@substrate/connect

Polkadot JS Provider for Smoldot Light Client

This is a prototype for using @polkadot/api with the smoldot WASM light client either by passing chainspecs or using the extension by predefined chains (e.g. westend2, ksmcc3).

ScProvider check existence of substrate extension. If it is installed and activated then smoldot clients of extension will be used. If not, a new smoldot client will start and sync with given chainspecs.

Usage

Provide a known Chain Name ('polkadot', 'ksmcc3', 'westend2', 'rococo_v2_1'):

import { ApiPromise } from '@polkadot/api';
import { createPolkadotJsScClient, SupportedChains } from '@substrate/connect';

const scClient = createPolkadotJsScClient();
const provider = await scClient.addWellKnownChain(SupportedChains.westend2);
const api = await ApiPromise.create({ provider });

or provide your custom substrate chain's name and chainspec:

import { ApiPromise } from '@polkadot/api';
import { createPolkadotJsScClient } from '@substrate/connect';
import mySubstrateChainSpec from './mySubstrateChainSpec.json';

const myChainSpec = JSON.stringify(mySubstrateChainSpec);

const scClient = createPolkadotJsScClient();
const provider = await scClient.addChain(myChainSpec);
const api = await ApiPromise.create({ provider });

Parachain support

For parachain support, you can providethe parachain's specs

import { ApiPromise } from '@polkadot/api';
import { createPolkadotJsScClient, SupportedChains } from '@substrate/connect';
import myParaChainSpec from './myParaChainSpec.json';

const parachainSpec =  JSON.stringify(myParaChainSpec);

const scClient = createPolkadotJsScClient();
await scClient.addWellKnownChain(SupportedChains.westend2)
const provider = await scClient.addChain(parachainSpec);
const api = await ApiPromise.create({ provider });

Scripts

• yarn test to run the unit tests
• yarn build to build @substrate-connect
• yarn lint to run linter for @substrate-connect