Glossary
Solver
An off-chain agent that competes to fulfill user intents by finding the best execution path and posting the settlement transaction on-chain in exchange for a fee.
Solvers are the supply side of intent-based systems. Given a user-signed intent ("swap X for at least Y by block N"), a solver searches liquidity venues, aggregates routes, batches orders, and constructs a transaction that satisfies the constraint — then settles it on-chain and keeps any surplus as its margin.
Because multiple solvers bid to fill the same intent, competition pushes execution quality toward the user: better prices, MEV protection, and gas abstraction. CoW Protocol runs periodic solver auctions, while UniswapX, 1inch Fusion, and cross-chain protocols like Across rely on solver (or "filler") networks. Sophisticated solvers internalize order flow, net opposing trades against each other (coincidence of wants), and tap their own inventory to beat public routing.