danielchernov7/wallet-activity-tracker

This project is a backend service that watches cryptocurrency wallets and sends alerts when something interesting happens in them. It listens to two kinds of blockchains: EVM chains, which is the family that includes Ethereum, Base, and Arbitrum, and Solana. When a transaction touches a wallet you have asked it to track, the service decodes the transaction, looks up the dollar value of the tokens involved, attaches a label if the other side of the trade is a known exchange or DEX, and then decides whether to send a notification. The code is structured as several pieces that pass work to each other through a queue. Chain listeners use ethers.js over a WebSocket for EVM chains and web3.js for Solana to receive new transactions in real time. These raw events get pushed into a BullMQ queue, which is a job queue built on Redis. A first worker enriches each transaction by classifying it, fetching token prices from Jupiter or CoinGecko with a 60 second cache, and looking up address labels in the database. A second worker checks the result against the alert rules and sends notifications. Data is stored in PostgreSQL using Prisma as the database layer. The README lists four kinds of alert rule. amount_gt fires when a transaction value in US dollars goes above a threshold. contract_interaction fires when the wallet touches a specific contract address. unusual_activity fires when a wallet has more than a given number of transactions in a time window. There is also a catch all called any. For each rule you choose where to send the alert: a Telegram chat, a webhook URL of your own, a WebSocket connection, or any combination of those. To run it locally, you copy a .env.example file and fill in RPC endpoints for the chains and Telegram credentials, then start PostgreSQL and Redis with docker compose, install dependencies with npm, generate the Prisma client, run database migrations, and seed a table of known addresses. The system then runs as three separate processes: a Fastify REST and WebSocket API on port 3000, the BullMQ workers, and the chain listeners. The REST API exposes routes for adding and removing tracked wallets, listing recent transactions, and managing alerts. The README also mentions design choices such as idempotent transaction upserts and graceful shutdown on SIGINT.