Blockchain API
Mainnet
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.
What can you do with the Kaspa API?
Read balances and history
Confirmed balances and transactions for any Kaspa address, and blocks.
Estimate fees
Fee recommendations for slow, standard and fast confirmation on Kaspa.
Prepare transactions
We build the unsigned transaction with the fee set; you sign it on your servers.
Get webhooks
We call your URL when coins arrive at an address and when the transaction confirms.
Same shape on 35+ networks
Swap kaspa for another chain in the path, such as Bitcoin or Litecoin.
How do I get a Kaspa address balance?
Send one GET request, authenticated with your API key, to Kaspa mainnet.
- Base URL
https://rest.cryptoapis.io - Auth: the X-API-Key header
- JSON responses, same shape on every chain
curl https://rest.cryptoapis.io/addresses-latest/kaspa/mainnet/YOUR_ADDRESS/balance \ -H "X-API-Key: YOUR_API_KEY"
const res = await fetch( "https://rest.cryptoapis.io/addresses-latest/kaspa/mainnet/YOUR_ADDRESS/balance", { headers: { "X-API-Key": process.env.CRYPTOAPIS_KEY } }, ); const { data } = await res.json(); console.log(data.item);
import os, requests r = requests.get( "https://rest.cryptoapis.io/addresses-latest/kaspa/mainnet/YOUR_ADDRESS/balance", headers={"X-API-Key": os.environ["CRYPTOAPIS_KEY"]}, ) print(r.json()["data"]["item"])
{
"confirmedBalance": {
"amount": "33.1794059",
"denomination": 1,
"unit": "KAS"
}
}
Which Kaspa endpoints are available?
The main calls. Kaspa is served on mainnet.
/blockchain-events/kaspa/mainnet/address-coins-transactions-confirmedHow do I send a Kaspa transaction without giving up my keys?
Crypto APIs never holds your private keys. You keep signing; we do the rest.
- Step 1 Prepare We build the unsigned transaction with the fee set.
- Step 2 Sign locally You sign on your own servers. Keys never leave.
- Step 3 Confirm A webhook tells you when it confirms.
Kaspa API vs Kaspa RPC: which do I need?
Most apps start with the API. Use RPC when you need a method the node exposes directly.
Kaspa RPC
Need raw node calls (JSON-RPC)? NodeGrid RPC will give you one endpoint with automatic failover between partner providers. Until then, JSON-RPC access is part of the Blockchain API.
Explore NodeGrid RPCCheck a Kaspa address for AML risk
A free risk band and sanctions check for any Kaspa address is coming soon. Today, screen addresses with the AML API.
Coming soonScalable 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.
Other UTXO chains on the same API
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.
Start building on Kaspa today
14-day free trial, mainnet included. No card needed.