Skip to main content

Checkpoint

Checkpoints contain finalized transactions and are used for node synchronization and global transaction ordering.

type Checkpoint {
  digest: String!
  sequenceNumber: UInt53!
  timestamp: DateTime!
  validatorSignatures: Base64!
  previousCheckpointDigest: String
  networkTotalTransactions: UInt53
  rollingGasSummary: GasCostSummary
  epoch: Epoch
  transactionBlocks(
    first: Int
    after: String
    last: Int
    before: String
    filter: TransactionBlockFilter
    scanLimit: Int
  ): TransactionBlockConnection!
  checkpointSummaryBcs: Base64
}

Fields​

Checkpoint.digest ● String! non-null scalar​

A 32-byte hash that uniquely identifies the checkpoint contents, encoded in Base58. This hash can be used to verify checkpoint contents by checking signatures against the committee, Hashing contents to match digest, and checking that the previous checkpoint digest matches.

Checkpoint.sequenceNumber ● UInt53! non-null scalar​

This checkpoint's position in the total order of finalized checkpoints, agreed upon by consensus.

Checkpoint.timestamp ● DateTime! non-null scalar​

The timestamp at which the checkpoint is agreed to have happened according to consensus. Transactions that access time in this checkpoint will observe this timestamp.

Checkpoint.validatorSignatures ● Base64! non-null scalar​

This is an aggregation of signatures from a quorum of validators for the checkpoint proposal.

Checkpoint.previousCheckpointDigest ● String scalar​

The digest of the checkpoint at the previous sequence number.

Checkpoint.networkTotalTransactions ● UInt53 scalar​

The total number of transaction blocks in the network by the end of this checkpoint.

Checkpoint.rollingGasSummary ● GasCostSummary object​

The computation cost, storage cost, storage rebate, and non-refundable storage fee accumulated during this epoch, up to and including this checkpoint. These values increase monotonically across checkpoints in the same epoch, and reset on epoch boundaries.

Checkpoint.epoch ● Epoch object​

The epoch this checkpoint is part of.

Checkpoint.transactionBlocks ● TransactionBlockConnection! non-null object​

Transactions in this checkpoint.

scanLimit restricts the number of candidate transactions scanned when gathering a page of results. It is required for queries that apply more than two complex filters (on function, kind, sender, recipient, input object, changed object, or ids), and can be at most serviceConfig.maxScanLimit.

When the scan limit is reached the page will be returned even if it has fewer than first results when paginating forward (last when paginating backwards). If there are more transactions to scan, pageInfo.hasNextPage (or pageInfo.hasPreviousPage) will be set to true, and PageInfo.endCursor (or PageInfo.startCursor) will be set to the last transaction that was scanned as opposed to the last (or first) transaction in the page.

Requesting the next (or previous) page after this cursor will resume the search, scanning the next scanLimit many transactions in the direction of pagination, and so on until all transactions in the scanning range have been visited.

By default, the scanning range consists of all transactions in this checkpoint.

Checkpoint.transactionBlocks.first ● Int scalar​
Checkpoint.transactionBlocks.after ● String scalar​
Checkpoint.transactionBlocks.last ● Int scalar​
Checkpoint.transactionBlocks.before ● String scalar​
Checkpoint.transactionBlocks.filter ● TransactionBlockFilter input​
Checkpoint.transactionBlocks.scanLimit ● Int scalar​

Checkpoint.checkpointSummaryBcs ● Base64 scalar​

The Base64 serialized BCS bytes of CheckpointSummary for this checkpoint.

Returned By​

checkpoint query

Member Of​

AvailableRange object ● CheckpointConnection object ● CheckpointEdge object ● TransactionBlockEffects object