1inch is a DEX Aggregator Using Pathfinder Split Routing

A large USDC-to-WETH swap across fragmented liquidity

A large USDC-to-WETH swap shows 1inch’s strongest use case: Pathfinder can divide one order among several pools when a single pool would impose greater price impact.

Comparing venue depth

USDC uses 6 decimal places on Ethereum, while WETH uses 18, so routing software normalizes raw token amounts before comparing quotes. One route might exchange USDC directly in Uniswap v3; another might pass through WETH liquidity on Curve or Balancer; a third might split volume between them. The user still signs one final route. Pool reserves, the trade’s size relative to those reserves, and each venue’s fee determine gross output. Pathfinder then prices the gas required by every hop, because a route returning extra tokens can still be worse after execution cost.

Settling a split as one transaction

Pathfinder expresses the chosen plan as router calldata. The router calls the included pools in sequence, enforces a minimum return, and sends the combined output to the recipient. Splitting doesn’t create separate wallet submissions, although each additional hop enlarges execution work.

Aggregation matters most when liquidity is fragmented or the order is large enough for price impact to matter. Tiny trades rarely justify elaborate route graphs.

Approvals, route complexity, and execution risk

Execution risk on 1inch comes from token approvals, changing pool state, and the number of contracts a route touches, so the displayed output must be read beside its minimum return.

An ERC-20 token normally requires one approval before the router can transfer it. A new allowance therefore turns a first Classic trade into two on-chain transactions: approval, then swap. An unlimited allowance is commonly represented by the uint256 maximum, 2^256−1, and it remains in contract state until changed. Setting only the intended amount narrows that continuing permission, while exact approvals may require another approval for a later trade. Native assets such as ETH don’t use ERC-20 allowances, though the swap itself still consumes network gas.

The 1inch Limit Order Protocol v4 represents an order as EIP-712 typed data, supports ERC-20 transfers directly, and provides extension paths for ERC-721 and ERC-1155 assets.

Pool state can change between quote and inclusion. Classic execution reverts when output falls below the encoded minimum, so the recipient never settles for less than that boundary. More hops also add contract dependencies and gas, so a visually impressive split isn’t automatically the best net route.

How do you make a first swap?

A first 1inch swap needs a compatible self-custody wallet, both tokens on the same network, enough native currency for Classic gas, and permission for the router to spend the input token. Connect MetaMask, 1inch Wallet, or WalletConnect, select the pair and amount, review the recipient amount, minimum return, route, and network cost, then sign. Match networks precisely: Ethereum is chain ID 1, Base is 8453, Arbitrum One is 42161, Optimism is 10, Polygon is 137, and BNB Chain is 56. A token on one chain isn’t the same balance on another.

Classic, Fusion, and Fusion+ serve different jobs

The 1inch product offers three distinct execution workflows: Classic sends an aggregator route directly, Fusion asks resolvers to fill a signed intent, and Fusion+ coordinates an intent across two blockchains.

Classic for direct submission

Classic gives the wallet direct control over the on-chain submission. The user pays network gas, chooses a slippage limit reflected in the minimum return, and receives or reverts within one transaction. It fits swaps where immediate submission and transparent pool routing matter.

Fusion for resolver settlement

Fusion turns the desired exchange into a signed order and runs a Dutch auction in which resolvers compete to settle it. The resolver submits the transaction and pays the chain’s gas, so the maker doesn’t need the native gas token for settlement. Fill quality and completion time follow the auction and available resolver competition, not a fixed promise.

Fusion+ for cross-chain intents

Fusion+ extends the intent model across chains with two escrows, hashlocks, and timelocks. A resolver provides destination liquidity, and a revealed secret coordinates settlement on both sides. This is a cross-chain swap mechanism, not Pathfinder’s ordinary same-chain pool splitting, and its extra stages create a different completion window, as described in 1inch questions.

Costs come from pools, execution, and route shape

Swap cost on 1inch combines the fees embedded in chosen liquidity pools, blockchain execution, price impact, and any applicable interface or integration charge, while Pathfinder compares routes on net output. A sibling page deals with 1inch app.

