# Interfaces

- [AcknowledgeListener](/dev/tools/billing/v21/references/interfaces/acknowledgelistener.md)
- [ConsumeListener](/dev/tools/billing/v21/references/interfaces/consumelistener.md)
- [IapResultListener](/dev/tools/billing/v21/references/interfaces/iapresultlistener.md)
- [ProductDetailsListener](/dev/tools/billing/v21/references/interfaces/productdetailslistener.md)
- [PurchaseClientStateListener](/dev/tools/billing/v21/references/interfaces/purchaseclientstatelistener.md)
- [PurchasesListener (deprecated)](/dev/tools/billing/v21/references/interfaces/purchaseslistener-deprecated.md)
- [PurchasesUpdatedListener](/dev/tools/billing/v21/references/interfaces/purchasesupdatedlistener.md)
- [QueryPurchasesListener](/dev/tools/billing/v21/references/interfaces/querypurchaseslistener.md)
- [RecurringProductListener](/dev/tools/billing/v21/references/interfaces/recurringproductlistener.md)
- [StoreInfoListener](/dev/tools/billing/v21/references/interfaces/storeinfolistener.md)