The Uniswap protocol is a peer-to-peer system designed for exchanging cryptocurrencies (ERC-20 Tokens) on the Ethereum blockchain (DEX). The protocol is implemented as a set of persistent, non-upgradable smart contracts; designed to prioritize censorship resistance, security, self-custody, and to function without any trusted intermediaries who may selectively restrict access.
There are currently four versions of the Uniswap protocol. v1 and v2 are open source and licensed under GPL. v3 introduced concentrated liquidity and is open source with slight modifications. v4 introduces the singleton pool architecture and hooks system, enabling unprecedented protocol customization. Each version of Uniswap, once deployed, will function in perpetuity, with 100% uptime, provided the continued existence of the Ethereum blockchain.
To understand how the Uniswap protocol differs from a traditional exchange, it is helpful to first look at two subjects: how the Automated Market Maker design deviates from traditional central limit order book-based exchanges, and how permissionless systems depart from conventional permissioned systems.
Most publicly accessible markets use a central limit order book style of exchange, where buyers and sellers create orders organized by price level that are progressively filled as demand shifts.
The Uniswap protocol takes a different approach, using an Automated Market Maker (AMM), sometimes referred to as a Constant Function Market Maker, in place of an order book. Through its evolution, the protocol has enhanced this model: v3 introduced concentrated liquidity for capital efficiency, and v4's singleton pool architecture and hooks system enable unprecedented customization of pool behavior while maintaining the core AMM principles.
An Automated Market Maker is like a robot cashier in a crypto store.
Instead of matching buyers and sellers like a normal store (called an order book), this robot:
An AMM replaces the buy and sell orders in an order book market with a liquidity pool of two assets, both valued relative to each other. As one asset is traded for the other, the relative prices of the two assets shift, and a new market rate for both is determined. In this dynamic, a buyer or seller trades directly with the pool, rather than with specific orders left by other parties.
The second departure from traditional markets is the permissionless and immutable design of the Uniswap protocol. These design decisions were inspired by Ethereum's core tenets, and their commitment to the ideals of permissionless access and immutability as indispensable components of a future in which anyone in the world can access financial services without fear of discrimination or counter-party risk.
Permissionless design means that the protocol's services are entirely open for public use, with no ability to selectively restrict who can or cannot use them. Anyone can swap, provide liquidity, or create new markets at will. This is a departure from traditional financial services, which typically restrict access based on geography, wealth status, and age.
The protocol is also immutable, in other words not upgradeable. No party is able to pause the contracts, reverse trade execution, or otherwise change the behavior of the protocol in any way. It is worth noting that Uniswap Governance has the right (but no obligation) to divert a percentage of swap fees on any pool to a specified address. However, this capability is known to all participants in advance, and to prevent abuse, the percentage is constrained between 10% and 25%.
UNI is the native Uniswap token, it servers for different use cases like governance, incentivizing participation, revenue sharing, and ecossystem development.