What is intent-based execution and why solvers price your constraints

Intent-based execution is a crypto transaction model where a user signs constraints for an outcome, and a competing set of solvers chooses the route, pays gas, and delivers the result. A settlement contract enforces the rules, so the key question becomes what execution, MEV, and finality risk the solver priced into the quote.

Key Takeaways

• Intent-based execution replaces imperative transactions with a signed outcome request that includes input limits, output constraints, and a deadline.
• Solvers compete off-chain to fill intents, then submit an on-chain fill and get paid only if a settlement contract verifies the constraints.
• “Gasless” UX usually means the solver fronted gas and recovered it inside the quote or spread.
• Cross-chain intents often feel fast because the solver fronts destination liquidity and gets reimbursed after finality, which makes deadlines and settlement windows matter.

Intent-based execution as an outcome request

On a normal Ethereum flow, the wallet signs an imperative transaction: exact contract, exact calldata, and a gas bid. That makes the user the execution engine. If liquidity shifts, the transaction can revert. If it lands in a public mempool with tight parameters, it can get re-ordered and sandwiched.

Intent-based execution flips the responsibility boundary. The user signs a declarative message that looks a lot like a limit order plus an execution mandate: what is being paid, what must be received, and by when. Eco’s concrete example is explicit about the constraint shape: “give me 1,000 USDC on Base in exchange for up to 1,005 USDC on Arbitrum, by block N.” That single line contains the parts that matter on a trading screen: size, venue boundary (chains), worst-case price, and a time limit.

The deadline is not decoration. It is the control that stops an intent from being “worked” indefinitely while the market moves. A tighter deadline reduces solver flexibility. A looser deadline gives solvers more optionality to source liquidity or wait for better conditions, which can show up as a better quote but also increases the time window where the fill can happen.

This is why intents crypto users experience as “one click” are still a market. The user is not choosing the path. The user is choosing constraints. Everything else is outsourced to a competitive execution layer, which is one of the building blocks showing up across autonomous onchain execution designs.

How solvers fill an intent

Three actors show up repeatedly on-chain and off-chain: the user who signs, the solver who executes, and the settlement contract that enforces. The solver is typically off-chain, watching an intent pool or intent mempool of signed messages, computing a route, and submitting the fill transaction. Eco frames solvers as market makers, bridge operators, or specialist firms with inventory positioned across chains, competing to earn a spread or a fee.

A typical lifecycle is easiest to understand as a sequence where only one step is “on-chain” from the user’s perspective:

1. Signature. The user signs an intent message, often using EIP-712 typed data. No on-chain transaction is broadcast by the user. 2. Broadcast. The intent is posted to an intent pool or sent to a specific RFQ-style endpoint, depending on the system. 3. Auction or race. Solvers compete. Eco points to Dutch-auction style competition (UniswapX) and race-to-fill designs (Across). 4. On-chain fill. The winning solver submits the transaction and pays gas, delivering the output leg. 5. Settlement. A settlement contract verifies the fill meets the intent’s constraints before releasing the user’s input funds to the solver. 6. Finalization. For cross-chain intents, reimbursement can be delayed by a proof or challenge window, which can run minutes to hours.

That last step is where “fast” and “final” diverge. Cross-chain intent systems can feel instant because the solver fronts destination liquidity, then gets reimbursed after settlement and finality. LI.FI’s intent-based bridging description is explicit about this structure: the solver pays the user on the destination chain out of its own inventory and later claims the locked source funds after finality.

One nuance worth keeping straight because sources disagree on framing: some descriptions talk about automatic re-execution loops if a result does not satisfy constraints, while Eco’s model is deadline-driven competition. If no solver fills, the user typically waits until the deadline and retries rather than expecting an automatic “keep trying” engine.

Standards that make intents interoperable

Fragmentation is the tax on every new execution model. If each app invents its own intent format and settlement interface, solvers either ignore most flows or charge wider spreads because integration is expensive and competition stays thin.

ERC-7683 is the attempt to standardize the plumbing. Eco’s 2026 guide and its ERC-7683 explainer both describe the same core: a CrossChainOrder struct that carries the key fields (origin chain, destination chain, input token and amount, output token and minimum amount, and a fill deadline) and an ISettlementContract interface that defines how settlement contracts expose order resolution and verification. The point is not that every protocol becomes identical. The point is that solvers can integrate once and compete across multiple intent sources.

