BaseSwap swaps suit one-time trades; its pools suit ongoing two-token exposure. It is a decentralized exchange on Base where you can trade tokens or supply the assets other traders use. Choose based on what you want to hold afterward: one token or a share of a pool.
What are the two ways to use it?
The options are a token swap and a liquidity deposit. They can involve the same assets but leave you with different positions:
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Token swap: BaseSwap trading fits when you want to exchange one Base token for another and hold the result. It does not fit if you want a share of trading fees; after swapping, you own only the received token.
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Provide liquidity: A pool deposit fits when you want to supply a token pair and earn the fees allocated to providers. It does not fit if you need a fixed quantity of either token when you withdraw; your share’s composition changes as traders use the pool.
How do the two options work?
A swap spends one asset for another at a rate set by available liquidity. In an illustrative side-by-side example, start with $200 in USDC on Base. Swapping all $200 for ETH leaves you holding ETH; depositing $100 in USDC and $100 worth of ETH into a two-token pool leaves you with a claim on both assets.
For a swap, check price impact, the change your trade causes in the pool’s rate, and minimum received, your lowest acceptable output after slippage. As an example, a 0.100 ETH quote with 1% slippage tolerance might fill as low as 0.099 ETH. If the output falls below the minimum before execution, the transaction should revert, though gas can still be spent.
For a pool deposit, trades change the proportions of the assets you can withdraw. If ETH rises against USDC, you generally withdraw less ETH and more USDC than you deposited, plus any earned fees. This creates divergence loss relative to holding the original pair; fees may offset it, so compare your withdrawn value with simply holding after all costs.
What do you need before acting?
You need a wallet on Base Mainnet, such as MetaMask, your input tokens and ETH on Base for gas. Base Mainnet’s chain ID is 8453; assets on another network must reach Base before you use them here. An ERC-20 swap or deposit may first require a separate token approval, which also uses gas.
Compare a token’s contract address with its issuer’s published address, then inspect it on BaseScan; names and tickers can be copied. Before signing, check quoted output, minimum received, price impact and estimated gas for a swap, or the pair and fee allocation for a pool. Costs vary with network conditions and the pool, so use the current transaction details.
Choose the route by the position you want, then decide how much ETH to leave for gas. If you want to trade a token pair or supply BaseSwap liquidity pools, the BaseSwap exchange lets you do that on Base. Afterward, use BaseScan to confirm the transaction; if you supplied liquidity, check the position again before withdrawing.