system_chain - Polkadot RPC Method

import { ApiPromise, WsProvider } from '@polkadot/api';

async function connectAndVerify(endpoint, expectedChain) {
  const provider = new WsProvider(endpoint);
  const api = await ApiPromise.create({ provider });

  const chain = await api.rpc.system.chain();
  const chainName = chain.toString();

  if (chainName !== expectedChain) {
    await api.disconnect();
    throw new Error(
      `Expected "${expectedChain}" but connected to "${chainName}"`
    );
  }

  console.log(`Verified connection to ${chainName}`);
  return api;
}

// Usage
const api = await connectAndVerify('https://api-polkadot.n.dwellir.com/YOUR_API_KEY', 'Polkadot');

async function getChainConfig(api) {
  const [chain, properties] = await Promise.all([
    api.rpc.system.chain(),
    api.rpc.system.properties()
  ]);

  const chainName = chain.toString();
  const configs = {
    Polkadot: { explorer: 'https://polkadot.subscan.io', confirmations: 1 },
    Kusama: { explorer: 'https://kusama.subscan.io', confirmations: 1 },
  };

  const config = configs[chainName] || { explorer: null, confirmations: 1 };

  return {
    name: chainName,
    tokenSymbol: properties.tokenSymbol.toString(),
    tokenDecimals: properties.tokenDecimals.toJSON(),
    ...config
  };
}

async function healthCheck(api) {
  const [chain, name, version] = await Promise.all([
    api.rpc.system.chain(),
    api.rpc.system.name(),
    api.rpc.system.version()
  ]);

  return {
    status: 'healthy',
    chain: chain.toString(),
    nodeImplementation: name.toString(),
    nodeVersion: version.toString(),
    timestamp: new Date().toISOString()
  };
}