PumperTaxHook

BSC

PumperTaxHook is a Uniswap v4 hook on BSC. Runs code on every swap. Can take tokens from swaps. Sets its own swap fee.

Contract name: PumperTaxHook

0x0e89abcdc093178ef91edbdd90427c8d027140cc 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

39m

Code size

2,391 B

How this hook works

Trading tax

A trading tax hook. It sets its own trading fee, takes a tax on trades and only takes simple trades.

Sets its own trading fee

Instead of a fixed fee chosen by the pool creator, it decides the fee itself on each trade.

The code that does this (beforeSwap):

function beforeSwap(address, PoolKey calldata key, SwapParams calldata params, bytes calldata)
    external
    returns (bytes4, BeforeSwapDelta, uint24)
{
    if (msg.sender != address(poolManager)) revert NotPoolManager();
    if (params.amountSpecified > 0) revert ExactOutputNotSupported();

    bool isBuy = _isBuy(key, params);
    if (!isBuy) {
        return (this.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, LPFeeLibrary.OVERRIDE_FEE_FLAG);
    }

    uint256 gross = uint256(-params.amountSpecified);
    (uint256 fee,) = PumperFeeMath.quoteFeeFromGross(gross, uint256(buyTaxBps + BASE_FEE_BPS) * 100);
    BeforeSwapDelta delta = toBeforeSwapDelta(int128(int256(fee)), 0);
    return (this.beforeSwap.selector, delta, LPFeeLibrary.OVERRIDE_FEE_FLAG);
}

Takes a tax on trades

On top of the normal pool fee, it keeps part of each trade as a tax. Buys and sells can be charged differently. The tax is paid out in the same trade.

The code that does this (beforeSwap):

function beforeSwap(address, PoolKey calldata key, SwapParams calldata params, bytes calldata)
    external
    returns (bytes4, BeforeSwapDelta, uint24)
{
    if (msg.sender != address(poolManager)) revert NotPoolManager();
    if (params.amountSpecified > 0) revert ExactOutputNotSupported();

    bool isBuy = _isBuy(key, params);
    if (!isBuy) {
        return (this.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, LPFeeLibrary.OVERRIDE_FEE_FLAG);
    }

    uint256 gross = uint256(-params.amountSpecified);
    (uint256 fee,) = PumperFeeMath.quoteFeeFromGross(gross, uint256(buyTaxBps + BASE_FEE_BPS) * 100);
    BeforeSwapDelta delta = toBeforeSwapDelta(int128(int256(fee)), 0);
    return (this.beforeSwap.selector, delta, LPFeeLibrary.OVERRIDE_FEE_FLAG);
}

Simple trades only

Trades must state the amount going in, not the amount coming out.

The code that does this (beforeSwap):

function beforeSwap(address, PoolKey calldata key, SwapParams calldata params, bytes calldata)
    external
    returns (bytes4, BeforeSwapDelta, uint24)
{
    if (msg.sender != address(poolManager)) revert NotPoolManager();
    if (params.amountSpecified > 0) revert ExactOutputNotSupported();

    bool isBuy = _isBuy(key, params);
    if (!isBuy) {
        return (this.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, LPFeeLibrary.OVERRIDE_FEE_FLAG);
    }

    uint256 gross = uint256(-params.amountSpecified);
    (uint256 fee,) = PumperFeeMath.quoteFeeFromGross(gross, uint256(buyTaxBps + BASE_FEE_BPS) * 100);
    BeforeSwapDelta delta = toBeforeSwapDelta(int128(int256(fee)), 0);
    return (this.beforeSwap.selector, delta, LPFeeLibrary.OVERRIDE_FEE_FLAG);
}

Who controls it: Nobody. The hook has no admin functions, and the code cannot be changed.

Based on the hook’s published code.

Safety report

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

5 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: PumperTaxHook).

Pools3 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.

iControls the swap fee1 of its pools use a dynamic fee the hook sets per trade, so LP income depends on its logic.

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.

Sets its own swap fee

Pools using it let the hook choose the swap fee instead of a fixed tier.

Hook history

Took its tax from a trade 4 times
Latest transactions
- 0xe435c0c9…1c930b block 132,790,487
- 0xe435c0c9…1c930b block 132,790,487
- 0x450aebd4…62c868 block 132,790,411
- 0x1eeaccc0…b867fc block 132,790,362
See every one on the explorer ↗

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

BSC / WBNB 39m 4 trades · 7d 0x9e0f…3c06 Tx ↗