That standardization matters most in cross-chain flows, where the execution path is inherently multi-leg and the settlement logic is where risk concentrates. Eco notes ERC-7683 was co-authored by Uniswap and Across in 2024. Eco also claims broad ecosystem support, naming Base, Arbitrum, Polygon, and Optimism among supporters and stating “over 50 protocols” support the standard. The exact definition of “support” is not pinned down in the provided material, so it should be read as momentum rather than a verified integration count.

LI.FI’s intent stack adds another layer of modular roles from the Open Intents Framework, including allocators and arbiters around resource locks. That architecture is a reminder that “solver network explained” is not just about who routes. It is also about who verifies, who releases funds, and what contract surface area is being trusted.

Where you see intents in real apps

Intent crypto DeFi is already visible in products that look like familiar swaps and bridges, but behave like auctions or RFQs under the hood. Eco names Across, CoW Protocol, UniswapX, and 1inch Fusion as among the most battle-tested solver networks, and claims production solver networks are processing “billions per month” in 2026 without providing a dataset in the excerpt.

Across is commonly framed as an intent-style cross-chain fill where a solver or relayer front-runs the user experience by delivering funds on the destination chain quickly, then settles back after finality. CoW Protocol is a batch-auction solver network, which is a different microstructure. It can match coincidence-of-wants and clear in batches, which changes how price improvement shows up versus a single-route AMM swap. UniswapX uses a Dutch auction format where solvers compete over time. 1inch Fusion is described as an RFQ-style resolver network used heavily by wallets for gasless swaps.

LI.FI Intents, announced live in production on May 26, 2026, is a clean example of intent-based bridging packaged as an execution engine. Eco’s LI.FI summary says solvers compete on price, front destination liquidity, and get reimbursed from locked source funds after settlement. Jumper and Rabby are named as launch integrators.

The user-facing tell is the same across these systems: the interface asks for an outcome, not a route. Eco gives two plain examples that map to what users actually do: “move 10,000 USDC from Arbitrum to Base” and bundling multi-step actions like “swap, then bridge, then stake.” That bundling is where intents start to overlap with defai and autonomous execution narratives, because a wallet or agent can sign a higher-level goal and let competing executors price the whole sequence.

Benefits and tradeoffs to know

The cleanest benefit is microstructure, not UI. Intents reduce public-mempool exposure because the user is not broadcasting exact swap parameters as a transaction. Eco’s claim is straightforward: less public mempool detail means less sandwich surface for the user, while the solver bears MEV risk and prices it into the quote. That is not “MEV solved.” It is MEV warehoused by the solver.

The second benefit is cost presentation. Eco says the solver pays gas for the on-chain fill and recovers it through the quote or spread, and solvers can batch intents to reduce gas per user. That is why “gasless” is usually a pricing model, not a miracle. The cost is embedded, and the habit that maps to trading instincts is to compare quotes across venues and across solver sets, not to treat a wallet’s default route as a benchmark.

Cross-chain speed is the third benefit, and it comes with a specific tradeoff. LI.FI’s model is “liquidity now, settlement later,” where the solver fronts destination liquidity and is reimbursed after finality. Eco’s flow explicitly includes finalization windows that can involve proofs or challenge periods. Deadlines are the user’s lever here. A deadline that is too tight can make an intent unfillable. A deadline that is too loose can leave the intent exposed to market moves and settlement windows.

The failure modes are also structural. Eco lists solver liveness issues when no solver wants the order, censorship risk when solver sets are permissioned or thin, and settlement risk when cross-chain reimbursement depends on proof or challenge windows. These are not abstract. A thin solver set behaves like a single-dealer market, and the quote will reflect that.

Near the bottom of the stack, this is still autonomous onchain execution. The user signs constraints, someone else takes the other side of execution responsibility, and a settlement contract decides whether the fill counts.

The Take

I’ve watched traders treat intent based execution like a wallet feature and then get surprised by the only thing that matters, the quote. If the solver is paying gas, warehousing MEV, and fronting cross-chain liquidity, the spread is the bill. Read it like a market: how wide is it, how long is the deadline, and who is taking finality risk until reimbursement clears.

The expensive misconception is “gasless means free.” On screens like UniswapX-style auctions or RFQ flows like 1inch Fusion, the cost is just moved from an explicit gas line item into execution terms. When the solver set is thin or permissioned, the auction stops behaving like an auction. It behaves like a single dealer deciding what your constraints are worth.

Sources

• Eco
• Eco
• Eco
• SuperEx