TokenSeller And TokenSellerFactory
Page status: To be updated with market making instructions.
The TokenSeller contract is created by a user on the Ethereum blockchain. This contract allows them to sell a digital asset for a specified price in ethers.
The user creating the smart contract to list the buy and/or sell trade is called the market Maker.
The user that executes a trade against a smart contract is called the market Taker.
Table of contents
- TokenSeller And TokenSellerFactory Contract Information
- Market Maker Operations
- How To Watch The TokenSellerFactory Contract In Ethereum Wallet / Mist
- How To Watch A TokenSeller Contract In Ethereum Wallet / Mist
- Source Code
-
TokenSellerFactory Mainnet Address:
0xb1eb96f752c624dc784d80961a1accfaf348c923 - TokenSellerFactory Testnet Address:
0x2b8ce19465f35419e757e4458defc1c3fd0ffb40 - TokenSeller Address:
This is generated dynamically by TokenSellerFactory - Maker can buy tokens?
NO - Maker can sell tokens?
Yes
In Ethereum Wallet / Mist, select the CONTRACTS tab and click WATCH CONTRACT to open the Watch contract window. Then:
-
Under CONTRACT NAME, enter
TokenSellerFactory -
Under CONTRACT ADDRESS:
- For Mainnet, enter
0xb1eb96f752c624dc784d80961a1accfaf348c923 - For Testnet, enter
0x2b8ce19465f35419e757e4458defc1c3fd0ffb40
- For Mainnet, enter
-
Copy the Application Binary Interface below and paste it into the JSON INTERFACE text box
[{"constant":false,"inputs":[{"name":"tokenAddress","type":"address"},{"name":"tokens","type":"uint256"}],"name":"ownerWithdrawERC20Token","outputs":[{"name":"ok","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"tradeContract","type":"address"}],"name":"verify","outputs":[{"name":"valid","type":"bool"},{"name":"owner","type":"address"},{"name":"asset","type":"address"},{"name":"sellPrice","type":"uint256"},{"name":"units","type":"uint256"},{"name":"sellsTokens","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"asset","type":"address"},{"name":"sellPrice","type":"uint256"},{"name":"units","type":"uint256"},{"name":"sellsTokens","type":"bool"}],"name":"createSaleContract","outputs":[{"name":"seller","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"type":"function"},{"payable":false,"type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"ownerAddress","type":"address"},{"indexed":true,"name":"tokenSellerAddress","type":"address"},{"indexed":true,"name":"asset","type":"address"},{"indexed":false,"name":"sellPrice","type":"uint256"},{"indexed":false,"name":"units","type":"uint256"},{"indexed":false,"name":"sellsTokens","type":"bool"}],"name":"TradeListing","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"tokenAddress","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"OwnerWithdrewERC20Token","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":true,"name":"_to","type":"address"}],"name":"OwnershipTransferred","type":"event"}]
-
Click OK
In Ethereum Wallet / Mist, select the CONTRACTS tab and click WATCH CONTRACT to open the Watch contract window. Then:
-
Under CONTRACT NAME, enter
TokenSeller {further identifying information} -
Under CONTRACT ADDRESS, enter the contract address as listed in https://cryptoderivatives.market/tokenTraderContracts . These contracts will have a Factory Name of TokenSellerFactory.
