Ledger Header

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Every ledger version has a unique header that describes the contents. You can look up a ledger's header information with the ledger method. The contents of the ledger header are as follows:

Field JSON Type Internal Type Description
ledger_index String UInt32 The sequence number of the ledger. Some API methods display this as a quoted integer; some display it as a native JSON number.
ledger_hash String Hash256 The SHA-512Half of the ledger header, excluding the ledger_hash itself. This serves as a unique identifier for this ledger and all its contents.
account_hash String Hash256 The SHA-512Half of this ledger's state tree information.
close_time Number UInt32 The approximate time this ledger closed, as the number of seconds since the Ripple Epoch of 2000-01-01 00:00:00. This value is rounded based on the close_time_resolution, so later ledgers can have the same value.
closed Boolean bool If true, this ledger version is no longer accepting new transactions. (However, unless this ledger version is validated, it might be replaced by a different ledger version with a different set of transactions.)
parent_hash String Hash256 The ledger_hash value of the previous ledger that was used to build this one. If there are different versions of the previous ledger index, this indicates from which one the ledger was derived.
total_coins String UInt64 The total number of drops of XRP owned by accounts in the ledger. This omits XRP that has been destroyed by transaction fees. The actual amount of XRP in circulation is lower because some accounts are "black holes" whose keys are not known by anyone.
transaction_hash String Hash256 The SHA-512Half of the transactions included in this ledger.
close_time_resolution Number Uint8 An integer in the range [2,120] indicating the maximum number of seconds by which the close_time could be rounded.
closeFlags (Omitted) UInt8 A bit-map of flags relating to the closing of this ledger.

Ledger Index

A ledger index is a 32-bit unsigned integer used to identify a ledger. The ledger index is also known as the ledger's sequence number. The very first ledger was ledger index 1, and each new ledger has a ledger index 1 higher than that of the ledger immediately before it.

The ledger index indicates the order of the ledgers; the Hash value identifies the exact contents of the ledger. Two ledgers with the same hash are always the same. For validated ledgers, hash values and sequence numbers are equally valid and correlate 1:1. However, this is not true for in-progress ledgers:

  • Two different rippled servers may have different contents for a current ledger with the same ledger index, due to latency in propagating transactions throughout the network.
  • There may be multiple closed ledger versions competing to be validated by consensus. These ledger versions have the same sequence number but different contents (and different hashes). Only one of these closed ledgers can become validated.
  • A current ledger's contents change over time, which would cause its hash to change, even though its ledger index number stays the same. The hash of a ledger is not calculated until the ledger is closed.

Close Flags

The ledger has only one flag defined for closeFlags: sLCF_NoConsensusTime (value 1). If this flag is enabled, it means that validators had different close times for the ledger, but built otherwise the same ledger, so they declared consensus while "agreeing to disagree" on the close time. In this case, the consensus ledger version contains a close_time value that is 1 second after that of the previous ledger. (In this case, there is no official close time, but the actual real-world close time is probably 3-6 seconds later than the specified close_time.)

The closeFlags field is not included in any JSON representations of a ledger, but is included in the binary representation of a ledger, and is one of the fields that determine the ledger's hash.

See Also

For ledger basics, see Ledgers.