Sub API ​

The sub-api is a powerful utility developed by KodaDot for managing connections with multiple parachains in a network. This documentation provides an overview of its key features and shows how to use them effectively.

To use it check out the documentation in the following link: SubApi@Github

Installation ​

To add the sub-api package to your project, use the following command:

yarn add @kodadot1/sub-api

Features ​

ApiFactory ​

The ApiFactory class is responsible for establishing and managing a connection to a parachain. The example below demonstrates how to establish a connection to a parachain:

import { ApiFactory } from '@kodadot1/sub-api'

const endpoint = 'wss://kusama-rpc.polkadot.io'
const api = await ApiFactory.useApiInstance(endpoint)

InstaApi ​

The InstaApi class provides you with direct control over the connection management process. This class is suitable for applications requiring only a single connection:

import { InstantApi as Api } from '@kodadot1/sub-api'

const endpoint = 'wss://kusama-rpc.polkadot.io'
const API = await (new API(endpoint)).getInstance()

Helpers ​

The sub-api package comes with a set of helper functions that make common tasks easier:

import { balanceOf, currentBlock } from '@kodadot1/sub-api'

const API = await ApiFactory.useApiInstance(endpoint)
const balance = await balanceOf(API, acc)
const block = await currentBlock(API)
console.log(balance, block)

Hooks ​

The package provides an onApiConnect hook that gets triggered when the API connects:

import { onApiConnect } from '@kodadot1/sub-api'

Types ​

More readable type definitions are provided in the sub-api package. For instance, SubmittableExtrinsic<'promise'> is exported as Extrinsic.

Usage Examples ​

Here is an example demonstrating how to fetch chain properties using the ApiFactory:

import { ApiFactory } from '@kodadot1/sub-api'

async function getChainProperties() {
  const endpoint = 'wss://kusama-rpc.polkadot.io'
  const API = await ApiFactory.useApiInstance(endpoint)
  const { chainSS58, chainDecimals, chainToken } = API.registry
  console.log('[API] Connect <3', { chainSS58, chainDecimals, chainToken })
}

In the following example, the onApiConnect hook is used to listen for the connect event and retrieve data when the connection is ready:

import { onApiConnect } from '@kodadot1/sub-api'

const endpoint = 'wss://kusama-rpc.polkadot.io'
onApiConnect(endpoint, async (API) => {
  const block = await API.query.system.number()
  console.log('[API] Connected to', endpoint, 'block', block)
})

These examples should provide you with a solid foundation to start using the sub-api package in your application. The sub-api package is an integral part of KodaDot's developer toolbox and should simplify the task of connecting to and interacting with multiple parachains.