Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 93,271,768
0x0A0e…A0cc
The eight checks
4 pools use this hook, the first one 46 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 0x00Fc981E76fc00A6455bd5710c8CF34166d8A466. Owner-style functions: setFeeSweepOperator, setFactory, rescuePoolFees, setProtocolFeeRecipient, transferOwnership, sweepPoolFees.
- 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 record4 pools over 45 days.
Measured at block 93,271,768. 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.
TRASH / sBTC3x
fee 0%- Swap TRASH → sBTC3xno liquidity below the price
- Swap sBTC3x → TRASHhook takes 1.00%
- Add, then remove liquiditycame back whole
pool 0x8e8306e46e52647676a495eb5a2c5c0646ced572178fdf74556ff80f02c6b17c
sBTC3x / TRASH
fee 0%- Swap sBTC3x → TRASHhook takes 2.00%
- Swap TRASH → sBTC3xhook takes 2%
- Add, then remove liquiditycame back whole
pool 0x3bf515bb05db1f29590ada2623f822b1fc941ffb580b634a44c39a584256b205
Read from the bytecode
- Code size
- 8,382 bytes
- Owner
- 0x00Fc981E76fc00A6455bd5710c8CF34166d8A466
- Proxy
- no
- DELEGATECALL
- absent
- SELFDESTRUCT
- absent
- Outside calls
- 9
- 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.
- 0x21d0ee70 beforeRemoveLiquidity
- 0x259982e5 beforeAddLiquidity
- 0x30040054 poolIdOf
- 0x436e888b holderRewardVault
- 0x54faf9c3 setFeeSweepOperator
- 0x569f2911 unknown
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.