# Harmony RPC Node  
Fast & Affordable

Connect to Harmony, the sharded EVM blockchain with 2-second finality. Experience ultra-low fees, high throughput, and seamless cross-chain connectivity.

[Documentation](https://docs-rpc.crypto-chief.com/chains/harmony) [Get a free endpoint ](https://auth.crypto-chief.com/registration)

##### 8 M+

Requests per Day

##### 99.9 %

Network Uptime

##### < 60 ms

Average Response Time

##### 24/7

Technical Support

## Specification Harmony Network

Technical characteristics and available endpoints

![Harmony ONE](/img/protocols/harmony.svg)

### Harmony ONE

Mainnet & Testnet Support

Chain ID 1666600000

Protocol HTTPS / WSS

Uptime 99.9%

Finality 2 seconds

Shards 4

EVM Compatible Yes

Harmony is a sharded proof-of-stake blockchain delivering 2-second transaction finality through innovative Fast Byzantine Fault Tolerance (FBFT) consensus and 4-shard parallel processing architecture. With transaction fees averaging \~$0.000001 and full EVM compatibility, Harmony enables high-performance DeFi, NFT, and gaming applications. The extensive Horizon Bridge ecosystem connects Harmony to Ethereum, Binance Smart Chain, Bitcoin, and other major chains, creating a cross-chain DeFi hub.

#### Key capabilities:

- 2-second transaction finality
- 4-shard parallel processing
- Ultra-low fees (\~$0.000001)
- Full EVM compatibility
- Fast Byzantine Fault Tolerance (FBFT)
- Horizon Bridge cross-chain ecosystem
- Secure proof-of-stake consensus
- High throughput capacity
- Growing DeFi ecosystem

#### 🔗 RPC Endpoints

HTTPS

`https://rpc.crypto-chief.com/harmony/{YOUR_API_KEY}`

WSS

`wss://rpc.crypto-chief.com/harmony/ws/{YOUR_API_KEY}`

Replace {YOUR\_API\_KEY} with your actual API key from the dashboard.

## What is a Harmony RPC Node?

Access sharded blockchain infrastructure

A Harmony RPC node provides applications with access to a sharded EVM-compatible blockchain achieving 2-second finality and ultra-low fees through innovative sharding and consensus technology. Harmony's unique architecture enables high-performance decentralized applications while maintaining security and decentralization, making it ideal for DeFi protocols, NFT marketplaces, and gaming platforms requiring fast, affordable transactions.

### Why 2-second finality changes everything

Traditional blockchains take minutes for transaction finality. Even fast chains require 10-15 seconds. **Harmony's 2-second finality** enables truly responsive user experiences — instant DEX swaps, real-time gaming interactions, and seamless NFT trading. Combined with fees averaging **\~$0.000001**, Harmony makes high-frequency blockchain interactions economically viable.

**Harmony advantages:**

- **2-second finality** — near-instant confirmation
- **4-shard architecture** — parallel transaction processing
- **Ultra-low fees** — \~$0.000001 per transaction
- **EVM compatible** — deploy Solidity contracts unchanged
- **Cross-chain bridges** — connect to major ecosystems
- **Proven security** — secure proof-of-stake since 2019

### Sharding for scalability

Harmony uses **state sharding** with 4 parallel shards processing transactions simultaneously. Each shard maintains its own state and validators, enabling horizontal scaling impossible on single-chain architectures. Fast Byzantine Fault Tolerance (FBFT) consensus achieves 2-second block times while maintaining security through randomized validator selection and cross-shard communication protocols.

**How Harmony sharding works:**

1. Network divided into 4 parallel shards
2. Validators randomly assigned to shards
3. Each shard processes transactions independently
4. FBFT consensus achieves 2-second blocks per shard
5. Cross-shard receipts enable inter-shard communication
6. Beacon chain coordinates overall network state

### Cross-chain DeFi hub

Harmony's **Horizon Bridge** and partner bridges create seamless connectivity to Ethereum, BSC, Bitcoin, and other major blockchains. This positions Harmony as a **cross-chain liquidity hub** where assets from multiple ecosystems converge for trading, lending, and yield farming. Developers can build applications accessing liquidity across the entire crypto ecosystem.

This cross-chain positioning creates unique opportunities for arbitrage, multi-chain yield strategies, and composable DeFi protocols.

