Update file structure

8 files changed, 1590 insertions, 0 deletions

diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
new file mode 100644
index 000000000..b6961a6ec
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
@@ -0,0 +1,99 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "./IERC20Token.sol";
+
+contract ERC20Token is IERC20Token {
+
+    string constant INSUFFICIENT_BALANCE = "ERC20_INSUFFICIENT_BALANCE";
+    string constant INSUFFICIENT_ALLOWANCE = "ERC20_INSUFFICIENT_ALLOWANCE";
+    string constant OVERFLOW = "Transfer would result in an overflow.";
+
+    mapping (address => uint256) balances;
+    mapping (address => mapping (address => uint256)) allowed;
+
+    uint256 public totalSupply;
+
+    function transfer(address _to, uint256 _value)
+        public
+        returns (bool)
+    {
+        require(
+            balances[msg.sender] >= _value,
+            INSUFFICIENT_BALANCE
+        );
+        require(
+            balances[_to] + _value >= balances[_to],
+            OVERFLOW
+        );
+        balances[msg.sender] -= _value;
+        balances[_to] += _value;
+        emit Transfer(msg.sender, _to, _value);
+        return true;
+    }
+
+    function transferFrom(address _from, address _to, uint256 _value)
+        public
+        returns (bool)
+    {
+        require(
+            balances[_from] >= _value,
+            INSUFFICIENT_BALANCE
+        );
+        require(
+            allowed[_from][msg.sender] >= _value,
+            INSUFFICIENT_ALLOWANCE
+        );
+        require(
+            balances[_to] + _value >= balances[_to],
+            OVERFLOW
+        );
+        balances[_to] += _value;
+        balances[_from] -= _value;
+        allowed[_from][msg.sender] -= _value;
+        emit Transfer(_from, _to, _value);
+        return true;
+    }
+
+    function approve(address _spender, uint256 _value)
+        public
+        returns (bool)
+    {
+        allowed[msg.sender][_spender] = _value;
+        emit Approval(msg.sender, _spender, _value);
+        return true;
+    }
+
+    function balanceOf(address _owner)
+        public view
+        returns (uint256)
+    {
+        return balances[_owner];
+    }
+
+    function allowance(address _owner, address _spender)
+        public
+        view
+        returns (uint256)
+    {
+        return allowed[_owner][_spender];
+    }
+}
diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
new file mode 100644
index 000000000..eb879b6a8
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
@@ -0,0 +1,73 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+contract IERC20Token {
+
+    /// @notice send `value` token to `to` from `msg.sender`
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transfer(address _to, uint256 _value)
+        public
+        returns (bool);
+
+    /// @notice send `value` token to `to` from `from` on the condition it is approved by `from`
+    /// @param _from The address of the sender
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transferFrom(address _from, address _to, uint256 _value)
+        public
+        returns (bool);
+    
+    /// @notice `msg.sender` approves `_spender` to spend `_value` tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @param _value The amount of wei to be approved for transfer
+    /// @return Whether the approval was successful or not
+    function approve(address _spender, uint256 _value)
+        public
+        returns (bool);
+
+    /// @param _owner The address from which the balance will be retrieved
+    /// @return The balance
+    function balanceOf(address _owner)
+        public view
+        returns (uint256);
+
+    /// @param _owner The address of the account owning tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @return Amount of remaining tokens allowed to spent
+    function allowance(address _owner, address _spender)
+        public view
+        returns (uint256);
+
+    event Transfer(
+        address indexed _from,
+        address indexed _to,
+        uint256 _value
+    );
+    
+    event Approval(
+        address indexed _owner,
+        address indexed _spender,
+        uint256 _value
+    );
+}
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
new file mode 100644
index 000000000..41ba149e3
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
@@ -0,0 +1,406 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Smart Contract Solutions, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+pragma solidity ^0.4.24;
+
+import "./IERC721Token.sol";
+import "./IERC721Receiver.sol";
+import "../../utils/SafeMath/SafeMath.sol";
+
+/**
+ * @title ERC721 Non-Fungible Token Standard basic implementation
+ * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
+ * Modified from https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/ERC721/ERC721BasicToken.sol
+ */
+contract ERC721Token is
+    IERC721Token,
+    SafeMath
+{
+    // Equals to `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`
+    // which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
+    bytes4 constant ERC721_RECEIVED = 0xf0b9e5ba;
+
+    // Mapping from token ID to owner
+    mapping (uint256 => address) internal tokenOwner;
+
+    // Mapping from token ID to approved address
+    mapping (uint256 => address) internal tokenApprovals;
+
+    // Mapping from owner to number of owned token
+    mapping (address => uint256) internal ownedTokensCount;
+
+    // Mapping from owner to operator approvals
+    mapping (address => mapping (address => bool)) internal operatorApprovals;
+
+    /**
+    * @dev Guarantees msg.sender is owner of the given token
+    * @param _tokenId uint256 ID of the token to validate its ownership belongs to msg.sender
