Likely dynamic fee hook on BNB Chain

Uniswap v4 Hook Contract 0x9ab76d9aa00bc2d8d31460734febf3d283874080 on BNB Chain · Dynamic fee

Volume (24h)
$0
Value locked (TVL)
$0
All-time volume
$279
Pools using this hook
12
Swaps (24h)
0 (0 traders)
Total swaps
12

What it does

A Uniswap v4 hook that applies an owner-configurable dynamic fee to swaps in its pool, with the fee computed before each swap.

This read was written for the hook 0x739b…0080 on Robinhood Chain 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

  • Runs a fee calculation in beforeSwap for each swap
  • Computes fees via calculateFee(uint256) using packed uint24 parameters
  • Stores owner-configurable fee settings in storage slots 2 to 5
  • Tracks a base currency address used for pricing or fee logic
  • Exposes owner-only functions for ownership transfer and parameter updates
Swap behaviour
beforeSwap (0x575e24b4) runs on every swap and uses packed fee parameters and pool state to determine the fee applied.
Liquidity behaviour
No liquidity callbacks.
Fee behaviour
Fees are computed by calculateFee(uint256) (0x99a5d747) using parameters packed in storage slot 5 and fee-related slots 2 to 4, which are updated by 0xf0893cb4 (three uint256 values). The owner-settable uint24 parameters in slot 5 suggest a dynamic fee derived from pool state.
Owner & admin controls
Owner (slot 0) can transfer ownership (0xf2fde38b), set the base currency (0xb478f416), and update fee parameters through 0x69c9e8a6 (six uint24 values written to packed slot 5). Owner-gated status is inferred from the ownable heuristic and storage reads, not from source.

Enabled Uniswap v4 callbacks

beforeSwap

beforeSwap is the only enabled callback; it is used to compute a fee or adjustment for each swap.

Security & trust assessment

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

Who controls it: The owner can change fee parameters and the base currency, and can transfer ownership. A malicious or compromised owner could set fees to extreme values to extract value from swappers.

Risk to user funds: The hook runs in beforeSwap and can influence the fee charged on swaps, which affects swapper output. It does not appear to hold custody of pool funds based on the decoded permissions, but owner-set fees could divert value from traders.

Security findings

  • [medium] Owner-adjustable fee parameters: Owner can update six uint24 fee-related parameters via 0x69c9e8a6 and three uint256 values via 0xf0893cb4, with no timelock visible in the decoded functions.
  • [info] Limited hook scope: beforeSwap is the only enabled permission, so the hook can alter swap pricing but does not take tokens via return deltas based on the decoded permissions.
  • [info] Unverified source: Hook selectors and storage layout were inferred from bytecode alone; behaviour of the owner-only functions could not be confirmed without verified source.

Contract details

Verified source
No
Bytecode size
4,839 bytes
Upgradeable proxy
No
Detected patterns
ownable

Pools using Likely dynamic fee hook