The Hypermedia Protocol relies on several RPC interfaces that may be used interchangeably depending on your use case.
Communication between unknown peers, connected with libp2p
Sharing of index information between trusted peers connected with libp2p
Communication between desktop app front-end and the node
Communication between web app front-end and the hosted node
Connection to Seed services like hosting, inbox, and payments
Important: the Hypermedia RPC protocols are highly unstable right now. Eventually we will stabilize these under a unified schema system. For now we are using a messy mix of gRPC and JSON REST APIs.
These RPCs are not yet documented, as they are very prone to change.