Polkadot JS API template

Sample code for connecting to the blockchain network 👉

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

async function main () {

  // Create connection to blockchain network 
  const wsProvider = new WsProvider(`wss://westend-rpc.polkadot.io`);

  // Create a new instance of APIPromise with the websocket provider
  const api = await ApiPromise.create({ provider: wsProvider , noInitWarn: true});
  
  /**
   *  1. fetch the chain information
   */
  const chainInfo = await api.registry.getChainProperties()
  console.log(`chainInfo ${chainInfo}`);

  // output for above code for Westend network
  // {"ss58Format":42,"tokenDecimals":[12],"tokenSymbol":["WND"]}
}


main().catch(console.error).finally(() => process.exit());;

Code example ➡️

Run the file at the path below, also refer to the Github link attached below.

ts-node src/0-template/template.ts

polkadot-js-recipes/template.ts at main · polkadotjs-developer-hub/polkadot-js-recipesGitHub

sample template

Output 👉

{"ss58Format":42,"tokenDecimals":[12],"tokenSymbol":["WND"]}

• ss58Format ss58 is the address format used. The format contains an address type prefix that identifies an address belonging to a specific network. e.g. 42, is the network prefix for Westend network https://wiki.polkadot.network/docs/learn-account-advanced#for-the-curious-how-prefixes-work
• tokenDecimals The number of decimal places used to represent the token’s smallest unit https://wiki.polkadot.network/docs/learn-DOT#the-planck-unit e.g. 12, tokenDecimals for Westend network
• tokenSymbol The currency symbol or name e.g. WND, tokenSymbol for Westend network

What is Westend network? Testnets and Westend network

More explanation on the above output terms is ahead. Hold on 🚀

Additional resource 👉

GitHub - kianenigma/polkadot-js-api-ts-template: A template project to kickstart hacking on top of `@polkadot/api`GitHub

API starter template by Kian