Frax is the first fractional-algorithmic stablecoin protocol. Frax is open-source, permissionless, and entirely on-chain – currently implemented on Ethereum and 12 other chains. The end goal of the Frax protocol is to provide a highly scalable, decentralized, algorithmic money in place of fixed-supply digital assets like BTC. The Frax ecosystem has 2 stablecoins: FRAX (pegged to the US dollar) & FPI (pegged to the Consumer Price Index).  
Frax is a new paradigm in stablecoin design. It brings together familiar concepts into a never before seen protocol:

Fractional-Algorithmic – Frax is the first and only stablecoin with parts of its supply backed by collateral and parts of the supply algorithmic. This means FRAX is the first stablecoin to have part of its supply floating/unbacked. The stablecoin (FRAX) is named after the "fractional-algorithmic" stability mechanism. The ratio of collateralized and algorithmic depends on the markets pricing of the FRAX stablecoin. If FRAX is trading at above $1, the protocol decreases the collateral ratio. If FRAX is trading at under $1, the protocol increases the collateral ratio. 

Decentralized & Governance-minimized – Community governed and emphasizing a highly autonomous, algorithmic approach with no active management. 

Fully on-chain oracles – Frax v1 uses Uniswap (ETH, USDT, USDC time-weighted average prices) and Chainlink (USD price) oracles. 
Two Tokens – FRAX is the stablecoin targeting a tight band around $1/coin. Frax Shares (FXS) is the governance token which accrues fees, seigniorage revenue, and excess collateral value.

Crypto Native CPI – Fraxs end vision is to build the first crypto native version of the CPI called the Frax Price Index (FPI) governed by FXS holders (and other protocol tokens). FRAX is currently pegged to USD but aspires to become the first decentralized, permissionless native unit of account which holds standard of living stable.

Frax Finance

Frax Finance