Bonding Curves Explained

// At launch
creatorBalance = 0;
teamBalance = 0;
insiderBalance = 0;

// Everyone buys from the curve

x × y = k

// Example bonding state
{
  realTokenReserves: 0,              // All 850M sold
  realNativeReserves: 500 ETH,       // Accumulated liquidity
  reservedTokens: 150M,              // Ready for DEX
  status: "bonded",
  readyForGraduation: true
}

// Token economics
uint256 public constant TOTAL_SUPPLY = 1_000_000_000 * 10**18;
uint256 public constant REAL_TOKEN_RESERVES = 850_000_000 * 10**18;
uint256 public constant VIRTUAL_TOKEN_RESERVES = 1_073_000_000 * 10**18;

// Fee structure
uint256 private constant PROTOCOL_FEE_BPS = 100;  // 1%
uint256 private constant CREATOR_SHARE_BPS = 3000;  // 30% of fee
uint256 private constant BASIS_POINTS = 10000;

function buy(uint256 nativeIn) returns (uint256 tokensOut) {
    // 1. Calculate fee
    uint256 fee = nativeIn * PROTOCOL_FEE_BPS / BASIS_POINTS;
    uint256 creatorFee = fee * CREATOR_SHARE_BPS / BASIS_POINTS;
    uint256 platformFee = fee - creatorFee;

    // 2. Net amount for trading
    uint256 netAmount = nativeIn - fee;

    // 3. Calculate tokens out (constant product)
    uint256 calculatedTokens = (netAmount * virtualTokenReserves) /
                                (virtualNativeReserves + netAmount);

    // 4. Take minimum (handles last buyer edge case)
    tokensOut = calculatedTokens < realTokenReserves
                ? calculatedTokens
                : realTokenReserves;

    // 5. Update reserves
    virtualNativeReserves += netAmount;
    realNativeReserves += netAmount;
    virtualTokenReserves -= tokensOut;
    realTokenReserves -= tokensOut;

    // 6. Accumulate creator fee
    accumulatedCreatorFees += creatorFee;

    // 7. Send platform fee to factory
    factory.transfer(platformFee);
}

function sell(uint256 tokensIn) returns (uint256 nativeOut) {
    // 1. Calculate gross native out (constant product)
    uint256 grossNative = (tokensIn * virtualNativeReserves) /
                          (virtualTokenReserves + tokensIn);

    // 2. Check reserves
    require(grossNative <= realNativeReserves, "Insufficient reserves");

    // 3. Calculate fee
    uint256 fee = grossNative * PROTOCOL_FEE_BPS / BASIS_POINTS;
    uint256 creatorFee = fee * CREATOR_SHARE_BPS / BASIS_POINTS;
    uint256 platformFee = fee - creatorFee;

    // 4. Net to user
    nativeOut = grossNative - fee;

    // 5. Update reserves (use GROSS for reserves)
    virtualTokenReserves += tokensIn;
    realTokenReserves += tokensIn;
    virtualNativeReserves -= grossNative;
    realNativeReserves -= grossNative;

    // 6. Accumulate creator fee
    accumulatedCreatorFees += creatorFee;

    // 7. Send platform fee to factory
    factory.transfer(platformFee);
}

// Buy with slippage protection
require(tokensOut >= minTokensOut, "Slippage exceeded");

// Sell with slippage protection
require(nativeOut >= minNativeOut, "Slippage exceeded");