The Maker Protocol incentivizes external agents, called keepers, to automate certain operations around the Ethereum blockchain. In order to ease their development, an API around most of the Maker contracts has been created. It can be used not only by keepers, but may also be found useful by authors of some other, unrelated utilities aiming to interact with these contracts.
You only need to install this project directly if you want to build your own keepers, or if you want to play with this API library itself. If you just want to install one of reference keepers, go to one of the repositories linked above and start from there. Each of these keepers references some version of pymaker via a Git submodule.
Installation
This project uses Python 3.6.6.
In order to clone the project and install required third-party packages please execute:
git clone https://github.com/makerdao/pymaker.git
cd pymaker
pip3 install -r requirements.txt
Known Ubuntu issues
In order for the secp256k Python dependency to compile properly, following packages will need to be installed:
Contributions from the community are much appreciated!
Code samples
Below you can find some code snippets demonstrating how the API can be used both for developing your own keepers and for creating some other utilities interacting with the Maker Protocol ecosystem contracts.
Token transfer
This snippet demonstrates how to transfer some SAI from our default address. The SAI token address is discovered by querying the Tub, so all we need as a Tub address:
from web3 import HTTPProvider, Web3
from pymaker import Address
from pymaker.token import ERC20Token
from pymaker.numeric import Wad
from pymaker.sai import Tub
web3 = Web3(HTTPProvider(endpoint_uri="http://localhost:8545"))
tub = Tub(web3=web3, address=Address(' 0xb7ae5ccabd002b5eebafe6a8fad5499394f67980'))
sai = ERC20Token(web3=web3, address=tub.sai())
sai.transfer(address=Address(' 0x0000000000111111111100000000001111111111'),
value=Wad.from_number(10)).transact()
Updating a DSValue
This snippet demonstrates how to update a DSValue with the ETH/USD rate pulled from CryptoCompare:
import json
import urllib.request
from web3 import HTTPProvider, Web3
from pymaker import Address
from pymaker.feed import DSValue
from pymaker.numeric import Wad
def cryptocompare_rate() -> Wad:
with urllib.request.urlopen("https://min-api.cryptocompare.com/data/price?fsym=ETH&tsyms=USD") as url:
data = json.loads(url.read().decode())
return Wad.from_number(data['USD'])
web3 = Web3(HTTPProvider(endpoint_uri="http://localhost:8545"))
dsvalue = DSValue(web3=web3, address=Address(' 0x038b3d8288df582d57db9be2106a27be796b0daf'))
dsvalue.poke_with_int(cryptocompare_rate().value).transact()
SAI introspection
This snippet demonstrates how to fetch data from Tub and Tap contracts:
from web3 import HTTPProvider, Web3
from pymaker import Address
from pymaker.token import ERC20Token
from pymaker.numeric import Ray
from pymaker.sai import Tub, Tap
web3 = Web3(HTTPProvider(endpoint_uri="http://localhost:8545"))
tub = Tub(web3=web3, address=Address(' 0x448a5065aebb8e423f0896e6c5d525c040f59af3'))
tap = Tap(web3=web3, address=Address(' 0xbda109309f9fafa6dd6a9cb9f1df4085b27ee8ef'))
sai = ERC20Token(web3=web3, address=tub.sai())
skr = ERC20Token(web3=web3, address=tub.skr())
gem = ERC20Token(web3=web3, address=tub.gem())
print(f"")
print(f"Token summary")
print(f"-------------")
print(f"SAI total supply : {sai.total_supply()} SAI")
print(f"SKR total supply : {skr.total_supply()} SKR")
print(f"GEM total supply : {gem.total_supply()} GEM")
print(f"")
print(f"Collateral summary")
print(f"------------------")
print(f"GEM collateral : {tub.pie()} GEM")
print(f"SKR collateral : {tub.air()} SKR")
print(f"SKR pending liquidation: {tap.fog()} SKR")
print(f"")
print(f"Debt summary")
print(f"------------")
print(f"Debt ceiling : {tub.cap()} SAI")
print(f"Good debt : {tub.din()} SAI")
print(f"Bad debt : {tap.woe()} SAI")
print(f"Surplus : {tap.joy()} SAI")
print(f"")
print(f"Feed summary")
print(f"------------")
print(f"REF per GEM feed : {tub.pip()}")
print(f"REF per SKR price : {tub.tag()}")
print(f"GEM per SKR price : {tub.per()}")
print(f"")
print(f"Tub parameters")
print(f"--------------")
print(f"Liquidation ratio : {tub.mat()*100} %")
print(f"Liquidation penalty : {tub.axe()*100 - Ray.from_number(100)} %")
print(f"Stability fee : {tub.tax()} %")
print(f"")
print(f"All cups")
print(f"--------")
for cup_id in range(1, tub.cupi()+1):
cup = tub.cups(cup_id)
print(f"Cup #{cup_id}, lad={cup.lad}, ink={cup.ink} SKR, tab={tub.tab(cup_id)} SAI, safe={tub.safe(cup_id)}")
Multi-collateral Dai
This snippet demonstrates how to create a CDP and draw Dai.
