Skip to main content
Lightning Network enables instant Bitcoin payments, but traditional Lightning wallets force a choice: run complex infrastructure or give up custody. Spark eliminates this tradeoff.

​
The Lightning Custody Problem

Traditional Lightning has a UX problem:

​
Option 1: Run Your Own Node

  • Manage channels and liquidity
  • Keep node online 24/7
  • Handle routing and rebalancing
  • Technical complexity deters most users

​
Option 2: Custodial Wallet

  • Easy to use
  • Someone else holds your Bitcoin
  • Counterparty risk
  • Not your keys, not your coins
Most users choose custodial wallets because self-custody Lightning is too hard. This undermines Bitcoin’s core value proposition.

​
Spark: Self-Custody Lightning Without the Complexity

Spark gives you true self-custody with native Lightning support: 
// Send a Lightning payment - you keep custody
const payment = await wallet.payLightningInvoice({
  invoice: "lnbc100n1p3..."
});

// Receive via Lightning - funds go to YOUR wallet
const invoice = await wallet.createLightningInvoice({
  amountSats: 10000,
  memo: "Payment for coffee"
});
No channels. No liquidity management. No node. Just Lightning payments where you control the keys.

​
How It Works

​
Sending Lightning Payments

When you pay a Lightning invoice from Spark:
  1. Your Spark wallet signs the payment authorization
  2. Spark Service Providers (SSPs) route the payment over Lightning
  3. The recipient gets paid instantly
  4. Your keys never leave your device
You pay a small routing fee (0.25% + network fees), but you maintain custody throughout.

​
Receiving Lightning Payments

When someone pays your Lightning invoice:
  1. SSPs receive the Lightning payment
  2. Funds are credited to your Spark wallet
  3. You can unilaterally exit to L1 anytime
The Bitcoin that arrives is real Bitcoin you control, not an IOU.

​
Custody Comparison

AspectCustodial LightningSelf-Custody (Node)Spark
Who holds keys?Service providerYouYou
Can they steal funds?YesNoNo
Channel management?N/ARequiredNone
Liquidity requirements?N/AYesNone
Node uptime required?N/AYesNo
Unilateral exit?NoYesYes

​
Real Self-Custody Guarantees

What makes Spark Lightning truly self-custodial:

​
1. Your Keys, Your Bitcoin

Private keys are generated and stored on your device. Spark operators never have access to move your funds without your signature.

​
2. Unilateral Exit

If Spark operators disappear, go rogue, or refuse to cooperate, you can exit to Bitcoin L1 by broadcasting a pre-signed transaction. No one can stop you.

​
3. No Counterparty Risk

Unlike custodial Lightning, there’s no single entity that can lose, steal, or freeze your funds. The system is designed to be trustless.

​
Use Cases

​
For Users

  • Daily payments: Pay Lightning invoices without custody tradeoffs
  • Receive tips/payments: Get paid in Lightning, keep self-custody
  • Store of value: Hold Bitcoin with Lightning accessibility

​
For Developers

  • Wallets: Build self-custody wallets with Lightning out of the box
  • Payment apps: Accept Lightning without custodial risk
  • Exchanges: Offer Lightning deposits/withdrawals with better security

​
Getting Started

​
1. Create a Wallet

import { SparkWallet } from "@buildonspark/spark-sdk";

const wallet = await SparkWallet.initialize({
  mnemonicOrSeed: "your twelve word mnemonic phrase here..."
});

​
2. Pay a Lightning Invoice

const result = await wallet.payLightningInvoice({
  invoice: "lnbc100n1p3..."
});

console.log(`Paid ${result.amountSats} sats, fee: ${result.feeSats}`);

​
3. Receive via Lightning

const invoice = await wallet.createLightningInvoice({
  amountSats: 50000,
  memo: "Self-custody Lightning payment"
});

console.log(`Share this invoice: ${invoice.bolt11}`);

​
The Bottom Line

Lightning Network is powerful but historically required either technical complexity or custody compromise. Spark removes this tradeoff:
  • Keep your keys: True self-custody, not custodial accounts
  • No infrastructure: No node, no channels, no liquidity
  • Unilateral exit: Always able to exit to L1 if needed
  • Simple SDK: Lightning payments in a few lines of code
Self-custody Lightning is finally accessible to everyone.

​
Learn More