CircuitBreakerHook

Uniswap V4 Hook | OKX Build-X Hackathon 2026 | X Layer Mainnet

Stock markets have circuit breakers. Meme pools don't. Until now.

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Deployed Contract

Network: X Layer Mainnet (Chain ID: 196)
Address: 0x3B6C42EC8628a18e226c1C5d619dAABF6382d0C0
PoolManager: 0x360E68faCcca8cA495c1B759Fd9EEe466db9FB32
Owner: 0x4e59b44847b379578588920cA78FbF26c0B4956C (CREATE2 factory — effectively ownerless. No admin key, no emergency pause. Code is law.)

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What It Does

CircuitBreakerHook implements a fully on-chain, oracle-free circuit breaker for Uniswap V4 meme token pools — mirroring NYSE's market halt mechanism.

State Machine

NORMAL → ALERT → HALTED → NORMAL (auto-reset)

Phase	Trigger	Same-Direction Fee	Counter-Direction Fee
NORMAL	—	0.05%	0.05%
ALERT	>8% price move in 5 min	3.00%	0.01%
HALTED	ALERT sustained 10 min	Reverted	0.01%

Parameters

Parameter	Value
Tick threshold	800 ticks (~8% price move)
Window duration	5 minutes
ALERT → HALTED escalation	10 minutes
HALT cooldown	3 minutes
Base fee	0.05% (500 bps)
ALERT same-direction fee	3.00% (30,000 bps)
Counter-direction incentive	0.01% (100 bps)

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Why It Works

Problem: Meme token pools on AMMs have no protection against pump-and-dump or flash crashes. Bots can drain LPs with impunity.

Solution:

1. When price crashes >8% in 5 minutes → raise same-direction fee to 3% (friction), drop counter-direction to 0.01% (incentivize recovery)
2. If extreme movement persists 10 minutes → hard halt for same-direction trades (3-minute pause)
3. Counter-direction (recovery) trading always allowed at near-zero fee

Key advantages over existing hooks:

• Zero external dependencies (no Chainlink, no ZK proof)
• Pool-level state aggregation — split orders can't bypass the trigger
• Fully verifiable on-chain — no black box
• Ownerless on mainnet — code is law

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Hook Flags

AFTER_INITIALIZE_FLAG | BEFORE_SWAP_FLAG | AFTER_SWAP_FLAG = 0x10C0

Address lower bits: 0x3B6C42EC8628a18e226c1C5d619dAABF6382d0C0

• bit 6 (AFTER_SWAP) ✅
• bit 7 (BEFORE_SWAP) ✅
• bit 12 (AFTER_INITIALIZE) ✅

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Usage

Pools using this hook must be initialized with DYNAMIC_FEE_FLAG:

PoolKey memory key = PoolKey({
    currency0: currency0,
    currency1: currency1,
    fee: LPFeeLibrary.DYNAMIC_FEE_FLAG, // 0x800000
    tickSpacing: 60,
    hooks: IHooks(0x3B6C42EC8628a18e226c1C5d619dAABF6382d0C0)
});

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Tests

forge test --match-contract CircuitBreakerHookTest -vv

15/15 tests pass, covering full state machine paths including split-order accumulation and auto-reset.

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Build

forge install
forge build

Requirements: Foundry, Solidity 0.8.26, EVM cancun

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Built With

• Uniswap V4 Core
• Foundry
• Deployed on X Layer by OKX

Built for the OKX Build-X Hackathon 2026 by Water Mirror (水镜) AI team.