GweiFunFeeHook on Ethereum

Uniswap v4 Hook Contract 0xd5d576d9f98ff76fb2360c766703a69488f1e088 on Ethereum · Launchpad · Verified contract

Volume (24h)
$358
Value locked (TVL)
$0
All-time volume
$358
Pools using this hook
1
Swaps (24h)
3 (2 traders)
Total swaps
3

What it does

A Gwei.fun launchpad fee hook that charges each swap 0% to 10% (protocol fee plus creator buy/sell levy, with early swaps paying an extra fading anti-sniper levy and exempt addresses paying nothing), splitting proceeds between creators and a buyback engine while leaving LP withdrawals untouched.

How it works step by step

  • Charges every swap on Gwei.fun launchpad pools a combined fee (protocol fee, creator buy/sell levy, and a fading anti-sniper opening levy), hard-capped at 10% per swap.
  • Takes the fee from the swap's specified amount: exact-input swaps have it deducted from what reaches the pool, and exact-output swaps pay it on top.
  • Splits the fee between the token creator's payee and a buyback engine, holding balances as claims on the PoolManager until claimed or swept.
  • Only allows pools to be initialized if fee terms were registered first, which prevents fee-free copycat pools on this hook.
  • Lets creators lower (never raise) their buy and sell levies and change their fee recipient.
Swap behaviour
On each swap by a non-exempt address, the hook charges protocol fee plus the direction-specific creator levy plus any decaying opening levy, capped at 10% of the specified amount. Buys and sells can carry different levies, and swaps early in the opening window pay more, with the extra levy falling linearly to zero.
Liquidity behaviour
No liquidity callbacks; LPs can add and withdraw freely as far as this hook is concerned. The launchpad itself locks its own launch liquidity permanently, but that happens outside this hook.
Fee behaviour
Pools use a 0% LP fee. The hook charges 0% to 10% per swap (protocol fee + buy or sell levy + an opening levy that fades to zero over a set window). The protocol portion is split between the creator and the buyback engine by a frozen ratio, and the creator payee also keeps the full creator levy.
Owner & admin controls
The owner can mark addresses as fee-exempt and choose who may register pool terms; registered terms are write-once and capped at 10% total. Creators can only lower levies and change their payee.

Enabled Uniswap v4 callbacks

beforeInitialize, beforeSwap, beforeSwapReturnDelta

beforeInitialize: blocks pools without registered fee terms; beforeSwap: calculates the current fee and books it to creator and buyback balances; beforeSwapReturnDelta: deducts the fee from the swap's specified amount.

Security & trust assessment

Risk level: low (verified source, high confidence).

Who controls it: The owner controls fee exemptions and term-writer access, and launchpad-approved factories can register new pools' terms within the 10% cap. No one can raise fees on an existing pool or touch pool reserves.

Risk to user funds: The hook only takes 0% to 10% of each swap's specified amount as a fee; accrued fees are claimable only by the creator payee or sent to the fixed buyback engine. LP principal cannot be locked or drained by this hook.

Security findings

  • [info] Hard 10% fee cap: Total swap charge is checked at registration and clamped on every swap to at most 10%, and terms cannot be raised after registration.
  • [low] Owner-controlled fee exemptions: The owner can exempt any address from fees, giving some traders zero-fee swaps; this does not affect other users' funds.
  • [info] LP withdrawals unaffected: Remove-liquidity callbacks and liquidity return deltas are disabled, so the hook cannot block or charge withdrawals.

Contract details

Verified source
Yes (GweiFunFeeHook)
Compiler
solc 0.8.26+commit.8a97fa7a
Bytecode size
12,454 bytes
Upgradeable proxy
No
Detected patterns
dynamic-fee, erc6909-claims, fee-sharing, launchpad, moves-currency, ownable, return-delta, self-unlock, tax

Pools using GweiFunFeeHook