BillingClient.BillingResponseCode Possible response codes. 
BillingClient.ConnectionState Connection state of billing client. 
BillingClient.FeatureType Features/capabilities supported by BillingClient.isFeatureSupported(String)
BillingClient.ProductType Supported Product types. 
BillingClient.SkuType This @interface is deprecated. Use BillingClient.ProductType instead.  
BillingFlowParams.ProrationMode This @interface is deprecated. use BillingFlowParams.SubscriptionUpdateParams.ReplacementMode instead.  
BillingFlowParams.SubscriptionUpdateParams.ReplacementMode Supported replacement modes to replace an existing subscription with a new one. 
InAppMessageParams.InAppMessageCategoryId A high-level category of the in-app message. 
InAppMessageResult.InAppMessageResponseCode Possible response codes. 
ProductDetails.RecurrenceMode Recurrence mode of the pricing phase. 
Purchase.PurchaseState Possible purchase states. 


AcknowledgePurchaseResponseListener Listener for the result of an acknowledge purchase request. 
AlternativeBillingListener Listener interface for the developer-managed alternative billing flow, when it is chosen by the user when initiating a purchase.  Included in documentation by the annotations: @Annotations.AlternativeBilling
BillingClientStateListener Callback for setup process. 
ConsumeResponseListener Callback that notifies when a consumption operation finishes. 
InAppMessageResponseListener Listener for the result of the in-app messaging flow. 
ProductDetailsResponseListener Listener to a result of product details query. 
PurchaseHistoryResponseListener Listener to a result of purchase history query. 
PurchasesResponseListener Listener to a result of purchases query. 
PurchasesUpdatedListener Listener interface for purchase updates which happen when, for example, the user buys something within the app or by initiating a purchase from Google Play Store. 
SkuDetailsResponseListener This interface is deprecated. Use BillingClient.queryProductDetailsAsync(QueryProductDetailsParams, ProductDetailsResponseListener) instead  


AccountIdentifiers Account identifiers that were specified when the purchase was made. 
AcknowledgePurchaseParams Parameters to acknowledge a purchase. 
AcknowledgePurchaseParams.Builder Helps construct AcknowledgePurchaseParams that are used to acknowledge a purchase. 
AlternativeChoiceDetails Details related to a user's choice of alternative billing.  Included in documentation by the annotations: @Annotations.AlternativeBilling
AlternativeChoiceDetails.Product Details about a product being purchased.  Included in documentation by the annotations: @Annotations.AlternativeBilling
BillingClient Main interface for communication between the library and user application code. 
BillingClient.Builder Builder to configure and create a BillingClient instance. 
BillingFlowParams Parameters to initiate a purchase flow. 
BillingFlowParams.Builder Helps to construct BillingFlowParams that are used to initiate a purchase flow. 
BillingFlowParams.ProductDetailsParams Params that describe the product to be purchased and the offer to purchase with. 
BillingFlowParams.ProductDetailsParams.Builder Helps to construct a BillingFlowParams.ProductDetailsParams
BillingFlowParams.SubscriptionUpdateParams Params that describe a subscription update. 
BillingFlowParams.SubscriptionUpdateParams.Builder Helps to construct BillingFlowParams.SubscriptionUpdateParams
BillingResult Params containing the response code and the debug message from In-app Billing API response. 
BillingResult.Builder Helps to construct BillingResult that are used to return response from In-app Billing API. 
ConsumeParams Parameters to consume a purchase. 
ConsumeParams.Builder Helps construct ConsumeParams that are used to consume a purchase. 
InAppMessageParams Parameters for in-app messaging. 
InAppMessageParams.Builder Helps construct InAppMessageParams
InAppMessageResult Results related to in-app messaging. 
ProductDetails Represents the details of a one time or subscription product. 
ProductDetails.OneTimePurchaseOfferDetails Represents the offer details to buy an one-time purchase product. 
ProductDetails.PricingPhase Represents a pricing phase, describing how a user pays at a point in time. 
ProductDetails.PricingPhases Pricing phases for purchasing an item through a offer. 
ProductDetails.SubscriptionOfferDetails Represents the available purchase plans to buy a subscription product. 
Purchase Represents an in-app billing purchase. 
PurchaseHistoryRecord Represents an in-app billing purchase history record. 
QueryProductDetailsParams Parameters to initiate a query for Product details BillingClient.queryProductDetailsAsync(QueryProductDetailsParams, ProductDetailsResponseListener)
QueryProductDetailsParams.Builder Helps construct QueryProductDetailsParams required to query ProductDetails
QueryProductDetailsParams.Product A Product identifier used for querying product details. 
QueryProductDetailsParams.Product.Builder Builder that helps construct QueryProductDetailsParams.Product
QueryPurchaseHistoryParams Parameters to initiate a query for purchase history. 
QueryPurchaseHistoryParams.Builder Helps construct QueryPurchaseHistoryParams required to query purchase history. 
QueryPurchasesParams Parameters to initiate a query for purchases. 
QueryPurchasesParams.Builder Helps construct QueryPurchasesParams required to query purchases. 
SkuDetails This class is deprecated. Use BillingClient.queryProductDetailsAsync(QueryProductDetailsParams, ProductDetailsResponseListener) instead  
SkuDetailsParams This class is deprecated. Use BillingClient.queryProductDetailsAsync(QueryProductDetailsParams, ProductDetailsResponseListener) instead  
SkuDetailsParams.Builder Helps to construct SkuDetailsParams that are used to query for SKU details.