diff --git a/python/CHANGELOG b/python/CHANGELOG
index 92805f7..e273351 100644
--- a/python/CHANGELOG
+++ b/python/CHANGELOG
@@ -1,7 +1,3 @@
-* 0.0.10-pending
-	- Upgrade chainlib dependency, providing customizable jsonrpc id
-* 0.0.9-unreleased
-* 0.0.8-unreleased
 * 0.0.7-unreleased
 	- Implement keystore signing.
 	- Change makefile to compile contract for Byzantium.
diff --git a/python/eth_erc20/erc20.py b/python/eth_erc20/erc20.py
index df66689..84ff8f9 100644
--- a/python/eth_erc20/erc20.py
+++ b/python/eth_erc20/erc20.py
@@ -19,13 +19,13 @@ from chainlib.eth.tx import (
         TxFactory,
         TxFormat,
         )
-from chainlib.jsonrpc import JSONRPCRequest
 from chainlib.eth.contract import (
         ABIContractEncoder,
         ABIContractDecoder,
         ABIContractType,
         abi_decode_single,
         )
+from chainlib.jsonrpc import jsonrpc_template
 from chainlib.eth.error import RequestMismatchException
 
 logg = logging.getLogger()
@@ -34,9 +34,8 @@ logg = logging.getLogger()
 class ERC20(TxFactory):
     
 
-    def balance_of(self, contract_address, address, sender_address=ZERO_ADDRESS, id_generator=None):
-        j = JSONRPCRequest(id_generator)
-        o = j.template()
+    def balance_of(self, contract_address, address, sender_address=ZERO_ADDRESS):
+        o = jsonrpc_template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('balanceOf')
@@ -47,17 +46,15 @@ class ERC20(TxFactory):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
-        o = j.finalize(o)
         return o
 
 
-    def balance(self, contract_address, address, sender_address=ZERO_ADDRESS, id_generator=None):
-        return self.balance_of(contract_address, address, sender_address=ZERO_ADDRESS, id_generator=id_generator)
+    def balance(self, contract_address, address, sender_address=ZERO_ADDRESS):
+        return self.balance_of(contract_address, address, sender_address=ZERO_ADDRESS)
 
 
-    def symbol(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
-        j = JSONRPCRequest(id_generator)
-        o = j.template()
+    def symbol(self, contract_address, sender_address=ZERO_ADDRESS):
+        o = jsonrpc_template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('symbol')
@@ -66,13 +63,11 @@ class ERC20(TxFactory):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
-        o = j.finalize(o)
         return o
 
 
-    def name(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
-        j = JSONRPCRequest(id_generator)
-        o = j.template()
+    def name(self, contract_address, sender_address=ZERO_ADDRESS):
+        o = jsonrpc_template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('name')
@@ -81,13 +76,11 @@ class ERC20(TxFactory):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
-        o = j.finalize(o)
         return o
 
     
-    def decimals(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
-        j = JSONRPCRequest(id_generator)
-        o = j.template()
+    def decimals(self, contract_address, sender_address=ZERO_ADDRESS):
+        o = jsonrpc_template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('decimals')
@@ -96,13 +89,11 @@ class ERC20(TxFactory):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
-        o = j.finalize(o)
         return o
 
 
-    def total_supply(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
-        j = JSONRPCRequest(id_generator)
-        o = j.template()
+    def total_supply(self, contract_address, sender_address=ZERO_ADDRESS):
+        o = jsonrpc_template()
         o['method'] = 'eth_call'
         enc = ABIContractEncoder()
         enc.method('totalSupply')
@@ -111,11 +102,10 @@ class ERC20(TxFactory):
         tx = self.set_code(tx, data)
         o['params'].append(self.normalize(tx))
         o['params'].append('latest')
-        o = j.finalize(o)
         return o
 
 
-    def transfer(self, contract_address, sender_address, recipient_address, value, tx_format=TxFormat.JSONRPC, id_generator=None):
+    def transfer(self, contract_address, sender_address, recipient_address, value, tx_format=TxFormat.JSONRPC):
         enc = ABIContractEncoder()
         enc.method('transfer')
         enc.typ(ABIContractType.ADDRESS)
@@ -125,7 +115,7 @@ class ERC20(TxFactory):
         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)
+        tx = self.finalize(tx, tx_format)
         return tx
 
 
@@ -179,11 +169,6 @@ class ERC20(TxFactory):
         return abi_decode_single(ABIContractType.UINT256, v)
 
