ChainApi

ChainApi interface is a concept that allows Dedot to enable Types & APIs suggestions for any Substrated-based blockchains. Each Substrate-based blockchain has its own ChainApi interface that exposes all of its Types & APIs to interact with the node & runtime.

A ChainApi interface ussually has the following structure:

export interface VersionedSubstrateApi<Rv extends RpcVersion>
  rpc: ChainJsonRpcApis<Rv>; // json-rpc methods
  consts: ChainConsts<Rv>; // runtime constants
  query: ChainStorage<Rv>; // on-chain storage queries
  errors: ChainErrors<Rv>; // on-chain errors
  events: ChainEvents<Rv>; // on-chain events
  call: RuntimeApis<Rv>; // runtime apis
  tx: ChainTx<Rv>; // transactions
}

export interface ChainApi {
  legacy: VersionedSubstrateApi<RpcLegacy>; // interface for legacy JSON-RPC
  v2: VersionedSubstrateApi<RpcV2>; // interface for new JSON-RPC
}

Access ChainApi interfaces

Dedot offers 2 different ways to access ChainApi interfaces for different Substrate-based blockchains.

Known ChainApi interfaces defined in @dedot/chaintypes package

Install package @dedot/chaintypes to get access to a list of known ChainApi interfaces. For example:

• PolkadotApi

• KusamaApi

• PolkadotAssetHubApi

• KusamaAssetHubApi

• ...

We're welcome everyone to open a pull request to add your favorite Substrate-based network to the existing list of supported networks in@dedot/chaintypes repo.

There is a job running twice a day to check for any runtime upgrades in the existing supported networks list and regenerate the ChainApi interface (Types & APIs) accordingly for these changes.

It's important to keep up with changes from the network that you're working with and prepare for any breaking upgrades coming up. Please refer to the Runtime upgrades page for more information.

Generate ChainApi interface using Dedot's CLI

You can also generate ChainApi interface for any Substrate-based blockchains using dedot' CLI.

Generate ChainApi interface for a local substrate-based blockchains running on ws://127.0.0.1:9944:

npx dedot chaintypes -w ws://127.0.0.1:9944

You can also generate ChainApi interface using a raw metadata file (.scale) or runtime wasm file (.wasm). More information about this can be found in the CLI page.

Using ChainApi interface

ChainApi interface is the generic parameter for Dedot's clients, so when intialize a Dedot client, make sure to pick the right ChainApi interface of the chain you're working with to enable Types & APIs suggestions for that particular chains.

Example working with Polkadot Asset Hub:

import { DedotClient, WsProvider } from 'dedot';
import type { PolkadotAssetHubApi } from '@dedot/chaintypes';

// Initialize providers & clients
const provider = new WsProvider('wss://polkadot-asset-hub-rpc.polkadot.io');
const client = await DedotClient.new<PolkadotAssetHubApi>(provider);