Home

Awesome

market-maker-keeper

Build Status codecov

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

Market Maker Keeper Setup Guide

Guide Outline

  1. Introduction
  2. Prerequisites
  3. Installation
  4. Testing
  5. Bands and Bands Configuration
    • Example
  6. Order Rate Limitation
  7. GasPrice configuration
  8. Data Templating Language
  9. Price Feed Configuration
    • Example
  10. Running Keepers
    • Example (OasisDEX)
  11. Known limitations
  12. Install and run using Docker and Docker Compose
  13. Token Configuration
  14. Support Information
  15. License

1. Introduction

A big part of the DAI Stablecoin System (DSS) is the incentivization of external agents, called Keepers (which can be human but are typically automated bots). In DSS, there are two primary forms: Market Maker Keepers and Auction Keepers. Market Maker Keepers facilitate market making on supported exchanges, and thereby ensure DAI markets are liquid with minimal slippage. Auction Keepers enable bidding on auctions that secure the DSS. This repository is focused on Market Maker Keepers. Auction Keepers are available here.

Market Maker Keepers work by creating a series of orders in so-called bands (defined later), which are configured with a JSON file containing parameters like spreads, maximum engagement, etc. These bands work in coordination with methods to check your available balance, as well as retrieving price from external price feeds, to ensure that liquiditiy is being placed at the correct amounts, and correct prices. Ultimately, the keepers trade an exchange pair motivated by the expected long-term convergence towards the indicated Target Price.

This guide is dedicated to showing you how to create your very own Market Maker Keeper Bot as well as educate the community and help both users and developers understand the value of this incredible software. We are proud to say that all of the code needed to get a Market Maker Keeper bot up and running is open-sourced.

List of current exchanges that Market Maker Keeper Bots can be built for

2. Prerequisite

3. Getting Started (Installation)

  1. Clone the market-maker-keeper repository and switch into its directory:
git clone https://github.com/makerdao/market-maker-keeper.git
cd market-maker-keeper
  1. Initializing the git submodules that will bring in both the pymaker and the pyexchange library.
git submodule update --init --recursive
  1. Check to make sure you have the correct version (Python 3.6.6) of Python by running:
python3 -V
  1. To set up the virtual environment and install requirements, run the following script:
./install.sh
  1. Source the new locally created virtual environment
source _virtualenv/bin/activate

Potential errors that could arise:

Other Potential Installation Issues:

Read the following document for other known Ubuntu and macOS issues (here).

4. Testing

There is quite a lot of value in running all the unit tests to make sure market-maker keeper has been installed properly. After the repository has been cloned and the installation has been completed, you can run unit tests by executing the following commands.

Firstly, the following command will install the libraries required to run unit tests:

pip3 install -r requirements-dev.txt

To run the unit tests (py.test, etc..), use the following script:

./test.sh

Example output:

    ===================================== test session starts =====================================
    platform darwin -- Python 3.6.6, pytest-3.3.0, py-1.8.0, pluggy-0.6.0
    rootdir: /Users/charlesst.louis/market-maker-keeper, inifile:
    plugins: timeout-1.2.1, mock-1.6.3, cov-2.5.1, asyncio-0.8.0
    collected 97 items

    tests/test_airswap_market_maker_keeper.py ................                              [ 16%]
    tests/test_band.py ......                                                               [ 22%]
    tests/test_etherdelta_market_maker_keeper.py ..........................                 [ 49%]
    tests/test_feed.py .                                                                    [ 50%]
    tests/test_limit.py .......                                                             [ 57%]
    tests/test_oasis_market_maker_cancel.py ...                                             [ 60%]
    tests/test_oasis_market_maker_keeper.py ...................                             [ 80%]
    tests/test_price_feed.py ............                                                   [ 92%]
    tests/test_reloadable_config.py .......                                                 [100%]

