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Overview

CurveLib is an internal Solidity library used by BondingCurve. It implements the constant-product AMM math with virtual reserves (pump.fun style). All functions are pure — no state reads or writes.

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Deployment Addresses

Library functions are inlined at compile time — CurveLib has no separate deployment address.

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Invariant

(virtualEth + ethRaised) * (virtualTokens - tokensSold) = k
Where k = virtualEth * virtualTokens (set at initialization). Spot price at any point: ethReserve / tokenReserve Initial price: virtualEth / virtualTokens

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Functions

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getTokensForEth

function getTokensForEth(
    uint256 ethReserve,
    uint256 tokenReserve,
    uint256 ethIn
) internal pure returns (uint256 tokensOut)
Calculates tokens received for a given ETH input. 
tokensOut = tokenReserve * ethIn / (ethReserve + ethIn)

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getCostForTokens

function getCostForTokens(
    uint256 ethReserve,
    uint256 tokenReserve,
    uint256 tokenAmount
) internal pure returns (uint256 cost)
Calculates ETH cost to purchase a specific number of tokens. Reverts if tokenAmount >= tokenReserve. 
cost = ethReserve * tokenAmount / (tokenReserve - tokenAmount)

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getRefundForTokens

function getRefundForTokens(
    uint256 ethReserve,
    uint256 tokenReserve,
    uint256 tokenAmount
) internal pure returns (uint256 ethOut)
Calculates ETH received for selling tokens back. 
ethOut = ethReserve * tokenAmount / (tokenReserve + tokenAmount)

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getCurrentPrice

function getCurrentPrice(
    uint256 ethReserve,
    uint256 tokenReserve
) internal pure returns (uint256 price)
Returns the current spot price in wei, scaled to 1e18. 
price = ethReserve * 1e18 / tokenReserve

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Precision

All division uses OpenZeppelin’s Math.mulDiv for full-precision (a * b) / c without intermediate overflow.