SAP HCI is created as Integration Platform-as-a-Provider (PAAS) which helps to combine a number of independent units/apps for a business procedure. HCI can perform Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid product. HCI delivers Adapters (Connectivity selections) including: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://s4-hana-cloud-faq35813.like-blogs.com/28017774/hana-cloud-integration