Uniswap was publicly announced and deployed to the Ethereum mainnet, marking the start of Uniswap as a live automated market maker (AMM) exchange. Instead of an order book (buyers and sellers posting bids/asks), it used liquidity pools run by smart contracts to let users swap tokens directly from their wallets.
Uniswap’s first production design centered on pools that paired native ETH with an ERC-20 token (for example, ETH/DAI). This design choice shaped early liquidity and trading patterns, because most swaps typically routed through ETH as the common asset.
Uniswap v2 was deployed, representing the protocol’s first major redesign after initial live usage. The release provided a path to move liquidity from v1 to v2 and set the stage for faster growth during 2020’s broader DeFi expansion.
A core v2 upgrade was support for direct ERC-20 to ERC-20 pools (for example, DAI/USDC), rather than requiring ETH in every pair. This reduced routing steps for many trades and made Uniswap more flexible for stablecoin and token-to-token markets.
Uniswap v2 introduced “flash swaps,” which allow tokens to be withdrawn before paying, as long as payment is completed within the same transaction—useful for arbitrage and complex DeFi actions. It also added price oracle improvements (onchain price references) designed to be harder to manipulate than simple spot prices.
Uniswap introduced UNI as a governance token, enabling token holders to vote on protocol-level decisions (such as upgrades and treasury use). This formalized Uniswap’s move toward community governance alongside ongoing development work.
Uniswap Labs presented Uniswap v3 as the next step in AMM design, aiming to improve trade execution and how efficiently liquidity is used. The announcement emphasized that v3 would change how liquidity providers (LPs) supply funds, moving beyond the “one pool spreads liquidity across all prices” model common in earlier AMMs.
A headline v3 change was “concentrated liquidity,” which lets LPs choose a price range where their funds are active, instead of covering the full price spectrum. This approach can improve capital efficiency (more liquidity near the current price) but can also require more active management by LPs.
Uniswap v3 introduced multiple fee tiers so pools could charge different swap fees depending on the expected volatility and trading needs of the pair. This mattered because stablecoin pairs and volatile assets often need different economics to attract liquidity and support efficient trading.
Uniswap v3 went live on Ethereum mainnet, turning the design changes from the March announcement into a usable production protocol. This launch marked the endpoint of the v1–v3 evolution phase, with v3 becoming the new flagship version for Uniswap’s core AMM innovation in this period.
Uniswap v3 core code launched under the Business Source License (BUSL) 1.1, a “time-delayed” license that limited commercial or production use for a period before later conversion to an open-source GPL license. This was a strategic shift from earlier versions and influenced how quickly competitors could legally reuse v3 code in production.
After the BUSL restriction period elapsed, Uniswap v3’s license converted to the GNU General Public License (GPL), allowing broader reuse and forking under GPL conditions. This conversion clarified the long-term outcome of Uniswap’s v3 licensing approach: delayed competition at launch, followed by standardized open-source availability.
Uniswap protocol evolution v1–v3 (2018–2021)