FastLaunchHook on HyperEVM

Uniswap v4 Hook Contract 0xb9b880a609eb5a2685db4e7cd786cd442f50b0c0 on HyperEVM · Launchpad · Verified contract

Volume (24h)
$0
Value locked (TVL)
$1.09
All-time volume
$2.45
Pools using this hook
1
Swaps (24h)
0 (0 traders)
Total swaps
3

What it does

A launchpad hook that starts a new token pool with a high fee that decays to a normal fee over a short window and caps how much can be bought during that opening period.

This read was written for the hook 0x5802…30c0 on Arc and reused here: the two share a code shape, so constants such as fees, owners and addresses can differ.

How it works step by step

  • Validates in beforeInitialize that only the factory can initialize a registered pool at the expected price, then records the launch timestamp.
  • Sets the pool's base dynamic LP fee to the normal fee in afterInitialize.
  • Computes a per-swap fee in beforeSwap that decays linearly from the initial fee to the normal fee over the configured duration.
  • Exempts the factory's atomic creation swap and the token0-side swap direction from the decaying fee.
  • Tracks cumulative opening-window buys in afterSwap and reverts with OpeningBuyLimit when the per-pool cap is exceeded.
  • Enforces that the hook address encodes the required permission flags at construction.
Swap behaviour
During the opening window, non-exempt swaps pay a linearly decaying dynamic fee, and buys in the capped direction are tracked and reverted once the opening buy limit is exceeded. Swaps by the factory and in the token0-side direction pay the normal fee.
Liquidity behaviour
No liquidity callbacks.
Fee behaviour
Pools are created with the dynamic-fee flag. After initialization the LP fee is set to the normal fee. During the opening window, swaps in the non-exempt direction pay a fee that decays linearly from initialFee to normalFee over durationSeconds; the factory's atomic create swap and swaps in the token0-side direction pay the normal fee. The hook returns the override flag with the fee on every swap.
Owner & admin controls
The hook itself has no owner or admin functions; its manager and factory are set once in the constructor and immutable. Admin power sits in the separate FastLaunchRegistry (Ownable2Step owner) which can change quote configurations, opening-buy and fee parameters, creation fee and snapshot signer for future launches only. Existing pools keep the guard parameters written at registration.

Enabled Uniswap v4 callbacks

beforeInitialize, afterInitialize, beforeSwap, afterSwap

beforeInitialize and afterInitialize validate that the pool is created by the factory with the registered price and set the base dynamic fee; beforeSwap computes the decaying opening fee and applies the dynamic-fee override flag; afterSwap tracks cumulative buy volume during the opening window and reverts when it exceeds the configured opening buy cap.

Security & trust assessment

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

Who controls it: The registry owner cannot change existing guard parameters or move funds, but controls future launch parameters, quote acceptance rules, creation fee and treasury-related settings used by the factory.

Risk to user funds: The hook holds no tokens and performs no return-delta accounting (beforeSwap returns zero delta), so it cannot take or move pool funds. Its only user-facing effect is fee override and a buy cap that can revert swaps during the opening window.

Security findings

  • [info] Opening buy cap can block swaps: afterSwap reverts with OpeningBuyLimit when the cumulative opening-window buys exceed the cap, so buys in that window can be blocked once the cap is reached until the window ends.
  • [info] Pool parameters fixed at registration: Opening fee and buy limits are fixed per pool at registration (bounded by registry checks, e.g. duration at most 3600 seconds, fee at most 90%), limiting owner influence over already-live pools.
  • [low] Exemption depends on factory correctness: Opening-window exemption is granted to the factory address and to the token0-side swap direction based on PoolManager-authenticated sender, not on user-supplied data, which is consistent with the stated design but means the exempt path depends on the factory contract's correctness.

Contract details

Verified source
Yes (FastLaunchHook)
Compiler
solc 0.8.26+commit.8a97fa7a
Bytecode size
3,852 bytes
Upgradeable proxy
No
Detected patterns
dynamic-fee, launchpad

Pools using FastLaunchHook