This is a service that watches for TRON (TRC20) USDT transactions and triggers a webhook when a specific transaction is completed or expired.

• Watch TRC20 USDT transactions on the TRON network.
• In-memory storage for watched transactions and processed events using JavaScript's Map.
• Automatically sends webhooks for completed and expired transactions.
• Uses express for routing, helmet for security, and winston for logging.

• Node.js
• Express.js
• TronWeb - To interact with the TRON blockchain.
• BigNumber.js - For handling large numbers in transactions.
• Winston - Logging framework.
• Axios - For sending webhooks.
• Zod - For validation.

• Node.js v14+
• NPM or Yarn
• TRON API Key (for TronWeb)

1. Clone the repository:

   git clone https://github.com/moha-abdi/TronWatch.git
   cd TronWatch

2. Install the dependencies:

   npm install

3. Create a .env file at the root of your project and add the following environment variables:

   PORT=3000
   TRON_FULL_HOST="https://api.trongrid.io"
   TRON_PRO_API_KEY="your-tron-api-key"
   USDT_CONTRACT_ADDRESS="TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"
   USDT_DEPOSIT_ADDRESS="YOUR USDT TRC-20 ADDRESS"
   API_KEY="your-secure-api-key"
   WEBHOOK_SECRET="your-secure-webhook-secret"
   

4. Build the project:

   npm run build

5. Run the application:

   npm start

For development, use the following command to start the server with ts-node-dev:

npm run dev

POST /api/watcher/watch

Request body:

{
  "id": "unique-transaction-id",
  "fromAddress": "TRX-address",
  "amount": 100,
  "webhookUrl": "https://yourwebhook.com/transaction"
}

DELETE /api/watcher/watch/:id

1. In-Memory Transactions: The service stores watched transactions and processed events in memory using JavaScript's Map instead of Redis.

2. Watching Transactions: The TronWatcher class listens for TRC20 Transfer events from the TRON network. If the transaction matches a watched one, a webhook is triggered.

3. Expired Transactions: Transactions are given a 5-minute window to be completed. If they expire, a webhook is sent notifying the user that the transaction has expired.

4. Webhook Notification: When a transaction is completed or expired, the service sends a POST request to the provided webhook URL with details of the transaction.

To ensure secure communication, each webhook request includes an X-Webhook-Signature header. The signature is generated using HMAC-SHA256 and a secret key (WEBHOOK_SECRET). This allows the receiving server to verify that the webhook request came from a trusted source.

To generate the signature, the payload is hashed using the WEBHOOK_SECRET:

import crypto from "crypto";

function generateSignature(payload: string): string {
  return crypto
    .createHmac("sha256", process.env.WEBHOOK_SECRET!)
    .update(payload)
    .digest("hex");
}

Feel free to fork this repository and contribute by submitting pull requests. For any major changes, please open an issue first to discuss the changes.

MIT