Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 93,240,528
0xb914…68CC
The eight checks
5 pools use this hook, the first one 38 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 1.55% of each swap on top of the pool fee.
- 03pass
LPs can get outLiquidity added and removed in the same block came back whole.
- 04caution
The fee is the feeIts pools use a dynamic fee that the hook sets before every swap. It stands at 0% now and can change.
- 05pass
No one holds the switchNo owner and no admin functions found.
- 06caution
The code cannot changeThe bytecode contains DELEGATECALL.
- 07pass
Only the PoolManager can call itEach callback refused a call that did not come from the PoolManager.
- 08pass
Track record5 pools over 37 days.
Measured at block 93,240,528. 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 & 0x3fff0x28cc · 10100011001100
- 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.
ETH / PFWA
fee dynamic, now 0%- Swap ETH → PFWAhook takes 1.05%
- Swap PFWA → ETHhook takes 0.81%
- Add, then remove liquiditycame back whole
pool 0xae34aabc8be9f38aa42d9f37e1e1f66724d01b4d53fc2375398b0442a6d8ef2a
ETH / NBM
fee dynamic, now 0%- Swap ETH → NBMhook takes 1.55%
- Swap NBM → ETHhook takes 0.30%
- Add, then remove liquiditycame back whole
pool 0x73b8db7337af99ee815376a59ae5dfe5ae830d3a650fdb5fe6f7aae47e157dfa
Read from the bytecode
- Code size
- 9,853 bytes
- Owner
- none found
- Proxy
- no
- DELEGATECALL
- present
- SELFDESTRUCT
- absent
- Outside calls
- 0
- 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.
- 0x0a009097 coordinator
- 0x236587a2 KERNEL_INSTANCE_LAYOUT_ID
- 0x3dbe6660 accountingKernelCodeHash
- 0x575e24b4 beforeSwap
- 0x6ec401d7 MAX_SQRT_PRICE_LIMIT
- 0x6fc2be50 stackRegistry
- 0x75d0c0dc
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 add liquidity. Can refuse a deposit, or only let some addresses provide liquidity.
- 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.
contractName
0x8549d9be REQUIRED_FLAGS0x8a24b7a6 KERNEL_FAMILY_ID0x8e14bd5a kernelInstanceLayoutId0xa0a8e460 contractVersion0xae9c67a5 accountingKernel0xb47b2fb1 afterSwap0xb4eebd6d MIN_SQRT_PRICE_LIMIT0xbf597bb0 MEV_CHECK_GAS_STIPEND0xdc4c90d3 poolManager0xe1a9111b STATEFUL_MODULE_MAGIC0xe606659d statefulModuleKernelMagic0xf26ef49d DYNAMIC_FEE_FLAG