Smart Contract

This is the crowdfunding Ethereum smart contract. It takes care of all the transactions generated by the crowdfunding. This smart contract is blocking the Ethers received until our 110 000€ crowdfunding goal is achieved. If the goal is not reached by December the 1st, all the funds will be returned to the backers.

Development Bounty:


Monitoring contract page

Address : 0x20d42F2e99A421147AcF198D775395cAc2E8b03d

100 000 Nxc if you find a bug or a breach in this contract. Spelling and typos in code comments do not count as bugs. The bug(s) found must be a threat to the security and/or the proper execution of the contract. Note that we should be able to reproduce the bug for it to be acknowledged.

//pragma solidity ^0.3.6;
contract Token {
	function balanceOf(address user) constant returns (uint256 balance);
	function transfer(address receiver, uint amount) returns(bool);

// A Sub crowdfunding contract. Its only purpose is to redirect ether it receives to the 
// main crowdfunding contract. This mecanism is usefull to know the sponsor to
// reward for an indirect donation. You can't give for someone else when you give through
// these contracts
contract AltCrowdfunding {
	Crowdfunding mainCf ;                                       // Referenre to the main crowdfunding contract
	function AltCrowdfunding(address cf){						// Construct the altContract with a reference to the main one
		mainCf = Crowdfunding(cf);
		mainCf.giveFor.value(msg.value)(msg.sender);			// Relay Ether sent to the main crowndfunding contract

contract Crowdfunding {

	struct Backer {
		uint weiGiven;										// Amount of Ether given
		uint ungivenNxc ;                                 	// (pending) If the first goal of the crowdfunding is not reached yet the NxC are stored here
	struct Sponsor {
	    uint nxcDirected;                                   // How much milli Nxc this sponsor sold for us
	    uint earnedNexium;                                  // How much milli Nxc this sponsor earned by solding Nexiums for us
	    address sponsorAddress;                             // Where Nexiums earned by a sponsor are sent
	    uint sponsorBonus;
	    uint backerBonus;
    //Every public variable can be read by everyone from the blockchain
	Token 	public nexium;                                  // Nexium contract reference
	address public owner;					               	// Contract admin (beyond the void)
	address public beyond;					            	// Address that will receive ether when the first step is be reached
	address public bitCrystalEscrow;   						// Our escrow for Bitcrystals (ie EverdreamSoft)
	uint 	public startingEtherValue;						// How much milli Nxc are sent by ether
	uint 	public stepEtherValue;					        // For every stage of the crowdfunding, the number of Nexium sent by ether is decreased by this number
	uint    public collectedEth;                            // Collected ether in wei
	uint 	public nxcSold;                                 // How much milli Nxc were sold 
	uint 	public perStageNxc;                             // How much milli Nxc we much sell for each stage
	uint 	public nxcPerBcy;                         		// How much milli Nxc we give for each Bitcrystal
    uint 	public collectedBcy;                            // Collected Bitcrystals
	uint 	public minInvest;				            	// Minimum to invest (in wei)
	uint 	public startDate;    							// crowndfunding startdate                               
	uint 	public endDate;									// crowndfunding enddate 
	bool 	public isLimitReached;                          // Tell if the first stage of the CrowdFunding is reached, false when not set
	address[] public backerList;							// Addresses of all backers
	address[] public altList;					     		// List of alternative contracts for sponsoring (useless for this contract)
	mapping(address => Sponsor) public sponsorList;	        // The sponsor linked to an alternative contract
	mapping(address => Backer) public backers;            	// The Backer for a given address

	modifier onlyBy(address a){
		if (msg.sender != a) throw;                         // Auth modifier, if the msg.sender isn't the expected address, throw.
	event Gave(address);									// 
	function Crowdfunding() {
		// Constructor of the contract. set the different variables
		nexium = Token(0x45e42d659d9f9466cd5df622506033145a9b89bc); 	// Nexium contract address
		beyond = 0x89E7a245d5267ECd5Bf4cA4C1d9D4D5A14bbd130 ;
		owner = msg.sender;
		minInvest = 10 finney;
		startingEtherValue = 700*1000;
		stepEtherValue = 25*1000;
		nxcPerBcy = 14;
		perStageNxc = 5000000 * 1000;
		startDate = 1478012400 ;
		endDate = 1480604400 ;
		bitCrystalEscrow = 0xef49D7Bf6cD9A01fA487f94d4e79A6be31F89a34;

