eth_getBalance - Astar RPC Method

Returns the balance of a given address on Astar.

Why Astar? Build on Polkadot's leading dApp hub supporting EVM, WASM, and upcoming PolkaVM environments with EVM + WASM + PolkaVM support, Build2Earn developer rewards, dApp Staking, and Soneium cross-layer integration.

When to Use This Method

eth_getBalance is fundamental for multi-chain dApp developers, DeFi builders, and teams leveraging Polkadot + Ethereum ecosystems:

• Wallet applications: Display user balances and enable balance-dependent operations on Astar
• Transaction validation: Verify accounts have sufficient funds before submitting transactions to Astar
• DeFi monitoring: Track collateral positions, liquidity pools, and TVL across cross-chain DeFi, multi-VM smart contracts, and XCM-enabled interoperability with Ethereum and Cosmos
• Accounting and reconciliation: Cross-reference on-chain balances against off-chain ledger entries for financial reporting

Common Use Cases

1. Display Formatted Wallet Balance with Ether Conversion

Retrieve and display a human-readable balance for any address on Astar. Convert the wei result to ether client-side using your web3 library.

import { JsonRpcProvider, formatEther } from 'ethers';

const provider = new JsonRpcProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY');

async function displayBalance(address) {
  const balanceWei = await provider.getBalance(address);
  const balance = formatEther(balanceWei);
  console.log(`Balance: ${balance} Astar`);
  return balance;
}

displayBalance('0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045');

2. Monitor Whale Wallet Activity with Polling and Threshold Alerts

Poll a high-value wallet on Astar at regular intervals. Trigger an alert when the balance crosses a defined threshold, useful for tracking DeFi movements or exchange hot wallet activity.

from web3 import Web3
import time

w3 = Web3(Web3.HTTPProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY'))
address = '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045'
threshold_wei = w3.to_wei(100, 'ether')

def monitor_balance():
    previous_balance = w3.eth.get_balance(address)
    while True:
        time.sleep(15)
        current_balance = w3.eth.get_balance(address)
        if abs(current_balance - previous_balance) > threshold_wei:
            print(f'Balance changed by more than 100 Astar')
        if current_balance > w3.to_wei(1000, 'ether'):
            print(f'Whale alert: wallet exceeds 1000 Astar')
        previous_balance = current_balance

monitor_balance()

3. Historical Balance Tracking Using Block Tags

Query an account's balance at a specific block height to build a historical balance timeline. This is essential for audit trails, tax reporting, and analyzing wallet behavior over time on Astar.

package main

import (
    "context"
    "fmt"
    "log"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/ethclient"
)

func main() {
    client, _ := ethclient.Dial("https://api-astar.n.dwellir.com/YOUR_API_KEY")

    address := common.HexToAddress("0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045")

    // Query balance at a specific block number
    blockNumber := big.NewInt(1000000)
    historicalBalance, _ := client.BalanceAt(context.Background(), address, blockNumber)
    fmt.Printf("Historical balance at block 1,000,000: %s wei\n", historicalBalance.String())

    // Query latest balance for comparison
    currentBalance, _ := client.BalanceAt(context.Background(), address, nil)
    change := new(big.Int).Sub(currentBalance, historicalBalance)
    fmt.Printf("Balance change: %s wei\n", change.String())
}

Best Practices

• Cache balances with short TTL: Set a 2-5 second cache duration for balance queries to reduce RPC calls while keeping data fresh enough for most UI use cases
• Convert wei to ether client-side: Use formatEther (ethers.js) or fromWei (web3.py) rather than relying on node-side conversion, which the JSON-RPC does not provide
• Use pending tag cautiously: Balances returned with the pending block tag may reflect unconfirmed state changes and differ from finalized on-chain values
• For batch balance queries, use eth_call with multicall: When querying balances for many addresses, bundle them through a multicall contract to reduce individual RPC round-trips

Code Examples

Error Handling

Related Methods

• eth_getCode - Get contract bytecode
• eth_getTransactionCount - Get account nonce