intro.md

description
Describes architecture of the spec

⚙ Specifications Overview

This page describes the basic workflow of the current spec broken down into the five steps for different wallets trying to implement this spec.

Workflow

• Trigger SendPayment method
  
  The lightning web application requests for WebLN provider by triggering SendPayment method.
  
  Provider passed by the wallet to the lightning web application shall contain an extended definition of SendPayment method

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

• Structure and Pass Metadata
  
  Using SendPayment method, the lightning web application passes an invoice along with additional metadata. WebLN provider delivers such data to the wallets.
  
  Before passing metadata to the wallet using the SendPayment method, metadata shall present in a structured form using the data models provided in a comprehensive guide.

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
    }
  })

• Validate Metadata
  
  Wallets validate received metadata against predefined data models/schemas.\

• Render Metadata in Confirmation Dialogue
  
  ✅ If metadata is passed and is valid, it is rendered in confirmation dialogue along with payment details.
  
  ❌ If metadata is passed and is not valid, even if the invoice is valid, there might be a possibility of fraud, and wallets don't allow it to proceed further.\

• Store, Interact and Do After Actions
  
  If metadata passed to the wallet is valid, also an invoice is paid - store, interact and do after actions with metadata.

Know More About Each Step

Follow our comprehensive guide to know more about each step and its implementation details.

{% content-ref url="make-a-request-to-wallet-for-webln-provider-via-triggering-sendpayment.md" %} make-a-request-to-wallet-for-webln-provider-via-triggering-sendpayment.md {% endcontent-ref %}

{% content-ref url="structure-metadata-and-pass-it-to-the-wallet-in-callback.md" %} structure-metadata-and-pass-it-to-the-wallet-in-callback.md {% endcontent-ref %}

{% content-ref url="validate-metadata-wallets.md" %} validate-metadata-wallets.md {% endcontent-ref %}

{% content-ref url="render-metadata-in-confirmation-dialogue-if-valid.md" %} render-metadata-in-confirmation-dialogue-if-valid.md {% endcontent-ref %}

{% content-ref url="store-interact-and-do-after-actions-with-metadata.md" %} store-interact-and-do-after-actions-with-metadata.md {% endcontent-ref %}