About 1inch Exchange:
1inch Exchange is a hackathon project presented at ETH New York in 2019. The project was created and developed by Sergej Kunz (co-founder & CEO) and Anton Bukov (co-founder & CTO). This project is a DEX aggregator that executes a swap of tokens at the best price in one transaction. A commonplace that a core problem of all DEXes (decentralized exchanges) is lack of liquidity because DEXes is a relatively new concept. First of all, 1inch DEX aggregator is addressing the liquidity problem, thus facilitating mass adoption. The optimizing algorithm splits up the trade across different exchanges and allows you to have the most efficient way to exercise a transaction. 1inch protocol sources liquidity from a broad range of DEXes, which genuinely makes it a single entry point to DeFi (decentralized finance) trading and creates an ecosystem experience.
For the record, 1inch protocol is not fully on-chain. It has integrations into the centralized off-chain 0x and AirSwap order books. But if you have a wish to examine and use the source code, you better look at 1Split - an open-source version of 1inch.
Undoubtedly, Chainlink has the most extensive collection of secure market data in the entire DeFi. 1inch has integrated some feeds from Chainlink Decentralized Price Reference Data for ETH pairs and ETH/USD pair into its UI. As a result, the end-user can be sure about the accuracy of displayed/used token prices and its US dollar equivalents.
You may wonder about translation fees, gas, and general economics of 1inch. The price efficiency is achieved not only by splitting up the trading value between multiple liquidity sources but also by not charging any on-top fees. 1inch utilizes the GST2 version of GasToken. If you are familiar with the GasToken concept, you understand that 1inch buys (mints) GST2 at the low price and sells (burns) this gas when it is high. 1inch's gas reserve is used to facilitate swaps on the platform. For burning GST2, 1inch obtains a refund from the GasToken contract when the entire bank contract gets deleted. This refund allows 1inch to discount your transaction cost by up to 42%.