iroh is a library to establish direct connections between two peers, wherever they are on the internet. It takes care of using different transports and holepunching as needed, to reliably establish connectivity. To the application a normal QUIC connection is presented. The aim is to be a connection layer for p2p, providing greater user agency.

Once there is a QUIC connection between two peers other network protocols can be run on top. iroh encouranges mixing and matching custom protocols as the application needs them. Two such building blocks maintained by the same team are iroh-gossip and iroh-blobs, implementations of gossip and verified streaming.

After explaining how the core iroh system works and what applications need to understand the idea of how iroh encourages modular protocols will be described and iroh-gossip and iroh-blobs building blocks will be presented briefly as part of this.