Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 93,206,016
0x331C…00CC
The eight checks
5 pools use this hook, the first one 50 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 3.00% 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 feeA fixed fee, but a high one: 3%.
- 05caution
No one holds the switchOwned by 0x67C0DE0750Cb6CA2e6D0930DC5E76946b1618E4B. Owner-style functions: withdrawFees, setCrank, 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 record5 pools over 50 days.
Measured at block 93,206,016. 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 & 0x3fff0x00cc · 00000011001100
- 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.
SWRM / MSFT
fee 3%- Swap SWRM → MSFThook takes 2.99%
- Swap MSFT → SWRMhook takes 2.99%
- Add, then remove liquiditycame back whole
pool 0xfe836b883c0fa15f10ead8ff6f3b7da44023dd8cbf093484824de2f4e930d6c6
AMZN / SWRM
fee 3%- Swap AMZN → SWRMhook takes 3.00%
- Swap SWRM → AMZNhook takes 3.00%
- Add, then remove liquiditycame back whole
pool 0x5f4b1986f1e98ede86fc1793b9ef868020eea731a04eaf05c3e23659ebf64a34
Read from the bytecode
- Code size
- 7,596 bytes
- Owner
- 0x67C0DE0750Cb6CA2e6D0930DC5E76946b1618E4B
- Proxy
- no
- DELEGATECALL
- absent
- SELFDESTRUCT
- absent
- Outside calls
- 8
- 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.
- 0x019b76b6 unknown
- 0x106268b4 swrm
- 0x164e68de withdrawFees
- 0x1b9c1fad unknown
- 0x1ef00ae7 unknown
- 0x21d0ee70 beforeRemoveLiquidity
bit 4
After donate
bit 3Before swap returns deltabit 2After swap returns deltabit 1After add returns deltabit 0After remove returns delta- 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.
0x259982e5
beforeAddLiquidity
0x2c928098 getFeeBps0x34a064b1 NORMAL_FEE_BPS0x575e24b4 beforeSwap0x68557b75 crankAddress0x6c2bbe7e afterRemoveLiquidity0x6fe7e6eb afterInitialize0x715018a6 renounceOwnership0x790ca413 launchTime0x8da5cb5b owner0x91dd7346 unlockCallback0x981d7f89 unknown0x9a0a61b0 setCrank0x9f063efc afterAddLiquidity0xb2b82570 unknown0xb47b2fb1 afterSwap0xb6a8b0fa beforeDonate0xc4e833ce getHookPermissions0xc9cc0f48 unknown0xdc4c90d3 poolManager0xdc98354e beforeInitialize0xe1a45218 BPS_DENOMINATOR0xe1b4af69 afterDonate0xef96a8be SNIPER_FEE_BPS0xf2fde38b transferOwnership0xf7c7724f executeArbitrage