    ---------- coverage: platform darwin, python 3.6.6-final-0 -----------
    Name                                                    Stmts   Miss  Cover
    ---------------------------------------------------------------------------
    market_maker_keeper/__init__.py                             0      0   100%
    market_maker_keeper/airswap_market_maker_keeper.py        252    142    44%
    market_maker_keeper/band.py                               260     37    86%
    market_maker_keeper/bibox_market_maker_keeper.py           93     93     0%
    market_maker_keeper/bitinka_market_maker_keeper.py         96     96     0%
    market_maker_keeper/bittrex_market_maker_keeper.py         96     96     0%
    market_maker_keeper/coinbase_market_maker_keeper.py       103    103     0%
    market_maker_keeper/coinbene_market_maker_keeper.py        95     95     0%
    market_maker_keeper/control_feed.py                         7      5    29%
    market_maker_keeper/ddex_market_maker_keeper.py           126    126     0%
    market_maker_keeper/ercdex_market_maker_keeper.py          12     12     0%
    market_maker_keeper/etherdelta_market_maker_keeper.py     193    142    26%
    market_maker_keeper/ethfinex_market_maker_keeper.py        94     94     0%
    market_maker_keeper/feed.py                                84     46    45%
    market_maker_keeper/gas.py                                 20     10    50%
    market_maker_keeper/gateio_market_maker_keeper.py         106    106     0%
    market_maker_keeper/gopax_market_maker_keeper.py           99     99     0%
    market_maker_keeper/hitbtc_market_maker_keeper.py          98     98     0%
    market_maker_keeper/idex_market_maker_keeper.py           193    193     0%
    market_maker_keeper/imtoken_pricing_server.py              51     51     0%
    market_maker_keeper/imtoken_utils.py                       97     97     0%
    market_maker_keeper/kucoin_market_maker_keeper.py         108    108     0%
    market_maker_keeper/limit.py                               46      0   100%
    market_maker_keeper/liquid_market_maker_keeper.py          97     97     0%
    market_maker_keeper/mpx_market_maker_keeper.py            137    137     0%
    market_maker_keeper/oasis_market_maker_cancel.py           38     22    42%
    market_maker_keeper/oasis_market_maker_keeper.py          133     94    29%
    market_maker_keeper/okex_market_maker_keeper.py            92     92     0%
    market_maker_keeper/order_book.py                         219    188    14%
    market_maker_keeper/order_history_reporter.py              38     26    32%
    market_maker_keeper/paradex_market_maker_keeper.py        131    131     0%
    market_maker_keeper/price_feed.py                         187     86    54%
    market_maker_keeper/reloadable_config.py                   67      3    96%
    market_maker_keeper/setzer.py                              24     17    29%
    market_maker_keeper/spread_feed.py                          7      5    29%
    market_maker_keeper/tethfinex_market_maker_keeper.py      149    149     0%
    market_maker_keeper/theocean_market_maker_keeper.py       129    129     0%
    market_maker_keeper/util.py                                 8      4    50%
    market_maker_keeper/zrx_market_maker_keeper.py            177    177     0%
    market_maker_keeper/zrxv2_market_maker_keeper.py           26     26     0%
    ---------------------------------------------------------------------------
    TOTAL                                                    3988   3232    19%


    ================================== 97 passed in 4.04 seconds ==================================

5. Understanding Bands Configuration

The Bands configuration file is directly related to how your Market Maker Keeper will work. As mentioned in the introduction, these Keepers continuously monitor and adjust their positions in the order book, maintaining open buy and sell orders in multiple bands at the same time. For each buy and sell band, the Keepers aim to have open orders for at least the minAmount. In both cases, they will ensure that the price of open orders stays within the <minMargin, maxMargin> range from the current price. When running, Keepers place orders for the average amounts (avgAmount) in each band by using use avgMargin to calculate the order price.

As long as the price of orders stays within the set band(s) (i.e. it's in between the <minMargin,maxMargin> range from the current price), the Keepers are kept open/running. If some orders leave the band, they either enter another adjacent band or fall outside all bands. In the case of the latter, they would be immediately canceled. In the case of the former, Keepers can keep these orders open as long as their amount is within the <minAmount,maxAmount> ranges for the band they just entered. If it is above the maximum, some of the open orders will get canceled and potentially a new one will be created to bring the total amount back within the range. If it is below the minimum, a new order gets created for the remaining amount so that the total amount of orders in this band is equal to avgAmount. The same process will happen if the total amount of open orders in a band falls below the minAmount as a result of other market participants taking these orders. In this case, a new order gets created for the remaining amount so the total amount of orders in this band is equal to avgAmount. There are some Keepers (which operate on decentralized exchanges) that will constantly use gas to cancel orders (ex: OasisDEX, EtherDelta and 0x) and create new ones (OasisDEX) as the price changes. Gas usage can be limited by setting the margin and amount ranges wide enough as well as by making sure that the bands are always adjacent to each other/set to the same value.

