Block Gas Tracker

Overview

Block Gas Tracker is a Bun-based TypeScript server that streams real-time block and gas metrics for multiple EVM-compatible blockchains. Clients connect via WebSocket and can subscribe to one or more chains to receive block data and metrics. The project uses Winston for debug-level logging with log rotation.

---

Features

• Real-time block and gas metrics for multiple EVM chains
• WebSocket API with multi-chain subscriptions per client
• Debug-level logging with Winston and log rotation (3 days)

---

Setup

1. Install dependencies:

   bun install

2. Copy .env.example to .env:

   cp .env.example .env

3. Configure your environment by updating the .env file with your WebSocket RPC URLs for each chain (see Environment Variables section below).
4. Start the server:

   bun run server.ts

---

Environment Variables

Set the following environment variables for RPC URLs (example names, see config/chains.ts for all):

• WSS_MAINNET_URL
• WSS_BSC_URL
• WSS_ARBITRUM_URL
• WSS_BASE_URL
• WSS_AVALANCHE_URL
• WSS_SONIC_URL
• WSS_OPTIMISM_URL
• WSS_MANTLE_URL
• WSS_POLYGON_URL
• WSS_LINEA_URL
• SERVER_PORT (optional, defaults to 8080)

---

Logging

This project uses Winston for logging. Logs are written to logs/application-%DATE%.log and rotated daily, retaining logs for 3 days. Console output is also enabled at debug level.

---

WebSocket API

• Endpoint: ws://localhost:8080
• How it works:
  Connect via WebSocket and send subscription/unsubscription messages for supported chains. The server streams block data for each subscribed chain.

Message Format

Client → Server:

• Subscribe: { "action": "subscribe", "chainId": "1" }
• Unsubscribe: { "action": "unsubscribe", "chainId": "1" }

Server → Client:

• On each new block:

   {
   	"blockNumber": "18456789",
   	"baseFeePerGas": "1234567890",
   	"gasUsed": "21000",
   	"gasLimit": "30000000",
   	"gasPrice": "1234567890"
   }

Example Usage

const ws = new WebSocket("ws://localhost:8080");
ws.onopen = () => {
	ws.send(JSON.stringify({ action: "subscribe", chainId: "1" }));
	ws.send(JSON.stringify({ action: "subscribe", chainId: "137" })); // Polygon
};
ws.onmessage = (msg) => console.log(JSON.parse(msg.data));

// To unsubscribe:
ws.send(JSON.stringify({ action: "unsubscribe", chainId: "1" }));

---

Supported Chains

See config/chains.ts for supported chain IDs and RPC URLs. Example:

Chain Name	Chain ID	Env Variable
Ethereum	1	WSS_MAINNET_URL
BSC	56	WSS_BSC_URL
Arbitrum	42161	WSS_ARBITRUM_URL
Polygon	137	WSS_POLYGON_URL
...	...	...

---

Dependencies

• Bun (runtime)
• TypeScript
• viem (EVM chain client)
• Winston & winston-daily-rotate-file (logging)

---

License

MIT