Main.netChain settings lookup

Chain profile

Harmony chain ID 1666600000 and mainnet RPC URL

Reviewed

Checked June 26, 2026. Harmony documentation lists Harmony Mainnet Shard 0 with RPC URL, chain ID 1666600000, ONE as currency symbol, and the Harmony explorer.

Chain ID1666600000 / 0x63564c40
RPC URLhttps://api.harmony.one
Explorerhttps://explorer.harmony.one
Gas tokenONE
VerificationVerified metadata
Manual reviewJune 26, 2026
Evidence snapshot

Verification record

Manual metadata review and automated evidence checks are tracked separately. This is not a live uptime, latency, or production reliability monitor.

Manual metadata review
Verification status
Verified metadata
Verification run
source-monitoring-2026-06-26
Verification tool
source-monitoring-refresh
Source set
Harmony docs
Manual review cadence
monthly; after July 26, 2026
Latest recorded chain ID probe
eth_chainId matched expected 0x63564c40; observed 0x63564c40 on

MethodologyReport a correction

Harmony wallet-add fields

Wallet directory sites often expose a connect button. Main.net keeps the same setup fields as text so developers can compare them with official/source docs before callingwallet_addEthereumChain.

chainId
0x63564c40 (1666600000)
chainName
Harmony
nativeCurrency
ONE; name ONE, symbol ONE, decimals 18
rpcUrls
https://api.harmony.one
blockExplorerUrls
https://explorer.harmony.one
GlossaryChain IDHow wallet and RPC software identify a mainnet network.GlossaryRPC endpointWhat an RPC URL does and why public endpoints can be rate-limited.GlossaryMainnetThe production network context for these chain settings.Gas tokenONE gas tokenOther mainnet rows that use ONE for gas.Network categoryEVM mainnetsCompare Harmony with related evm mainnets by chain ID, RPC URL, explorer, and source links.Network categoryL1 mainnetsCompare Harmony with related l1 mainnets by chain ID, RPC URL, explorer, and source links.GuideChain ID listChain IDs, RPC URLs, explorers, and source links across Main.net.

Monitoring evidence

These checks are review signals only. They are not uptime, latency, privacy, or production reliability claims.

Snapshot generated
Source checks
2 sources checked
Source changes
0 changes since the previous source hash snapshot
Source fetch failures
0
eth_chainId probe
matched expected 0x63564c40
Per-source check timing
Included in the monitoring snapshot, not used as this page's review date

View monitoring snapshots orsource change history.

Network endpoints

Primary public RPC
https://api.harmony.one
Explorer
https://explorer.harmony.one
Official/source documentation
Harmony docs
Chain type
EVM L1 mainnet
Chain ID hex
0x63564c40
Manual review cadence
monthly; next review after July 26, 2026

Harmony common questions

What is the Harmony mainnet RPC URL?
Harmony's listed primary public RPC URL is https://api.harmony.one.
What is Harmony's chain ID?
Harmony's listed chain ID is 1666600000.
What block explorer does Harmony use?
Harmony's listed block explorer is https://explorer.harmony.one.
What gas token does Harmony use?
Harmony's listed gas token is ONE.

Copy-ready config

Neutral app configuration built from the verified fields above. Copy buttons only place text on your clipboard; they do not connect a wallet, request permissions, or rank RPC providers.

Chain ID decimal1666600000
Chain ID hex0x63564c40
RPC URLhttps://api.harmony.one
Explorer URLhttps://explorer.harmony.one
EIP-3085-shaped JSON

Rendered as text for manual review before use.

{
  "chainId": "0x63564c40",
  "chainName": "Harmony",
  "nativeCurrency": {
    "name": "ONE",
    "symbol": "ONE",
    "decimals": 18
  },
  "rpcUrls": [
    "https://api.harmony.one"
  ],
  "blockExplorerUrls": [
    "https://explorer.harmony.one"
  ]
}

Developer snippets

Static examples generated from Main.net fields. These snippets are for manual configuration review and read-only RPC checks; they do not connect wallets, create signers, submit writes, or rank providers.

ts

viem chain definition

Read-only snippet generated from Main.net fields. Review official sources before production use.

import { defineChain } from 'viem'

export const harmonyMainnet = defineChain({
  id: 1666600000,
  name: "Harmony",
  nativeCurrency: {
    name: "ONE",
    symbol: "ONE",
    decimals: 18,
  },
  rpcUrls: {
    default: { http: ["https://api.harmony.one"] },
    public: { http: ["https://api.harmony.one"] },
  },
  blockExplorers: {
    default: {
      name: "explorer.harmony.one",
      url: "https://explorer.harmony.one",
    },
  },
})
ts

wagmi read-only config

Read-only transport example generated from Main.net fields. It does not include account adapters or transaction actions.

import { createConfig, http } from 'wagmi'
import { harmonyMainnet } from './harmony'

export const config = createConfig({
  chains: [harmonyMainnet],
  transports: {
    [harmonyMainnet.id]: http("https://api.harmony.one"),
  },
})
ts

ethers read-only provider

Read-only JsonRpcProvider example generated from Main.net fields. It does not create a signer.

import { JsonRpcProvider } from 'ethers'

export const provider = new JsonRpcProvider("https://api.harmony.one", {
  chainId: 1666600000,
  name: "harmony",
})

const network = await provider.getNetwork()
console.log(network.chainId)
bash

curl eth_chainId check

Minimal JSON-RPC identity check. This verifies the endpoint-reported chain ID only, not uptime or production suitability.

curl -s -X POST \
  -H 'content-type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' \
  https://api.harmony.one

# Expected chain ID: 1666600000 / 0x63564c40

Developer signals

External dashboards a developer may inspect before choosing where to deploy. Main.net links to these references but does not collect the metric values, normalize methodologies, rank chains, or recommend deployments.

explorerHarmony explorerExplorer-hosted blocks, transactions, contracts, token transfers, and verification tools from the listed explorer.

Source links

Add Harmony to MetaMaskHarmony network and faucets

Safety note

Harmony documentation distinguishes mainnet shards. Use Shard 0 settings for common wallet, exchange, and staking workflows unless a source requires another shard.

Main.net is an independent reference site. It does not operate this chain, custody assets, execute transactions, or provide investment advice.

Report a correction

If this page has stale RPC, explorer, chain ID, or source information, open a public correction issue with a source link so it can be checked.

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