File format

The bands configuration file consists of two main sections:

  1. buyBands
  2. sellBands

Note: Each section is an array containing one object (band).

The minMargin and maxMargin fields in each band object represent the margin (spread) range of that band. These ranges may not overlap for bands of the same type (buy or sell), and should be adjacent to each other for better Keeper performance (where fewer orders will get canceled if the bands are adjacent to each other). The avgMargin represents the margin (spread) of newly created orders within a band.

Glossary

  1. minAmount - the minimum amount for keeper engagement for a band.
  2. avgAmount - the target amount for keeper engagement for a band.
  3. maxAmount - the maximum amount for keeper engagement for a band.
  4. dustCutoff - a field for the minimum amount of every single order created in each individual band (expressed in buy tokens for buy bands and in sell tokens for sell bands).
    • By setting the dustCutoff to a non-zero value prevents Keepers from creating a lot of very tiny orders, which can cost a lot of gas. For example, in the case of OasisDEX, it can result in a very small order getting rejected by other exchanges.

Setting up your own Bands Configuration File:

1. Creating your bands.json file

To start, take the sample configuration file below and copy-paste it to a .json file within the root directory of your market-maker-keeper folder. For ease of use, we sugges to name it bands.json. This bands file will get configured as a command-line argument when we start up the Market Maker Keeper.

Sample bands.json file containing two Bands

This example shows bands for the ETH-DAI pair, where ETH represents the base currency and DAI as the quote currency:

{
    "_buyToken": "DAI",
    "buyBands": [
        {
            "minMargin": 0.005,
            "avgMargin": 0.01,
            "maxMargin": 0.02,
            "minAmount": 20.0,
            "avgAmount": 30.0,
            "maxAmount": 40.0,
            "dustCutoff": 0.0
        },
        {
            "minMargin": 0.02,
            "avgMargin": 0.025,
            "maxMargin": 0.03,
            "minAmount": 40.0,
            "avgAmount": 60.0,
            "maxAmount": 80.0,
            "dustCutoff": 0.0
        }
    ],
    "buyLimits": [],

    "_sellToken": "ETH",
    "sellBands": [
        {
            "minMargin": 0.005,
            "avgMargin": 0.01,
            "maxMargin": 0.02,
            "minAmount": 2.5,
            "avgAmount": 5.0,
            "maxAmount": 7.5,
            "dustCutoff": 0.0
        },
        {
            "minMargin": 0.02,
            "avgMargin": 0.025,
            "maxMargin": 0.05,
            "minAmount": 4.0,
            "avgAmount": 6.0,
            "maxAmount": 8.0,
            "dustCutoff": 0.0
        }
    ],
    "sellLimits": []
}

This bands.json file should be adequate enough for you to copy and paste it and run it as is. Of course, you are free to configure it however you would like.

Note: Since this example will be focused on getting a Market Maker Keeper set up on Kovan, you need to make certain that you have enough Kovan ETH (K-Eth) to get your Keeper up and running. To receive Kovan ETH, join the following Gitter Channel: https://gitter.im/kovan-testnet/faucet and post your ETH address from your MetaMask account to the main chat. The Kovan faucet will then populate your wallet with the test funds. This process could take a couple of minutes or a couple of hours as it is done manually by the Gitter channel’s administrator.

2. Setting Amounts

You will need to set this up if you are going to be trading small amounts to start. This will need to be set up such that the amounts are sufficiently meaningful on the exchange you want to work with (based on the rules of the exchanges that you want to work. For example, their specificly set dust limits).

As mentioned above, there is one parameter in the configuration file (dustCutoff) that will be used to determine the minAmount of trade quantity. The dustCutoff will need to be set higher than/or equal to the minAmount trade quantity of the specific exchange. This is to make sure you don't create trades that are less than an exchanges' minimum trade requirements. Note that in your configuration file, you can also lower the required quantities to make it easier on yourself. Reducing the K-ETH amounts will be helpful in reducing wait times as you likely won't want to wait long periods in order to get enough K-ETH to run your Keeper).

