Instant Bitcoin Deposits
Credit on-chain Bitcoin deposits instantly with 0-conf. No waiting for block confirmations, no pending states, no support tickets about slow deposits.
Trusted by teams like Breez, Xverse, and Cake building on Spark
Slow Bitcoin deposits create friction at the worst possible moment
On-chain Bitcoin transactions require 3-6 confirmations before most platforms credit user accounts. That's 10 to 60 minutes of waiting after a deposit transaction broadcasts. Users see their balance as pending, refresh repeatedly, open support tickets asking when funds will arrive, or abandon the deposit entirely. Your team spends time explaining confirmation times and reassuring users their money is safe. It's operational overhead on your side and a poor first impression for users who just want to trade or spend.
What we do
Credit deposits instantly, handle confirmation risk at protocol level
Instant 0-conf deposits
Spark credits on-chain Bitcoin deposits the moment a transaction is broadcast. Users see funds available in seconds, not blocks. No pending states, no waiting for confirmations.
Protocol handles risk, not your team
Spark validates transactions at broadcast time and absorbs double-spend risk. Your platform doesn't need to manage confirmation thresholds, fee analysis, or RBF detection. The protocol layer handles it.
Self-custodial for users
Every wallet is backed by the user's own keys. You don't hold funds, so you avoid custodial risk, regulatory overhead, and the operational burden of managing user balances securely.
Works with Lightning and stablecoins
Spark's SDK handles on-chain deposits, Lightning payments, and native stablecoins in the same integration. One API for all Bitcoin and stablecoin rails.
Go deeper
Everything between the mempool and your user's balance, handled
Deposit UX
Funds show up before the block does.
Your app generates a deposit address through the Spark SDK. The moment the user's transaction hits the mempool, Spark validates it and credits the balance. The user sees spendable funds in seconds, on the first deposit and every one after.
Read the SDK docs →const wallet = await SparkWallet.initialize({
mnemonicOrSeed: seed,
options: { network: "MAINNET" },
});
const address =
await wallet.getSingleUseDepositAddress();
// user sends BTC to address
// balance is spendable in secondsRisk handling
The protocol absorbs 0-conf risk, not your team.
Accepting unconfirmed transactions safely is the hard part of instant deposits. Spark does the transaction validation, fee analysis, RBF detection, and mempool monitoring, and resolves the rare failure cases automatically.
- Double-spend and RBF checks at broadcast time
- Continuous mempool and chain monitoring until finality
- No confirmation-threshold logic in your codebase
- No support tickets about pending deposits
One integration
On-chain, Lightning, and stablecoins in one SDK.
Deposits are just the front door. The same integration gives your users instant Lightning send and receive, fee-free transfers between Spark wallets, and native stablecoins, all self-custodial.
- One API surface for every Bitcoin rail
- Users hold their own keys: no custodial risk on your balance sheet
- Swap between Bitcoin and stablecoins in the same wallet
Why Spark
One integration, instant deposits across all Bitcoin rails
User initiates deposit to their Spark wallet
Your app generates a Bitcoin deposit address via the Spark SDK. This address is unique to the user and tied to their self-custodial keys.
Transaction broadcasts to the network
The user sends Bitcoin from an external wallet or exchange. The transaction hits the mempool and Spark detects it immediately.
Spark validates and credits instantly
Spark validates the transaction, checks for double-spend risk, and credits the user's balance in under a second. No confirmations required.
Funds are available for trading or spending
The user sees their balance update in real time. They can trade, withdraw to Lightning, swap to stablecoins, or send to another user immediately.
Spark settles on-chain in the background
The protocol waits for block confirmations and finalizes the deposit on-chain. Your app doesn't need to track this: it's handled at the protocol layer.
Compare
Every way to handle Bitcoin deposits, side by side
Most platforms pick between making users wait, taking custody, or building Lightning infrastructure in-house. Spark removes the trade-off.
| Spark | Wait for confirmations | Custodial ledger | Self-hosted Lightning | |
|---|---|---|---|---|
| Time to credit | ✓ Under a second | ✗ 10-60 minutes | ✓ Instant (internal ledger) | ✓ Instant, if channels are funded |
| Custody | ✓ User holds keys | ✓ User holds keys | ✗ You hold user funds | ✗ Platform-managed node custody |
| 0-conf risk | ✓ Absorbed by protocol | — Avoided by waiting | ✗ Yours to manage | ✗ Yours to manage |
| Engineering lift | ✓ SDK, days to integrate | ✓ Low, but poor UX | ✗ Ledger, security, compliance | ✗ Nodes, channels, liquidity ops |
| Regulatory surface | ✓ Non-custodial | ✓ Non-custodial | ✗ Money transmission licensing | ✗ Depends on custody model |
| Stablecoins on the same rail | ✓ Native | ✗ No | — Separate system | ✗ No |
Based on typical implementations: 3-6 confirmation deposit policies, omnibus custodial ledgers, and self-managed LND/CLN infrastructure.
Products
Instant Bitcoin Deposits
Receive on-chain bitcoin in seconds with 0-conf
Self-Custodial Lightning
Full Lightning send and receive, no nodes or channels
Bitcoin Buy and Sell
The cheapest way to buy and sell bitcoin directly to a self-custodial wallet
Bitcoin Rewards
Distribute bitcoin rewards and incentives at scale
Cross-Chain Bitcoin Swaps
The fastest, cheapest way to move bitcoin into stablecoins and other assets
Stablecoin Issuance
Issue and manage stablecoins natively on Bitcoin
Trusted by the world's best bitcoin developers.
From wallets to stablecoin issuers, the best teams ship on Spark.Spark and WDK unlock programmable, resilient Bitcoin over Lightning: instant global payments without compromising custody or privacy.
We care deeply about network effects. Issuing on Spark is a no-brainer for Brale, it has the potential to bring billions of people to stablecoins.
Our goal is to make Xverse the definitive home of BitcoinFi, and integrating Spark is a monumental step.
Spark is transformative. It redefines what Bitcoin can be, evolving it from a monetary network into an application platform.
We're excited to build on Spark to unlock powerful Bitcoin-based rails for all the users we serve without requiring them to be crypto-native.
Flashnet couldn't exist without Spark. It's the best infrastructure for building real money apps on Bitcoin, period.
FAQ
Spark validates Bitcoin transactions at broadcast time, checking for double-spend risk, fee adequacy, and RBF flags. The protocol credits the deposit instantly and absorbs the confirmation risk. Your platform doesn't need to manage thresholds or edge cases: Spark handles it.
Spark monitors the mempool and on-chain state continuously. If a transaction fails to confirm or is replaced, the protocol resolves it automatically. Your app doesn't need to handle these edge cases.
Yes. Once funds are credited, users can withdraw to Lightning, swap to stablecoins, send to another Spark user, or withdraw on-chain. Transfers within Spark are instant and fee-free.
Yes. Spark handles both on-chain and Lightning deposits in the same SDK. Users can deposit via either rail and see funds instantly. Your integration supports both with no additional work.
Transfers within Spark are fee-free. You only pay Bitcoin network fees when users deposit to or withdraw from Spark. There are no per-transaction fees for crediting deposits or managing balances.
Add instant Bitcoin deposits to your platform
Spark integrates in days and handles the complexity of 0-conf, Lightning, and stablecoins behind one API.