Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 92,973,361
0x2Ab6…e0cC
The eight checks
17 pools use this hook, the first one 98 d ago.
- 01caution
Permissions that touch your moneyThe address enables before swap returns delta, after swap returns delta. The hook is allowed to take; the next two checks measure whether it does.
- 02caution
What it takes from a swapIt takes 2% of each swap on top of the pool fee.
- 03pass
LPs can get outLiquidity added and removed in the same block came back whole.
- 04pass
The fee is the feeA fixed fee of 0%, written in the pool key.
- 05caution
No one holds the switchOwned by 0xd51778f6238560d8442a3D868C7a2bDED13626F9. Owner-style functions: claimPartnerFees, setCreator, claimProtocolFees, setHarvestParams, claimCreatorFees, transferOwnership.
- 06pass
The code cannot changeNot a proxy, no DELEGATECALL, no SELFDESTRUCT.
- 07pass
Only the PoolManager can call itEach callback refused a call that did not come from the PoolManager.
- 08pass
Track record17 pools over 97 days.
Measured at block 92,973,361. A hook with an owner or a dynamic fee can behave differently later; scan again before a large trade.
What the address allows
A v4 hook's permissions are the last fourteen bits of its address. The PoolManager calls only what they switch on.
address & 0x3fff0x20cc · 10000011001100
- bit 13Before initialize
- bit 12After initialize
- bit 11Before add liquidity
- bit 10After add liquidity
- bit 9Before remove liquidity
- bit 8After remove liquidity
- bit 7Before swap
- bit 6After swap
- bit 5Before donate
What it did to a real swap
A small swap each way and a liquidity round trip, run through the PoolManager and this hook inside a call that is never sent. The pool fee is expected; anything else missing is the hook.
HOWIE / WETH
fee 0%- Swap HOWIE → WETHhook takes 2%
- Swap WETH → HOWIEhook takes 2.00%
- Add, then remove liquiditycame back whole
pool 0x02089beb376e47181bae9a0feae4d56faf646cf95cbbae13fe65b8ad4860ec9a
ROBIN / WETH
fee 0%- Swap ROBIN → WETHno liquidity below the price
- Swap WETH → ROBINhook takes 1.00%
- Add, then remove liquiditycame back whole
pool 0x1d242520a21ff8ce92df275544f93617846dfc141fb7506b66969091b62e440c
Read from the bytecode
- Code size
- 18,919 bytes
- Owner
- 0xd51778f6238560d8442a3D868C7a2bDED13626F9
- Proxy
- no
- DELEGATECALL
- absent
- SELFDESTRUCT
- absent
- Outside calls
- 30
- Callbacks open to anyone
- none
Its functions, uncensored
Selectors found in the dispatcher, named from the public signature database. Red ones are what an owner usually keeps for itself.
- 0x01099984 harvest
- 0x16eebd1e launcher
- 0x1d8ef3ef currentFeeBps
- 0x3b14a781 claimPartnerFees
- 0x575e24b4 beforeSwap
- 0x578fd68b harvestSlippageBps
bit 4
After donate
bit 3Before swap returns deltabit 2After swap returns deltabit 1After add returns deltabit 0After remove returns delta- Before initialize. Runs once, when a pool is created.
- Before swap. Runs before every swap. On a dynamic-fee pool it can set the fee each time.
- After swap. Runs after every swap.
- Before swap returns delta. Can take part of what you put into a swap, or change how much is swapped.
- After swap returns delta. Can take part of what you get out of every swap.
0x715018a6
renounceOwnership
0x76e3b12e flywheel0x79ba5097 acceptOwnership0x7b103999 registry0x8080da69 flywheelRegistered0x85ec9bd9 setCreator0x891ebbac minHarvestWeth0x8cebd942 poolInfo0x8da5cb5b owner0x91dd7346 unlockCallback0xa1306fe0 registerFlywheel0xb47b2fb1 afterSwap0xb738d2cc claimProtocolFees0xccdd1429 flywheelPendingWeth0xcfd6d5e9 keeperRewardBps0xd63b8a78 setHarvestParams0xdc4c90d3 poolManager0xdc98354e beforeInitialize0xe30c3978 pendingOwner0xeca9ad5d feeBalances0xedd6d1f6 claimCreatorFees0xef635c0e register0xf2fde38b transferOwnership0xf4c094c8 setLauncher0xff94e4f3 creatorOf