
`unmount()`	Remove it; the instance may be mounted again.
`destroy()`	Remove Checkout and listeners permanently.
`onReady(handler)`	Subscribe to readiness.
`onValidation(handler)`	Subscribe to hosted-form state.
`onPaymentResult(handler)`	Subscribe to merchant-actionable outcomes.
`onCheckoutError(handler)`	Subscribe to initialization and loading errors.
`on(event, handler)` / `off(event, handler?)`	Advanced event subscription.
`isMounted()` / `isReady()` / `isValid()`	Read UI state only.

ConfigError is thrown for invalid configuration or server-side construction. MountError is thrown when Checkout cannot mount.

Last modified on August 7, 2026

​Checkout SDK reference