Chain IDs

Complete reference for Monolythium chain identifiers.

!!! info "Canonical Source" The canonical source of truth for all network configuration values is the monolythium/networks repository. All tools (monarch, monod) fetch configuration from this repository to prevent configuration drift.

Chain ID Summary

Network	Cosmos Chain ID	EVM Chain ID (Dec)	EVM Chain ID (Hex)
Localnet	mono-local-1	262145	0x40001
Testnet	mono_6940-1	6940	0x1B1C
Mainnet	mono_6941-1	6941	0x1B1D

Cosmos Chain IDs

Used for:

• Cosmos SDK transactions
• CLI commands
• Monolythium Browser Wallet / Keplr / Leap wallet configuration
• LythiumBFT connections

Format: mono-<environment>-<version>

Verifying Chain ID

# Via RPC
curl -s localhost:26657/status | jq '.result.node_info.network'

# Via CLI
monod status | jq '.NodeInfo.network'

EVM Chain IDs

Used for:

• MetaMask network configuration
• EIP-155 transaction signing
• Smart contract deployment
• ethers.js/web3.js configuration

Verifying EVM Chain ID

curl -X POST -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' \
  localhost:8545

Response:

{"jsonrpc":"2.0","id":1,"result":"0x1B1C"}

Configuration Examples

MetaMask

Field	Testnet Value
Network Name	Monolythium Testnet
Chain ID	6940
Currency Symbol	LYTH

Hardhat

module.exports = {
  networks: {
    testnet: {
      chainId: 6940,
      url: "https://evm.testnet.mononodes.xyz"
    },
    testnet: {
      chainId: 6940,
      url: "https://evm.testnet.mononodes.xyz"
    },
    mainnet: {
      chainId: 6941,
      url: "https://evm.mainnet.mononodes.xyz"
    }
  }
};

Keplr

{
  chainId: "mono_6940-1",
  chainName: "Monolythium Testnet",
  // ...
}

Common Issues

Wrong Chain ID

If transactions fail with "Chain ID mismatch":

1. Verify you're using the correct chain ID for the network
2. Remove and re-add the network in your wallet
3. Reset the wallet connection

EVM vs Cosmos Confusion

Remember:

• Cosmos operations use string chain IDs (mono_6940-1)
• EVM operations use numeric chain IDs (6940)

Both represent the same network.

Related

• Networks - Network overview
• MetaMask Setup - Wallet configuration