Farcaster

Farcaster is the protocol behind much of crypto Twitter's energy — short posts called casts, channels for topics, and clients like Warpcast that feel familiar while storing social state in a hybrid architecture. It is not fully on-chain; hubs replicate signed messages off-chain with on-chain registry for identities and storage.

Each user gets a Farcaster ID (FID) linked to custody and signing keys. Casts are signed payloads replicated across hubs — fast to publish and cheap compared to posting every tweet on Ethereum mainnet. Frames extend casts into interactive mini-apps inside the feed, enabling swaps, polls, and mints without leaving the client.

Channels organize conversation around themes like /ethereum or /memes, giving builders distribution hooks. Developers integrate via APIs and hub software; power users run hubs to support decentralization. Farcaster's success shows hybrid social can ship consumer-grade UX while keeping identity and graph portability as first-class goals.