 
-    @classmethod
-    def parse_total_supply(self, v):
-        return abi_decode_single(ABIContractType.UINT256, v)
-
-
     @classmethod
     def parse_transfer_request(self, v):
         v = strip_0x(v)
diff --git a/python/eth_erc20/runnable/balance.py b/python/eth_erc20/runnable/balance.py
index 29eeeda..8da63a5 100644
--- a/python/eth_erc20/runnable/balance.py
+++ b/python/eth_erc20/runnable/balance.py
@@ -27,6 +27,10 @@ from eth_abi import encode_single
 
 # external imports
 from chainlib.eth.address import to_checksum
+from chainlib.jsonrpc import (
+        jsonrpc_template,
+        jsonrpc_result,
+        )
 from chainlib.eth.connection import EthHTTPConnection
 from chainlib.eth.gas import (
         OverrideGasOracle,
@@ -40,9 +44,8 @@ from eth_erc20 import ERC20
 logging.basicConfig(level=logging.WARNING)
 logg = logging.getLogger()
 
-default_eth_provider = os.environ.get('RPC_PROVIDER')
-if default_eth_provider == None:
-    default_eth_provider = os.environ.get('ETH_PROVIDER', 'http://localhost:8545')
+default_abi_dir = os.environ.get('ETH_ABI_DIR', '/usr/share/local/cic/solidity/abi')
+default_eth_provider = os.environ.get('ETH_PROVIDER', 'http://localhost:8545')
 
 argparser = argparse.ArgumentParser()
 argparser.add_argument('-p', '--provider', dest='p', default=default_eth_provider, type=str, help='Web3 provider url (http only)')
@@ -50,7 +53,6 @@ argparser.add_argument('-a', '--token-address', dest='a', required=True, type=st
 argparser.add_argument('-f', '--format', dest='f', type=str, default='terminal', help='Output format [terminal (default), raw, brief]')
 argparser.add_argument('-i', '--chain-spec', dest='i', type=str, default='evm:ethereum:1', help='Chain specification string')
 argparser.add_argument('-u', '--unsafe', dest='u', action='store_true', help='Auto-convert address to checksum adddress')
-argparser.add_argument('--seq', action='store_true', help='Use sequential rpc ids')
 argparser.add_argument('-v', action='store_true', help='Be verbose')
 argparser.add_argument('-vv', action='store_true', help='Be more verbose')
 argparser.add_argument('address', type=str, help='Account address')
diff --git a/python/eth_erc20/runnable/transfer.py b/python/eth_erc20/runnable/transfer.py
index 2594af8..b393937 100644
--- a/python/eth_erc20/runnable/transfer.py
+++ b/python/eth_erc20/runnable/transfer.py
@@ -24,9 +24,7 @@ from hexathon import (
         strip_0x,
         )
 from chainlib.eth.connection import EthHTTPConnection
-from chainlib.jsonrpc import (
-        IntSequenceGenerator,
-        )
+from chainlib.jsonrpc import jsonrpc_template
 from chainlib.eth.nonce import (
         RPCNonceOracle,
         OverrideNonceOracle,
@@ -47,12 +45,9 @@ logg = logging.getLogger()
 logging.getLogger('web3').setLevel(logging.WARNING)
 logging.getLogger('urllib3').setLevel(logging.WARNING)
 
-default_eth_provider = os.environ.get('RPC_PROVIDER')
-if default_eth_provider == None:
-    default_eth_provider = os.environ.get('ETH_PROVIDER', 'http://localhost:8545')
-
+default_abi_dir = '/usr/local/share/cic/solidity/abi'
 argparser = argparse.ArgumentParser()
-argparser.add_argument('-p', '--provider', dest='p', default=default_eth_provider, type=str, help='Web3 provider url (http only)')
+argparser.add_argument('-p', '--provider', dest='p', default='http://localhost:8545', type=str, help='Web3 provider url (http only)')
 argparser.add_argument('-w', action='store_true', help='Wait for the last transaction to be confirmed')
 argparser.add_argument('-ww', action='store_true', help='Wait for every transaction to be confirmed')
 argparser.add_argument('-i', '--chain-spec', dest='i', type=str, default='evm:ethereum:1', help='Chain specification string')
@@ -64,7 +59,6 @@ argparser.add_argument('-s', '--send', dest='s', action='store_true', help='Send
 argparser.add_argument('--nonce', type=int, help='Override nonce')
 argparser.add_argument('--gas-price', dest='gas_price', type=int, help='Override gas price')
 argparser.add_argument('--gas-limit', dest='gas_limit', type=int, help='Override gas limit')
-argparser.add_argument('--seq', action='store_true', help='Use sequential rpc ids')
 argparser.add_argument('-v', action='store_true', help='Be verbose')
 argparser.add_argument('-vv', action='store_true', help='Be more verbose')
 argparser.add_argument('recipient', type=str, help='Recipient account address')
@@ -97,33 +91,22 @@ if args.y != None:
     logg.debug('now have key for signer address {}'.format(signer_address))
 signer = EIP155Signer(keystore)
 