-
Copy the Application Binary Interface below and paste it into the JSON INTERFACE text box
[{"constant":false,"inputs":[{"name":"ethers","type":"uint256"}],"name":"makerWithdrawEther","outputs":[{"name":"ok","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"asset","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"sellPrice","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"sellsTokens","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"toTokenSeller","type":"address"},{"name":"tokens","type":"uint256"}],"name":"makerTransferAsset","outputs":[{"name":"ok","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"units","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"tokenAddress","type":"address"},{"name":"tokens","type":"uint256"}],"name":"makerWithdrawERC20Token","outputs":[{"name":"ok","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"takerBuyAsset","outputs":[],"payable":true,"type":"function"},{"constant":false,"inputs":[{"name":"tokens","type":"uint256"}],"name":"makerWithdrawAsset","outputs":[{"name":"ok","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_sellsTokens","type":"bool"}],"name":"activate","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"type":"function"},{"inputs":[{"name":"_asset","type":"address"},{"name":"_sellPrice","type":"uint256"},{"name":"_units","type":"uint256"},{"name":"_sellsTokens","type":"bool"}],"payable":false,"type":"constructor"},{"payable":true,"type":"fallback"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sells","type":"bool"}],"name":"ActivatedEvent","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"tokens","type":"uint256"}],"name":"MakerWithdrewAsset","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"toTokenSeller","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"MakerTransferredAsset","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"tokenAddress","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"MakerWithdrewERC20Token","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"ethers","type":"uint256"}],"name":"MakerWithdrewEther","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"buyer","type":"address"},{"indexed":false,"name":"ethersSent","type":"uint256"},{"indexed":false,"name":"ethersReturned","type":"uint256"},{"indexed":false,"name":"tokensBought","type":"uint256"}],"name":"TakerBoughtAsset","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":true,"name":"_to","type":"address"}],"name":"OwnershipTransferred","type":"event"}]
TokenSellerFactory has the following methods:
createSaleContract(address _asset, uint256 _sellPrice, uint256 _units, bool _sellsTokens) returns (address)
verify(address saleContract) constant returns (bool valid, address asset, uint256 sellPrice, uint256 units, bool sellsTokens)
Following is the source code for TokenSellerFactory contract (which includes TokenSeller) on:
- Mainnet - 0xb1eb96f752c624dc784d80961a1accfaf348c923
- Testnet - 0x2b8ce19465f35419e757e4458defc1c3fd0ffb40
pragma solidity ^0.4.4;
// ------------------------------------------------------------------------
// TokenSellerFactory
//
// Decentralised trustless ERC20-partially-compliant token to ETH exchange
// contract on the Ethereum blockchain.
//
// This caters for the Golem Network Token which does not implement the
// ERC20 transferFrom(...), approve(...) and allowance(...) methods
//
// History:
// Jan 25 2017 - BPB Added makerTransferAsset(...)
// Feb 05 2017 - BPB Bug fix in the change calculation for the Unicorn
// token with natural number 1
//
// Enjoy. (c) JonnyLatte, Cintix & BokkyPooBah 2017. The MIT licence.
// ------------------------------------------------------------------------
// https://github.com/ethereum/EIPs/issues/20
contract ERC20Partial {
function totalSupply() constant returns (uint totalSupply);
function balanceOf(address _owner) constant returns (uint balance);
function transfer(address _to, uint _value) returns (bool success);
// function transferFrom(address _from, address _to, uint _value) returns (bool success);
// function approve(address _spender, uint _value) returns (bool success);
// function allowance(address _owner, address _spender) constant returns (uint remaining);
event Transfer(address indexed _from, address indexed _to, uint _value);
// event Approval(address indexed _owner, address indexed _spender, uint _value);
}
contract Owned {
address public owner;
event OwnershipTransferred(address indexed _from, address indexed _to);
function Owned() {
owner = msg.sender;
}
modifier onlyOwner {
if (msg.sender != owner) throw;
_;
}
function transferOwnership(address newOwner) onlyOwner {
OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
// contract can sell tokens for ETH
// prices are in amount of wei per batch of token units
contract TokenSeller is Owned {
address public asset; // address of token
uint256 public sellPrice; // contract sells lots of tokens at this price
uint256 public units; // lot size (token-wei)
bool public sellsTokens; // is contract selling
event ActivatedEvent(bool sells);
event MakerWithdrewAsset(uint256 tokens);
