UniHooks

Arbitrum

UniHooks is a Uniswap v4 hook on Arbitrum, also known as UniHooksShared. Runs code on every swap. Can take tokens from swaps. Can block LP withdrawals. Gates who can add liquidity. Runs at pool creation.

Contract name: UniHooksShared

0x79137cc216eefcc442a7ce6d0b74db81bbb16acc First pool 10 Nov 2026View on explorer

Launch a pool with this hook

CBe carefulNot in Uniswap’s hook registry · Can take tokens out of swaps?

Pools

Last new pool

Code size

17,949 B

How this hook works

Trading tax

A trading tax hook. It takes a tax on trades, pays extra to liquidity providers and limits some actions to approved addresses.

Takes a tax on trades

On top of the normal pool fee, it keeps part of each trade as a tax.

The code that does this (beforeSwap):

function _beforeSwap(address sender, PoolKey calldata key, SwapParams calldata p, bytes calldata)
    internal override returns (bytes4, BeforeSwapDelta, uint24)
{
    PoolId id = key.toId();
    Config storage c = _cfg[id];
    if (!seeded[id]) revert NotSeeded();
    if (block.timestamp < c.tradingStart) revert TradingNotStarted(c.tradingStart);
    if (_allowlistActive(c) && !_allowed(id, sender)) revert NotAllowlisted(tx.origin);

    (bool buy,) = _isBuy(key, p);
    if (buy && _inWindow(id, c) && p.amountSpecified > 0) revert ExactOutputNotAllowedDuringLaunch();
    if (c.sameBlockGuard) {
        if (buy && lastSellBlock[id][tx.origin] == block.number) revert SameBlockTrade();
        if (!buy && lastBuyBlock[id][tx.origin] == block.number) revert SameBlockTrade();
    }
    if (c.volatilityBpsPerTick > 0 || c.sandwichBps > 0) {
        (, int24 tick,,) = poolManager.getSlot0(id);
        _setTickBefore(tick);
        if (_openBlock[id] != block.number) { _openBlock[id] = block.number; _openTick[id] = tick; }
    }
    // Platform fee, part 1: when the amount the swapper fixed (input for exact-in, output for exact-out)
    // is the paired token, take 0.20% of it here. Otherwise it is taken in afterSwap from the other side.
    Currency specified = (p.amountSpecified < 0) == p.zeroForOne ? key.currency0 : key.currency1;
    if (Currency.unwrap(specified) != Currency.unwrap(projectTokenOf[id])) {
        uint256 fee = _abs(p.amountSpecified) * PROTOCOL_FEE_BPS / BPS;
        if (fee > 0) {
            poolManager.take(specified, protocolFeeTo, fee);
            emit ProtocolFee(id, Currency.unwrap(specified), fee);
            return (this.beforeSwap.selector, toBeforeSwapDelta(int128(int256(fee)), 0), 0);
        }
    // …

Pays extra to liquidity providers

It sends extra rewards straight into the pool for liquidity providers.

The code that does this (afterSwap):

function _afterSwap(address, PoolKey calldata key, SwapParams calldata p, BalanceDelta delta, bytes calldata)
    internal override returns (bytes4, int128)
{
    (bool buy, Currency outCur) = _isBuy(key, p);
    PoolId id = key.toId();
    bool exactIn = p.amountSpecified < 0;
    // Platform fee, part 2: the unspecified side is the paired token (exact-in sell, or exact-out buy).
    uint256 pfee;
    Currency unspecified = exactIn == p.zeroForOne ? key.currency1 : key.currency0;
    if (Currency.unwrap(unspecified) != Currency.unwrap(projectTokenOf[id])) {
        int128 u = unspecified == key.currency0 ? delta.amount0() : delta.amount1();
        pfee = _abs(int256(u)) * PROTOCOL_FEE_BPS / BPS;
        if (pfee > 0) {
            poolManager.take(unspecified, protocolFeeTo, pfee);
            emit ProtocolFee(id, Currency.unwrap(unspecified), pfee);
        }
    }
    int128 outDelta = p.zeroForOne ? delta.amount1() : delta.amount0();
    if (outDelta <= 0) return (this.afterSwap.selector, int128(uint128(pfee)));
    uint256 out = uint256(uint128(outDelta));
    Config storage c = _cfg[id];

    uint256 burnAmt; uint256 rewardAmt; uint256 treasuryAmt; uint256 launchAmt;
    if (buy) {
        bool inWindow = _inWindow(id, c);
        if (inWindow && !outCur.isAddressZero()) {
            uint256 supply = IERC20Supply(Currency.unwrap(outCur)).totalSupply();
            uint256 maxOut = supply * c.snipeMaxBps / BPS;
            // The cap counts everything a wallet buys in one block, so splitting a buy does not get around it.
            uint256 inBlock = (_buyBlock[id][tx.origin] == block.number ? _boughtInBlock[id][tx.origin] : 0) + out;
    // …

