Implement python interface, deposit and swap test

.gitignore

@@ -0,0 +1,7 @@
+__pycache__
+*.pyc
+*.egg-info
+build/
+dist/
+solidity/*.json
+solidity/*.bin

python/erc20_pool/__init__.py

@@ -0,0 +1 @@
+from .pool import Pool

python/erc20_pool/data/SwapPool.json

@@ -0,0 +1 @@
+[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"},{"internalType":"bytes32","name":"_declaration","type":"bytes32"},{"internalType":"address","name":"_tokenRegistry","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bool","name":"_final","type":"bool"},{"indexed":false,"internalType":"uint256","name":"_sealState","type":"uint256"}],"name":"SealStateChange","type":"event"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_token","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"deposit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_state","type":"uint256"}],"name":"isSealed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"maxSealState","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_state","type":"uint256"}],"name":"seal","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"sealState","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_fee","type":"uint256"}],"name":"setFee","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_feeAddress","type":"address"}],"name":"setFeeAddress","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"}],"name":"withdraw","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"},{"internalType":"address","name":"_inToken","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"withdraw","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"withdraw","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"}]

python/erc20_pool/data/SwapPool.metadata.json

@@ -0,0 +1 @@
+{"compiler":{"version":"0.8.19+commit.7dd6d404"},"language":"Solidity","output":{"abi":[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"},{"internalType":"bytes32","name":"_declaration","type":"bytes32"},{"internalType":"address","name":"_tokenRegistry","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bool","name":"_final","type":"bool"},{"indexed":false,"internalType":"uint256","name":"_sealState","type":"uint256"}],"name":"SealStateChange","type":"event"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_token","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"deposit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_state","type":"uint256"}],"name":"isSealed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"maxSealState","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_state","type":"uint256"}],"name":"seal","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"sealState","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_fee","type":"uint256"}],"name":"setFee","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_feeAddress","type":"address"}],"name":"setFeeAddress","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"}],"name":"withdraw","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"},{"internalType":"address","name":"_inToken","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"withdraw","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_outToken","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"withdraw","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"}],"devdoc":{"kind":"dev","methods":{},"version":1},"userdoc":{"kind":"user","methods":{},"version":1}},"settings":{"compilationTarget":{"SwapPool.sol":"SwapPool"},"evmVersion":"byzantium","libraries":{},"metadata":{"bytecodeHash":"ipfs"},"optimizer":{"enabled":false,"runs":200},"remappings":[]},"sources":{"SwapPool.sol":{"keccak256":"0xe353d1255baee8fd9937c51600b0710e041108f041062a0130e6833a51c5c873","license":"AGPL-3.0-or-later","urls":["bzz-raw://56811f458f4310e26fbe8cf177eff3165898f324bfe74a6ca954771d20f3b498","dweb:/ipfs/QmYa1bep3hAvcNr7w1PHjRa65CLUkcJKmZRftKXZGG8wwS"]}},"version":1}

python/erc20_pool/data/__init__.py

@@ -0,0 +1,3 @@
+import os
+
+data_dir = os.path.realpath(os.path.dirname(__file__))

