Reading the hook.
The address, the bytecode, then a swap each way through its pool. A few seconds.
v4 hook · Robinhood Chain · block 93,146,712
0x88A9…a8E4
The eight checks
6 pools use this hook, the first one 75 d ago.
- 01caution
Permissions that touch your moneyThe address enables after swap returns delta. The hook is allowed to take; the next two checks measure whether it does.
- 02fail
What it takes from a swapEvery swap through it was refused: InvalidTradeContext. Only an approved router may get through.
- 03n/a
LPs can get outClosed to outside LPs: only the hook's own liquidity is in the pool.
- 04pass
The fee is the feeA fixed fee of 0%, written in the pool key.
- 05pass
No one holds the switchNo owner and no admin functions found.
- 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 75 days.
Measured at block 93,146,712. 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 & 0x3fff0x28e4 · 10100011100100
- 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.
WETH / NMS
fee 0%- Swap WETH → NMSrefused: InvalidTradeContext
- Swap NMS → WETHrefused: InvalidTradeContext
- Add, then remove liquiditydeposit refused: LiquidityAuthorizationFailed
pool 0x1dc39f2490c6bb047f106333a58568bc4dc07ee0b55bb4aa2a77c35abe1dd042
WETH / NMS
fee 0%- Swap WETH → NMSrefused: InvalidTradeContext
- Swap NMS → WETHrefused: InvalidTradeContext
- Add, then remove liquiditydeposit refused: LiquidityAuthorizationFailed
pool 0xb5d5e998f69cf825968018e46718234024dd641986b7059fa5b3d909a424f59d
Read from the bytecode
- Code size
- 22,908 bytes
- Owner
- none found
- 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.
- 0x028541ed positionManagerCodeHash
- 0x13821bf7 OBSERVATION_PERIOD
- 0x15ab64af activateTrading
- 0x21d0ee70 beforeRemoveLiquidity
- 0x259982e5 beforeAddLiquidity
- 0x38b90333 CONTRACT_VERSION
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 donate. Runs before a donation to LPs.
- After swap returns delta. Can take part of what you get out of every swap.