## Technical Documentation

Quick start for developers

### Supported RPC Methods

Harmony supports all standard Ethereum JSON-RPC methods plus Harmony-specific extensions:

- **eth\_blockNumber** — current block number
- **eth\_getBalance** — ONE token balance
- **eth\_call** — execute read-only contract functions
- **eth\_sendRawTransaction** — broadcast signed transactions
- **eth\_getTransactionReceipt** — get transaction confirmation
- **eth\_getLogs** — query event logs
- **eth\_gasPrice** — current gas price
- **eth\_estimateGas** — estimate transaction gas
- **hmy\_getStakingTransactionByHash** — query staking transactions
- **eth\_subscribe** — WebSocket event subscriptions

### Code Examples

💻

#### JavaScript (ethers.js) — Harmony Connection:

```
const { ethers } = require('ethers');

const provider = new ethers.JsonRpcProvider('https://rpc.crypto-chief.com/harmony/YOUR_API_KEY');

// Verify connection to Harmony
const network = await provider.getNetwork();
console.log('Chain ID:', network.chainId); // 1666600000
console.log('Network:', network.name); // harmony

// Get ONE balance
const address = '0x...';
const balance = await provider.getBalance(address);
console.log('ONE Balance:', ethers.formatEther(balance));

// Deploy contract with 2-second finality
const factory = new ethers.ContractFactory(abi, bytecode, wallet);
const contract = await factory.deploy();
const receipt = await contract.waitForDeployment();

console.log('Contract deployed in ~2 seconds!');
console.log('Address:', await contract.getAddress());
console.log('Block:', receipt.blockNumber);
```

💻

#### Python (web3.py) — Harmony Setup:

```
from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://rpc.crypto-chief.com/harmony/YOUR_API_KEY'))

print('Connected to Harmony:', w3.is_connected())
print('Chain ID:', w3.eth.chain_id)  # 1666600000
print('Latest block:', w3.eth.block_number)

# Ultra-low gas price
gas_price = w3.eth.gas_price
print(f'Gas price: {w3.from_wei(gas_price, "gwei")} Gwei')

# Get ONE balance
address = '0x...'
balance = w3.eth.get_balance(address)
print(f'ONE Balance: {w3.from_wei(balance, "ether")} ONE')

# Fast transaction confirmation
tx_hash = w3.eth.send_raw_transaction(signed_tx)
receipt = w3.eth.wait_for_transaction_receipt(tx_hash, timeout=5)
print(f'Transaction confirmed in {receipt.blockNumber} block')
print('Finality achieved in ~2 seconds!')
```

💻

#### WebSocket — Monitor 2-Second Blocks:

```
const { ethers } = require('ethers');
const provider = new ethers.WebSocketProvider('wss://rpc.crypto-chief.com/harmony/ws/YOUR_API_KEY');

let lastBlockTime = Date.now();

// Monitor rapid block production
provider.on('block', async (blockNumber) => {
  const now = Date.now();
  const timeSinceLastBlock = (now - lastBlockTime) / 1000;
  lastBlockTime = now;
  
  const block = await provider.getBlock(blockNumber);
  console.log(`Block ${blockNumber}: ${timeSinceLastBlock.toFixed(2)}s since last`);
  console.log(`Transactions: ${block.transactions.length}`);
});

// Monitor cross-chain bridge events
const HORIZON_BRIDGE = '0x...'; // Horizon Bridge contract
const bridgeFilter = {
  address: HORIZON_BRIDGE,
  topics: [ethers.id('TokensLocked(address,uint256,uint256,uint256)')]
};

provider.on(bridgeFilter, (log) => {
  const decoded = ethers.AbiCoder.defaultAbiCoder().decode(
    ['address', 'uint256', 'uint256', 'uint256'],
    log.data
  );
  console.log('Cross-chain bridge activity:');
  console.log('User:', decoded[0]);
  console.log('Amount:', ethers.formatEther(decoded[1]));
});
```

### Harmony Best Practices

- **Fast Finality UX:** Design interfaces for 2-second confirmation times
- **Cross-Chain Integration:** Leverage Horizon Bridge for multi-chain strategies
- **Shard Awareness:** Understand cross-shard transaction implications
- **Ultra-Low Fees:** Enable high-frequency interactions (micro-transactions, gaming)
- **Bridge Security:** Use official Harmony bridges for asset transfers
- **Staking:** Implement ONE staking for validator rewards
- **Testing:** Thoroughly test on Harmony testnet before mainnet deployment

## Why choose us?

Sharded blockchain infrastructure

### 2-Second Finality

Infrastructure delivering true 2-second finality with &lt;60ms RPC latency for responsive user experiences.

