Definition
An atomic swap is a cryptographic protocol that enables the direct peer-to-peer exchange of two crypto-assets across different blockchains or within the same chain, without a centralized intermediary, using time-locked and hash-locked smart contracts to ensure both legs execute together or neither executes. Atomic swaps are the on-chain expression of delivery-versus-payment: both parties deliver simultaneously, or neither does. They are a building block for institutional cross-chain settlement and decentralized exchange workflows.
Example
Two counterparties agree to swap 100 BTC for 1,500 ETH across different chains. An atomic swap protocol using hash time-locked contracts ensures that if either party fails to complete their leg within the time window, the entire swap reverts and both parties retain their original assets.
How Liquid Mercury Handles This
Mercury Pro integrates atomic swap capabilities where they exist on supported venues, surfacing the execution as standard OMS flow while preserving the atomic guarantees of the underlying protocol.