ConstantProductCurveLib.sol

Overview

ConstantProductCurveLib implements the Geocurve bonding curve math. It uses a virtual constant-product formula — the same x × y = k as Uniswap, but with virtual reserves that anchor the starting price. This library handles all launch-mode settlement: computing the clearing price from the curve, determining fills, and calculating how many tokens to dispense or absorb.

Curve Formula

(Vt - S) × (Ve + E) = K = Vt × Ve

Variable	Meaning
Vt	Virtual token reserve (immutable, ≥ totalSupply)
Ve	Virtual ETH reserve (immutable)
S	Cumulative tokens distributed
E	Cumulative real ETH raised
K	Invariant constant

Core Functions

`computeLaunchSettlement()`

Main entry point for launch-mode batch settlement. Replaces ClearingPriceLib.computeClearingPrice() during the Active phase.

function computeLaunchSettlement(
    GeodeIntent[] memory buys,
    GeodeIntent[] memory sells,
    uint256 maxBatchSize,
    LaunchState memory ls,
    uint256 settlementFeeBps,
    uint256 deployerRoyaltyBps
) internal pure returns (
    SettlementResult memory result,
    bool[] memory buyFills,
    bool[] memory sellFills
)

Behavior:

Computes the current curve price as the clearing price
Determines which intents fill at that price
Deducts settlement fees from inputs
Computes internal match amounts
Calculates curveDispensed (net buy residual → tokens from hook) and curveAbsorbed (net sell residual → tokens back to hook)
Computes deployer royalty

`curvePrice()`

Returns the current marginal price on the curve:

function curvePrice(
    uint256 Vt, uint256 Ve,
    uint256 cumulativeDistributed, uint256 ethReserve
) internal pure returns (uint256 priceX18)

price = (Ve + E) / (Vt - S)

`ethCostToBuy()`

How much ETH to buy deltaTokens from the current state:

function ethCostToBuy(
    uint256 Vt, uint256 Ve,
    uint256 cumulativeDistributed, uint256 ethReserve,
    uint256 deltaTokens
) internal pure returns (uint256 ethIn)

ethIn = K / (Vt - S - Δs) - (Ve + E)

`tokensForEth()`

How many tokens for spending ethIn ETH:

function tokensForEth(
    uint256 Vt, uint256 Ve,
    uint256 cumulativeDistributed, uint256 ethReserve,
    uint256 ethIn
) internal pure returns (uint256 deltaTokens)

Δs = (Vt - S) - K / (Ve + E + ethIn)

`ethReturnOnSell()`

How much ETH returned for selling deltaTokens:

function ethReturnOnSell(
    uint256 Vt, uint256 Ve,
    uint256 cumulativeDistributed, uint256 ethReserve,
    uint256 deltaTokens
) internal pure returns (uint256 ethOut)

ethOut = (Ve + E) - K / (Vt - S + Δs)

Price Behavior

Action	S	E	Price
Buy	↑ increases	↑ increases	↑ rises
Sell	↓ decreases	↓ decreases	↓ falls
Nothing	unchanged	unchanged	unchanged

The curve is fully reversible — tokens can be bought and sold at any time during the Active phase.

Asymptotic pricing: When Vt = totalSupply, the price approaches infinity as 100% of tokens are distributed. When Vt > totalSupply, the curve has a finite maximum price at full distribution.

Source