1inch

1inch is a DEX aggregation protocol and multi-chain trading application launched in 2019, providing users and developers with access to token swap routing across multiple decentralized exchanges and AMM liquidity pools simultaneously. Rather than executing a swap against a single pool, 1inch's Pathfinder algorithm evaluates available liquidity across supported DEX sources on the selected network and identifies the split routing path that minimizes slippage and maximizes the output amount for a given input token. The trading interface is accessible at app.1inch.io and supports ERC-20 token swaps across Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, and other EVM-compatible networks from a single connected wallet

The 1inch ecosystem comprises multiple protocol layers — the Aggregation Protocol for multi-source swap routing, the Limit Order Protocol for on-chain conditional swap execution, and the Fusion mode for intent-based order execution where third-party resolvers compete to fill swap orders. The 1INCH token is used for governance participation through the governance forum at gov.1inch.network and for staking within the protocol's governance and incentive mechanisms. Protocol components including the Aggregation Protocol and Limit Order Protocol are published as open-source under the 1inch GitHub organization, with an audits repository maintained at github.com/1inch/1inch-audits containing audit reports for protocol contract versions

The primary trading experience on 1inch begins at app.1inch.io, where users connect an EVM-compatible wallet, select a source and destination token on the chosen network, and receive a Pathfinder-computed routing quote showing the expected output amount, split across identified liquidity sources, estimated price impact, and applicable fees. The interface presents routing options at varying slippage tolerance levels, allowing users to review the trade-off between execution certainty and output optimization before submitting the swap transaction on-chain. Swaps execute directly against the identified pool contracts on the selected network — no custodial transfer of assets occurs during the routing or execution process

Beyond standard market swaps, the 1inch interface supports limit order placement through the Limit Order Protocol, where users specify an input token, output token, price condition, and expiry parameters that are stored as signed off-chain orders. These limit orders are monitored by keeper bots that execute the on-chain fill when the specified price condition is met and the order has not expired, settling the trade atomically on-chain without requiring the user to remain connected at execution time. Fusion mode offers an alternative execution path where the user's swap intent is submitted as a request that resolvers compete to fill — resolvers route the order through their own liquidity access and are compensated from the price improvement they generate rather than from user-paid gas fees

The 1inch Aggregation Protocol is the core routing layer that queries on-chain state across supported DEX sources — including Uniswap, Curve, Balancer, and other AMM deployments on each supported network — to construct a split trade route that distributes the input amount across multiple pools where doing so results in a better aggregate output than any single pool can provide. The Pathfinder algorithm evaluates a range of possible split configurations and selects the route that maximizes output at the given input size and current pool state, encoding the full routing path as a sequence of on-chain calls that execute atomically in a single user transaction. This single-transaction multi-source routing model allows traders to benefit from aggregated liquidity across the DEX ecosystem without manually executing partial swaps across individual platforms

The 1inch Limit Order Protocol provides on-chain infrastructure for conditional swap execution, enabling users to place orders that specify an exact input token amount, a minimum output amount representing the desired price, and an expiry time. These orders are held as signed EIP-712 structured data messages off-chain until a fill condition is detected by monitoring infrastructure, at which point a keeper executes the order on-chain by calling the fill function on the Limit Order Protocol contract, which verifies the signature and executes the swap atomically if the price condition is satisfied. The Limit Order Protocol's open-source contract allows developers to build applications that submit, monitor, and cancel limit orders programmatically through the 1inch API or by interacting directly with the deployed protocol contract

Fusion is 1inch's intent-based execution model, where a user submits a swap request specifying the desired input, output, and acceptable price range without publishing a standard on-chain transaction. Third-party resolvers — entities that have staked 1INCH and been approved to fill Fusion orders — compete to fill the order by sourcing the required output liquidity from any available on-chain source and delivering it to the user at or better than the specified terms. This resolver competition model shifts gas cost responsibility away from the user, since the resolver pays the gas for the execution transaction and recovers costs from the price improvement they achieve. Fusion orders are therefore particularly relevant for users who wish to avoid on-chain gas exposure while still benefiting from multi-source DEX routing

1inch supports token swaps and Limit Order Protocol execution across multiple EVM-compatible chains including Ethereum mainnet, BNB Chain, Polygon, Arbitrum, Optimism, Avalanche, Base, and other supported networks. The Aggregation Protocol and Limit Order Protocol are deployed independently on each supported chain, with chain-specific contract addresses and supported DEX source lists documented in the 1inch documentation at docs.1inch.io. This multi-chain coverage allows developers and traders to access 1inch's routing and conditional execution infrastructure on networks beyond Ethereum without requiring asset bridges or cross-chain operations for single-network swaps

1inch supports a range of DeFi and multi-chain trading use cases: retail traders use the app.1inch.io interface to execute ERC-20 token swaps on their selected EVM network with Pathfinder-optimized routing to reduce slippage compared to single-pool DEX execution; yield strategy operators use the Aggregation Protocol to route large-denomination token conversions across multiple pools and minimize market impact on protocol-level rebalancing operations; traders who want to enter or exit positions at specific price levels set limit orders through the Limit Order Protocol without requiring manual on-chain monitoring; developers build swap-routing integrations, wallet-native trading features, and DeFi protocol token conversion flows using the 1inch API documented at docs.1inch.io; and 1INCH token holders participate in governance through the forum at gov.1inch.network to influence protocol parameters and incentive structures across supported chains

Developer integration with 1inch is supported through the documentation at docs.1inch.io, which covers the Aggregation Protocol API for swap quote retrieval and transaction construction, the Limit Order Protocol API for order submission and management, and the Fusion mode API for intent-based order flows. The 1inch REST APIs accept network and token pair parameters and return routing data including split paths, estimated output amounts, and encoded transaction calldata that can be submitted directly to the connected wallet for on-chain execution without custom contract construction. Open-source protocol contract source code is available on GitHub at github.com/1inch, with the audits repository at github.com/1inch/1inch-audits providing security review documentation for developers building on top of the deployed protocol infrastructure

1inch maintains a dedicated audits repository at github.com/1inch/1inch-audits containing security review reports for the Aggregation Protocol, Limit Order Protocol, and other protocol contract versions, providing transparent access to the audit history for developers and users reviewing the security assessment record. All open-source protocol contract code is publicly available on GitHub under the 1inch organization for independent inspection and verification. As a non-custodial protocol, 1inch does not hold user assets between transactions — swap executions transfer tokens atomically within a single on-chain transaction through the routing contract, with no intermediate custody of input assets. Users should review the official channels documentation at help.1inch.com and apply standard Web3 wallet security practices, including verifying token approval scopes and transaction calldata before confirming swaps through the interface

1inch provides DEX aggregation infrastructure for multi-chain ERC-20 token swap routing, on-chain conditional order execution through the Limit Order Protocol, and intent-based swap fulfillment through Fusion, with routing protocol components published as open-source and audit reports maintained in a public GitHub repository. The Pathfinder algorithm, multi-chain deployments across Ethereum and other EVM networks, and REST API coverage give developers and traders structured tools for integrating 1inch's routing and order execution capabilities into applications and on-chain protocols. Teams and users evaluating 1inch should review the documentation at docs.1inch.io, the audits repository at github.com/1inch/1inch-audits, and the official channels guide at help.1inch.com to understand integration requirements, security documentation, and support resources before building on or trading through the protocol