python/erc20_pool/pool.py

@@ -0,0 +1,119 @@
+# standard imports
+import logging
+import os
+import enum
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.constant import ZERO_CONTENT
+from chainlib.eth.contract import (
+    ABIContractEncoder,
+    ABIContractDecoder,
+    ABIContractType,
+    abi_decode_single,
+)
+from chainlib.eth.jsonrpc import to_blockheight_param
+from chainlib.eth.error import RequestMismatchException
+from chainlib.eth.tx import (
+    TxFactory,
+    TxFormat,
+)
+from chainlib.jsonrpc import JSONRPCRequest
+from chainlib.block import BlockSpec
+from hexathon import (
+    add_0x,
+    strip_0x,
+)
+from chainlib.eth.cli.encode import CLIEncoder
+
+# local imports
+from erc20_pool.data import data_dir
+
+logg = logging.getLogger()
+
+
+class Pool(TxFactory):
+
+    __abi = None
+    __bytecode = None
+
+    def constructor(self, sender_address, name, symbol, decimals, declaration=None, accounts_registry=None, tx_format=TxFormat.JSONRPC, version=None):
+        code = self.cargs(name, symbol, decimals, declaration=declaration, accounts_registry=accounts_registry, version=version)
+        tx = self.template(sender_address, None, use_nonce=True)
+        tx = self.set_code(tx, code)
+        return self.finalize(tx, tx_format)
+
+
+    @staticmethod
+    def cargs(name, symbol, decimals, declaration=None, accounts_registry=None, version=None):
+        if declaration == None:
+            declaration = ZERO_CONTENT
+        if accounts_registry == None:
+            accounts_registry = ZERO_ADDRESS
+        code = Pool.bytecode(version=version)
+        enc = ABIContractEncoder()
+        enc.string(name)
+        enc.string(symbol)
+        enc.uint256(decimals)
+        enc.bytes32(declaration)
+        enc.address(accounts_registry)
+        args = enc.get()
+        code += args
+        logg.debug('constructor code: ' + args)
+        return code
+
+
+    @staticmethod
+    def gas(code=None):
+        return 4000000
+
+
+    @staticmethod
+    def abi():
+        if Pool.__abi == None:
+            f = open(os.path.join(data_dir, 'SwapPool.json'), 'r')
+            Pool.__abi = json.load(f)
+            f.close()
+        return Pool.__abi
+
+
+    @staticmethod
+    def bytecode(version=None):
+        if Pool.__bytecode == None:
+            f = open(os.path.join(data_dir, 'SwapPool.bin'))
+            Pool.__bytecode = f.read()
+            f.close()
+        return Pool.__bytecode
+
+
+    def deposit(self, contract_address, sender_address, token_address, value, tx_format=TxFormat.JSONRPC, id_generator=None):
+        enc = ABIContractEncoder()
+        enc.method('deposit')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.typ(ABIContractType.UINT256)
+        enc.address(token_address)
+        enc.uint256(value)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format, id_generator=id_generator)
+        return tx
+
+
+    def swap(self, contract_address, sender_address, token_address_out, token_address_in, value, tx_format=TxFormat.JSONRPC, id_generator=None):
+        enc = ABIContractEncoder()
+        enc.method('withdraw')
+        enc.typ(ABIContractType.ADDRESS)
+        enc.typ(ABIContractType.ADDRESS)
+        enc.typ(ABIContractType.UINT256)
+        enc.address(token_address_out)
+        enc.address(token_address_in)
+        enc.uint256(value)
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format, id_generator=id_generator)
+        return tx
+
+
+

python/erc20_pool/unittest/__init__.py

@@ -0,0 +1 @@
+from .base import *

python/erc20_pool/unittest/base.py

@@ -0,0 +1,63 @@
+# standard imports
+import logging
+import time
+
+# external imports
+from chainlib.eth.unittest.ethtester import EthTesterCase
+from chainlib.connection import RPCConnection
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.address import to_checksum_address
+from giftable_erc20_token.unittest import TestGiftableToken
+from eth_erc20 import ERC20
+from chainlib.eth.block import block_latest
+from eth_accounts_index.unittest import TestAccountsIndex
+from eth_accounts_index.registry import AccountRegistry
+from giftable_erc20_token import GiftableToken
+
+# local imports
+from erc20_pool import Pool
+
+logg = logging.getLogger(__name__)
+
+hash_of_foo = '2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'
+hash_of_bar = 'fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9'
+hash_of_baz = 'baa5a0964d3320fbc0c6a922140453c8513ea24ab8fd0577034804a967248096'
+
+
+class TestERC20Pool(TestGiftableToken):
+
+    expire = 0
+
+    def setUp(self):
+        super(TestERC20Pool, self).setUp()
+
+        self.foo_address = self.address
+        self.bar_address = self.publish_giftable_token('Bar Token', 'BAR', 16)
+        self.baz_address = self.publish_giftable_token('Baz Token', 'BAZ', 16)
+        self.initial_supply_bar = 1 << 20
+        self.initial_supply_baz = 1 << 15
+
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
+        c = GiftableToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.mint_to(self.bar_address, self.accounts[0], self.accounts[1], self.initial_supply_bar)
+        r = self.conn.do(o)
+        o = receipt(tx_hash)
+        r = self.conn.do(o)
+        self.assertEqual(r['status'], 1)
+
+        (tx_hash, o) = c.mint_to(self.baz_address, self.accounts[0], self.accounts[2], self.initial_supply_baz)
+        r = self.conn.do(o)
+        o = receipt(tx_hash)
+        r = self.conn.do(o)
+        self.assertEqual(r['status'], 1)
+
+        c = Pool(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.constructor(self.accounts[0], "Big Pool", "BIG", 16)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+        self.voter_address = to_checksum_address(r['contract_address'])
+        logg.debug('published bar token {}, baz token {}'.format(self.bar_address, self.baz_address))
+        logg.debug('published voter on address {} with hash {}'.format(self.voter_address, tx_hash))

