# API for Mobile with UnionPay-SecurePay

- [Payment Request API](/payment-api/in-app-union-pay-secure-pay/payment-request-api.md)
- [Query Transaction API](/payment-api/in-app-union-pay-secure-pay/query-transaction-api.md)
- [Code Samples(Web App, Android, iOS)](/payment-api/in-app-union-pay-secure-pay/code-samples-web-app-android-ios.md): To invoke Union Pay-Secure Pay