What is Lightning Network?

The Lightning Network is a "Layer 2" payment protocol built on top of Bitcoin that enables fast, low-cost transactions.

Why Lightning?

Traditional Bitcoin transactions:

  • Can take 10+ minutes to confirm
  • Have transaction fees that can be high during busy times
  • Are recorded on the blockchain forever

Lightning Network transactions:

  • Are instant (sub-second)
  • Have minimal fees (often less than 1 satoshi)
  • Are private (not all details go on the blockchain)
  • Enable micropayments (pay fractions of a cent)

How It Works (Simplified)

  1. Payment Channels: Two parties open a channel by creating a special Bitcoin transaction
  2. Off-Chain Transactions: They can then make unlimited instant transactions between each other
  3. Network of Channels: Payments can route through multiple channels to reach any destination
  4. Settlement: Channels can be closed at any time, settling the final balance on the Bitcoin blockchain

Lightning in Portal

Portal uses Lightning Network for:

Single Payments

One-time payments for purchases, tips, or services:

await client.requestSinglePayment(
  userKey,
  [],
  {
    amount: 1000,        // 1 sat (1000 millisats)
    currency: Currency.Millisats,
    description: "Premium subscription"
  },
  (status) => {
    if (status.status === 'paid') {
      console.log('Payment received!');
    }
  }
);

Recurring Payments

Subscription-based payments with automatic billing:

await client.requestRecurringPayment(
  userKey,
  [],
  {
    amount: 10000,       // 10 sats per month
    currency: Currency.Millisats,
    recurrence: {
      calendar: "monthly",
      first_payment_due: Timestamp.fromNow(86400),
      max_payments: 12
    },
    expires_at: Timestamp.fromNow(3600)
  }
);

Nostr Wallet Connect (NWC)

Portal uses Nostr Wallet Connect, a protocol that allows:

  • Requesting payments through Nostr messages
  • User approval through their Lightning wallet
  • Real-time payment status updates
  • Non-custodial payment flow (users maintain control of funds)

The user's Lightning wallet could be:

Payment Flow in Portal

  1. Payment Request: Your app requests a payment through Portal
  2. Nostr Message: Request is sent to the user via Nostr
  3. Wallet Notification: User's wallet shows the payment request
  4. User Approval: User approves or denies the payment
  5. Lightning Payment: Wallet sends payment via Lightning Network
  6. Confirmation: Your app receives real-time payment confirmation

All within seconds, with minimal fees.

Benefits for Your Business

  • Instant Settlement: Receive payments immediately
  • Global Reach: Accept payments from anyone, anywhere
  • No Chargebacks: Bitcoin payments are final
  • Low Fees: Typically < 1% (often much less)
  • No Middlemen: Direct payment from customer to you
  • Privacy: No personal information required

Learn More

Next: Start integrating Portal with the Quick Start Guide