Batch

Batches are ordered sets of blocks within a blockchain. Each batch includes multiple blocks covering specific height ranges along with transaction hashes and DA data. Vulcan, by default, is configured to settle batches every 6 hours or when the maximum blob size is reached, whichever happens first.

The main motivations for using batches are cost savings, by amortizing settlement costs across multiple blocks, and composability, by supporting atomic execution and interconnectedness between different micro rollups.

Batches on Stackr

A batch in Stackr framework looks like this

interface BatchInfo {
  hash: string;
  sequenceNumber: number;
  firstBlockHeight: number;
  lastBlockHeight: number;
  daMetadata: Record<DA, Record<string, never>>;
  l1TransactionHash: string;
  l1BlockNumber?: number;
}

• hash: Keccak256 of encoded blocksRoot (Merkle root of the Block hashes), sequencerNumber and width (number of blocks in the batch) of the batch.
• sequenceNumber: The sequential order in which batches are created, starting from 1.
• firstBlockHeight: The block height of the first block included in the batch.
• lastBlockHeight: The block height of the last block included in the batch.
• daMetadata: Data Pointers of the posted batch on DA (like blockNumber, height or txHash, etc.)
• l1TransactionHash: The transaction hash for the finalisation of the batch on L1.
• l1BlockNumber: The block number of the block containing the transaction on L1.