Getting started

Every example on this page was run against the live PezkuwiChain network, except the final signAndSend, which needs a funded account. Each runs as an ES module (node example.mjs) on Node.js 18 or newer, and works the same way in a browser bundle.

Install

npm install @pezkuwi/api @pezkuwi/keyring
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Connect

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

const api = await ApiPromise.create({
  provider: new WsProvider('wss://rpc.pezkuwichain.io')
});

const [chain, nodeName, nodeVersion] = await Promise.all([
  api.rpc.system.chain(),
  api.rpc.system.name(),
  api.rpc.system.version()
]);

console.log(`Connected to ${chain} via ${nodeName} v${nodeVersion}`);
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ApiPromise.create resolves once the API has fetched the runtime metadata, so from that point api.query, api.tx and api.consts reflect exactly what the connected chain supports.

Read chain state

const header = await api.rpc.chain.getHeader();
console.log(`Best block: #${header.number}`);

const { tokenSymbol, tokenDecimals } = api.registry.getChainProperties().toHuman();
console.log('Token:', tokenSymbol, 'decimals:', tokenDecimals); // [ 'HEZ' ] [ '12' ]

const address = '5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty';
const { data: { free } } = await api.query.system.account(address);
console.log(`Free balance: ${free} TYR`);
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HEZ has 12 decimals: 1 HEZ = 10^12 TYR. Balances come back in TYR, the smallest unit.

Follow new blocks

const unsubscribe = await api.rpc.chain.subscribeNewHeads((head) => {
  console.log(`New block #${head.number}`);
});

// later
unsubscribe();
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Build, price and send a transfer

import { Keyring } from '@pezkuwi/keyring';

const keyring = new Keyring({ type: 'sr25519' });
const sender = keyring.addFromUri('//Alice'); // a development key: never hold real funds with it

const recipient = '5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty';
const amount = 10n ** 12n; // 1 HEZ

const tx = api.tx.balances.transferKeepAlive(recipient, amount);

const { partialFee } = await tx.paymentInfo(sender);
console.log(`Estimated fee: ${partialFee} TYR`);

// Submitting needs a funded account:
const unsub = await tx.signAndSend(sender, ({ status, dispatchError }) => {
  if (dispatchError) {
    console.error(dispatchError.toString());
  }
  if (status.isInBlock) {
    console.log(`Included in block ${status.asInBlock}`);
  }
  if (status.isFinalized) {
    unsub();
  }
});
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transferKeepAlive refuses a transfer that would take the sender below the existential deposit and reap the account. Use transferAllowDeath only when that is what you want.

Disconnect

await api.disconnect();
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Other networks

The same code works against any endpoint listed on the home page, for example wss://asset-hub-rpc.pezkuwichain.io for PezkuwiChain Asset Hub.