Approved addresses only

Some actions are limited to addresses on an approved list.

The code that does this (beforeSwap):

function _beforeSwap(address sender, PoolKey calldata key, SwapParams calldata p, bytes calldata)
    internal override returns (bytes4, BeforeSwapDelta, uint24)
{
    PoolId id = key.toId();
    Config storage c = _cfg[id];
    if (!seeded[id]) revert NotSeeded();
    if (block.timestamp < c.tradingStart) revert TradingNotStarted(c.tradingStart);
    if (_allowlistActive(c) && !_allowed(id, sender)) revert NotAllowlisted(tx.origin);

    (bool buy,) = _isBuy(key, p);
    if (buy && _inWindow(id, c) && p.amountSpecified > 0) revert ExactOutputNotAllowedDuringLaunch();
    if (c.sameBlockGuard) {
        if (buy && lastSellBlock[id][tx.origin] == block.number) revert SameBlockTrade();
        if (!buy && lastBuyBlock[id][tx.origin] == block.number) revert SameBlockTrade();
    }
    if (c.volatilityBpsPerTick > 0 || c.sandwichBps > 0) {
        (, int24 tick,,) = poolManager.getSlot0(id);
        _setTickBefore(tick);
        if (_openBlock[id] != block.number) { _openBlock[id] = block.number; _openTick[id] = tick; }
    }
    // Platform fee, part 1: when the amount the swapper fixed (input for exact-in, output for exact-out)
    // is the paired token, take 0.20% of it here. Otherwise it is taken in afterSwap from the other side.
    Currency specified = (p.amountSpecified < 0) == p.zeroForOne ? key.currency0 : key.currency1;
    if (Currency.unwrap(specified) != Currency.unwrap(projectTokenOf[id])) {
        uint256 fee = _abs(p.amountSpecified) * PROTOCOL_FEE_BPS / BPS;
        if (fee > 0) {
            poolManager.take(specified, protocolFeeTo, fee);
            emit ProtocolFee(id, Currency.unwrap(specified), fee);
            return (this.beforeSwap.selector, toBeforeSwapDelta(int128(int256(fee)), 0), 0);
        }
    // …

Launch protection

It limits trading, for example a max buy or wallet size or a cooldown, to stop bots grabbing the supply before real traders.

The code that does this (afterSwap):

function _afterSwap(address, PoolKey calldata key, SwapParams calldata p, BalanceDelta delta, bytes calldata)
    internal override returns (bytes4, int128)
{
    (bool buy, Currency outCur) = _isBuy(key, p);
    PoolId id = key.toId();
    bool exactIn = p.amountSpecified < 0;
    // Platform fee, part 2: the unspecified side is the paired token (exact-in sell, or exact-out buy).
    uint256 pfee;
    Currency unspecified = exactIn == p.zeroForOne ? key.currency1 : key.currency0;
    if (Currency.unwrap(unspecified) != Currency.unwrap(projectTokenOf[id])) {
        int128 u = unspecified == key.currency0 ? delta.amount0() : delta.amount1();
        pfee = _abs(int256(u)) * PROTOCOL_FEE_BPS / BPS;
        if (pfee > 0) {
            poolManager.take(unspecified, protocolFeeTo, pfee);
            emit ProtocolFee(id, Currency.unwrap(unspecified), pfee);
        }
    }
    int128 outDelta = p.zeroForOne ? delta.amount1() : delta.amount0();
    if (outDelta <= 0) return (this.afterSwap.selector, int128(uint128(pfee)));
    uint256 out = uint256(uint128(outDelta));
    Config storage c = _cfg[id];

    uint256 burnAmt; uint256 rewardAmt; uint256 treasuryAmt; uint256 launchAmt;
    if (buy) {
        bool inWindow = _inWindow(id, c);
        if (inWindow && !outCur.isAddressZero()) {
            uint256 supply = IERC20Supply(Currency.unwrap(outCur)).totalSupply();
            uint256 maxOut = supply * c.snipeMaxBps / BPS;
            // The cap counts everything a wallet buys in one block, so splitting a buy does not get around it.
            uint256 inBlock = (_buyBlock[id][tx.origin] == block.number ? _boughtInBlock[id][tx.origin] : 0) + out;
    // …