event MakerTransferredAsset(address toTokenSeller, uint256 tokens);
event MakerWithdrewERC20Token(address tokenAddress, uint256 tokens);
event MakerWithdrewEther(uint256 ethers);
event TakerBoughtAsset(address indexed buyer, uint256 ethersSent,
uint256 ethersReturned, uint256 tokensBought);
// Constructor - only to be called by the TokenSellerFactory contract
function TokenSeller (
address _asset,
uint256 _sellPrice,
uint256 _units,
bool _sellsTokens
) {
asset = _asset;
sellPrice = _sellPrice;
units = _units;
sellsTokens = _sellsTokens;
ActivatedEvent(sellsTokens);
}
// Maker can activate or deactivate this contract's
// selling status
//
// The ActivatedEvent() event is logged with the following
// parameter:
// sellsTokens this contract can sell asset tokens
function activate (
bool _sellsTokens
) onlyOwner {
sellsTokens = _sellsTokens;
ActivatedEvent(sellsTokens);
}
// Maker can withdraw asset tokens from this contract, with the
// following parameter:
// tokens is the number of asset tokens to be withdrawn
//
// The MakerWithdrewAsset() event is logged with the following
// parameter:
// tokens is the number of tokens withdrawn by the maker
//
// This method was called withdrawAsset() in the old version
function makerWithdrawAsset(uint256 tokens) onlyOwner returns (bool ok) {
MakerWithdrewAsset(tokens);
return ERC20Partial(asset).transfer(owner, tokens);
}
// Maker can transfer asset tokens from this contract to another
// TokenSeller contract, with the following parameter:
// toTokenSeller Another TokenSeller contract owned by the
// same owner
// tokens is the number of asset tokens to be moved
//
// The MakerTransferredAsset() event is logged with the following
// parameters:
// toTokenSeller The other TokenSeller contract owned by
// the same owner
// tokens is the number of tokens transferred
//
// The asset Transfer() event is logged from this contract to
// the other contract
//
function makerTransferAsset(
TokenSeller toTokenSeller,
uint256 tokens
) onlyOwner returns (bool ok) {
if (owner != toTokenSeller.owner() || asset != toTokenSeller.asset()) {
throw;
}
MakerTransferredAsset(toTokenSeller, tokens);
return ERC20Partial(asset).transfer(toTokenSeller, tokens);
}
// Maker can withdraw any ERC20 asset tokens from this contract
//
// This method is included in the case where this contract receives
// the wrong tokens
//
// The MakerWithdrewERC20Token() event is logged with the following
// parameter:
// tokenAddress is the address of the tokens withdrawn by the maker
// tokens is the number of tokens withdrawn by the maker
//
// This method was called withdrawToken() in the old version
function makerWithdrawERC20Token(
address tokenAddress,
uint256 tokens
) onlyOwner returns (bool ok) {
MakerWithdrewERC20Token(tokenAddress, tokens);
return ERC20Partial(tokenAddress).transfer(owner, tokens);
}
// Maker withdraws ethers from this contract
//
// The MakerWithdrewEther() event is logged with the following parameter
// ethers is the number of ethers withdrawn by the maker
//
// This method was called withdraw() in the old version
function makerWithdrawEther(uint256 ethers) onlyOwner returns (bool ok) {
if (this.balance >= ethers) {
MakerWithdrewEther(ethers);
return owner.send(ethers);
}
}
// Taker buys asset tokens by sending ethers
//
// The TakerBoughtAsset() event is logged with the following parameters
// buyer is the buyer's address
// ethersSent is the number of ethers sent by the buyer
// ethersReturned is the number of ethers sent back to the buyer as
// change
// tokensBought is the number of asset tokens sent to the buyer
//
// This method was called buy() in the old version
function takerBuyAsset() payable {
if (sellsTokens || msg.sender == owner) {
// Note that sellPrice has already been validated as > 0
uint order = msg.value / sellPrice;
// Note that units has already been validated as > 0
uint can_sell = ERC20Partial(asset).balanceOf(address(this)) / units;
uint256 change = 0;
if (msg.value > (can_sell * sellPrice)) {
change = msg.value - (can_sell * sellPrice);
order = can_sell;
}
if (change > 0) {
if (!msg.sender.send(change)) throw;
}
if (order > 0) {
if (!ERC20Partial(asset).transfer(msg.sender, order * units)) throw;
}
TakerBoughtAsset(msg.sender, msg.value, change, order * units);
}
// Return user funds if the contract is not selling
else if (!msg.sender.send(msg.value)) throw;
}
// Taker buys tokens by sending ethers
function () payable {
takerBuyAsset();
}
}
// This contract deploys TokenSeller contracts and logs the event
contract TokenSellerFactory is Owned {
event TradeListing(address indexed ownerAddress, address indexed tokenSellerAddress,
address indexed asset, uint256 sellPrice, uint256 units, bool sellsTokens);
event OwnerWithdrewERC20Token(address indexed tokenAddress, uint256 tokens);
mapping(address => bool) _verify;
// Anyone can call this method to verify the settings of a
// TokenSeller contract. The parameters are:
// tradeContract is the address of a TokenSeller contract
//
// Return values:
// valid did this TokenTraderFactory create the TokenTrader contract?