-rpc_id_generator = None
-if args.seq:
-    rpc_id_generator = IntSequenceGenerator()
-
-auth = None
-#if os.environ.get('RPC_AUTHENTICATION') == 'custom_token':
-
-if os.environ.get('RPC_AUTHENTICATION') == 'basic':
-    from chainlib.auth import BasicAuth
-    #auth = CustomHeaderTokenAuth('x-api-key', os.environ['RPC_AUTHENTICATION_STRING'])
-    auth = BasicAuth(os.environ['RPC_USERNAME'], os.environ['RPC_PASSWORD'])
 conn = EthHTTPConnection(args.p)
 
 nonce_oracle = None
 if args.nonce != None:
-    nonce_oracle = OverrideNonceOracle(signer_address, args.nonce, id_generator=rpc_id_generator)
+    nonce_oracle = OverrideNonceOracle(signer_address, args.nonce)
 else:
-    nonce_oracle = RPCNonceOracle(signer_address, conn, id_generator=rpc_id_generator)
+    nonce_oracle = RPCNonceOracle(signer_address, conn)
 
-#def _max_gas(code=None):
-#    return 8000000
+def _max_gas(code=None):
+    return 8000000
 
 gas_oracle = None
 if args.gas_price != None or args.gas_limit != None:
-    gas_oracle = OverrideGasOracle(price=args.gas_price, limit=args.gas_limit, id_generator=rpc_id_generator, conn=conn)
+    gas_oracle = OverrideGasOracle(price=args.gas_price, limit=args.gas_limit)
 else:
-    gas_oracle = RPCGasOracle(conn, code_callback=ERC20.gas, id_generator=rpc_id_generator)
+    gas_oracle = RPCGasOracle(conn, code_callback=_max_gas)
 
 chain_spec = ChainSpec.from_chain_str(args.i)
 chain_id = chain_spec.network_id()
@@ -135,8 +118,8 @@ send = args.s
 g = ERC20(chain_spec, signer=signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
 
 
-def balance(token_address, address, id_generator=None):
-    o = g.balance(token_address, address, id_generator=id_generator)
+def balance(token_address, address):
+    o = g.balance(token_address, address)
     r = conn.do(o)
     hx = strip_0x(r)
     return int(hx, 16)
@@ -148,22 +131,18 @@ def main():
         raise ValueError('invalid checksum address')
 
     if logg.isEnabledFor(logging.DEBUG):
-        sender_balance = balance(args.a, signer_address, id_generator=rpc_id_generator)
-        recipient_balance = balance(args.a, recipient, id_generator=rpc_id_generator)
-        logg.debug('sender {} balance after: {}'.format(signer_address, sender_balance))
-        logg.debug('recipient {} balance after: {}'.format(recipient, recipient_balance))
+        logg.debug('sender {} balance after: {}'.format(signer_address, balance(args.a, signer_address)))
+        logg.debug('recipient {} balance after: {}'.format(recipient, balance(args.a, recipient)))
 
-    (tx_hash_hex, o) = g.transfer(args.a, signer_address, recipient, value, id_generator=rpc_id_generator)
+    (tx_hash_hex, o) = g.transfer(args.a, signer_address, recipient, value)
 
