API Reference

Complete API reference for the Primer Checkout Android SDK

Primer Checkout Android SDK is currently in beta (v3.0.0-beta.4). The API is subject to change before the stable release.

Core API

Component	Description
PrimerCheckoutController	Main checkout session controller with state observation and actions
PrimerCheckoutState	Unified checkout state — lifecycle (Loading, Ready), session updates, and terminal outcomes (Success, Failure)
Payment outcomes	How Success / Failure and PrimerCheckoutData are surfaced through PrimerCheckoutState
PrimerCheckoutSheet	Modal bottom sheet composable with built-in navigation and screen slots
PrimerCheckoutHost	Inline host composable for embedding checkout components in your layout

Card Form

Component	Description
PrimerCardForm	Card payment form composable with slot-based layout
PrimerCardFormController	Card form state holder with field data, validation, and submit action
CardFormDefaults	Pre-built field components for custom card form layouts
Card Field Components	Individual field composables (CardNumberField, ExpiryField, CvvField, etc.)

Payment Methods

Component	Description
PrimerPaymentMethods	Payment method list composable
PrimerPaymentMethodsController	Payment methods state holder with available methods
PaymentMethodsDefaults	Pre-built sub-components for custom payment method layouts
PrimerVaultedPaymentMethodsController	Saved payment methods state holder with select, delete, and management

Theming

Component	Description
PrimerTheme	Root theme container holding all design token groups
LightColorTokens / DarkColorTokens	Color tokens for light and dark mode
SpacingTokens	Spacing values for padding and margins
TypographyTokens / TypographyStyle	Font sizes, weights, and line heights
RadiusTokens / BorderWidthTokens / SizeTokens	Corner radius, border widths, and component sizes

Common Objects

Component	Description
PrimerSettings	SDK configuration (payment handling mode, options)
PrimerError	Error details with diagnostics ID and recovery suggestion
Validation	Field validation result with error details
PrimerCardNetwork	Card network type for co-badged card selection
PrimerCountry	Country data class and selection controller for billing address

Controller pattern

All stateful components follow the same remember* controller pattern:

val checkout = rememberPrimerCheckoutController(clientToken)
val cardFormController = rememberCardFormController(checkout)
val paymentMethodsController = rememberPaymentMethodsController(checkout)
val vaultedMethodsController = rememberVaultedPaymentMethodsController(checkout)

Each controller is created with a remember* composable function, exposes state via StateFlow, and provides action methods.