Add BackGeoOracle hook on ethereum

[claude]

Summary

BackGeoOracle is a TWAP oracle hook with built-in backrun protection. It records on-chain price observations and automatically executes reverse swaps after large price-impact trades to restore the pool price toward the geometric mean, crediting the original swapper with ERC6909 tokens. Only exact-input swaps are supported, and liquidity positions must be full-range.

Flags

Flag	Value
beforeInitialize	true
afterInitialize	true
beforeAddLiquidity	true
afterAddLiquidity	false
beforeRemoveLiquidity	true
afterRemoveLiquidity	false
beforeSwap	true
afterSwap	true
beforeDonate	false
afterDonate	false
beforeSwapReturnsDelta	false
afterSwapReturnsDelta	true
afterAddLiquidityReturnsDelta	false
afterRemoveLiquidityReturnsDelta	false

Properties

Property	Value
dynamicFee	false
upgradeable	false
requiresCustomSwapData	false

Warnings

• The hook requires calling routers to implement IMsgSender.msgSender() when a backrun is triggered; routers that don't implement this interface will cause the transaction to revert. This is a router compatibility constraint, not a hookData requirement.
• Only exact-input swaps are supported; exact-output swaps will revert with NotExactIn.

Closes #373

[vercel]

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Project	Deployment	Actions	Updated (UTC)
hooklist	Ready	Preview, Comment	Mar 23, 2026 5:37pm

[github-actions]

Automated Review: APPROVE

Hook Review: BackGeoOracle (0xB13250f0Dc8ec6dE297E81CDA8142DB51860BaC4) on Ethereum

Address Bitmask Verification

Address last 14 bits: 0x3AC4 (11101011000100)

Bit	Flag	Address	JSON	Source
13	beforeInitialize	✅ true	true	true
12	afterInitialize	✅ true	true	true
11	beforeAddLiquidity	✅ true	true	true
10	afterAddLiquidity	✅ false	false	false
9	beforeRemoveLiquidity	✅ true	true	true
8	afterRemoveLiquidity	✅ false	false	false
7	beforeSwap	✅ true	true	true
6	afterSwap	✅ true	true	true
5	beforeDonate	✅ false	false	false
4	afterDonate	✅ false	false	false
3	beforeSwapReturnsDelta	✅ false	false	false
2	afterSwapReturnsDelta	✅ true	true	true
1	afterAddLiquidityReturnsDelta	✅ false	false	false
0	afterRemoveLiquidityReturnsDelta	✅ false	false	false

All 14 flags match the address bitmask and getHookPermissions() in source.

Properties Verification

• dynamicFee: false ✅ — _beforeSwap returns 0 for the fee override; no updateDynamicLPFee() calls anywhere.
• upgradeable: false ✅ — No proxy patterns, no delegatecall, no SELFDESTRUCT. Standard non-upgradeable contract.
• requiresCustomSwapData: false ✅ — Neither _beforeSwap nor _afterSwap reads from hookData; the bytes calldata parameter is unused in both.

Metadata Verification

• name: BackGeoOracle matches ContractName from Etherscan ✅
• chain / chainId: ethereum / 1 ✅
• verifiedSource: true — confirmed verified on Etherscan ✅
• deployer: Valid 0x address format ✅
• Proxy: Not a proxy contract ✅

Notes

The hook only supports exactIn swaps (reverts with NotExactIn if amountSpecified >= 0), and the _afterSwap backrun logic requires the calling router to implement IMsgSender.msgSender() (reverts with CallingRouterDoesNotReturnSender otherwise when a backrun is triggered). Neither condition relates to hookData, so requiresCustomSwapData: false is correct.

All flags, properties, and metadata are accurate. ✅

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A human reviewer must still approve this PR before merge.