Skip to main content
Pays a Lightning invoice via the SparkWallet.

​
Method Signature

interface PayLightningInvoiceParams {
  invoice: string;
  maxFeeSats: number;
  preferSpark?: boolean;
  amountSatsToSend?: number;
  idempotencyKey?: string;
}

async payLightningInvoice(params: PayLightningInvoiceParams): Promise<LightningSendRequest | WalletTransfer>

​
Parameters

​
invoice
string
required
The BOLT11-encoded Lightning invoice to pay
​
maxFeeSats
number
required
Maximum fee in satoshis to pay for the invoice
​
preferSpark
boolean
When true, initiate a Spark transfer if a valid Spark address is found in the invoice (default: false)
​
amountSatsToSend
number
Amount in satoshis to send for zero-amount invoices
​
idempotencyKey
string
Optional client-provided idempotency key for deduplication. Multiple requests with the same key will return the same result instead of creating duplicate payments or returning errors. Use this to prevent duplicate transactions when retrying failed requests.

​
Returns

​
request
LightningSendRequest | WalletTransfer
required
The Lightning payment request details, or a WalletTransfer if preferSpark is true and a valid Spark address was found in the invoice
The payment preimage is not returned immediately. To retrieve the preimage after payment completes, call getLightningSendRequest(id) with the returned request ID.
When preferSpark: true and the invoice contains a valid Spark fallback address, the method returns a WalletTransfer instead of LightningSendRequest. If no valid Spark address is found, it falls back to Lightning.

​
Examples

// Pay a regular invoice via Lightning
const payment_response = await wallet.payLightningInvoice({
  invoice: "lnbc100n...", // Regular Lightning invoice with amount
  maxFeeSats: 5,
});
console.log("Payment Response:", payment_response);

// Pay a zero-amount invoice
const zeroAmountPayment = await wallet.payLightningInvoice({
  invoice: "lnbc...", // Zero-amount Lightning invoice
  maxFeeSats: 5,
  amountSatsToSend: 1000, // Specify amount for zero-amount invoice
});
console.log("Zero-amount Payment Response:", zeroAmountPayment);

// Prefer Spark transfer if invoice has Spark fallback address
const sparkPreferred = await wallet.payLightningInvoice({
  invoice: "lnbc100n...", // Invoice with Spark fallback
  maxFeeSats: 5,
  preferSpark: true, // Will use Spark transfer if available
});
// Returns WalletTransfer if Spark used, LightningSendRequest otherwise

// Use idempotency key to prevent duplicate payments
const idempotentPayment = await wallet.payLightningInvoice({
  invoice: "lnbc100n...",
  maxFeeSats: 5,
  idempotencyKey: "unique-payment-id-123", // Prevents duplicate if retried
});
// Safe to retry with same key - won't create duplicate payment