In decentralized finance, a solver is an independent operator, often a trading firm or a bot, that competes to fulfil users' requests in intent-based systems. Instead of building a swap step by step, a user signs a message stating the outcome they want, such as "sell this token for at least this much of another". Solvers then search across decentralized exchanges, their own inventory and other sources to find the best way to meet it, and the winner, often chosen in a batch auction, settles the trade on-chain and pays the fees. The model aims to give users better prices and protection from maximal extractable value, and is used by protocols such as CoW Protocol and UniswapX. Critics note that solving tends to be dominated by a few well-funded firms. Also see intents and DEX aggregators.
Last updated 13 Nov 2026