Index / Sell guard

pattern · MIT · last updated 2026-08-27

Sell guard

Sell cooldown blocks rapid dumps; repeat sells in a window pay ramp fee.

First-party rewrite inspired by FairTrade (ETHNYC) and SafeSwap. Native-pair dynamic fee pool. beforeSwap enforces cooldownBlocks between sells and ramps fee after repeat sells in windowBlocks. Trader keyed via abi.encode(trader) in hookData. Complements buy-side AntiSnipe. Experimental. Listing is not an audit. Forge tests under test/SellGuard.t.sol.

Permission bits

These bits must match the deployed address. Confirm on-chain before you route.

afterInitializebeforeSwapafterSwap

Solidity

Excerpt from contracts/SellGuard.sol. Copy the full file to implement this. Not an audit.

function getHookPermissions() public pure override returns (Hooks.Permissions memory) {
    return Hooks.Permissions({
        beforeInitialize: false,
        afterInitialize: true,
        beforeAddLiquidity: false,
        afterAddLiquidity: false,
        beforeRemoveLiquidity: false,
        afterRemoveLiquidity: false,
        beforeSwap: true,
        afterSwap: true,
        beforeDonate: false,
        afterDonate: false,
        beforeSwapReturnDelta: false,
        afterSwapReturnDelta: false,
        afterAddLiquidityReturnDelta: false,
        afterRemoveLiquidityReturnDelta: false
    });
}

Spec

FAQ

Can I paste this into production? The snippet is an excerpt. Use the full file at the source URL, match flags to the address, and treat this page as a map, not a guarantee.

How do I build this safely? Start with secure v4 hooks and the OpenZeppelin hooks guide.