// owner is the owner of the TokenTrader contract
// asset is the ERC20 asset address
// sellPrice is the sell price in ethers per `units` of asset tokens
// units is the number of units of asset tokens
// sellsTokens is the TokenTrader contract selling tokens?
//
function verify(address tradeContract) constant returns (
bool valid,
address owner,
address asset,
uint256 sellPrice,
uint256 units,
bool sellsTokens
) {
valid = _verify[tradeContract];
if (valid) {
TokenSeller t = TokenSeller(tradeContract);
owner = t.owner();
asset = t.asset();
sellPrice = t.sellPrice();
units = t.units();
sellsTokens = t.sellsTokens();
}
}
// Maker can call this method to create a new TokenSeller contract
// with the maker being the owner of this new contract
//
// Parameters:
// asset is the ERC20 asset address
// sellPrice is the sell price in ethers per `units` of asset tokens
// units is the number of units of asset tokens
// sellsTokens is the TokenSeller contract selling tokens?
//
// For example, listing a TokenSeller contract on the GNT Golem Network Token
// where the contract will sell GNT tokens at a rate of 170/100000 = 0.0017 ETH
// per GNT token:
// asset 0xa74476443119a942de498590fe1f2454d7d4ac0d
// sellPrice 170
// units 100000
// sellsTokens true
//
// The TradeListing() event is logged with the following parameters
// ownerAddress is the Maker's address
// tokenSellerAddress is the address of the newly created TokenSeller contract
// asset is the ERC20 asset address
// sellPrice is the sell price in ethers per `units` of asset tokens
// unit is the number of units of asset tokens
// sellsTokens is the TokenSeller contract selling tokens?
//
// This method was called createTradeContract() in the old version
//
function createSaleContract(
address asset,
uint256 sellPrice,
uint256 units,
bool sellsTokens
) returns (address seller) {
// Cannot have invalid asset
if (asset == 0x0) throw;
// Cannot set zero or negative price
if (sellPrice <= 0) throw;
// Cannot sell zero or negative units
if (units <= 0) throw;
seller = new TokenSeller(
asset,
sellPrice,
units,
sellsTokens);
// Record that this factory created the trader
_verify[seller] = true;
// Set the owner to whoever called the function
TokenSeller(seller).transferOwnership(msg.sender);
TradeListing(msg.sender, seller, asset, sellPrice, units, sellsTokens);
}
// Factory owner can withdraw any ERC20 asset tokens from this contract
//
// This method is included in the case where this contract receives
// the wrong tokens
//
// The OwnerWithdrewERC20Token() event is logged with the following
// parameter:
// tokenAddress is the address of the tokens withdrawn by the maker
// tokens is the number of tokens withdrawn by the maker
function ownerWithdrawERC20Token(address tokenAddress, uint256 tokens) onlyOwner returns (bool ok) {
OwnerWithdrewERC20Token(tokenAddress, tokens);
return ERC20Partial(tokenAddress).transfer(owner, tokens);
}
// Prevents accidental sending of ether to the factory
function () {
throw;
}
}