+    */
+    modifier onlyOwnerOf(uint256 _tokenId) {
+        require(ownerOf(_tokenId) == msg.sender);
+        _;
+    }
+
+    /**
+    * @dev Checks msg.sender can transfer a token, by being owner, approved, or operator
+    * @param _tokenId uint256 ID of the token to validate
+    */
+    modifier canTransfer(uint256 _tokenId) {
+        require(isApprovedOrOwner(msg.sender, _tokenId));
+        _;
+    }
+
+    function ERC721Token(
+        string _name,
+        string _symbol)
+        public
+    {
+        name_ = _name;
+        symbol_ = _symbol;
+    }
+
+    /**
+    * @dev Gets the token name
+    * @return string representing the token name
+    */
+    function name()
+        public
+        view
+        returns (string)
+    {
+        return name_;
+    }
+
+    /**
+    * @dev Gets the token symbol
+    * @return string representing the token symbol
+    */
+    function symbol()
+        public
+        view
+        returns (string)
+    {
+        return symbol_;
+    }
+
+    /**
+    * @dev Gets the balance of the specified address
+    * @param _owner address to query the balance of
+    * @return uint256 representing the amount owned by the passed address
+    */
+    function balanceOf(address _owner)
+        public
+        view
+        returns (uint256)
+    {
+        require(_owner != address(0));
+        return ownedTokensCount[_owner];
+    }
+
+    /**
+    * @dev Gets the owner of the specified token ID
+    * @param _tokenId uint256 ID of the token to query the owner of
+    * @return owner address currently marked as the owner of the given token ID
+    */
+    function ownerOf(uint256 _tokenId)
+        public
+        view
+        returns (address)
+    {
+        address owner = tokenOwner[_tokenId];
+        require(owner != address(0));
+        return owner;
+    }
+
+    /**
+    * @dev Returns whether the specified token exists
+    * @param _tokenId uint256 ID of the token to query the existance of
+    * @return whether the token exists
+    */
+    function exists(uint256 _tokenId)
+        public
+        view
+        returns (bool)
+    {
+        address owner = tokenOwner[_tokenId];
+        return owner != address(0);
+    }
+
+    /**
+    * @dev Approves another address to transfer the given token ID
+    * @dev The zero address indicates there is no approved address.
+    * @dev There can only be one approved address per token at a given time.
+    * @dev Can only be called by the token owner or an approved operator.
+    * @param _to address to be approved for the given token ID
+    * @param _tokenId uint256 ID of the token to be approved
+    */
+    function approve(address _to, uint256 _tokenId)
+        public
+    {
+        address owner = ownerOf(_tokenId);
+        require(_to != owner);
+        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));
+
+        if (getApproved(_tokenId) != address(0) || _to != address(0)) {
+            tokenApprovals[_tokenId] = _to;
+            emit Approval(owner, _to, _tokenId);
+        }
+    }
+
+    /**
+    * @dev Gets the approved address for a token ID, or zero if no address set
+    * @param _tokenId uint256 ID of the token to query the approval of
+    * @return address currently approved for a the given token ID
+    */
+    function getApproved(uint256 _tokenId)
+        public
+        view
+        returns (address)
+    {
+        return tokenApprovals[_tokenId];
+    }
+
+    /**
+    * @dev Sets or unsets the approval of a given operator
+    * @dev An operator is allowed to transfer all tokens of the sender on their behalf
+    * @param _to operator address to set the approval
+    * @param _approved representing the status of the approval to be set
+    */
+    function setApprovalForAll(address _to, bool _approved)
+        public
+    {
+        require(_to != msg.sender);
+        operatorApprovals[msg.sender][_to] = _approved;
+        emit ApprovalForAll(msg.sender, _to, _approved);
+    }
+
+    /**
+    * @dev Tells whether an operator is approved by a given owner
+    * @param _owner owner address which you want to query the approval of
+    * @param _operator operator address which you want to query the approval of
+    * @return bool whether the given operator is approved by the given owner
+    */
+    function isApprovedForAll(address _owner, address _operator)
+        public
+        view
+        returns (bool)
+    {
+        return operatorApprovals[_owner][_operator];
+    }
+
+    /**
+    * @dev Transfers the ownership of a given token ID to another address
+    * @dev Usage of this method is discouraged, use `safeTransferFrom` whenever possible
+    * @dev Requires the msg sender to be the owner, approved, or operator
+    * @param _from current owner of the token
+    * @param _to address to receive the ownership of the given token ID
+    * @param _tokenId uint256 ID of the token to be transferred
+    */
+    function transferFrom(address _from, address _to, uint256 _tokenId)
+        public
+        canTransfer(_tokenId)
+    {
+        require(_from != address(0));
+        require(_to != address(0));
+
+        clearApproval(_from, _tokenId);
+        removeTokenFrom(_from, _tokenId);
+        addTokenTo(_to, _tokenId);
+
+        emit Transfer(_from, _to, _tokenId);
+    }
+
+    /**
+    * @dev Safely transfers the ownership of a given token ID to another address
+    * @dev If the target address is a contract, it must implement `onERC721Received`,
+    *  which is called upon a safe transfer, and return the magic value
+    *  `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`; otherwise,
+    *  the transfer is reverted.
