Chain Information

Access chain metadata and supported networks

Overview

The Nexus SDK provides comprehensive chain metadata and utilities to query supported networks and tokens.

getSupportedChains

Get all supported chains and tokens for a specific network environment.

import { getSupportedChains } from '@avail-project/nexus-core';

// Get mainnet chains
const mainnet = getSupportedChains('mainnet');

// Get testnet chains
const testnet = getSupportedChains('testnet');

// Via SDK instance
const chains = sdk.utils.getSupportedChains();

Parameters

env · 'mainnet' | 'testnet'

The network environment. Defaults to SDK’s configured network.

Returns

result · SupportedChainsAndTokensResult

chains · Chain[]

Array of supported chains with metadata

tokens · TokenInfo[]

Array of supported tokens across chains

Examples

Get All Chains

import { getSupportedChains } from '@avail-project/nexus-core';

const { chains, tokens } = getSupportedChains('mainnet');

chains.forEach(chain => {
  console.log(`${chain.name} (ID: ${chain.id})`);
  console.log(`Native: ${chain.nativeCurrency.symbol}`);
  console.log(`Explorer: ${chain.blockExplorers.default.url}`);
});

---

CHAIN_METADATA

Static metadata for all supported chains indexed by chain ID.

import { CHAIN_METADATA } from '@avail-project/nexus-core';

const ethereum = CHAIN_METADATA[1];
console.log(ethereum.name); // "Ethereum"
console.log(ethereum.nativeCurrency.symbol); // "ETH"

const polygon = CHAIN_METADATA[137];
console.log(polygon.name); // "Polygon"
console.log(polygon.shortName); // "matic"

Structure

ChainMetadata · object

id · number

Chain ID (e.g., 1 for Ethereum, 137 for Polygon)

name · string

Full chain name (e.g., “Ethereum”, “Arbitrum One”)

shortName · string

Short identifier (e.g., “eth”, “arb1”, “matic”)

logo · string

Chain logo URL

nativeCurrency · object

name · string

Native currency name (e.g., “Ether”)

symbol · string

Native currency symbol (e.g., “ETH”)

decimals · number

Decimals (usually 18)

rpcUrls · string[]

RPC endpoint URLs

blockExplorerUrls · string[]

Block explorer URLs

Examples

Get Chain Info

import { CHAIN_METADATA } from '@avail-project/nexus-core';

function getChainInfo(chainId: number) {
  const chain = CHAIN_METADATA[chainId];
  if (!chain) {
    throw new Error(`Chain ${chainId} not supported`);
  }
  return chain;
}

const base = getChainInfo(8453);
console.log(base.name); // "Base"
console.log(base.blockExplorerUrls[0]); // "https://basescan.org"

---

TOKEN_METADATA

Metadata for supported tokens across all chains.

import { TOKEN_METADATA } from '@avail-project/nexus-core';

const usdc = TOKEN_METADATA['USDC'];
console.log(usdc.name); // "USD Coin"
console.log(usdc.decimals); // 6
console.log(usdc.icon); // URL to USDC icon

Structure

TokenMetadata · object

symbol · string

Token symbol (e.g., “USDC”, “ETH”, “USDT”)

name · string

Full token name (e.g., “USD Coin”)

decimals · number

Decimal places (e.g., 6 for USDC, 18 for ETH)

icon · string

Token icon URL

coingeckoId · string

CoinGecko API identifier

isNative · boolean

Whether this is a native token (true for ETH)

Examples

Display Token Info

import { TOKEN_METADATA } from '@avail-project/nexus-core';

function TokenInfo({ symbol }: { symbol: string }) {
  const token = TOKEN_METADATA[symbol];
  if (!token) return null;
  
  return (
    <div className="token-info">
      <img src={token.icon} alt={symbol} />
      <div>
        <div className="symbol">{token.symbol}</div>
        <div className="name">{token.name}</div>
      </div>
    </div>
  );
}

---

SUPPORTED_CHAINS

Constants for all supported chain IDs.

import { SUPPORTED_CHAINS } from '@avail-project/nexus-core';

console.log(SUPPORTED_CHAINS.ETHEREUM); // 1
console.log(SUPPORTED_CHAINS.BASE); // 8453
console.log(SUPPORTED_CHAINS.ARBITRUM); // 42161
console.log(SUPPORTED_CHAINS.POLYGON); // 137

