What Is an Intent?
How it works
In a conventional DeFi trade, the user constructs the entire transaction: which router contract to call, which pool path to route through, what gas to pay. An intent inverts this. The user signs a structured off-chain message (typically EIP-712) declaring only constraints — the asset and amount to sell, the minimum acceptable output, a deadline, and a recipient. That signature goes to a solver network instead of being broadcast to the public mempool.
Solvers (also called fillers or relayers) then compete to fulfill it. Designs vary: CoW Protocol runs batch auctions where solvers bid to deliver the most surplus across a whole batch of orders and can match opposing orders peer-to-peer; UniswapX runs a Dutch auction in which the offered price decays until a filler accepts; Across applies the model cross-chain, with relayers fronting funds on the destination chain and getting reimbursed after settlement. In every case the winning solver submits the settlement transaction and pays the gas.
An on-chain settlement contract enforces the user's terms: it verifies the signature and reverts unless the minimum output reaches the recipient before the deadline. The guarantee comes from the contract, not from trusting the solver. The main design risk is solver centralization — weak competition means worse execution — so credible systems keep solver sets permissionless and often require bonds that can be slashed for misbehavior.
Why it matters
Intents attack two of DeFi's worst problems at once. First, complexity: routing across dozens of pools, chains, and bridges becomes the solver's job, so a user can express "I want USDC on Base" without knowing how it happens. Second, MEV: because signed intents skip the public mempool, sandwich bots never see the order, and competitive auctions force solvers to hand price improvement back to users instead of pocketing it. The trade-off is a new trust surface — orderflow concentrates in off-chain solver markets, and if only a few solvers actually compete, execution quality quietly degrades. How open and contestable the solver set is has become a key criterion for judging these protocols.
Real-world examples
CoW Swap, live on Ethereum since 2021 as the successor to Gnosis Protocol, is the canonical intent-based exchange. Users sign off-chain orders stating what they want; solvers then compete in periodic batch auctions to settle each batch at the best achievable prices. When two users' orders offset each other — a "coincidence of wants" — they are matched peer-to-peer without touching an AMM at all. Because orders never enter the public mempool, sandwich bots cannot front-run them, and solver competition returns price surplus to traders.
FAQ
How is an intent different from a normal transaction?
A transaction specifies exactly what to execute — which contract, which function, which route. An intent specifies only the acceptable outcome (asset in, minimum out, deadline) and lets a competing solver choose the execution path. The settlement contract reverts if the constraints aren't satisfied, so the user never accepts a worse result than they signed for.
Do intents protect against MEV?
Largely, for sandwich attacks: signed intents go to a solver network rather than the public mempool, so bots can't see and front-run the order. But MEV doesn't disappear — it shifts to the solver layer. That's why intent systems rely on competitive auctions, so solvers are forced to return extracted value to users as better prices.
Who pays the gas fee for an intent?
The winning solver submits the settlement transaction and pays gas, pricing that cost into the quote. If no solver fills the order or the fill fails, the user typically pays nothing, since they only ever signed an off-chain message rather than broadcasting a transaction.
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