+    * @dev Requires the msg sender to be the owner, approved, or operator
+    * @param _from current owner of the token
+    * @param _to address to receive the ownership of the given token ID
+    * @param _tokenId uint256 ID of the token to be transferred
+    */
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId)
+        public
+        canTransfer(_tokenId)
+    {
+        // solium-disable-next-line arg-overflow
+        safeTransferFrom(_from, _to, _tokenId, "");
+    }
+
+    /**
+    * @dev Safely transfers the ownership of a given token ID to another address
+    * @dev If the target address is a contract, it must implement `onERC721Received`,
+    *  which is called upon a safe transfer, and return the magic value
+    *  `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`; otherwise,
+    *  the transfer is reverted.
+    * @dev Requires the msg sender to be the owner, approved, or operator
+    * @param _from current owner of the token
+    * @param _to address to receive the ownership of the given token ID
+    * @param _tokenId uint256 ID of the token to be transferred
+    * @param _data bytes data to send along with a safe transfer check
+    */
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId,
+        bytes _data)
+        public
+        canTransfer(_tokenId)
+    {
+        transferFrom(_from, _to, _tokenId);
+        // solium-disable-next-line arg-overflow
+        require(checkAndCallSafeTransfer(_from, _to, _tokenId, _data));
+    }
+
+    /**
+    * @dev Returns whether the given spender can transfer a given token ID
+    * @param _spender address of the spender to query
+    * @param _tokenId uint256 ID of the token to be transferred
+    * @return bool whether the msg.sender is approved for the given token ID,
+    *  is an operator of the owner, or is the owner of the token
+    */
+    function isApprovedOrOwner(address _spender, uint256 _tokenId)
+        internal
+        view
+        returns (bool)
+    {
+        address owner = ownerOf(_tokenId);
+        return _spender == owner || getApproved(_tokenId) == _spender || isApprovedForAll(owner, _spender);
+    }
+
+    /**
+    * @dev Internal function to mint a new token
+    * @dev Reverts if the given token ID already exists
+    * @param _to The address that will own the minted token
+    * @param _tokenId uint256 ID of the token to be minted by the msg.sender
+    */
+    function _mint(address _to, uint256 _tokenId)
+        internal
+    {
+        require(_to != address(0));
+        addTokenTo(_to, _tokenId);
+        emit Transfer(address(0), _to, _tokenId);
+    }
+
+    /**
+    * @dev Internal function to burn a specific token
+    * @dev Reverts if the token does not exist
+    * @param _tokenId uint256 ID of the token being burned by the msg.sender
+    */
+    function _burn(address _owner, uint256 _tokenId)
+        internal
+    {
+        clearApproval(_owner, _tokenId);
+        removeTokenFrom(_owner, _tokenId);
+        emit Transfer(_owner, address(0), _tokenId);
+    }
+
+    /**
+    * @dev Internal function to clear current approval of a given token ID
+    * @dev Reverts if the given address is not indeed the owner of the token
+    * @param _owner owner of the token
+    * @param _tokenId uint256 ID of the token to be transferred
+    */
+    function clearApproval(address _owner, uint256 _tokenId)
+        internal
+    {
+        require(ownerOf(_tokenId) == _owner);
+        if (tokenApprovals[_tokenId] != address(0)) {
+            tokenApprovals[_tokenId] = address(0);
+            emit Approval(_owner, address(0), _tokenId);
+        }
+    }
+
+    /**
+    * @dev Internal function to add a token ID to the list of a given address
+    * @param _to address representing the new owner of the given token ID
+    * @param _tokenId uint256 ID of the token to be added to the tokens list of the given address
+    */
+    function addTokenTo(address _to, uint256 _tokenId)
+        internal
+    {
+        require(tokenOwner[_tokenId] == address(0));
+        tokenOwner[_tokenId] = _to;
+        ownedTokensCount[_to] = safeAdd(ownedTokensCount[_to], 1);
+    }
+
+    /**
+    * @dev Internal function to remove a token ID from the list of a given address
+    * @param _from address representing the previous owner of the given token ID
+    * @param _tokenId uint256 ID of the token to be removed from the tokens list of the given address
+    */
+    function removeTokenFrom(address _from, uint256 _tokenId)
+        internal
+    {
+        require(ownerOf(_tokenId) == _from);
+        ownedTokensCount[_from] = safeSub(ownedTokensCount[_from], 1);
+        tokenOwner[_tokenId] = address(0);
+    }
+
+    /**
+    * @dev Internal function to invoke `onERC721Received` on a target address
+    * @dev The call is not executed if the target address is not a contract
+    * @param _from address representing the previous owner of the given token ID
+    * @param _to target address that will receive the tokens
+    * @param _tokenId uint256 ID of the token to be transferred
+    * @param _data bytes optional data to send along with the call
+    * @return whether the call correctly returned the expected magic value
+    */
+    function checkAndCallSafeTransfer(
+        address _from,
+        address _to,
+        uint256 _tokenId,
+        bytes _data)
