Volatility oracle

Require a dynamic fee on initialize, then ramp LP fee by elapsed time after deploy.

Uniswap’s VolatilityOracle example is a teaching dynamic-fee hook, not a live volatility feed. beforeInitialize requires key.fee.isDynamicFee(). afterInitialize calls setFee, which starts at 3000 and adds 100 bps per elapsed minute via poolManager.updateDynamicLPFee. UNLICENSED example-contracts file. Use it to learn the initialize-plus-poke pattern; do not treat the contract name as an oracle. Copy the full file from the permalink. Listing is not an audit.

Permission bits

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

Initialize

Liquidity

baba

Swap

Donate

Return delta

baaa

beforeInitializeafterInitialize

Solidity

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

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

function beforeInitialize(address, PoolKey calldata key, uint160, bytes calldata)
    external
    pure
    override
    returns (bytes4)
{
    if (!key.fee.isDynamicFee()) revert MustUseDynamicFee();
    return VolatilityOracle.beforeInitialize.selector;
}

function setFee(PoolKey calldata key) public {
    uint24 startingFee = 3000;
    uint32 lapsed = _blockTimestamp() - deployTimestamp;
    uint24 fee = startingFee + (uint24(lapsed) * 100) / 60; // 100 bps a minute
    manager.updateDynamicLPFee(key, fee); // initial fee 0.30%
}

Spec

Kind	pattern
Status	experimental
License	UNLICENSED
Source	https://github.com/Uniswap/v4-periphery
Categories	Dynamic fees
Properties	Dynamic fee Vanilla swap
Chains	Ethereum
Docs	https://docs.uniswap.org/contracts/v4/concepts/hooks

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.