Dai (DAI) is a decentralized stablecoin cryptocurrency built on the Ethereum blockchain. It is designed to maintain a stable value relative to the US Dollar and is backed by a reserve of collateral-backed tokens and other assets. Dai is an ERC-20 token, meaning it is fully compatible with other networks and wallets that support Ethereum-based tokens, making it an ideal medium of exchange and store of value.

Dai was initially launched by MakerDAO as a single-collateral stablecoin backed solely by Ether (ETH). In 2019, the project introduced Multi-Collateral Dai (MCD), enabling support for additional collateral types. The original version was renamed Single-Collateral Dai (SAI) before being phased out, with holders encouraged to migrate to the new DAI system. Now, as part of MakerDAO's Endgame plan, the project is transitioning into Sky, introducing Sky Dollar (USDS) and the SKY governance token. Starting September 18, 2024, DAI holders have the option to upgrade their tokens to USDS, while MKR holders can upgrade to SKY. However, both DAI and MKR will continue to function as usual, allowing users to choose between the established tokens or the new versions with enhanced governance and features.