grandpa_roundState

Returns the state of the current GRANDPA finality round on Acala. GRANDPA (GHOST-based Recursive ANcestor Deriving Prefix Agreement) is the finality gadget used by Substrate chains.

Use Cases

• Finality monitoring - Track consensus progress for decentralized stablecoin (aUSD), liquid DOT staking (LDOT), and cross-chain AMM DEX
• Validator analysis - Monitor prevote/precommit participation
• Chain health checks - Detect finality delays or stalls

Parameters

This method takes no parameters.

Returns

Field	Type	Description
setId	u64	Current authority set ID
best	RoundState	Best round state
background	Vec<RoundState>	Background rounds

RoundState Structure

Field	Type	Description
round	u64	Round number
totalWeight	u64	Total validator weight
thresholdWeight	u64	Weight needed for supermajority
prevotes	Prevotes	Prevote information
precommits	Precommits	Precommit information

Code Examples

cURL

curl https://api-acala.n.dwellir.com/YOUR_API_KEY \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "grandpa_roundState",
    "params": [],
    "id": 1
  }'

JavaScript

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

const provider = new WsProvider('wss://api-acala.n.dwellir.com/YOUR_API_KEY');
const api = await ApiPromise.create({ provider });

const roundState = await api.rpc.grandpa.roundState();
console.log('Set ID:', roundState.setId.toString());
console.log('Best round:', roundState.best.round.toString());
console.log('Total weight:', roundState.best.totalWeight.toString());
console.log('Threshold:', roundState.best.thresholdWeight.toString());

await api.disconnect();

Python

import requests

url = 'https://api-acala.n.dwellir.com/YOUR_API_KEY'
payload = {
    'jsonrpc': '2.0',
    'method': 'grandpa_roundState',
    'params': [],
    'id': 1
}

response = requests.post(url, json=payload)
result = response.json()['result']

print(f"Set ID: {result['setId']}")
print(f"Round: {result['best']['round']}")
print(f"Total weight: {result['best']['totalWeight']}")

Understanding GRANDPA Rounds

1. Prevote phase - Validators vote on best block they've seen
2. Precommit phase - Validators commit to finalize if supermajority prevoted
3. Finalization - Block is finalized when 2/3+ weight precommits

Related Methods

• chain_subscribeFinalizedHeads - Subscribe to finalized blocks
• chain_getFinalizedHead - Get current finalized hash
• beefy_getFinalizedHead - BEEFY finality (if enabled)