Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 93,172,226
0x6487…70cC
The eight checks
6 pools use this hook, the first one 29 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.
- 02fail
What it takes from a swapOne direction works and the other is refused (PartialFillDisabled). You may be able to buy and not sell.
- 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 switchNo owner() but it has setupAdmin.
- 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 record6 pools over 28 days.
Measured at block 93,172,226. 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 & 0x3fff0x30cc · 11000011001100
- 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 / CHAINU
fee 0%- Swap ETH → CHAINUhook takes 2.00%
- Swap CHAINU → ETHrefused: PartialFillDisabled
- Add, then remove liquiditycame back whole
pool 0x9933428644fc37c9e4dc4f6da2fb081aa38fdebea6c604ee14ae8b4dcf3e4b56
Read from the bytecode
- Code size
- 9,400 bytes
- Owner
- none found
- Proxy
- no
- DELEGATECALL
- absent
- SELFDESTRUCT
- absent
- Outside calls
- 4
- 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.
- 0x16850c12 unknown
- 0x21505f88 getOracleState
- 0x21d0ee70 beforeRemoveLiquidity
- 0x23f6a41c getObservation
- 0x259982e5 beforeAddLiquidity
- 0x2ed9666f observationCount
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.
- After initialize. Runs once, right after 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.