	// Use this function to buy Nexiums for someone (can be you of course)
	function giveFor(address beneficiary){
		if (msg.value < minInvest) throw;                                      // Throw when the minimum to invest isn't reached
		if (endDate < now || (now < startDate && now > startDate - 3 hours )) throw;        // Check if the crowdfunding is started and not already over
		// Computing the current amount of Nxc we send per ether. 
		uint currentEtherValue = getCurrEthValue();
		//it's possible to invest before the begining of the crowdfunding but the price is x10.
		//Allow backers to test the contract before the begining.
		if(now < startDate) currentEtherValue /= 10; // Computing the number of milli Nxc we will send to the beneficiary uint givenNxc = (msg.value * currentEtherValue)/(1 ether); nxcSold += givenNxc; //Updating the sold Nxc amount if (nxcSold >= perStageNxc) isLimitReached = true ; 
		Sponsor sp = sponsorList[msg.sender];
		//Check if the user gives through a sponsor contract
		if (sp.sponsorAddress != 0x0000000000000000000000000000000000000000) {
		    sp.nxcDirected += givenNxc;                                        // Update the number of milli Nxc this sponsor sold for us
		    // This part compute the bonus rate NxC the sponsor will have depending on the total of Nxc he sold.
		    uint bonusRate = sp.nxcDirected / 80000000;
		    if (bonusRate > sp.sponsorBonus) bonusRate = sp.sponsorBonus;
		    // Giving to the sponsor the amount of Nxc he earned by this last donation
		    uint sponsorNxc = (sp.nxcDirected * bonusRate)/100 - sp.earnedNexium;
			if (!giveNxc(sp.sponsorAddress, sponsorNxc))throw;
			sp.earnedNexium += sponsorNxc;                                     // Update the number of milli Nxc this sponsor earned
			givenNxc = (givenNxc*(100 + sp.backerBonus))/100;                  // Increase by x% the number of Nxc we will give to the backer
		if (!giveNxc(beneficiary, givenNxc))throw;                             // Give to the Backer the Nxc he just earned
		// Add the new Backer to the list, if he gave for the first time
		Backer backer = backers[beneficiary];
		if (backer.weiGiven == 0){
			backerList[backerList.length++] = beneficiary;
		backer.weiGiven += msg.value;                                          // Update the gave wei of this Backer
		collectedEth += msg.value;                                             // Update the total wei collcted during the crowdfunding     
		Gave(beneficiary);                                                     // Trigger an event 
	// If you gave ether before the first stage is reached you might have some ungiven
	// Nxc for your address. This function, if called, will give you the nexiums you didn't
	// received. /!\ Nexium bonuses for your partner rank will not be given during the crowdfunding
	function claimNxc(){
	    if (!isLimitReached) throw;
	    address to = msg.sender;
	    nexium.transfer(to, backers[to].ungivenNxc);
	    backers[to].ungivenNxc = 0;
	// This function can be called after the crowdfunding if the first goal is not reached
	// It gives back the ethers of the specified address
	function getBackEther(){
	function getBackEtherFor(address account){
	    if (now > endDate && !isLimitReached){
	        uint sentBack = backers[account].weiGiven;
	        backers[account].weiGiven = 0;                                     // No DAO style re entrance 😉
	    } else throw ;
	// The anonymous function automatically make a donation for the person who gave ethers

    //Create a new sponsoring contract 
	function addAlt(address sponsor, uint _sponsorBonus, uint _backerBonus)
	    if (_sponsorBonus > 10 || _backerBonus > 10 || _sponsorBonus + _backerBonus > 15) throw;
		altList[altList.length++] = address(new AltCrowdfunding(this));
		sponsorList[altList[altList.length -1]] = Sponsor(0, 0, sponsor, _sponsorBonus, _backerBonus);
	// Set the value of BCY gave by the SOG network. Only our BCY escrow can modify it.
    function setBCY(uint newValue)
        if (now < startDate || now > endDate) throw;
        if (newValue != 0 && newValue < 714285714) collectedBcy = newValue; // 714285714 * 14 ~= 10 000 000 000 mili Nxc maximum to avoid wrong value
        else throw;
    // If the minimum goal is reached, beyond the void can have the ethers stored on the contract
    function withdrawEther(address to, uint amount)
        if (!isLimitReached) throw;
        var r = to.send(amount);
    function withdrawNxc(address to, uint amount)
        nexium.transfer(to, amount);
    //If there are still Nexiums or Ethers on the contract after 100 days after the end of the crowdfunding
    //This function send all of it to the multi sig of the beyond the void team (emergency case)
    function blackBox(){
        if (now < endDate + 100 days)throw;
        nexium.transfer(beyond, nexium.balanceOf(this));
        var r = beyond.send(this.balance);
	// Each time this contract send Nxc this function is called. It check if
	// the minimum goal is reached before sending any nexiums out.
	function giveNxc(address to, uint amount) internal returns (bool){
	    bool res;
	    if (isLimitReached){
	        if (nexium.transfer(to, amount)){
	            // If there is some ungiven Nxc remaining for this address, send it.
	            if (backers[to].ungivenNxc != 0){
	                 res = nexium.transfer(to, backers[to].ungivenNxc); 
	                 backers[to].ungivenNxc = 0;
	            } else {
	                res = true;
	        } else {
	            res = false;
		// If the limit is not reached yet, the nexiums are not sent but stored in the contract waiting this goal being reached.
		// They are released when the same backer gives ether while the limit is reached, or by claiming them after the minimal goal is reached .
	    } else {
	        backers[to].ungivenNxc += amount;
	        res = true;
	    return res;
	function getCurrEthValue() returns(uint){
	    return  startingEtherValue - stepEtherValue * ((nxcSold + collectedBcy * nxcPerBcy)/perStageNxc);