# Kaspa API

The Crypto APIs Kaspa API, part of the Blockchain API, lets you read KAS balances and transactions, estimate fees and prepare transactions without running a node. Kaspa is served on mainnet, and webhooks tell your server when a payment confirms.

## Key facts

| | |
| --- | --- |
| Networks | Mainnet |
| Model | UTXO (blockDAG) |
| Endpoints | 11 |
| Confirmations webhook | Yes, per address |
| Custody | Non-custodial, you sign |
| Free trial | 14 days, no card |

## How do I get a Kaspa address balance?

Send one GET request, authenticated with your API key, to Kaspa mainnet.

```
curl https://rest.cryptoapis.io/addresses-latest/kaspa/mainnet/YOUR_ADDRESS/balance \
  -H "X-API-Key: YOUR_API_KEY"
```

## Which Kaspa endpoints are available?

The main calls. Kaspa is served on mainnet.

| What it does | Method and path | Reference |
| --- | --- | --- |
| Address balance | `GET /addresses-latest/kaspa/mainnet/{address}/balance` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/address-latest-kaspa/get-address-balance-kaspa/get) |
| Transactions of an address | `GET /addresses-latest/kaspa/mainnet/{address}/transactions` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/address-latest-kaspa/list-confirmed-transactions-by-address-kaspa/get) |
| Transaction by hash | `GET /transactions/kaspa/mainnet/{transactionId}` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/transactions-data-kaspa/get-transaction-details-by-transaction-id-kaspa/get) |
| Fee recommendations | `GET /blockchain-fees/kaspa/mainnet/mempool` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/blockchain-fees-kaspa/get-fee-recommendations-kaspa/get) |
| Prepare an unsigned transaction | `POST /prepare-transactions/kaspa/mainnet/native-coins` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/prepare-transactions-kaspa/prepare-kaspa-transaction/post) |
| Webhook on a confirmed payment | `POST /blockchain-events/kaspa/mainnet/address-coins-transactions-confirmed` | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-coins-transactions/post) |

## Kaspa API questions

**Is there a free Kaspa API?** You can try it free for 14 days. The Blockchain API free trial covers Kaspa and every feature, with no card. It ends after 14 days or when its credits run out; after that, calls need a subscription, listed on the pricing page.

**How do I get the balance of a Kaspa address?** Call the address balance endpoint with the address; it returns the confirmed KAS balance, the sum of the address's unspent outputs.

**Can I send Kaspa transactions?** Crypto APIs prepares the unsigned Kaspa transaction with the fee set, and you sign it on your own servers. Broadcasting Kaspa transactions is not in the API yet.

**Is there a Kaspa testnet?** Not on this API: Kaspa is served on mainnet only. Build against a chain that has a test network first; the request shapes are the same.

**What makes Kaspa different to work with?** It is a UTXO chain with a blockDAG consensus, so blocks confirm in parallel rather than in a single line. Balances are the sum of unspent outputs as on Bitcoin, but blocks arrive roughly once a second, so a deposit watcher sees confirmations far sooner and should reason in confirmation counts rather than elapsed minutes.

**How do I know when a Kaspa transaction is confirmed?** Create a webhook subscription for the address. Crypto APIs calls your URL when a transaction to or from it confirms on Kaspa.

## Scalable PoW blockchain with BlockDAG structure

Kaspa is a scalable proof-of-work blockchain using GHOSTDAG for fast transactions and instant confirmations. Its blockDAG architecture improves efficiency, speed, and decentralization, ideal for high-throughput applications.

Kaspa blockchain was developed to address scalability limitations and enhance transaction throughput by using a Directed Acyclic Graph (DAG) structure. Its design enables fast transaction confirmations, increased security, and decentralization, overcoming challenges faced by traditional blockchains.

| About Kaspa | |
| --- | --- |
| Released | 2021 |
| Consensus | Proof of work (PoW) |
| Block time | 1 second |
| Smart contracts | Yes |

## Other UTXO chains on the same API

- [Bitcoin API](/chains/bitcoin)
- [Litecoin API](/chains/litecoin)
- [Dogecoin API](/chains/doge)

## Pointers

- [Blockchain API](/products/blockchain-api)
- [All networks](/what-we-support)
- [Pricing](/pricing)
- [Developer portal](https://developers.cryptoapis.io/)