Getting Started

1. Clone this repository: git clone [email protected]:FatKidddd/tokkalabs.git
2. Navigate to the project directory: cd tokkalabs
3. Create a .env file from .env.local cp .env.local .env, fill in missing API key

Development (preferred)

1. Start db: sudo docker-compose -f db-only.yml up -d
2. Install deps: yarn install
3. Run tests to verify: yarn test
4. Run express server & script: yarn start:dev
5. Visit http://localhost:3000/api-docs to interact with Swagger UI
6. sudo docker-compose down to stop all services

Note: to set up pre-commit linting + prettier yarn husky:prepare

Database commands (to view live addition of txn fees in db)

1. To access db: sudo docker exec -it txnfeesdb psql -U user -d txnfeesdb
2. To view all txnfees SELECT * from txnfees;

Production (takes a while to build & can't see tests log)

1. Start db & express server (takes 3 mins to build): sudo docker-compose up --build
2. Visit http://localhost:3000/api-docs to interact with Swagger UI
3. sudo docker-compose down to stop all services

Planning

Functionality

• (txn hash) -> USDT txn fee

  • find in db
    • if found:
      • retrieve from db
      • return USDT txn fee
    • else:
      • query txn hash from etherscan
        • parse fields
      • using timeStamp, query binance API klines with startTime = timeStamp - epsilon, endTime = timeStamp + epsilon, where epsilon is probably some seconds
        • mid = (low + high) / 2
      • add to db
      • return USDT txn fee

• (Batch job) (startBlock, endBlock) -> transactions with all their prices

  • function that takes in (startBlock, endBlock) -> populate db

DB schema

1. txn hash
2. timeStamp
3. gasUsed
4. gasPrice
5. binance ETHUSDT price
6. txn fee in USDT

Notes

Useful Binance API live data - websocket current avg price historical data - use klines / candlesticks OHLC

Useful Etherscan API live data - websocket ERC20 transfers historical - convert timestamps into closest blocks, query using start and end blocks

Further improvements

• Use Redis for caching
• (not implemented) making batch processing more efficient by avoiding repeated queries
• (not implemented) make batch processing able to handle larger query range
• Inaccurate pricing dependent on timeframe given to binance API -> should add in uncertainty / another field for resolution

License

This project is licensed under the MIT License - see the LICENSE file for details

Boilerplate with TypeScript, Express, ESLint, Prettier, Husky + Lint-staged, and Vitest