What are intents and solvers? The invisible layer executing your DeFi trades

Intent-based protocols separate what a user wants from how it gets done, outsourcing execution to competitive solvers who find the best price across fragmented liquidity. Summary An intent is a signed message describing a desired outcome (for example, “swap 1 ETH for at least 3,200 USDC”) rather than a specific execution path. Solvers are specialized agents that compete to fill intents, searching across DEXs, CEXs, private inventory, and cross-chain liquidity to find the optimal route. CoW Protocol, UniswapX, and Across are the three largest intent-based systems, collectively processing billions in monthly volume by mid-2026. Intent architectures protect users from MEV extraction by removing transactions from the public mempool, where frontrunners and sandwich bots operate. The tradeoff is trust: users must trust that the solver auction is competitive and that the protocol’s settlement contract enforces the promised outcome. Introduction Most DeFi users believe they interact directly with an automated market maker when they swap tokens on Uniswap or SushiSwap. In 2022, this was broadly true. A user signed a transaction, that transaction entered the public mempool, a validator included it in a block, and the AMM’s constant-product formula determined the price. This model has a problem. Public mempools are hunting grounds. MEV bots monitor pending transactions and execute sandwich attacks: they buy before your trade pushes the price up, then sell after, extracting value from the spread. Flashbots estimated that MEV extraction on Ethereum exceeded $600 million in cumulative profit by 2023, with a significant share coming from sandwich attacks on retail swaps. For a deeper look at how this extraction works, see what is MEV. Intent-based protocols restructure this flow. Instead of broadcasting a transaction that specifies every execution detail, the user signs an intent: a declarative statement of the desired result. A network of solvers then competes to fill that intent at the best possible price, off-chain, without exposing the order to the public mempool. This guide explains the mechanics of intents and solvers, how the major protocols implement them, and what tradeoffs users accept. The problem with direct AMM interaction When a user swaps tokens through a traditional AMM, the transaction encodes a specific path: swap token A for token B on pool X, with a minimum output of Y, by deadline Z. This specificity creates three problems. MEV vulnerability. The transaction sits in the public mempool until a validator includes it. During that window, bots can see the intended trade and sandwich it, extracting value from the user. Academic research from the Flashbots team documented that sandwich attacks cost retail users an estimated $200 million to $300 million annually on Ethereum alone. One particularly striking case saw a DeFi trader suffer 100% slippage in a sandwich attack, losing the entire value of the trade. Suboptimal routing.