Chains

Chain definitions and lookup utilities for common EVM-compatible blockchains.

import { chains, getChain } from '@web3marketlabs/sdk'

ChainConfig Interface

Every chain is represented by the ChainConfig interface:

interface ChainConfig {
  /** Numeric chain ID */
  id: number
  /** Human-readable chain name */
  name: string
  /** The chain's native currency */
  nativeCurrency: {
    name: string
    symbol: string
    decimals: number
  }
  /** RPC endpoint URLs */
  rpcUrls: {
    public: { http: readonly string[] }
    default: { http: readonly string[] }
  }
  /** Block explorer URLs (if available) */
  blockExplorers?: {
    etherscan?: { name: string; url: string }
    default: { name: string; url: string }
  }
  /** Whether this is a testnet */
  testnet?: boolean
}

`chains`

A Record<string, ChainConfig> containing all supported chain configurations, keyed by their string identifier.

import { chains } from '@web3marketlabs/sdk'
 
chains.ethereum    // { id: 1, name: 'Ethereum', ... }
chains.sepolia     // { id: 11155111, name: 'Sepolia', ... }
chains.base        // { id: 8453, name: 'Base', ... }

Available Chains

Key	ID	Name	Native Currency	Symbol	Testnet
`anvil`	31337	Anvil	Ether	ETH	Yes
`ethereum`	1	Ethereum	Ether	ETH	No
`sepolia`	11155111	Sepolia	Sepolia Ether	ETH	Yes
`arbitrum`	42161	Arbitrum One	Ether	ETH	No
`arbitrumSepolia`	421614	Arbitrum Sepolia	Ether	ETH	Yes
`base`	8453	Base	Ether	ETH	No
`baseSepolia`	84532	Base Sepolia	Ether	ETH	Yes
`polygon`	137	Polygon	POL	POL	No
`polygonAmoy`	80002	Polygon Amoy	POL	POL	Yes
`optimism`	10	Optimism	Ether	ETH	No
`optimismSepolia`	11155420	Optimism Sepolia	Ether	ETH	Yes

All chains have decimals: 18 for their native currency. The Anvil chain uses http://127.0.0.1:8545 as its RPC endpoint and does not have block explorers configured.

Default RPC Endpoints

Chain	Default RPC URL
Anvil	`http://127.0.0.1:8545`
Ethereum	`https://eth.llamarpc.com`
Sepolia	`https://rpc.sepolia.org`
Arbitrum One	`https://arb1.arbitrum.io/rpc`
Arbitrum Sepolia	`https://sepolia-rollup.arbitrum.io/rpc`
Base	`https://mainnet.base.org`
Base Sepolia	`https://sepolia.base.org`
Polygon	`https://polygon-rpc.com`
Polygon Amoy	`https://rpc-amoy.polygon.technology`
Optimism	`https://mainnet.optimism.io`
Optimism Sepolia	`https://sepolia.optimism.io`

`getChain(chainIdOrName)`

Look up a chain by its numeric chain ID or string key name.

function getChain(chainIdOrName: number | string): ChainConfig | undefined

Parameters

Parameter	Type	Description
`chainIdOrName`	`number \| string`	A numeric chain ID (e.g., `1`) or a chain key string (e.g., `"ethereum"`)

Returns

Returns the matching ChainConfig object, or undefined if no chain matches.

When given a string, performs a direct key lookup on the chains record.
When given a number, searches through all chain values to find one with a matching id.

Examples

import { getChain } from '@web3marketlabs/sdk'
 
// Look up by numeric ID
getChain(1)            // { id: 1, name: 'Ethereum', ... }
getChain(11155111)     // { id: 11155111, name: 'Sepolia', ... }
getChain(137)          // { id: 137, name: 'Polygon', ... }
 
// Look up by string key
getChain('ethereum')   // { id: 1, name: 'Ethereum', ... }
getChain('sepolia')    // { id: 11155111, name: 'Sepolia', ... }
getChain('base')       // { id: 8453, name: 'Base', ... }
 
// Returns undefined for unknown chains
getChain(999999)       // undefined
getChain('unknown')    // undefined

Source

Defined in @web3marketlabs/sdk — src/chains.ts.

Index Clients