Blockchain API
Mainnet + Fuji
Avalanche API
The Crypto APIs Avalanche API, part of the Blockchain API, lets you read balances, token transfers and blocks on Avalanche and send transactions without running a node. One API key covers mainnet and fuji. Webhooks tell your server when a payment confirms, and we never hold your private keys.
What can you do with the Avalanche API?
Read balances and history
Confirmed balances and transactions for any Avalanche address, and blocks.
Work with tokens
Read or prepare Avalanche token transfers through the same API.
Estimate fees
Fee recommendations for slow, standard and fast confirmation on Avalanche.
Prepare and broadcast
We build the unsigned transaction. You sign it, and we send it to the network.
Get webhooks
We call your URL when coins arrive at an address and when the transaction confirms.
Same shape on 35+ networks
Swap avalanche for another chain in the path, such as Ethereum or Polygon.
How do I get the latest Avalanche block?
Send one GET request with your API key; the same request works on fuji when you replace mainnet with fuji in the path.
- Base URL
https://rest.cryptoapis.io - Auth: the X-API-Key header
- JSON responses, same shape on every chain
curl https://rest.cryptoapis.io/blocks/evm/avalanche/mainnet/latest/details \ -H "X-API-Key: YOUR_API_KEY"
const res = await fetch( "https://rest.cryptoapis.io/blocks/evm/avalanche/mainnet/latest/details", { 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/blocks/evm/avalanche/mainnet/latest/details", headers={"X-API-Key": os.environ["CRYPTOAPIS_KEY"]}, ) print(r.json()["data"]["item"])
{
"height": 234324,
"hash": "0x6b1fdd6357845016fb238d1bd58992a01b01c94e668f55e9502d65f0a50ac021",
"transactionsCount": 23432,
"timestamp": 1681893875
}
Which Avalanche endpoints are available?
The main calls. Every path takes the network: mainnet or fuji.
/addresses-latest/evm/avalanche/mainnet/{address}/tokens-transfers/blockchain-events/avalanche/mainnet/address-coins-transactions-confirmedHow do I send a Avalanche 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 Broadcast We push the signed transaction to the Avalanche network.
- Step 4 Confirm A webhook tells you when it confirms.
Avalanche API vs Avalanche RPC: which do I need?
Most apps start with the API. Use RPC when you need a method the node exposes directly.
Avalanche 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 Avalanche address for AML risk
A free risk band and sanctions check for any Avalanche address is coming soon. Today, screen addresses with the AML API.
Coming soonWhat makes Avalanche unique?
Avalanche is an open-source platform offering decentralized application development within an interoperable and scalable ecosystem. Its robust consensus mechanism ensures near-instant transaction finality.
Avalanche is an open-source blockchain protocol enabling decentralized application development within an interoperable, decentralized, and highly scalable ecosystem. Its robust consensus mechanism makes it the first ecosystem tailored for global finance, ensuring near-instant transaction finality.
Other EVM chains, same request shape
Avalanche API questions
Is there a free Avalanche API?
You can try it free for 14 days. The Blockchain API free trial covers Avalanche 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 Avalanche address?
Call the address balance endpoint with the address; it returns the confirmed AVAX balance. Token balances live in the token contracts, so list the address's token transfers to see them.
How do I broadcast a Avalanche transaction?
Sign the transaction on your own server, then send the signed raw transaction to the broadcast endpoint, authenticated with your API key, and Crypto APIs pushes it to the Avalanche network and returns the transaction ID. We can prepare the unsigned transaction for you first.
Do you support Avalanche fuji?
Yes. Every Avalanche endpoint works on mainnet and fuji. Change mainnet to fuji in the path; the same API key works on both.
What makes Avalanche different to work with?
It is an account-model EVM chain — every address has a single balance and a nonce. Tokens live in their own contracts rather than in the account balance, so reading them means calling the token contract; and every transaction needs the account's next nonce, which the same API returns.
How do I know when a Avalanche transaction is confirmed?
Create a webhook subscription for the address. Crypto APIs calls your URL when a transaction to or from it confirms on Avalanche.
Start building on Avalanche today
14-day free trial, mainnet included. No card needed.