     if send:
         conn.do(o)
         if block_last:
             r = conn.wait(tx_hash_hex)
             if logg.isEnabledFor(logging.DEBUG):
-                sender_balance = balance(args.a, signer_address, id_generator=rpc_id_generator)
-                recipient_balance = balance(args.a, recipient, id_generator=rpc_id_generator)
-                logg.debug('sender {} balance after: {}'.format(signer_address, sender_balance))
-                logg.debug('recipient {} balance after: {}'.format(recipient, recipient_balance))
+                logg.debug('sender {} balance after: {}'.format(signer_address, balance(args.a, signer_address)))
+                logg.debug('recipient {} balance after: {}'.format(recipient, balance(args.a, recipient)))
             if r['status'] == 0:
                 logg.critical('VM revert. Wish I could tell you more')
                 sys.exit(1)
diff --git a/python/giftable_erc20_token/data/GiftableToken.bin b/python/giftable_erc20_token/data/GiftableToken.bin
index 73cdd59..7cfc0cb 100644
--- a/python/giftable_erc20_token/data/GiftableToken.bin
+++ b/python/giftable_erc20_token/data/GiftableToken.bin
@@ -1 +1 @@
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\ No newline at end of file
diff --git a/python/giftable_erc20_token/data/GiftableToken.json b/python/giftable_erc20_token/data/GiftableToken.json
index 4f132e7..1373f28 100644
--- a/python/giftable_erc20_token/data/GiftableToken.json
+++ b/python/giftable_erc20_token/data/GiftableToken.json
@@ -1 +1 @@
-[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","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":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
+[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","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":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
diff --git a/python/giftable_erc20_token/factory.py b/python/giftable_erc20_token/factory.py
index 20708a6..501dcf9 100644
--- a/python/giftable_erc20_token/factory.py
+++ b/python/giftable_erc20_token/factory.py
@@ -40,7 +40,6 @@ class GiftableToken(TxFactory):
     def gas(code=None):
         return 1500000
 