Bands Example

Here, we will be going over some example interactions using the bands.json file described above. These examples assume that it is denominated in DAI and that the price of 10 DAI is 1 ETH.

Using Band 1

Using Band 2

The Market Maker Keeper will now reset it's bands by performing the following actions:

  1. Creating an order in Band 1 (5 ETH @ 98.475 DAI) using avgMargin and avgAmount.
  2. Cancelling the second order (5 ETH @ 102.5 DAI) (which is now in Band 2) becuase maxMargin has been breached (when price + (price * maxMargin) = orderPrice -> 97.5 + (97.5 * 0.05) -> 102.375 > 102.5).
  3. Keep the first order (5 ETH @ 101 DAI), which is now in Band 2 because it is within minMargin and maxMargin of Band 2.
  4. Creating an order in Band 2 (1 ETH @ 99.937 DAI) using avgMargin and avgAmount.

This results in a total of 3 placed orders:

6. Order Rate Limitation

Next, we want to add the Rate Limitation to the configurations file. This will make sure that we don't constantly churn out old orders as well as help manage our gas consumption. We do this because we want the period and the amount to be set to a low amount when we start out. This is done because we don't want new users' Market Maker Keeper bots to be frantically trading all of the time. The goal here is that we want to set up our initial states such that it is only placing an order every 5 min or so (or whatever time amount you decide on).

There are two (optional) limit sections (buyLimits and sendLimits) that can be used for limiting the maximum rate of orders created by Market Maker Keepers. They both use the same format as displayed below.

Example of order rate limits:

    "buyLimits": [ { "period": "1h", "amount": 50.0 }, { "period": "1d", "amount": 200.0 } ]

In the example above, the periods are set to 1-hour and 1-day and the amounts are set to 50.0 orders and 200.0 orders. This means that over the course of 1-hour, only 50.0 orders can be placed and over the course of 1-day, only 200.0 orders can be placed. The amounts will be expressed in terms of either the buy or the sell token (this will depend on the section). Note that the above code snippet imposes a limit of 50.0 buy token within each 60-minute window. Additionally, a maximum of 200.0 buy tokens within each 24-hour window.

Note: The supported time units are s, m, h, d, and w.

7. Gas price

Providers

Four different providers can be configured in the startup script:

Tuning parameters

By default, speedup transactions will be submitted after 42 seconds (roughly three blocks). This can be adjusted with --gas-replace-after. Take care not to set this below the time it takes for the node to provide block updates. 30 seconds is probably an acceptable minimum value. The provider's price can be scaled by a coefficient controlled by --gas-initial-multiplier. Aggressiveness of speedup replacements can be tuned with --gas-reactive-multiplier.
The maximum amount of gas for a single transaction, in Gwei, is limited by --gas-maximum.

8. Data Templating Language

The Jsonnet data templating language can be used for the configuration file.

In the case of the data templating language, think of this like a pre-processing language for parsing the file. The whole purpose of the jsonnet is to set up a configuration file such that you can have it increment based on a price. Therefore, in addition to the price feed, you can also base percentages away from the market price. As you can see below, there is a hardcoded amount/price as well as the amounts below it which are dependent on the price.

{
  "_price": 10,

  "_buyToken": "DAI",
  "buyBands": [
    {
      "minMargin": 0.020,
      "avgMargin": 0.050,
      "maxMargin": 0.075,
      "minAmount": 0.05 * $._price,
      "avgAmount": 0.25 * $._price,
      "maxAmount": 0.35 * $._price,
      "dustCutoff": 0.1
    }
  ],

  "_sellToken": "ETH",
  "sellBands": []
}

Notes:

9. Price Feed Configuration

The price feed is one of the most important determining factors of success in a Market Maker Keeper. If you have the bands set up the way you want, the price feed will help make sure your bands are set at meaningful levels relative to the inside market. If you have wide bands and your strategy is to add liquidity to handle market imbalances, then the price feed is not as important. However, as you tighten up the spreads, the price feed is a crucial component to ensure that you are going to profit in the market.

Below, we list some of the existing public feeds. You can also use web sockets if you have your own price feed that you want to use. In short, it works by each Market Maker Keeper taking in a --price-feed command-line argument which then determines the price used for market-making.

