Decentralized Granola Order Book Brings Atomic Swaps to Cashu Ecosystem

Granola, a decentralized order book for Cashu atomic swaps, has been showcased in its first public demo. The system enables users to trade between different types of ecash tokens without relying on a central server or intermediary.

Developed by Breno Brito and luisschwab during a hackathon in November 2024, Granola uses two existing protocols as building blocks: Cashu provides the ecash tokens themselves, while Nostr handles public broadcasting of orders and private coordination between trading parties.

The settlement process follows a three-message protocol: a trader proposes a reserve, the counterparty accepts it, and then a quote gets locked in. This system borrows from HTLC-style mechanisms, creating an atomic guarantee that either both sides of the trade complete or neither does.