Mangrove is a Decentralized Exchange (DEX) that employs an order book model and allows liquidity providers to post arbitrary smart contracts as offers, referred to as Smart Offers. This unique approach enables participants to list offers that are not fully provisioned; instead, they are "promises" rather than locked commitments. The liquidity promised can be shared, borrowed, or lent elsewhere, and simultaneously displayed on Mangrove's order-book, ready to be sourced when an offer is taken.