Dynamic fee hook on Polygon

Uniswap v4 Hook Contract 0x86ff650df79afc2af0a229aef4b0d74f05e0e0cc on Polygon · Dynamic fee

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

What it does

A per-pool configurable dynamic-fee hook that charges swappers a fee bounded by built-in min/max limits and splits it among protocol, royalties and a vault, while leaving LP deposits and withdrawals untouched.

This read was written for the hook 0x2dbe…20cc 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 per-pool fee system where each pool has its own admin, configuration and optional plug-in modules that can shape the swap fee.
  • Checks pool setup at creation time and registers the pool with its settings (fee bounds, update interval, staleness limits).
  • Computes a fee on each swap within contract-defined minimum and maximum fee constants, with a fixed protocol share and capped total royalties.
  • Can take a portion of swap amounts through swap return deltas, apparently routed to a vault, protocol and royalty recipients.
  • Does not run on liquidity adds or removals, so LPs can deposit and withdraw freely.
Swap behaviour
Before and after each swap the hook looks up the pool's configuration and modules, computes a fee, and can adjust swap amounts to collect it. Exact fee values and caps (MIN_FEE, MAX_FEE, MAX_TOTAL_ROYALTY_BPS) exist as constants but cannot be read from the bytecode summary.
Liquidity behaviour
No liquidity callbacks are enabled; LPs can add and withdraw freely and the hook cannot block or charge withdrawals.
Fee behaviour
Swap fees are set per pool between hard-coded minimum and maximum constants and may be collected via return deltas, with a fixed protocol share and capped royalties sent to recipients/vault. Exact percentages are unknown from bytecode.
Owner & admin controls
Each pool has an admin (transferable or resignable) who can change fee settings, module configuration, royalty splits and price/tick parameters, apparently within contract constants like MAX_FEE and MAX_TOTAL_ROYALTY_BPS whose values are not visible.

Enabled Uniswap v4 callbacks

beforeInitialize, beforeSwap, afterSwap, beforeSwapReturnDelta, afterSwapReturnDelta

beforeInitialize: registers and validates new pools; beforeSwap: computes the fee and may take part of the input; afterSwap: updates state and may take part of the output; beforeSwapReturnDelta/afterSwapReturnDelta: lets the hook deduct fees from swap amounts.

Security & trust assessment

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

Who controls it: Per-pool admins can adjust fees, royalties and modules within contract-defined bounds whose values are unknown; admin can be transferred or resigned.

Risk to user funds: The hook can take a fee from swap input or output up to an unverified MAX_FEE plus royalties; LP principal stays in the PoolManager and withdrawals are unrestricted.

Security findings

  • [medium] Unverified hook with active swap deltas: The hook can deduct from swap amounts and per-pool admins can tune fees and royalties; exact caps cannot be confirmed without source.
  • [low] External fee modules: Admin-configured modules are called with a gas limit during swaps and may influence fees or cause swaps to fail.
  • [info] LP withdrawals unrestricted: Remove-liquidity callbacks are disabled, so LP principal cannot be locked by the hook.

Contract details

Verified source
No
Bytecode size
23,722 bytes
Upgradeable proxy
No
Detected patterns
return-delta

Pools using Dynamic fee hook