As of today, these are the possible values of this argument ( existing public feeds) that we list:

Note: The --price-feed command line argument can also contain a comma-separated list of several different price feeds. In this case, if one of them becomes unavailable, the next one in the list will be used instead. All listed price feeds will be constantly running in the background where the second one listed and following ones ready to take over when the first one (or prior one) becomes unavailable. In the example below (in the Running Keepers section), you can see an example of how to use a fixed price amount.

10. Running Market Maker Keepers

Each Market Maker Keeper is a command-line tool which takes in generic command-line arguments (such as --config, --price-feed, --price-feed-expiry, --debug, etc.) as well as some arguments which are specific to that particular Keeper. For example, Ethereum node parameters, addresses, exchange API keys, etc. All accepted command-line arguments are listed in the example section below. They can also be discovered by trying to start a Market Maker Keeper with the --help argument.

Example (Oasis Market Maker Keeper)

In order to run oasis-market-maker-keeper, you will need to go through the following process:

  1. Firstly, you would deploy an Ethereum node (we recommend Parity).
  2. Generate an account in it.
  3. Permanently unlock that account.
  4. Transfer some tokens to it.
  5. Run the Market Maker Keeper (as seen below).

The below file should be copy and pasted into a new file within the root directory of the repository (market-maker-keeper). This should be placed within the same folder where you put the bands.json file.

#!/bin/bash

    bin/oasis-market-maker-keeper \
        --rpc-host 127.0.0.1 \
        --rpc-port <port number> \
        --rpc-timeout 10 \
        --eth-from [address of your generated Ethereum account] \
    		--eth-key "key_file=./keystore.json,pass_file=keystore.pass" \
        --tub-address 0x448a5065aebb8e423f0896e6c5d525c040f59af3 \
        --oasis-address 0x14fbca95be7e99c15cc2996c6c9d841e54b79425 \
        --price-feed fixed:200 \
        --buy-token-address [address of the quote token, could be DAI] \
        --sell-token-address [address of the base token, could be WETH] \
        --config [path to the json bands configuration file, e.g. bands.json] \
        --smart-gas-price \
        --ethgasstation-api-key API_KEY_HERE \
        --min-eth-balance 0.001

List of required Kovan Addresses for the above :

V2_OASIS_SERVER1_ADDRESS= <account address on Kovan>
V2_OASIS_SERVER1_KEY="key_file=/home/ed/Projects/member-account.json,pass_file=/home/ed/Projects/member-account.pass"
TUB_ADDRESS=0xa71937147b55deb8a530c7229c442fd3f31b7db2 # tub-address
SAI_ADDRESS=0xc4375b7de8af5a38a93548eb8453a498222c4ff2 # buy-token-address
WETH_ADDRESS=0xd0a1e359811322d97991e03f863a0c30c2cf029c # sell-token-address
OASIS_ADDRESS_NEW=0x4a6bc4e803c62081ffebcc8d227b5a87a58f1f8f # oasis-address

General Notes:

Once completed, you can now run your Market Maker Keeper! Follow the next steps to get it running:

  1. Open up your terminal
  2. Run: chmod +x <the file name of your version of the above bin/oasis-market-maker-keeper snippet>
  3. Run ./<the file name of your version of the above bin/oasis-market-maker-keeper snippet>
  4. That's it, your Keeper should now be running!

Keepers on Centralized Exchanges vs. Decentralized Exchanges

In the situation where you want to use a centralized exchange vs. a decentralized exchange, the process differs a little:

  1. You would need to have an existing account or create an account (on the exchange itself).
  2. Get the set of API keys with trading permissions (will usually need to be generated as well).
  3. Deposit tokens in your account on the exchange (as the keepers do not handle deposits and withdrawals themselves).
  4. Run the Market Maker Keeper.

11. Known limitations

The gate.io API sometimes does not acknowledge order creation, returning following error message: Oops... reloading...<font color=white> 29.148 </font> <script> function r(){window.location.reload();}setTimeout('r()',3000);</script>. This error seems to depend on the API address of the caller. Despite these errors, orders get properly created and registered in the backend, the keeper will find out about it the next time it queries the open orders list (which happens every few seconds).

