Chain API

The Chain API is mainly used to get information needed to build and sign transactions. This API is available through the ChainApi class from the polkadart package.

Sample usage

import 'package:polkadart/apis/apis.dart';
import 'package:polkadart/polkadart.dart' show Provider, ChainApi;

void main() async {
  final provider = Provider.fromUri(Uri.parse('wss://rpc.polkadot.io'));
  final chainApi = ChainApi(provider);

  final header = await chainApi.getChainHeader();

  print(header.toString());
}

You will get the following output:

23198099

Methods

There are a few methods available in the ChainApi class, you can find them below:

getBlockHash

Future<BlockHash> getBlockHash({int? blockNumber})

Returns the BlockHash for the given block number. If no block number is provided, it will return the hash of the latest block at chain height.

getChainHeader

Future<int> getChainHeader({BlockHash? at})

Get the latest block number or specific block number by BlockHash.