python/requirements.txt

@@ -0,0 +1,3 @@
+eth-erc20~=0.7.3
+chainlib-eth~=0.4.22
+#chainlib~=0.4.14

python/test_requirements.txt

@@ -0,0 +1,4 @@
+eth_tester==0.5.0b3
+py-evm==0.3.0a20
+eth-interface==0.1.1
+eth-accounts-index~=0.5.3

python/tests/test_base.py

@@ -0,0 +1,77 @@
+# standard imports
+import unittest
+import logging
+import os
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import block_latest
+from hexathon import same as same_hex
+from eth_erc20 import ERC20
+from giftable_erc20_token import GiftableToken
+
+# local imports
+from erc20_pool.unittest import TestERC20Pool
+from erc20_pool import Pool
+#from evm_tokenvote.unittest.base import hash_of_foo
+#from evm_tokenvote import Voter
+#from evm_tokenvote import ProposalState
+
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+class TestPoolBase(TestERC20Pool):
+
+    def test_deposit(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.approve(self.foo_address, self.accounts[0], self.voter_address, 1024)
+        self.rpc.do(o)
+
+        c = Pool(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.deposit(self.voter_address, self.accounts[0], self.foo_address, 1024)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        o = c.balance_of(self.foo_address, self.voter_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertEqual(int(r, 16), 1024)
+
+
+    def test_swap(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.approve(self.foo_address, self.accounts[0], self.voter_address, 1024)
+        self.rpc.do(o)
+
+        c = Pool(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.deposit(self.voter_address, self.accounts[0], self.foo_address, 1024)
+        self.rpc.do(o)
+
+        nonce_oracle = RPCNonceOracle(self.accounts[1], conn=self.conn)
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.approve(self.bar_address, self.accounts[1], self.voter_address, 768)
+        self.rpc.do(o)
+
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.approve(self.foo_address, self.accounts[1], self.voter_address, 768)
+        self.rpc.do(o)
+
+        c = Pool(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.swap(self.voter_address, self.accounts[1], self.foo_address, self.bar_address, 768)
+        self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        o = c.balance_of(self.foo_address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        self.assertEqual(int(r, 16), 768)
+
+
+if __name__ == '__main__':
+    unittest.main()

solidity/Makefile

@@ -7,6 +7,6 @@ all:
 	truncate -s -1 SwapPool.bin
 
 install: all
-	cp -v *.json ../python/erc20_swap_pool/data/
+	cp -v *.json ../python/erc20_pool/data/
-	cp -v *.bin ../python/erc20_swap_pool/data/
+	cp -v *.bin ../python/erc20_pool/data/
 

solidity/SwapPool.sol

@@ -6,27 +6,98 @@ pragma solidity ^0.8.0;
 // Description: Voting contract using ERC20 tokens as shares
 
