How to query chainspec with @polkadot/api

Question

In the documentation getChainProperties(https://polkadot.js.org/docs/api/examples/promise/chain-info/) is mentioned for getting the properties for a blockchain, but it contains very little amount of information.

How could I query the chainspec of a blockchain from an RPC? I am specifically interested in the name and para_id(if a parachain) fields.

Answer 1

I did not find a specific way to query the chainspec, but using a different approach I am able to get the parachain id and the name of the blockchain.

import { ApiPromise } from '@polkadot/api';

/* snip */

// Create an API
api = await ApiPromise.create({ provider: wsProvider, noInitWarn: true });

// Get the blockchain name:
const name = await api.rpc.system.chain();
console.log(name.toHuman());

// Get the parachain id:
const parachainId = await api.query.parachainInfo.parachainId();
console.log(parachainId.toHuman());

Answer 2

The RPC call sync_state => genSyncSpec. Unfortunately atm only available for the relay chains it seems (ref).