What is a Uniswap hook?
7 November 2026
A hook is a small smart contract that is attached to a Uniswap pool when the pool is created. Every time someone swaps, adds liquidity or removes liquidity in that pool, Uniswap calls the hook first, afterwards, or both. The hook can then run its own code.
That one idea lets a pool behave in ways a normal pool can't: charge a tax on sells, stop bots at launch, lock liquidity, change the fee when the price swings, and much more.
What a hook can do
- Run code on every swap. For example, block a buy that is too big, or check that trading has started.
- Take a cut of swaps. Some hooks keep part of each trade, for a treasury, a burn or a reward. This is where taxes and fees come from.
- Set the pool fee. A hook can raise or lower the trading fee, for example when the price moves fast.
- Control liquidity. It can decide who may add liquidity, or stop anyone removing it until a date.
What a hook can't do
A hook only acts inside its own pool. It can't touch tokens in your wallet, and it only sees the trades that go through that pool. Once a pool is created, its hook can never be swapped for a different one.
How to tell what a hook does
Every hook's address encodes which of these powers it has, so they can be read straight from the chain. On UniHooks, each hook page lists them in plain English ("Runs code on every swap", "Can take tokens from swaps") and gives the hook a grade. See how to read a hook's grade.
Want to see real ones? Trending hooks shows the hooks getting the most new pools right now, and New hooks lists every hook the moment its first pool goes live.