12. Install and run using Docker and Docker Compose

  1. Install Docker Community Edition for your OS:
https://docs.docker.com/install/
  1. Install Docker Compose for your OS:
https://docs.docker.com/compose/install/
  1. Clone the market-maker-keeper repository and switch into its directory:
git clone https://github.com/makerdao/market-maker-keeper.git
cd market-maker-keeper
  1. Initializing the git submodules that will bring in both the pymaker and the pyexchange library.
git submodule update --init --recursive
  1. Build keeper Docker image.
docker-compose build keeper
  1. Create configuration directory.
    This directory will hold all configuration files (bands) for keepers
mkdir docker-config
  1. Create environment variables.
    Create a file named .env and add all environment variables required to run keeper. docker-compose.yml file contains a configuration example for Coinbase ETH-DAI keeper that can be started with an .env file similar with the one below
COINBASE_API_KEY=API_KEY_HERE
COINBASE_SECRET_KEY=SECRET_KEY_HERE
COINBASE_PASSWORD=PASSWORD_HERE
ETH_DAI_PRICE_FEED=ws://user:readonly@localhost:7777/price/ETH-DAI/socket
COINBASE_ETH_DAI_BANDS=coinbase-ethdai-bands.json

where:
COINBASE_API_KEY, COINBASE_SECRET_KEY and COINBASE_PASSWORD are specific to your Coinbase account
ETH_DAI_PRICE_FEED is the price feed that keeper will use to place orders on Coinbase (see https://github.com/makerdao/uniswap-price-feed for how you can start a Uniswap price feed)
COINBASE_ETH_DAI_BANDS is the name of bands file to be used by keeper (file should be placed in docker-config directory)

  1. Run keeper.
docker-compose up coinbase-ethdai-keeper

13. Token Configuration

An Example token configuration files can be seen below. This configuration should be placed into a seperate .json file, with the path to that file passed as an argument to any keeper requiring pymaker.model.Token objects which simplify decimal normalization within pairs, while also enhancing type checking.

MAKE SURE TO CHECK ALL TOKEN ADDRESSES AND DECIMALS IN CONFIGURATION PRIOR TO RUNNING KEEPERS WITH REAL FUNDS

{
  "tokens": {
    "ETH": {
      "tokenAddress": "0x0000000000000000000000000000000000000000"
    },
    "WETH": {
      "tokenAddress": "<WETH TOKEN ADDRESS>"
    },
    "DAI": {
      "tokenAddress": "<DAI TOKEN ADDRESS>"
    },
    "MKR": {
      "tokenAddress": "<MKR TOKEN ADDRESS>"
    },
    "BAT": {
      "tokenAddress": "<BAT TOKEN ADDRESS>"
    },
    "WBTC": {
      "tokenAddress": "<WBTC TOKEN ADDRESS>",
      "tokenDecimals": 8
    },
    "USDC": {
      "tokenAddress": "<USDC TOKEN ADDRESS>",
      "tokenDecimals": 6
    }
  }
}

14. Support

We are here to help! We welcome any questions about the market making in the #keeper channel in the Maker Chat.

15. License

See COPYING file.

Disclaimer

YOU (MEANING ANY INDIVIDUAL OR ENTITY ACCESSING, USING OR BOTH THE SOFTWARE INCLUDED IN THIS GITHUB REPOSITORY) EXPRESSLY UNDERSTAND AND AGREE THAT YOUR USE OF THE SOFTWARE IS AT YOUR SOLE RISK. THE SOFTWARE IN THIS GITHUB REPOSITORY 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. YOU RELEASE AUTHORS OR COPYRIGHT HOLDERS FROM ALL LIABILITY FOR YOU HAVING ACQUIRED OR NOT ACQUIRED CONTENT IN THIS GITHUB REPOSITORY. THE AUTHORS OR COPYRIGHT HOLDERS MAKE NO REPRESENTATIONS CONCERNING ANY CONTENT CONTAINED IN OR ACCESSED THROUGH THE SERVICE, AND THE AUTHORS OR COPYRIGHT HOLDERS WILL NOT BE RESPONSIBLE OR LIABLE FOR THE ACCURACY, COPYRIGHT COMPLIANCE, LEGALITY OR DECENCY OF MATERIAL CONTAINED IN OR ACCESSED THROUGH THIS GITHUB REPOSITORY.