+        internal
+        returns (bool)
+    {
+        if (!isContract(_to)) {
+            return true;
+        }
+        bytes4 retval = IERC721Receiver(_to).onERC721Received(_from, _tokenId, _data);
+        return (retval == ERC721_RECEIVED);
+    }
+
+    function isContract(address addr)
+        internal
+        view
+        returns (bool)
+    {
+        uint256 size;
+        // XXX Currently there is no better way to check if there is a contract in an address
+        // than to check the size of the code at that address.
+        // See https://ethereum.stackexchange.com/a/14016/36603
+        // for more details about how this works.
+        // TODO Check this again before the Serenity release, because all addresses will be
+        // contracts then.
+        assembly { size := extcodesize(addr) }  // solium-disable-line security/no-inline-assembly
+        return size > 0;
+    }
+}
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
new file mode 100644
index 000000000..b0fff3c90
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
@@ -0,0 +1,60 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Smart Contract Solutions, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+pragma solidity ^0.4.24;
+
+/**
+ * @title ERC721 token receiver interface
+ * @dev Interface for any contract that wants to support safeTransfers
+ *      rom ERC721 asset contracts.
+ * Modified from https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/ERC721/ERC721Receiver.sol
+ */
+contract IERC721Receiver {
+    /**
+    * @dev Magic value to be returned upon successful reception of an NFT
+    *  Equals to `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`,
+    *  which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
+    */
+    bytes4 constant ERC721_RECEIVED = 0xf0b9e5ba;
+
+    /**
+    * @notice Handle the receipt of an NFT
+    * @dev The ERC721 smart contract calls this function on the recipient
+    *  after a `safetransfer`. This function MAY throw to revert and reject the
+    *  transfer. This function MUST use 50,000 gas or less. Return of other
+    *  than the magic value MUST result in the transaction being reverted.
+    *  Note: the contract address is always the message sender.
+    * @param _from The sending address
+    * @param _tokenId The NFT identifier which is being transfered
+    * @param _data Additional data with no specified format
+    * @return `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`
+    */
+    function onERC721Received(
+        address _from,
+        uint256 _tokenId,
+        bytes _data)
+        public
+        returns (bytes4);
+}
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
new file mode 100644
index 000000000..345712d67
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
@@ -0,0 +1,105 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Smart Contract Solutions, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+pragma solidity ^0.4.24;
+
+/**
+ * @title ERC721 Non-Fungible Token Standard basic interface
+ * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
+ * Modified from https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/ERC721/ERC721Basic.sol
+ */
+contract IERC721Token {
+    string internal name_;
+    string internal symbol_;
+
+    event Transfer(
+        address indexed _from,
+        address indexed _to,
+        uint256 _tokenId
+    );
+    event Approval(
+        address indexed _owner,
+        address indexed _approved,
+        uint256 _tokenId
+    );
+    event ApprovalForAll(
+        address indexed _owner,
+        address indexed _operator,
+        bool _approved
+    );
+
+    function name()
+        public
+        view
+        returns (string);
+    function symbol()
+        public
+        view
+        returns (string);
+
+    function balanceOf(address _owner)
+        public
+        view
+        returns (uint256 _balance);
+    function ownerOf(uint256 _tokenId)
+        public
+        view
+        returns (address _owner);
+    function exists(uint256 _tokenId)
+        public
+        view
+        returns (bool _exists);
+
+    function approve(address _to, uint256 _tokenId)
+        public;
+    function getApproved(uint256 _tokenId)
+        public
+        view
+        returns (address _operator);
+
+    function setApprovalForAll(address _operator, bool _approved)
+        public;
+    function isApprovedForAll(address _owner, address _operator)
+        public
+        view
+        returns (bool);
+
+    function transferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId)
+        public;
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId)
+        public;
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId,
+        bytes _data)
+        public;
+}
diff --git a/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
new file mode 100644
index 000000000..f62602ab3
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
@@ -0,0 +1,58 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "../ERC20Token/ERC20Token.sol";
+
+contract UnlimitedAllowanceToken is ERC20Token {
+
+    uint256 constant MAX_UINT = 2**256 - 1;
+
+    /// @dev ERC20 transferFrom, modified such that an allowance of MAX_UINT represents an unlimited allowance. See https://github.com/ethereum/EIPs/issues/717
+    /// @param _from Address to transfer from.
