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Crypto Observability

NoxPay tracks blockchain transactions in real-time to provide a seamless checkout experience for crypto payments.

⛓️ Supported Networks​

  • Solana: Real-time monitoring for USDC and SOL deposits.
  • Polygon (PoS): High-speed tracking for USDT (ERC-20) transfers.

🔍 The Crypto Observer​

The Worker includes a CryptoObserver class that polls public RPC nodes to find payments matching your merchant address.

Solana Polling​

The worker uses the getSignaturesForAddress and getTransaction RPC methods to:

  1. Monitor your Solana wallet for new incoming signatures.
  2. Parse the jsonParsed transaction data to verify the recipient and amount.
  3. Cross-reference the transaction hash as proof of payment.

Polygon/Ethereum Polling​

For EVM-compatible chains like Polygon, the worker:

  1. Uses eth_getLogs to monitor Transfer events from the USDT smart contract.
  2. Filters events where the to address matches your configured merchant wallet.
  3. Extracts the transactionHash for settlement verification.

⚙️ RPC Configuration​

For production use, we recommend using a private RPC provider (e.g., Helius, Alchemy, or QuickNode) to avoid rate limits on public nodes.

Configure your nodes in the .env file:

  • SOLANA_RPC_URL: Your Solana RPC endpoint.
  • POLYGON_RPC_URL: Your Polygon RPC endpoint.
  • SOLANA_WATCH_ADDRESS: Your merchant wallet address for Solana.
  • POLYGON_WATCH_ADDRESS: Your merchant wallet address for Polygon.

⏳ Poll Interval​

By default, the worker polls crypto networks every 10 seconds. This ensures customers see a "Payment Confirmed" screen shortly after their transaction is finalized on the blockchain.