Reference

Contract reference

Two contracts: KolanHook, the Uniswap v4 hook that holds the liquidity and the windows, and KolanToken, the token it deploys. Neither has an owner or an upgrade path.

Addresses#

On Ethereum. Each address opens on etherscan.io.

Contract	Address
`KolanHook`	0x0136feCf49E0217BFd2D9551E8e7b05f174Ba8eC
`KolanToken`	0x2CADc4F2660Bb77a118b0e74fC9E48E935b3a1bF

Parameters#

Fixed in the hook's constructor, for good.

Name	Shipped value	Meaning
`TAX_BPS`	100	The tax on the ETH side of every swap and window, in basis points. Ceiling 500
`REFERENCE_PREMIUM`	0.05 ETH	The premium that buys BASE_WINDOW
`BASE_WINDOW`	6 hours
`MIN_WINDOW`	30 minutes	The shortest window; a premium too small for it is refused
`MAX_WINDOW`	7 days	The longest; premium past it is refunded
`MAX_PREMIUM_BPS`	3000	The most a premium may be, of the ETH a purchase spends
`DEV`		Receives the tax, in ETH
`TOKEN`		The token, its whole supply minted to the hook

Buying and closing#

buy(address recipient, uint256 premium, uint256 minTokens, uint256 deadline) payable returns (uint256 id, uint256 tokens)

Opens a window for recipient. The value pays the ETH to spend, 1% tax on it, the premium, and a 1,000 wei rounding allowance; whatever is not used is refunded. Reverts with TooFewTokens under minTokens.

cancel(uint256 id)the owner, before expiry

Undoes the window: every wei of its ETH back to the owner, the tokens back into the pool, the premium spent buying tokens back to burn.

accept(uint256 id)the owner at any time, anyone after expiry

Keeps the window: the tokens to the owner, the ETH into the pool, the premium spent buying tokens back to burn.

claimDev() returns (uint256 amount)anyone

Pays the tax owed to DEV, in ETH.

launch(int24 tick) payablethe launcher, once

Opens the pool at tick and puts the whole supply in it. Nobody else can open a pool on this hook.

Views#

quote(uint256 eth) view returns (uint256 tokens, uint256 cost)

What a window spending eth would take out of the pool now, and what it would cost.

windowFor(uint256 premium) view returns (uint256)

Seconds a premium buys, before the floor and the ceiling.

windows(uint256 id) view returns (address owner, uint40 expiry, uint8 cuts, uint96 eth, uint96 tokens, uint64 premium)

A window still held. A closed window reads as zero.

cutsOf(uint256 id) view returns (Cut[])

Where a window's tokens came from: the ranges it took out of the pool.

held() view returns (uint128 eth, uint128 tokens)

ETH (with premiums) and tokens held for every open window.

segments(int24 lower) view / hint() view

The hook's positions, as a chain in tick order, and where it last changed.

poolKey() view / poolId() view / devOwed() view / windowCount() view

The pool, and the counters.

Events#

event Launched(PoolId indexed id, int24 tick, uint128 liquidity, uint256 tokens);
event Taxed(address indexed payer, uint256 fee);
event DevPaid(address indexed dev, uint256 amount);
event WindowOpened(uint256 indexed id, address indexed owner, uint256 eth, uint256 tokens,
                   uint256 premium, uint256 expiry, int24 lower, int24 upper);
event WindowClosed(uint256 indexed id, address indexed owner, bool kept, bool backInPlace, uint256 burned);

Errors a buyer can meet#

Error	Meaning
`TooFewTokens`	The price moved past your tolerance
`TooLate`	The transaction waited past its deadline
`PremiumTooLow`	The premium buys less than MIN_WINDOW
`PremiumTooHigh`	The premium is more than MAX_PREMIUM_BPS of what the purchase spends
`NothingToBuy`	The amount is too small to take anything out of the pool
`WindowExpired`	Undo after the expiry: the window can only be kept now
`WindowStillOpen`	Someone other than the owner tried to keep a window still running
`NotOwner`	Someone other than the owner tried to undo

KolanToken#

A plain ERC-20 with a fixed supply, minted once to the hook in its constructor. Nothing can mint more; anyone can burn their own, which is how premiums burn what they buy back.