What is a hook? In Uniswap v4 a hook is a small smart contract attached to a liquidity pool. It runs custom code at key moments — before/after a swap, when liquidity is added or removed, on donations, or when the pool is created. A hook's powers are baked into the last bits of its contract address, so we can read exactly what it is allowed to do.

How to read a card:

• 0x2ea5…6ae0 — the hook contract address (tap to open details). #1 is its rank by number of pools.
• 19 pools — how many Unichain pools use this hook.
• ⚡ Dynamic fee — the hook can change the swap fee on the fly instead of a fixed tier.
• Category chips (Swap logic, Liquidity logic, Custom accounting…) — a plain-language summary of what it does.
• Flag chips (beforeSwap, afterSwap…) — the exact permissions the hook holds. Hover any chip for a description.

Tap a card to open the full permission matrix (green dot = enabled), the tokens it is used with, and a one-line summary of what the hook actually does.

Rule of thumb: more permissions = more custom behaviour. A hook with only beforeSwap + dynamic fee is usually a fee/pricing hook; liquidity flags mean it reacts to LP changes; “return delta” flags mean it can take custom fees or change amounts — powerful, but worth extra scrutiny.