Payment Monitor

The PaymentMonitor is the component that watches for incoming DERO payments by polling the wallet RPC.

How It Works

1. The monitor runs on a configurable interval (default: 5 seconds)
2. Each poll calls GetTransfers on the wallet RPC
3. Incoming transfers are matched against pending invoices by payment ID
4. When a match is found, the invoice transitions from pending → confirming
5. The monitor continues tracking until the required number of confirmations is reached
6. Once confirmed, the invoice moves to completed

Configuration

The payment monitor is managed by the InvoiceEngine — you typically don't create one directly. Configuration is passed through the engine:

const engine = new InvoiceEngine({
  walletRpcUrl: "http://127.0.0.1:10103/json_rpc",
  daemonRpcUrl: "http://127.0.0.1:10102/json_rpc",
 
  // Monitor-specific options
  pollInterval: 5000,          // How often to check (ms)
  confirmationsRequired: 1,    // Blocks to wait after detection
});

Confirmations

DERO's DAG-based block structure means confirmations work differently than linear blockchains:

• 1 confirmation (default) — The transaction is included in a block
• Higher values — More blocks have been mined since inclusion

Partial Payments

If a customer sends less DERO than the invoice amount:

• The invoice transitions to partial status
• The received amount is tracked
• The monitor continues watching for additional payments
• If the total reaches the invoice amount, it moves to confirming → completed
• If the expiry window closes first, it moves to expired (with the partial amount recorded)