grandpa_roundState

Description

Returns detailed information about the current GRANDPA round: the set of voters, ongoing rounds, and last finalized block. Useful for diagnosing finality stalls or verifying collator participation.

Parameters

This method does not take parameters.

Returns

Field	Type	Description
setId	number	Identifier of the current voter set
best	object	Information about the best round
background	array	Additional rounds executing in the background
prevote/precommit	object	Per-round vote state
finalized	object	Last finalized block (hash and number)

Request Example

{
  "jsonrpc": "2.0",
  "method": "grandpa_roundState",
  "params": [],
  "id": 1
}

Response Example

{
  "jsonrpc": "2.0",
  "result": {
    "setId": 423,
    "best": {
      "round": 1264,
      "prevotes": {
        "currentWeight": 5120,
        "missing": []
      },
      "precommits": {
        "currentWeight": 5120,
        "missing": []
      }
    },
    "background": [],
    "finalized": {
      "hash": "0x0783f5b163e338d4d74a1ee39a0f631bc2dffbd8862460407f6cc97c903194e1",
      "number": 9453706
    }
  },
  "id": 1
}

Values shown correspond to the 2025-10-03 finality round; actual weights depend on the relay-chain validator set.

Code Examples

JavaScript

const roundState = await api.rpc.grandpa.roundState();
console.log(roundState.toHuman());

Rust

let round = api.rpc().grandpa_round_state().await?;
println!("Current set: {}", round.set_id);
println!("Best round: {}", round.best.as_ref().map(|r| r.round).unwrap_or_default());

Usage Notes

• If missing lists grow or precommits.currentWeight stalls below the total weight, investigate validator participation.
• Combine with chain_subscribeFinalizedHeads to correlate GRANDPA finality with block numbers.