+    /// @param _to Address to transfer to.
+    /// @param _value Amount to transfer.
+    /// @return Success of transfer.
+    function transferFrom(address _from, address _to, uint256 _value)
+        public
+        returns (bool)
+    {
+        uint256 allowance = allowed[_from][msg.sender];
+        require(
+            balances[_from] >= _value,
+            INSUFFICIENT_BALANCE
+        );
+        require(
+            allowance >= _value,
+            INSUFFICIENT_ALLOWANCE
+        );
+        require(
+            balances[_to] + _value >= balances[_to],
+            OVERFLOW
+        );
+        balances[_to] += _value;
+        balances[_from] -= _value;
+        if (allowance < MAX_UINT) {
+            allowed[_from][msg.sender] -= _value;
+        }
+        emit Transfer(_from, _to, _value);
+        return true;
+    }
+}
diff --git a/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol b/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
new file mode 100644
index 000000000..733ca414b
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
@@ -0,0 +1,756 @@
+// Copyright (C) 2015, 2016, 2017 Dapphub
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+pragma solidity ^0.4.18;
+
+contract WETH9 {
+    string public name     = "Wrapped Ether";
+    string public symbol   = "WETH";
+    uint8  public decimals = 18;
+
+    event  Approval(address indexed src, address indexed guy, uint wad);
+    event  Transfer(address indexed src, address indexed dst, uint wad);
+    event  Deposit(address indexed dst, uint wad);
+    event  Withdrawal(address indexed src, uint wad);
+
+    mapping (address => uint)                       public  balanceOf;
+    mapping (address => mapping (address => uint))  public  allowance;
+
+    function() public payable {
+        deposit();
+    }
+    function deposit() public payable {
+        balanceOf[msg.sender] += msg.value;
+        Deposit(msg.sender, msg.value);
+    }
+    function withdraw(uint wad) public {
+        require(balanceOf[msg.sender] >= wad);
+        balanceOf[msg.sender] -= wad;
+        msg.sender.transfer(wad);
+        Withdrawal(msg.sender, wad);
+    }
+
+    function totalSupply() public view returns (uint) {
+        return this.balance;
+    }
+
+    function approve(address guy, uint wad) public returns (bool) {
+        allowance[msg.sender][guy] = wad;
+        Approval(msg.sender, guy, wad);
+        return true;
+    }
+
+    function transfer(address dst, uint wad) public returns (bool) {
+        return transferFrom(msg.sender, dst, wad);
+    }
+
+    function transferFrom(address src, address dst, uint wad)
+        public
+        returns (bool)
+    {
+        require(balanceOf[src] >= wad);
+
+        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
+            require(allowance[src][msg.sender] >= wad);
+            allowance[src][msg.sender] -= wad;
+        }
+
+        balanceOf[src] -= wad;
+        balanceOf[dst] += wad;
+
+        Transfer(src, dst, wad);
+
+        return true;
+    }
+}
+
+
+/*
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
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diff --git a/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
new file mode 100644
index 000000000..2e5b61e0b
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
@@ -0,0 +1,33 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.11;
+
+import { UnlimitedAllowanceToken_v1 as UnlimitedAllowanceToken } from "../../../1.0.0/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol";
+
+contract ZRXToken is UnlimitedAllowanceToken {
+
+    uint8 constant public decimals = 18;
+    uint public totalSupply = 10**27; // 1 billion tokens, 18 decimal places
+    string constant public name = "0x Protocol Token";
+    string constant public symbol = "ZRX";
+
+    function ZRXToken() {
+        balances[msg.sender] = totalSupply;
+    }
+}