 contract SwapPool {
+	// Implements EIP173
+	address public owner;
+
 	address registry;
 	address quoter;
 	uint256 feePpm;
 	address feeAddress;
+	bytes32 declaration;
+
+	string public name;
+	string public symbol;
+	uint256 public immutable decimals;
+
 	uint256 public totalSupply;
+
 	mapping ( address => uint256 ) fees;
-	
+
-	constructor(address _tokenRegistry) {
+	// Implements Seal
+	uint256 public sealState;
+	uint8 constant FEE_STATE = 1;
+	uint8 constant FEEADDRESS_STATE = 2;
+	uint256 constant public maxSealState = 3;
+
+	// Implements Seal
+	event SealStateChange(bool indexed _final, uint256 _sealState);
+
+	// EIP173
+	event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); // EIP173
+
+	constructor(string memory _name, string memory _symbol, uint8 _decimals, bytes32 _declaration, address _tokenRegistry) {
+		name = _name;
+		symbol = _symbol;
+		decimals = _decimals;
 		registry = _tokenRegistry;
+		declaration = _declaration;
+	}
+
+	function seal(uint256 _state) public returns(uint256) {
+		require(_state <= maxSealState, 'ERR_INVALID_STATE');
+		require(_state & sealState == 0, 'ERR_ALREADY_LOCKED');
+		sealState |= _state;
+		emit SealStateChange(sealState == maxSealState, sealState);
+		return uint256(sealState);
+	}
+
+	function isSealed(uint256 _state) public view returns(bool) {
+		require(_state < maxSealState);
+		if (_state == 0) {
+			return sealState == maxSealState;
+		}
+		return _state & sealState == _state;
+	}
+
+	// Change address for collecting fees
+	function setFeeAddress(address _feeAddress) public {
+		require(!isSealed(FEEADDRESS_STATE), "ERR_SEAL");
+		require(msg.sender == owner, "ERR_AXX");
+		feeAddress = _feeAddress;
+	}
+
+	// Change address for collecting fees
+	function setFee(uint256 _fee) public {
+		require(!isSealed(FEE_STATE), "ERR_SEAL");
+		require(msg.sender == owner, "ERR_AXX");
+		require(_fee < 1000000, "ERR_FEE_TOO_HIGH");
+		feePpm = _fee;
+	}
+
+	// Implements EIP173
+	function transferOwnership(address _newOwner) public returns (bool) {
+		address oldOwner;
+
+		require(msg.sender == owner);
+		oldOwner = owner;
+		owner = _newOwner;
+
+		emit OwnershipTransferred(oldOwner, owner);
+		return true;
 	}
 
 	function deposit(address _token, uint256 _value) public {
 		bool r;
 		bytes memory v;
 
-		allowedToken(_token, registry);
+		mustAllowedToken(_token, registry);
 
 		(r, v) = _token.call(abi.encodeWithSignature('transferFrom(address,address,uint256)', msg.sender, this, _value));
 		require(r, "ERR_TOKEN");
 		r = abi.decode(v, (bool));
 		require(r, "ERR_TRANSFER");
+
+		totalSupply += _value;
 	}
 
 	function getFee(uint256 _value) private view returns (uint256) {
@@ -71,7 +142,7 @@ contract SwapPool {
 
 		deposit(_inToken, _value);
 
-		(r, v) = _outToken.call(abi.encodeWithSignature('transferFrom(address,address,uint256)', this, msg.sender, netValue));
+		(r, v) = _outToken.call(abi.encodeWithSignature('transfer(address,uint256)', msg.sender, netValue));
 		require(r, "ERR_TOKEN");
 		r = abi.decode(v, (bool));
 		require(r, "ERR_TRANSFER");
@@ -81,11 +152,30 @@ contract SwapPool {
 		}
 	}
 
-	function withdraw(address _token, uint256 _value) public returns (uint256) {
+	// Withdraw token to fee address
+	function withdraw(address _outToken) public returns (uint256) {
+		uint256 balance;
 
+		balance = fees[_outToken];
+
+		return withdraw(_outToken, balance);
 	}
 
-	function allowedToken(address _token, address _registry) private {
+	function withdraw(address _outToken, uint256 _value) public returns (uint256) {
+		bool r;
+		bytes memory v;
+
+		require(feeAddress != address(0), "ERR_AXX");
+
+		(r, v) = _outToken.call(abi.encodeWithSignature('transferFrom(address,address,uint256)', this, feeAddress, _value));
+		require(r, "ERR_TOKEN");
+		r = abi.decode(v, (bool));
+		require(r, "ERR_TRANSFER");
+
+		return _value;
+	}
+
+	function mustAllowedToken(address _token, address _registry) private {
 		bool r;
 		bytes memory v;
 
@@ -98,4 +188,18 @@ contract SwapPool {
 		r = abi.decode(v, (bool));
 		require(r, "ERR_UNAUTH_TOKEN");
 	}
+
+	// Implements EIP165
+	function supportsInterface(bytes4 _sum) public pure returns (bool) {
+		if (_sum == 0x01ffc9a7) { // ERC165
+			return true;
+		}
+		if (_sum == 0x9493f8b2) { // ERC173
+			return true;
+		}
+		if (_sum == 0x0d7491f8) { // Seal
+			return true;
+		}
+		return false;
+	}
 }