Token hook on Ethereum

Uniswap v4 Hook Contract 0x9d73426042d4e3b3a1c66e7b8132fa3d1b6640cc on Ethereum · Token

Volume (24h)
$112
Value locked (TVL)
$0
All-time volume
$112
Pools using this hook
1
Swaps (24h)
1 (1 traders)
Total swaps
1

What it does

This hook applies fixed buy and sell taxes (exact rates unverified) to swaps while the token's toll switch is active, burning or forwarding part of the tax, while LPs can add and withdraw liquidity freely.

How it works step by step

  • Charges a 'toll' tax on swaps in its pool, with separate rates for buys and sells set as fixed constants in the contract.
  • Takes part of the swap amount out of the pool and moves it out through the Uniswap v4 PoolManager.
  • Appears to burn or send away a portion of the collected tax, based on a fixed burn rate constant.
  • Checks an external 'tollActive' flag on the associated token, which can switch the tax on or off.
  • Does nothing on liquidity actions, so LPs can add and withdraw freely.
Swap behaviour
On each swap the hook can take a tax from the swap amounts, either before the swap or from the output after it. Buys and sells use separate fixed rates, and the tax only applies while the token's toll switch is active.
Liquidity behaviour
No liquidity callbacks; LPs can add and withdraw freely.
Fee behaviour
Charges fixed buy and sell tax rates plus a burn share, all stored as constants. Their exact percentages cannot be read from the decoded bytecode. The collected tokens are pulled out of the pool, with part apparently burned or sent to a fixed destination.
Owner & admin controls
No owner functions and no storage were found in the hook. However, the tax can be switched on or off through the 'tollActive' flag on the external token contract, which may be controlled by that token's owner.

Enabled Uniswap v4 callbacks

beforeSwap, afterSwap, beforeSwapReturnDelta, afterSwapReturnDelta

beforeSwap: checks the toll switch and can take the tax from the swap input; afterSwap: can take the tax from the swap output; beforeSwapReturnDelta and afterSwapReturnDelta: let the hook change swap amounts to collect the tax.

Security & trust assessment

Risk level: medium, estimated (decoded bytecode, medium confidence).

Who controls it: The hook itself has no admin, and its tax rates are constants. The external token contract may let its controller toggle the tax on or off.

Risk to user funds: The hook can take a fixed-rate share of each swap's input or output; the exact percentage is unknown without verified source. LP principal cannot be locked or drained by this hook.

Security findings

  • [medium] Unverified swap tax with unknown rates: The hook deducts buy and sell taxes through swap return deltas. The rates are fixed constants, but their values cannot be confirmed from bytecode alone.
  • [low] Tax toggle controlled externally: Whether the tax applies depends on a 'tollActive' flag read from the token contract. Whoever controls that flag can turn the tax on or off.
  • [info] LP withdrawals unrestricted: The remove-liquidity callbacks are disabled in the hook's address, so the hook can never block or charge LP withdrawals.

Contract details

Verified source
No
Bytecode size
3,150 bytes
Upgradeable proxy
No
Detected patterns
erc20, moves-currency, return-delta, tax

Pools using Token hook