### FBFT Security

Production-grade infrastructure with Fast BFT consensus achieving 99.9% uptime and proven security since 2019.

### Shard Analytics

Comprehensive monitoring of 4-shard activity, cross-shard communication, bridge volumes, and network performance.

### Global Network

Strategically deployed nodes across continents ensuring low-latency access to Harmony's sharded blockchain.

### Horizontal Scaling

Infrastructure designed to scale with Harmony's sharded architecture supporting growing transaction volumes.

### Harmony Experts

24/7 support from engineers specialized in sharding, FBFT consensus, and cross-chain bridge integration.

## Examples of Use

Build fast & affordable dApps

Harmony's 2-second finality and ultra-low fees enable responsive DeFi protocols, cross-chain applications, NFT platforms, and high-frequency gaming applications.

#### Cross-Chain DEXs

Build decentralized exchanges aggregating liquidity from Ethereum, BSC, Bitcoin via Horizon Bridge with instant swaps.

#### Yield Aggregators

Create multi-chain yield optimization platforms leveraging Harmony's bridges to access opportunities across ecosystems.

#### Fast DeFi Protocols

Deploy lending, trading, and derivatives platforms where 2-second finality enables responsive user interactions.

#### NFT Marketplaces

Launch NFT platforms where ultra-low fees make minting, trading, and collecting economically viable.

#### Blockchain Gaming

Build games leveraging 2-second finality for real-time interactions and \~$0.000001 fees for frequent actions.

#### Payment Applications

Develop payment systems where instant finality and minimal fees enable micro-transactions and remittances.

## Got questions?  
we are here to help

## What is Harmony? 

Harmony is a sharded proof-of-stake blockchain with 2-second finality, 4 parallel shards, ultra-low fees (\~$0.000001), and full EVM compatibility.

## How does Harmony achieve 2-second finality? 

Through Fast Byzantine Fault Tolerance (FBFT) consensus combined with efficient sharding architecture enabling rapid block production and finalization.

## What is state sharding on Harmony? 

Harmony divides the network into 4 parallel shards, each processing transactions independently while maintaining cross-shard communication for horizontal scaling.

## Is Harmony EVM compatible? 

Yes, Harmony is fully EVM-compatible. Deploy Solidity smart contracts using standard Ethereum development tools without modifications.

## How much do transactions cost on Harmony? 

Harmony transactions typically cost around $0.000001 (one millionth of a dollar), making it one of the most affordable EVM chains.

## What is the Horizon Bridge? 

Horizon is Harmony's trustless bridge enabling cross-chain asset transfers between Harmony and Ethereum, BSC, Bitcoin, and other major blockchains.

## What is the ONE token? 

ONE is Harmony's native cryptocurrency used for transaction fees, staking validator rewards, and network governance.

## Can I bridge Bitcoin to Harmony? 

Yes, Harmony's bridge ecosystem supports Bitcoin and many other major cryptocurrencies for cross-chain DeFi applications.

## Do you support Harmony testnet? 

Yes, we provide RPC access to both Harmony mainnet (Chain ID 1666600000) and testnet for development and testing.

## Why choose Harmony for DeFi? 

Harmony offers 2-second finality for responsive UX, ultra-low fees for frequent interactions, and cross-chain bridges for multi-ecosystem liquidity access.

## Pricing that grows with your needs.

### Free

Start building on Web3 — no credit card.

##### $0

- 5 reqs/sec RPC
- 5 reqs/min Unified API
- 1 req/day AML
- Ultimate chains
- WSS, Statistics
- Community support

[Get started ](https://auth.crypto-chief.com/registration)

### Pay for use

Flexible pay-as-you-go for any workload.

##### From $10

- 400 reqs/sec RPC
- 300 reqs/min Unified API
- 5 reqs/sec AML
- EventStream
- Ultimate chains
- WSS, Whitelists, Statistics
- Support portal

[Get started](https://auth.crypto-chief.com/registration)

### Subscription

From $500 monthly plus 20% extra value.

##### From $500

- 400 reqs/sec RPC
- 300 reqs/min Unified API
- 5 reqs/sec AML
- EventStream
- Ultimate chains
- WSS, Whitelists, Statistics
- Support portal

[Get started ](https://auth.crypto-chief.com/registration)

### Enterprise

Tailored solution for expert builders

##### Custom terms

All Subscription features plus:

- Flexible rate limits
- Engineering team support
- Custom SLA
- Personal manager

[Contact Sales ](/contact/)