il-apr-comparator

This tool gets the annual percentage rates (APRs) of the crypto currency liquidity mining pools from Bake (https://app.bake.io/liquidity-mining). Then it calculates for a given period of time the impermanent losses (ILs) of the specified pools and compares them with the according APRs. In the end it sends a notification to subscribers informing about the differences between IL and APR and the resulting yield.

Architecture and application specifics

• The application is written with Python
• It is running via a Docker container inside an AWS Lambda function
• The Docker images are saved in an AWS Elastic Container Registry (ECR) repository
• The Lambda function is triggered on a schedule defined in AWS EventBridge
• Notifications are sent via AWS Simple Notification Service (SNS) to all subscribers
• To get notifications one has to manually add a subscription to the according SNS topic via the AWS console
• Necessary parameters are stored in the Parameter Store of the AWS Systems Manager
• Before running the calculator one has to specify all coin pairs for which the IL should be calculated as a list in the according Parameter Store entry
• To get the information about the liquidity mining pools the website of Bake (https://app.bake.io/liquidity-mining) is scraped on two different ways:
  • Classic HTML scraping when running the application locally
  • AI based scraping with the external service https://www.browse.ai/ when running inside the Lambda function or when running locally
• One needs to create an account for the browse.ai service and set up a robot to extract the necessary data from the Bake website
• The corresponding API Key and Robot ID from browse.ai are used to access the robot from the application
• The extracted data from the robot must match the following form:
  • Name of the table: Coin_Pairs_LM_APR

  • Position	coin_pair	apr
    1	BTC-DFI	XX%
    2	ETH-DFI	XX%
    ...	...	...

• The data for the coin prices is taken from the public API of CoinGecko (https://www.coingecko.com/)
• Impermanent Loss is calculated based on the Uniswap's constant product formula. A simple online calculator can be found here: https://dailydefi.org/tools/impermanent-loss-calculator/

Update dependencies for Python

• Install pipreqs Python package:
  • pip install pipreqs
• Create requirements.txt. Use --force to override already existent file:
  • pipreqs --force <path_to_source_folder>
• Manually (re)add any necessary dependencies removed by pipreqs (e.g. lxml)

Build and deployment process

The whole build and deployment process is automated via CircleCI pipelines using Continuous Integration (CI) and Continuous Deployment (CD).

Necessary variables in CircleCI

Project environment variables

• AWS_ROLE_ARN
• AWS_SECRET_KEY
• For executions in a local environment
  • AWS_ACCESS_KEY
  • AWS_ACCOUNT_ID
  • AWS_REGION

Contexts

• Context named github with a variable called GH_PAT_CFN_SCRIPTS_REPO (Personal Access Token for the GitHub repo containing the CloudFormation deployment scripts)