Architecture

Farcaster has a hybrid architecture that stores identity onchain and data offchain.

Onchain

Farcaster's onchain systems are implemented as contracts on OP Mainnet. Actions are performed onchain only when security and consistency are critical. Use of onchain actions is kept at a minimum to reduce costs and improve performance.

Only a handful of actions are performed onchain, including:

• Creating an account.
• Paying rent to store data.
• Adding account keys for connected apps.

Offchain

Farcaster's offchain system is a peer-to-peer network of servers called Hubs which store user data. The majority of user actions are performed offchain. These include:

• Posting a new public message.
• Following another user.
• Reacting to a post.
• Updating your profile picture.

Actions are performed offchain when performance and cost are critical. Use of offchain actions is typically preferred when consistency isn't a strict requirement. Offchain systems achieve security by relying on signatures from onchain systems.