Rules for adding or removing liquidity

It decides who can add or remove liquidity, or when.

The code that does this (beforeAddLiquidity):

function _beforeAddLiquidity(address sender, PoolKey calldata key, ModifyLiquidityParams calldata p, bytes calldata)
    internal override returns (bytes4)
{
    PoolId id = key.toId();
    Config storage c = _cfg[id];
    if (_allowlistActive(c) && !_allowed(id, sender)) revert NotAllowlisted(tx.origin);
    // An empty pool's price can be pushed anywhere for free. Until the creator has put liquidity in, nobody
    // can trade and nobody else can add liquidity, so the starting price is the one the creator set.
    if (!seeded[id]) {
        if (tx.origin != creatorOf[id]) revert NotSeeded();
        if (p.liquidityDelta > 0) seeded[id] = true;
    }
    // The lock follows the liquidity, not the wallet: what the creator adds must stay in that position until
    // the lock ends, whoever holds the position by then.
    if (c.lpLockUntil != 0 && block.timestamp < c.lpLockUntil && tx.origin == creatorOf[id] && p.liquidityDelta > 0) {
        lockedLiquidity[id][Position.calculatePositionKey(sender, p.tickLower, p.tickUpper, p.salt)] += uint256(p.liquidityDelta);
    }
    return this.beforeAddLiquidity.selector;
}

Who controls it: No admin functions: nobody can change its rules after deployment.

Based on the hook’s published code.

Safety report

Before you build on it. Automated checks, not an audit

6 to review3 passed1 info1 unknown

Contract

✓Code is fixedNo proxy, so the code that runs today is the code that runs tomorrow.

✓No admin key foundIt has no owner wallet, so the hook developer has no single key to change its rules (as far as the standard check goes).

✓Source code publishedThe code on the block explorer matches what's deployed (contract: UniHooksShared).

Pools4 to review

!Pools don’t trade in Uniswap’s app yetIt runs code on swaps, so Uniswap’s app only routes it once Uniswap Labs approves it, and it isn’t approved yet. Adding liquidity still works, and other apps can trade it.

!Can reject swapsIt runs on every trade and can block it. Used for things like launch limits and start times.

!Can change swap amountsIt has return-delta permissions, so it can take or add tokens in every trade (taxes, fees, burns, custom curves). Check where that value goes and who controls it.

!Can lock liquiditybeforeRemoveLiquidity can refuse withdrawals. Fine as an intended LP lock, a problem if LPs need to exit. Check the unlock conditions.

iControls who can add liquiditybeforeAddLiquidity checks every deposit, so outside LPs may be blocked.

Track record2 to review

!Not in Uniswap’s hook registryNot listed by Uniswap Labs, so nobody outside the hook developer has looked at it. Most abandoned and malicious hooks are unlisted.

!Brand newIts first pool was created less than a day ago, so it has no track record. Prefer proven hooks for a real launch.

?No audit linkedNothing in the registry. Ask the hook developer for one or review the source yourself.

What it can do

Runs code on every swap

Its code executes inside each trade in pools that use it.

Can take tokens from swaps

It can take or add tokens during a swap. Fees, burns and custom curves work this way, and so do scams.

Can block LP withdrawals

It runs before liquidity is removed, so it can delay or refuse LP exits.

Gates who can add liquidity

It checks every deposit before it goes in.

Runs at pool creation

It runs when a pool is created, often to lock in that pool’s settings.

Hook history

Settings changes: set up a pool (1 time).

Counted from what the hook recorded on-chain across all its pools, for every action in its published code, plus token transfers in and out of it.

Pools

1 total

PairCreatedTrades · 7dPool ID

ETH / UHT 3h - 0xdfbf…3539 Tx ↗