uniswap

Call exactInputSingle on SwapRouter02 (0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45) with tokenIn, tokenOut, fee tier, amountIn, and amountOutMinimum. Quote first with QuoterV2, then apply a slippage tolerance such as 0.5% to compute amountOutMinimum.

V3 deploys one contract per pool identified by (token0, token1, fee), while V4 uses a singleton PoolManager holding all pools identified by a PoolKey. V4 also supports hooks — contracts attached at pool creation that run custom logic on swaps and liquidity changes.

Compute (sqrtPriceX96 / 2^96)^2, then adjust for token decimal differences by multiplying by 10^(decimals0 - decimals1). Always verify token ordering via pool.token0() since the numerically smaller address is token0.

STF means the token transfer failed — check balance and that the router or Permit2 is approved. 'Too little received' means slippage exceeded amountOutMinimum; re-quote before executing and widen tolerance or use Flashbots Protect to avoid sandwich attacks.

No. UniversalRouter requires tokens approved to the Permit2 contract (0x000000000022D473030F116dDEE9F6B43aC78BA3), not the router itself. Approve Permit2 once with a uint160 maximum, then sign gasless permits per transaction.

The hook address must encode its callback permissions in leading address bits. Use HookMiner.find from v4-periphery to mine a CREATE2 salt matching your flags, deploy the hook at that address, then initialize the pool referencing it.