Mainnet Chains

SUPPORTED_CHAINS · object

ETHEREUM · 1

Ethereum Mainnet

BASE · 8453

Base

ARBITRUM · 42161

Arbitrum One

OPTIMISM · 10

Optimism

POLYGON · 137

Polygon PoS

AVALANCHE · 43114

Avalanche C-Chain

SCROLL · 534352

Scroll

KAIA · 8217

Kaia Mainnet

CITREA · 4114

Citrea Mainnet

BNB · 56

BNB Smart Chain

HYPEREVM · 999

Hyper EVM

MEGAETH · 4326

MegaETH

MONAD · 143

Monad

Testnet Chains

SUPPORTED_CHAINS · object

SEPOLIA · 11155111

Sepolia

BASE_SEPOLIA · 84532

Base Sepolia

ARBITRUM_SEPOLIA · 421614

Arbitrum Sepolia

OPTIMISM_SEPOLIA · 11155420

Optimism Sepolia

POLYGON_AMOY · 80002

Polygon Amoy

MONAD_TESTNET · 10143

Monad Testnet

CITREA_TESTNET · 5115

Citrea Testnet

Examples

Type-Safe Chain IDs

import { SUPPORTED_CHAINS } from '@avail-project/nexus-core';

// Use constants instead of magic numbers
await sdk.bridge({
  token: 'USDC',
  amount: 100_000_000n,
  toChainId: SUPPORTED_CHAINS.POLYGON,
});

// Check if chain is supported
function isSupportedChain(chainId: number): boolean {
  return Object.values(SUPPORTED_CHAINS).includes(chainId);
}

---

SDK Utils Instance

The SDK instance provides utility methods for chain queries.

import { NexusSDK } from '@avail-project/nexus-core';

const sdk = new NexusSDK({ network: 'mainnet' });
await sdk.initialize(window.ethereum);

// Get supported chains
const chains = sdk.utils.getSupportedChains();

// Check if chain is supported
const isSupported = sdk.utils.isSupportedChain(137);

// Check if token is supported
const isTokenSupported = sdk.utils.isSupportedToken('USDC');

// Get swap-supported chains
const swapChains = sdk.utils.getSwapSupportedChainsAndTokens();

Available Methods

sdk.utils · NexusUtils

getSupportedChains · (env?: Network) => SupportedChainsAndTokensResult

Get all supported chains and tokens

isSupportedChain · (chainId: number) => boolean

Check if a chain ID is supported

isSupportedToken · (token: string) => boolean

Check if a token symbol is supported

getSwapSupportedChainsAndTokens · () => SupportedChainsResult

Get chains and tokens that support swap operations

getCoinbaseRates · () => Promise<Record<string, string>>

Get current token prices from Coinbase

Examples

Chain Validation

if (!sdk.utils.isSupportedChain(chainId)) {
  throw new Error(`Chain ${chainId} is not supported`);
}

if (!sdk.utils.isSupportedToken('CUSTOM')) {
  throw new Error('Token not supported');
}

---

Best Practices

Use constants for chain IDs

Always use SUPPORTED_CHAINS constants instead of hardcoding chain IDs for better maintainability.

Validate before operations

Use isSupportedChain() and isSupportedToken() to validate inputs before SDK operations.

Cache chain metadata

CHAIN_METADATA and TOKEN_METADATA are static - cache them in your app to avoid repeated lookups.

Display user-friendly names

Use chain.name from metadata instead of chain IDs when displaying to users.

Common Patterns

Chain Dropdown Component

import { CHAIN_METADATA, SUPPORTED_CHAINS } from '@avail-project/nexus-core';

const MAINNET_CHAINS = [
  SUPPORTED_CHAINS.ETHEREUM,
  SUPPORTED_CHAINS.BASE,
  SUPPORTED_CHAINS.ARBITRUM,
  SUPPORTED_CHAINS.POLYGON,
];

function ChainDropdown({ 
  value, 
  onChange 
}: { 
  value: number;
  onChange: (chainId: number) => void;
}) {
  return (
    <select value={value} onChange={e => onChange(Number(e.target.value))}>
      {MAINNET_CHAINS.map(chainId => {
        const chain = CHAIN_METADATA[chainId];
        return (
          <option key={chainId} value={chainId}>
            {chain.name}
          </option>
        );
      })}
    </select>
  );
}