-
     @staticmethod
     def abi():
         if GiftableToken.__abi == None:
diff --git a/python/requirements.txt b/python/requirements.txt
index a23d4c9..d7adb5b 100644
--- a/python/requirements.txt
+++ b/python/requirements.txt
@@ -1,4 +1,4 @@
 confini~=0.3.6rc3
-crypto-dev-signer~=0.4.14b6
-chainlib~=0.0.4a1
+crypto-dev-signer~=0.4.14b3
+chainlib~=0.0.3a1
 potaahto~=0.0.1a2
diff --git a/python/setup.cfg b/python/setup.cfg
index 3ba2719..2f2a956 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = eth-erc20
-version = 0.0.10a1
+version = 0.0.9a2
 description = ERC20 interface and simple contract with deployment script that lets any address mint and gift itself tokens.
 author = Louis Holbrook
 author_email = dev@holbrook.no
diff --git a/python/tests/conftest.py b/python/tests/conftest.py
new file mode 100644
index 0000000..3b9aa9e
--- /dev/null
+++ b/python/tests/conftest.py
@@ -0,0 +1,25 @@
+# standard imports
+import os
+
+# external imports
+import pytest
+from crypto_dev_signer.keystore.dict import DictKeystore
+from crypto_dev_signer.eth.signer import ReferenceSigner as EIP155Signer
+
+
+@pytest.fixture(scope='session')
+def keystore():
+    ks = DictKeystore()
+    
+    pk = os.urandom(32)
+    ks.import_raw_key(pk)
+    return ks
+
+
+@pytest.fixture(scope='session')
+def signer(
+    keystore,
+        ):
+
+    s = EIP155Signer(keystore)
+    return s
diff --git a/python/tests/test_erc20.py b/python/tests/test_erc20.py
new file mode 100644
index 0000000..23da239
--- /dev/null
+++ b/python/tests/test_erc20.py
@@ -0,0 +1,74 @@
+# standard imports
+import logging
+import os 
+
+# external imports
+from hexathon import (
+        strip_0x,
+        add_0x,
+        )
+from chainlib.eth.address import to_checksum_address
+from chainlib.eth.tx import (
+        unpack,
+        TxFormat,
+        )
+from chainlib.eth.pytest import *
+
+# local imports
+from eth_erc20 import ERC20
+
+logg = logging.getLogger()
+
+contract_address = to_checksum_address('0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef')
+benefactor_address = to_checksum_address('0xefdeadbeefdeadbeefdeadbeefdeadbeefdeadbe')
+
+
+# TODO: use unittest instead
+def test_erc20_balance(
+    default_chain_spec,
+        ):
+    e = ERC20(default_chain_spec,)
+
+    holder_address = to_checksum_address('0xbeefdeadbeefdeadbeefdeadbeefdeadbeefdead')
+    o = e.balance_of(contract_address, holder_address)
+    assert len(o['params'][0]['data']) == 64 + 8 + 2
+    assert o['params'][0]['data'][:10] == add_0x('70a08231')
+
+
+def test_erc20_decimals(
+        default_chain_spec,
+        ):
+    e = ERC20(default_chain_spec)
+
+    o = e.decimals(contract_address)
+    assert o['params'][0]['data'] == add_0x('313ce567')
+
+
+def test_erc20_transfer(
+        keystore,
+        signer,
+        default_chain_spec,
+        ):
+    e = ERC20(default_chain_spec, signer=signer)
+
+    addresses = keystore.list()
+    (tx_hash_hex, o) = e.transfer(contract_address, addresses[0], benefactor_address, 1024)
+
+
+def test_erc20_parse_transfer_request(
+        keystore,
+        signer,
+        default_chain_spec,
+        ):
+
+    e = ERC20(default_chain_spec, signer=signer)
+
+    addresses = keystore.list()
+    (tx_hash_hex, o) = e.transfer(contract_address, addresses[0], benefactor_address, 1024, tx_format=TxFormat.RLP_SIGNED)
+    b = bytes.fromhex(strip_0x(o))
+
+    #chain_spec = ChainSpec('evm', 'foo', 1, 'bar')
+    tx = unpack(b, default_chain_spec)
+    r = ERC20.parse_transfer_request(tx['data'])
+    assert r[0] == benefactor_address
+    assert r[1] == 1024
diff --git a/python/tests/test_erc20_interface.py b/python/tests/test_erc20_interface.py
deleted file mode 100644
index 0749dba..0000000
--- a/python/tests/test_erc20_interface.py
+++ /dev/null
@@ -1,189 +0,0 @@
-# standard imports
-import logging
-import unittest
-
-# external imports
-from chainlib.eth.unittest.ethtester import EthTesterCase
-from chainlib.connection import RPCConnection
-from chainlib.eth.nonce import RPCNonceOracle
-from chainlib.eth.gas import OverrideGasOracle
-from chainlib.eth.tx import (
-        transaction,
-        receipt,
-        )
-from chainlib.eth.address import to_checksum_address
-
-# local imports
-from giftable_erc20_token import GiftableToken
-from eth_erc20 import ERC20
-
-logg = logging.getLogger(__name__)
-
-
-class TestToken(EthTesterCase):
-
-    def setUp(self):
-        super(TestToken, self).setUp()
-        self.conn = RPCConnection.connect(self.chain_spec, 'default')
-        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
-        c = GiftableToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        self.symbol = 'FOO'
-        self.name = 'Foo Token'
-        self.decimals = 16
-        (tx_hash, o) = c.constructor(self.accounts[0], self.name, self.symbol, self.decimals)
-        r = self.conn.do(o)
-        logg.debug('deployed with hash {}'.format(r))
-        
-        o = receipt(r)
-        r = self.conn.do(o)
-        self.address = to_checksum_address(r['contract_address'])
-
-        self.initial_supply = 1 << 40
-        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[0], self.initial_supply)
-        r = self.conn.do(o)
-        o = receipt(tx_hash)
-        r = self.conn.do(o)
-        self.assertEqual(r['status'], 1)
-
-
-    def test_balance(self):
-        c = ERC20(self.chain_spec)
-        o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
-        r = self.conn.do(o)
-        balance = ERC20.parse_balance(r)
-        self.assertEqual(self.initial_supply, balance)
-
-
-    def test_supply(self):
-        c = ERC20(self.chain_spec)
-        o = c.total_supply(self.address, sender_address=self.accounts[0])
-        r = self.conn.do(o)
-        supply = ERC20.parse_total_supply(r)
