arbitrage-keeper

The DAI Stablecoin System incentivizes external agents, called keepers, to automate certain operations around the Ethereum blockchain.

arbitrage-keeper performs arbitrage on OasisDEX, join, exit, boom and bust.

Keeper constantly looks for profitable enough arbitrage opportunities and executes them the moment they become available. It can make profit on:

• taking orders on OasisDEX (on DAI/PETH, DAI/W-ETH and PETH/W-ETH pairs),
• calling join and exit to exchange between W-ETH and PETH,
• calling boom and bust to exchange between DAI and PETH.

Opportunities discovered by the keeper are sequences of token exchanges executed using methods listed above. An opportunity can consist of two or three steps, technically it could be more but practically it will never be more than three.

Steps can be executed sequentially (each one as a separate Ethereum transaction, checking if one has been successful before executing the next one) or in one ago. The latter method requires a TxManager contract deployed, its address has to be passed as the --tx-manager argument. Also the TxManager contract has to be owned by the account the keeper operates from.

You can find the source code of the TxManager here: https://github.com/makerdao/tx-manager.

The base token is the token all arbitrage opportunities will start with. Some amount of this token will be exchanged to some other token(s) and then exchanged back to the base token, aiming to end up with more of it than we started with. It implies that some amount of this token has to be provided to the keeper. The higher the amount, the more profitable each arbitrage may be. Maximum engagement in terms of base token can be set using the --max-engagement argument.

It is also beneficial to provide very small amounts of other tokens to the keeper as well, mostly because of the rounding issues which may occur on subsequent arbitrage steps. Currently the keeper operates on DAI, PETH and W-ETH. It means that if we choose DAI as the base token, we should also give it some tiny amounts of PETH and W-ETH. It may happen that due to rounding issues these amounts will increase or decrease over time. Usually it is no more than 1 Wei increase or decrease per one arbitrage opportunity.

The keeper is aware of gas costs and takes a rough estimate of these costs while calculating arbitrage profitability. Having said that, this feature still requires some improvement (see makerdao#1).

https://chat.makerdao.com/channel/keeper

Installation

This project uses Python 3.6.2.

In order to clone the project and install required third-party packages please execute:

git clone https://github.com/makerdao/arbitrage-keeper.git
git submodule update --init --recursive
pip3 install -r requirements.txt

For some known macOS issues see the pymaker README.

Usage

usage: arbitrage-keeper [-h] [--rpc-host RPC_HOST] [--rpc-port RPC_PORT]
                        [--rpc-timeout RPC_TIMEOUT] --eth-from ETH_FROM
                        --tub-address TUB_ADDRESS --tap-address TAP_ADDRESS
                        --oasis-address OASIS_ADDRESS
                        [--tx-manager TX_MANAGER] [--gas-price GAS_PRICE]
                        --base-token BASE_TOKEN --min-profit MIN_PROFIT
                        --max-engagement MAX_ENGAGEMENT
                        [--max-errors MAX_ERRORS] [--debug]

optional arguments:
  -h, --help            show this help message and exit
  --rpc-host RPC_HOST   JSON-RPC host (default: `localhost')
  --rpc-port RPC_PORT   JSON-RPC port (default: `8545')
  --rpc-timeout RPC_TIMEOUT
                        JSON-RPC timeout (in seconds, default: 10)
  --eth-from ETH_FROM   Ethereum account from which to send transactions
  --tub-address TUB_ADDRESS
                        Ethereum address of the Tub contract
  --tap-address TAP_ADDRESS
                        Ethereum address of the Tap contract
  --oasis-address OASIS_ADDRESS
                        Ethereum address of the OasisDEX contract
  --tx-manager TX_MANAGER
                        Ethereum address of the TxManager contract to use for
                        multi-step arbitrage
  --gas-price GAS_PRICE
                        Gas price in Wei (default: node default)
  --base-token BASE_TOKEN
                        The token all arbitrage sequences will start and end
                        with
  --min-profit MIN_PROFIT
                        Minimum profit (in base token) from one arbitrage
                        operation
  --max-engagement MAX_ENGAGEMENT
                        Maximum engagement (in base token) in one arbitrage
                        operation
  --max-errors MAX_ERRORS
                        Maximum number of allowed errors before the keeper
                        terminates (default: 100)
  --debug               Enable debug output

License

See COPYING file.