Buying and selling

function buyFor(uint256 amount, uint256 minTokensOut) payable
function sellFor(uint256 tokensIn, uint256 minQuoteOut)
function buy(uint256 amount) payable          // legacy, minOut = 0
function sell(uint256 tokensIn)               // legacy, minOut = 0
function snipeTaxBps(address buyer) view returns (uint256)
function spotPrice() view returns (uint256)

Prefer buyFor / sellFor. A token still on its curve sends 1% slippage as minOut and does not show a slippage control. A listed pool uses the slippage set in the widget. For an ERC-20 quote, approve the curve first. For a sell, approve the launch token on the curve.

A token still on its bonding curve uses a direct swap. Market, limit, and the slippage control appear only after that stage is finished and the token trades as a listed pool. The token on the page cannot be replaced, and selling it pays ETH only. There is no resting order book. If the widget says there is no route, that token has no curve and no Uniswap v4 ETH pool.