Track UTXO Balances Across Bitcoin, Litecoin and Dogecoin with Crypto APIs

The Challenge of UTXO‑Based Balance Calculation

Calculating the exact balance of an address on a UTXO‑based blockchain (such as Bitcoin, Litecoin, Dogecoin & Dash) requires scanning the full history of transactions to identify unspent transaction outputs (UTXOs) and exclude those that have already been spent. Doing this traditionally demands running a full node, maintaining indexes, and continually updating state - a resource-intensive, slow, and costly process.

Crypto APIs offers a radically simpler approach. With pre‑indexed, real‑time data accessible via REST endpoints, retrieving UTXOs becomes nearly instantaneous, highly cost‑effective, and extremely scalable.

What are UTXOs and Why They Matter

In UTXO‑based cryptocurrencies, each transaction consumes prior outputs and creates new ones. An unspent transaction output (UTXO) represents value available for spending under the owner’s private key. To compute an address’s current balance, one must:

• Identify all UTXOs ever received.
   
• Determine which have not yet been spent.
   
• Sum the balances of remaining UTXOs.

Traditional methods require heavy infrastructure. Crypto APIs handles all of that indexing and state tracking efficiently for you.

How Crypto APIs Retrieves UTXOs Efficiently

Crypto APIs provides dedicated REST endpoints under various of our blockchain infrastructure suite solutions, allowing to retrieve UTXOs quickly:

🧩 UTXO Endpoint (Confirmed Unspent Outputs)

Using the List Unspent Transaction Outputs by Address endpoint you receive:

• Transaction ID (txid)
   
• Output index (vout)
   
• Amount and unit
   
• Block height, timestamp
   
• Flags: isConfirmed, isAvailable

Responses are delivered in milliseconds, with no need to scan the blockchain yourself. Historical UTXOs and newly unconfirmed outputs are tracked through indexed data.

Accurate Balance via UTXO Summation

Before retrieving balance data, the client must first sync an address/wallets. Crypto APIs simplifies this process with a radically easier approach. Once an address, wallet, xpub, ypub, or zpub is synced, we begin indexing the data and continue updating it in real time. This enables fast, cost-effective, and scalable access to UTXOs via REST endpoints.

Get Address Balance Endpoint - Returns the confirmed balance by summing only confirmed UTXOs. This eliminates the noise of mempool and unconfirmed transactions, ensuring accuracy when precise accounting is required.

HD Wallet Management: Sync (not Create) xPubs, yPubs, zPubs

Crypto APIs supports HD Wallet Management, letting customers index their existing HD wallets - via xPub, yPub, or zPub - to enable:

• Derivation and tracking of addresses
   
• Monitoring transaction history
   
• Viewing assets and balances per synced extended public key
   
• Security and usage insights across chains

Once a wallet is synced, Crypto APIs maintains constant updates and allows API access to all relevant UTXOs, transactions, and derived addresses 

Real‑Time Monitoring with Blockchain Events (Webhooks)

Crypto APIs’ Blockchain Events product offers real-time notifications for:

• New UTXO creation
   
• Spent outputs
   
• Incoming or outgoing transactions
   
• Transaction confirmations

Developers subscribe to address-level events using REST-based webhook subscriptions. Notifications are sent under 100 ms of the event occurrence, enabling responsive applications such as wallets, dashboards, or compliance systems

Fully Indexed UTXO Data, No Node Required

Crypto APIs maintains full indexing of UTXO history for all supported blockchains (Bitcoin, Litecoin, Dash, Zcash, Dogecoin, etc.) from genesis onward. This enables users to:

• Query the full set of UTXOs tied to any known address
   
• Access confirmed and available outputs
   
• Perform analytics, auditing, and historic balance tracking

All this is provided through REST API—with no need to run your own nodes or indexers 

Benefits of Using Crypto APIs for UTXO Retrieval

Example Workflow: Get UTXOs for a Bitcoin Address

1. Use the List Unspent Transaction Outputs by Address endpoint to fetch confirmed, spendable UTXOs.
    
2. Sum UTXOs to compute total balance or filter by certain criteria (e.g. minimum confirmations).
    
3. Optionally subscribe to address-level webhooks to track new UTXO creations and spent outputs.
    
4. For HD wallet tracking, sync your extended public keys to automatically monitor derived UTXOs across addresses.

Final Thoughts: UTXO Retrieval Made Easy

Manually indexing entire blockchain history and running your own nodes presents time, cost, and scalability challenges - especially when the goal is only to get UTXOs for one or more addresses. Crypto APIs eliminates this complexity through:

• Pre‑indexed, confirmed-only UTXO retrieval APIs
   
• Balance endpoints that avoid unconfirmed noise
   
• HD wallet sync capability for xPub/yPub/zPub tracking
   
• Real-time webhook notifications for dynamic UTXO updates
   
• Fully historical UTXO data accessible via simple REST

For further information you can refer to our technical documentation or you can contact our team to help you get started using our services.