import sys
from web3 import Web3, HTTPProvider
from pymaker import Address
from pymaker.deployment import DssDeployment
from pymaker.keys import register_keys
from pymaker.numeric import Wad
web3 = Web3(HTTPProvider(endpoint_uri="https://localhost:8545",
request_kwargs={"timeout": 10}))
web3.eth.defaultAccount = sys.argv[1] # ex: 0x0000000000000000000000000000000aBcdef123
register_keys(web3, [sys.argv[2]]) # ex: key_file=~keys/default-account.json,pass_file=~keys/default-account.pass
mcd = DssDeployment.from_json(web3=web3, conf=open("tests/config/kovan-addresses.json", "r").read())
our_address = Address(web3.eth.defaultAccount)
# Choose the desired collateral; in this case we'll wrap some Eth
collateral = mcd.collaterals['ETH-A']
ilk = collateral.ilk
collateral.gem.deposit(Wad.from_number(3)).transact()
# Add collateral and allocate the desired amount of Dai
collateral.approve(our_address)
collateral.adapter.join(our_address, Wad.from_number(3)).transact()
mcd.vat.frob(ilk, our_address, dink=Wad.from_number(3), dart=Wad.from_number(153)).transact()
print(f"CDP Dai balance before withdrawal: {mcd.vat.dai(our_address)}")
# Mint and withdraw our Dai
mcd.approve_dai(our_address)
mcd.dai_adapter.exit(our_address, Wad.from_number(153)).transact()
print(f"CDP Dai balance after withdrawal: {mcd.vat.dai(our_address)}")
# Repay (and burn) our Dai
assert mcd.dai_adapter.join(our_address, Wad.from_number(153)).transact()
print(f"CDP Dai balance after repayment: {mcd.vat.dai(our_address)}")
# Withdraw our collateral
mcd.vat.frob(ilk, our_address, dink=Wad(0), dart=Wad.from_number(-153)).transact()
mcd.vat.frob(ilk, our_address, dink=Wad.from_number(-3), dart=Wad(0)).transact()
collateral.adapter.exit(our_address, Wad.from_number(3)).transact()
print(f"CDP Dai balance w/o collateral: {mcd.vat.dai(our_address)}")
Asynchronous invocation of Ethereum transactions
This snippet demonstrates how multiple token transfers can be executed asynchronously:
from web3 import HTTPProvider
from web3 import Web3
from pymaker import Address, synchronize
from pymaker.numeric import Wad
from pymaker.sai import Tub
from pymaker.token import ERC20Token
web3 = Web3(HTTPProvider(endpoint_uri="http://localhost:8545"))
tub = Tub(web3=web3, address=Address(' 0x448a5065aebb8e423f0896e6c5d525c040f59af3'))
sai = ERC20Token(web3=web3, address=tub.sai())
skr = ERC20Token(web3=web3, address=tub.skr())
synchronize([sai.transfer(Address(' 0x0101010101020202020203030303030404040404'), Wad.from_number(1.5)).transact_async(),
skr.transfer(Address(' 0x0303030303040404040405050505050606060606'), Wad.from_number(2.5)).transact_async()])
Multiple invocations in one Ethereum transaction
This snippet demonstrates how multiple token transfers can be executed in one Ethereum transaction. A TxManager instance has to be deployed and owned by the caller.
from web3 import HTTPProvider
from web3 import Web3
from pymaker import Address
from pymaker.approval import directly
from pymaker.numeric import Wad
from pymaker.sai import Tub
from pymaker.token import ERC20Token
from pymaker.transactional import TxManager
web3 = Web3(HTTPProvider(endpoint_uri="http://localhost:8545"))
tub = Tub(web3=web3, address=Address(' 0x448a5065aebb8e423f0896e6c5d525c040f59af3'))
sai = ERC20Token(web3=web3, address=tub.sai())
skr = ERC20Token(web3=web3, address=tub.skr())
tx = TxManager(web3=web3, address=Address(' 0x57bFE16ae8fcDbD46eDa9786B2eC1067cd7A8f48'))
tx.approve([sai, skr], directly())
tx.execute([sai.address, skr.address],
[sai.transfer(Address(' 0x0101010101020202020203030303030404040404'), Wad.from_number(1.5)).invocation(),
skr.transfer(Address(' 0x0303030303040404040405050505050606060606'), Wad.from_number(2.5)).invocation()]).transact()
Ad-hoc increasing of gas price for asynchronous transactions
import asyncio
from random import randint
from web3 import Web3, HTTPProvider
from pymaker import Address
from pymaker.gas import FixedGasPrice
from pymaker.oasis import SimpleMarket
web3 = Web3(HTTPProvider(endpoint_uri=f"http://localhost:8545"))
otc = SimpleMarket(web3=web3, address=Address(' 0x375d52588c3f39ee7710290237a95C691d8432E7'))
async def bump_with_increasing_gas_price(order_id):
gas_price = FixedGasPrice(gas_price=1000000000)
task = asyncio.ensure_future(otc.bump(order_id).transact_async(gas_price=gas_price))
while not task.done():
await asyncio.sleep(1)
gas_price.update_gas_price(gas_price.gas_price + randint(0, gas_price.gas_price))
return task.result()
bump_task = asyncio.ensure_future(bump_with_increasing_gas_price(otc.get_orders()[-1].order_id))
event_loop = asyncio.get_event_loop()
bump_result = event_loop.run_until_complete(bump_task)
print(bump_result)
print(bump_result.transaction_hash)
