Spark SDK

Spark is the fastest, cheapest, and most UX-friendly way to build financial apps and launch assets natively on Bitcoin. It’s a Bitcoin L2 that lets developers move Bitcoin and Bitcoin-native assets (including stablecoins) instantly, at near-zero cost, while staying fully connected to Bitcoin’s infrastructure.

For complete documentation, visit https://docs.spark.money

Installation

``bash
npm install @buildonspark/spark-sdk


or

yarn add @buildonspark/spark-sdk

or

pnpm add @buildonspark/spark-sdk
`

Quick Start

$3

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

// Create a new wallet (generates a new mnemonic)
const { wallet, mnemonic } = await SparkWallet.create({
options: {
network: "MAINNET", // or "REGTEST" for testing
},
});

// Or initialize with an existing mnemonic
const wallet = await SparkWallet.initialize({
mnemonicOrSeed: "your twelve word mnemonic phrase here ...",
options: {
network: "MAINNET",
},
});
`

$3

`typescript
const balance = await wallet.getBalance();
console.log(Bitcoin balance: ${balance.balance} sats);
console.log(Token balances:, balance.tokenBalances);
`

$3

`typescript
// Single-use deposit address (one-time use)
const address = await wallet.getSingleUseDepositAddress();
console.log(Deposit Bitcoin to: ${address});
`

$3

Static deposit addresses are reusable and allow you to receive multiple deposits to the same address.

`typescript
// Get a reusable static deposit address
const staticAddress = await wallet.getStaticDepositAddress();
console.log(Static deposit address: ${staticAddress});

// After sending Bitcoin to the address from an external wallet,
// get a quote for claiming the deposit
const quote = await wallet.getClaimStaticDepositQuote(transactionId);
console.log(Credit amount: ${quote.creditAmountSats} sats);
console.log(Fee: ${quote.feeSats} sats);

// Claim the deposit with the quote
await wallet.claimStaticDeposit({
transactionId,
creditAmountSats: quote.creditAmountSats,
sspSignature: quote.signature,
});

// Or use the convenience method with a max fee
await wallet.claimStaticDepositWithMaxFee({
transactionId,
maxFee: 500, // Will throw if fee exceeds this amount
});

// Query all your static deposit addresses
const addresses = await wallet.queryStaticDepositAddresses();

// Get confirmed UTXOs for a deposit address
const utxos = await wallet.getUtxosForDepositAddress(staticAddress);
for (const utxo of utxos) {
console.log(UTXO: ${utxo.txid}:${utxo.vout});
}
`

$3

`typescript
// Transfer to another Spark address
const transfer = await wallet.transfer({
receiverSparkAddress: "sp1q...",
amountSats: 10000,
});

// Withdraw to on-chain Bitcoin address
const withdrawal = await wallet.withdraw({
onchainAddress: "bc1q...",
amountSats: 50000,
exitSpeed: "FAST", // or "MEDIUM", "SLOW"
});
`

$3

`typescript
// Create a Lightning invoice
const invoice = await wallet.createLightningInvoice({
amountSats: 1000,
memo: "Payment for services",
});
console.log(Invoice: ${invoice.invoice.encodedInvoice});

// Pay a Lightning invoice
const payment = await wallet.payLightningInvoice({
invoice: "lnbc...",
maxFeeSats: 100,
});
`

$3

`typescript
// Get token balances
const { tokenBalances } = await wallet.getBalance();
for (const [tokenId, info] of tokenBalances) {
console.log(${info.tokenMetadata.tokenName}: ${info.balance});
}

// Transfer tokens
const tokenTransfer = await wallet.transferTokens({
tokenIdentifier: "spark1...",
receiverSparkAddress: "sp1q...",
tokenAmount: 100n,
});
`

$3

`typescript
import { SparkWalletEvent } from "@buildonspark/spark-sdk";

// Listen for incoming transfers
wallet.on(SparkWalletEvent.TransferClaimed, (transferId, newBalance) => {
console.log(Received transfer ${transferId}, new balance: ${newBalance});
});

// Listen for confirmed deposits
wallet.on(SparkWalletEvent.DepositConfirmed, (depositId, newBalance) => {
console.log(Deposit ${depositId} confirmed, new balance: ${newBalance});
});
``

Platform Support

The SDK supports multiple JavaScript runtimes:

- Browser
- Node.js
- React Native