-        self.assertEqual(self.initial_supply, supply)
-
-
-    def test_name(self):
-        c = ERC20(self.chain_spec)
-        o = c.name(self.address, sender_address=self.accounts[0])
-        r = self.conn.do(o)
-        name = ERC20.parse_name(r)
-        self.assertEqual(self.name, name)
-
-
-    def test_symbol(self):
-        c = ERC20(self.chain_spec)
-        o = c.symbol(self.address, sender_address=self.accounts[0])
-        r = self.conn.do(o)
-        symbol = ERC20.parse_symbol(r)
-        self.assertEqual(self.symbol, symbol)
-
-
-    def test_transfer(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
-        gas_oracle = OverrideGasOracle(limit=100000, conn=self.conn)
-        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=gas_oracle)
-        (tx_hash, o) = c.transfer(self.address, self.accounts[0], self.accounts[1], 1000)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        balance = c.parse_balance(r)
-        self.assertEqual(balance, self.initial_supply - 1000)
-
-        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        balance = c.parse_balance(r)
-        self.assertEqual(balance, 1000)
-
-        o = transaction(tx_hash)
-        r = self.rpc.do(o)
-        data = c.parse_transfer_request(r['data'])
-        self.assertEqual(data[0], self.accounts[1])
-        self.assertEqual(data[1], 1000)
-
-
-    def test_transfer_from(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
-        gas_oracle = OverrideGasOracle(limit=100000, conn=self.conn)
-        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=gas_oracle)
-        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 1000)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        o = transaction(tx_hash)
-        r = self.rpc.do(o)
-        data = c.parse_approve_request(r['data'])
-        self.assertEqual(data[0], self.accounts[1])
-        self.assertEqual(data[1], 1000)
-
-        nonce_oracle = RPCNonceOracle(self.accounts[1], conn=self.conn)
-        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=gas_oracle)
-        (tx_hash, o) = c.transfer_from(self.address, self.accounts[1], self.accounts[0], self.accounts[2], 1001)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 0)
-
-        o = transaction(tx_hash)
-        r = self.rpc.do(o)
-        data = c.parse_transfer_from_request(r['data'])
-        self.assertEqual(data[0], self.accounts[0])
-        self.assertEqual(data[1], self.accounts[2])
-        self.assertEqual(data[2], 1001)
-
-        (tx_hash, o) = c.transfer_from(self.address, self.accounts[1], self.accounts[0], self.accounts[2], 1000)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-
-        o = c.balance_of(self.address, self.accounts[0], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        balance = c.parse_balance(r)
-        self.assertEqual(balance, self.initial_supply - 1000)
-
-        o = c.balance_of(self.address, self.accounts[2], sender_address=self.accounts[0])
-        r = self.rpc.do(o)
-        balance = c.parse_balance(r)
-        self.assertEqual(balance, 1000)
-
-
-    def test_revoke_approve(self):
-        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.conn)
-        gas_oracle = OverrideGasOracle(limit=100000, conn=self.conn)
-        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=gas_oracle)
-        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 1000)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-        
-        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 999)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 0)
-     
-        (tx_hash, o) = c.approve(self.address, self.accounts[0], self.accounts[1], 0)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 1)
-        
-        nonce_oracle = RPCNonceOracle(self.accounts[1], conn=self.conn)
-        c = ERC20(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle, gas_oracle=gas_oracle)
-        (tx_hash, o) = c.transfer_from(self.address, self.accounts[1], self.accounts[0], self.accounts[2], 1)
-        r = self.rpc.do(o)
-        o = receipt(tx_hash)
-        r = self.rpc.do(o)
-        self.assertEqual(r['status'], 0)
-
-
-
-if __name__ == '__main__':
-    unittest.main()
diff --git a/solidity/GiftableToken.bin b/solidity/GiftableToken.bin
index 73cdd59..7cfc0cb 100644
--- a/solidity/GiftableToken.bin
+++ b/solidity/GiftableToken.bin
@@ -1 +1 @@
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\ No newline at end of file
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\ No newline at end of file
diff --git a/solidity/GiftableToken.json b/solidity/GiftableToken.json
index 4f132e7..1373f28 100644
--- a/solidity/GiftableToken.json
+++ b/solidity/GiftableToken.json
@@ -1 +1 @@
-[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","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":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
+[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","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":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
diff --git a/solidity/GiftableToken.sol b/solidity/GiftableToken.sol
index e1f8629..f74c9dc 100644
--- a/solidity/GiftableToken.sol
+++ b/solidity/GiftableToken.sol
@@ -82,16 +82,13 @@ contract GiftableToken {
 
 	// Implements ERC20
 	function approve(address _spender, uint256 _value) public returns (bool) {
-		if (_value > 0) {
-			require(allowance[msg.sender][_spender] == 0);
-		}
-		allowance[msg.sender][_spender] = _value;
+		allowance[msg.sender][_spender] += _value;
 		emit Approval(msg.sender, _spender, _value);
 		return true;
 	}
 
 	// Implements EIP165
-	function supportsInterface(bytes4 _sum) public returns (bool) {
+	function supportsInterface(bytes4 _sum) {
 		if (_sum == 0xc6bb4b70) { // ERC20
 			return true;
 		}