Uniswap v3 pools use defined fee tiers of 0.01%, 0.05%, 0.30%, and 1%, and a 1inch route includes the tier charged by every Uniswap pool it traverses. Other venues apply their own rules. Curve pools use parameters set for a specific pool, while PancakeSwap v3 exposes its own tiered pools. Ethereum’s base fee, priority fee, and gas used set Classic execution cost; Layer 2 networks add their own execution and data components. A shorter route uses fewer calls, but a longer one wins when its price improvement exceeds that extra work.

Worked example: every changing input in this hypothetical comparison is labeled by assumption. Assume Route A returns 1 000 USDC and its estimated gas is worth 4 USDC. Assume Route B returns 1 003.5 USDC and its gas is worth 10 USDC. Route A’s net value is 996 USDC; Route B’s is 993.5 USDC. Pathfinder should prefer Route A by 2.5 USDC after cost, despite Route B’s gross quote being 3.5 USDC higher. The calculation isolates gas and output; real routing also evaluates pool fees, price impact, and whether the quote remains executable.

The 1INCH token beside the swap product

The 1INCH token belongs to the network’s governance and staking layer, separating protocol participation from Pathfinder’s immediate job of calculating and executing swap routes for traders.

The 1INCH launch allocation set the total token supply at 1.5 billion units, with ERC-20 precision of 18 decimal places. Holders can stake and delegate within 1inch governance mechanisms, but token market value, circulating supply, and reward rates move over time and aren’t route-quality metrics. Evaluating a swap means comparing the quoted tokens received and execution cost, not treating the governance token’s price as a proxy for Pathfinder performance.

How does Pathfinder assemble a route?

Pathfinder assembles a 1inch route by modeling tokens and liquidity sources as a graph, testing direct and multi-hop paths, splitting volume, and scoring the candidates after estimated gas.

Graph search across connectors

Tokens form vertices, while swaps through Uniswap, Curve, Balancer, PancakeSwap, and other integrated sources form edges. Connectors such as WETH can bridge two pools when no strong direct pair exists. The engine tests how marginal output changes as each slice moves through a venue, because automated market maker curves make the next unit’s price differ from the first. This graph step explains why one quote may contain both direct USDC-to-WETH flow and an indirect leg through another liquid asset.

Gas-aware split scoring

Pathfinder doesn’t maximize gross token output blindly. It estimates the gas of candidate paths, translates that burden into a comparable value, and rejects extra complexity when the improvement is too small. The split also respects available liquidity and the transaction’s minimum return. This optimization is recomputed for the requested amount; doubling an order doesn’t imply doubling every route share, because pool curves are nonlinear.

Router settlement

On many EVM deployments, 1inch Router v6 and Limit Order Protocol v4 share one contract address, while zkSync Era and HyperEVM use network-specific addresses. The router executes the encoded calls atomically: all required state changes settle, or the transaction reverts. EVM chain IDs remain part of the signing context, which is why a signature prepared for Avalanche C-Chain ID 43114 doesn’t authorize the same order on Gnosis Chain ID 100. The route’s hard boundary is the liquidity and gas state available when validators include it.

Uniswap, CoW Protocol, Matcha, and direct DEX routes

Alternatives to 1inch differ mainly in workflow and dependency: Uniswap offers direct pool routing, CoW Protocol uses solver competition and batch auctions, and Matcha presents another aggregation interface.

A direct Uniswap v3 trade reduces the number of brands involved and exposes the chosen protocol’s own routing, yet it searches only liquidity available through that system. Curve is compelling for assets its StableSwap design serves efficiently, particularly closely priced tokens. CoW Protocol centers on signed trade intents and solver settlement, making execution style its defining distinction. Matcha also aggregates decentralized liquidity, so quote output, supported network, approval target, and transaction path decide between the two aggregators.

Choose by net quoted output, custody model, supported chain, settlement dependency, and whether direct submission or intent-based execution better matches the trade. No venue wins every pair and size.