Harmony Onchain Data API

Get token balances and transactions for Harmony. Testnet supported.

Overview

Explore Harmony, the open blockchain with 2-second finality, low fees, and secure cross-chain bridges for Ethereum apps. Dive into historical data now!

GoldRush offers the most comprehensive Harmony Data API suite for developers, analysts, and enterprises. Whether you’re building a DeFi dashboard, a wallet, a trading bot, an AI agent or a compliance platform, our Harmony Data APIs provide fast, accurate, and developer-friendly access to the essential onchain data you need.

Supported APIs

Mainnet

Property	Value
Chain Name	harmony-mainnet
Chain ID	1666600000
Network Type	Archived Chain
Support Level	archived
Block Explorer	Explorer
Official Website	Harmony Website
Native Gas Token	ONE

Testnet

Property	Value
Chain Name	harmony-testnet
Chain ID	1666700000
Purpose	Development and testing network
Support Level	archived
Block Explorer	Explorer
Official Website	Harmony Testnet Website
Native Gas Token	ONE

API Usage

To use this blockchain network in GoldRush API calls, use:

Chain Name

• harmony-mainnet (mainnet)
• harmony-testnet (testnet)

Example Streaming Subscription

GraphQL Subscription

subscription {
  walletTxs(
    chain_name: HARMONY_MAINNET,
    wallet_addresses: ["0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"]
  ) {
    block_signed_at
    block_height
    tx_hash
    tx_offset
    successful
    decoded_type
  }
}

import { GoldRushClient, StreamingChain } from "@covalenthq/client-sdk";

const client = new GoldRushClient("<GOLDRUSH_API_KEY>");

client.StreamingService.subscribeToWalletTxs(
  {
    chain_name: StreamingChain.HARMONY_MAINNET,
    wallet_addresses: ["0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"],
  },
  {
    next: (data) => console.log("Received data:", data),
    error: (error) => console.error("Error:", error),
    complete: () => console.log("Stream completed"),
  }
);

Connect via WebSocket at wss://streaming.goldrushdata.com/graphql with your API key in the connection parameters. See the Streaming API Quickstart for full setup details.

Additional Resources

• GoldRush API Documentation
• Supported Chains List
• API Reference