📑Extending SendPayment Method

Extending sendPayment method to add optional metadata field

WebLN SendPayment which takes paymentRequest parameter holding the Bolt11 Invoice, we can extend this function to add an extra “optional” parameter named metadata which will store metadata as a string and is passed further to the Wallets.

Function Signature:

sendPayment(paymentRequest: string, metadata?: string): Promise<SendPaymentResponse>;

WebLN Provider attached by wallets before

WebLN provider attachted by wallets before

WebLN Provider attached by wallets after implementation of this spec

WebLN provider attached by wallets after

Passing Metadata Via SendPayment Method

Now the extended version of the SendPayment method implemented by the wallet is sent to the WebLN-enabled client. Now clients can pass metadata along with Invoice using such function.

Example:

webln.sendPayment(invoice, metadata)
  .then(function (r) {
    // Required constraint to protect metadata as a rule while paying empty invoices
    if (r != undefined) {
      // Provide metadata after successful payment
      // Eg. Allow users to download a song after payment is successful
    }
  })