Alipay Open Platform Integration: App Types, RSA2 Signing, and Async Notifications
The hard part of Alipay Open Platform is not calling endpoints but three things: choosing the wrong app type, misconfiguring keys, and writing async notification verification incorrectly. This walkthrough covers key generation and upload under the public key model, which payment product fits which scenario, verification and idempotency for async notifications, and the correct use of query and close.