Uniswap v1

Launched in November 2018.

Uniswap V1 had many different liquidity pools but all of the pools had to contain at least Ethereum. This meant that you could only swap ETH for a single ERC20 token, or vice versa. For example, you could swap ETH for USDC, or USDC for ETH.

However, you could not directly swap USDC for DAI. To do this, you would need to first swap USDC for ETH, and then swap the ETH for DAI. This is known as a two-step trade.

Uniswap V1 used a constant product formula, also known as the x*y=k formula, to determine the exchange rate between two tokens in a liquidity pool. This formula ensured that the product of the quantities of the two tokens remained constant, and it automatically adjusted the exchange rate as one token was bought or sold.