Call the reverseLedgerEntry mutation to reverse a posted Ledger Entry:

mutation ReverseLedgerEntry(
  $id: ID!
) {
  reverseLedgerEntry(
    id: $id
  ) {
    __typename
    ... on ReverseLedgerEntryResult {
      reversingLedgerEntry {
        ik
        id
        type
        posted
        created
        reverses {
          id
          created
        }
        reversalPosition
      }
      reversedLedgerEntry {
        ik
        id
        type
        posted
        created
        reversedBy {
          id
          created
        }
        reversalPosition
        reversedAt
      }
      isIkReplay
    }
    ... on Error {
      code
      message
    }
  }
}

{
  "id": "<ID of the entry to reverse>"
}

You cannot reverse a Ledger Entry using ik because the reversing, reversed, and any subsequent reposting of the Ledger Entry will all share the same ik. This ensures all versions of a Ledger Entry are idempotent. Attempting to reverse a reversing Ledger Entry will return isIkReplay: true.

The reversing Ledger Entry will also have:

• The same number of lines with opposite amount values in the same currency as the Ledger Entry that it is reversing.
• The same posted timestamp as the Ledger Entry that it is reversing. This ensures that the net balance effect at the posted timestamp is 0. They will however have unique created timestamps.
• The same Tags and Groups as the Ledger Entry that it is reversing. However, both the reversing and reversed Ledger Entries can no longer be updated using updateLedgerEntry.
• A reverses field that references the Ledger Entry it reverses.
• A reversalPosition value of one greater than the Ledger Entry that it is reversing. This position value is 1 indexed.

The reversed Ledger Entry will be updated to include:

• A reversedBy field that references the Ledger Entry that reversed it.
• A reversedAt timestamp that is the created timestamp of the reversing Ledger Entry.

Once a Ledger Entry has been reversed, it can be reposted by using the same ik value. Any Entry Type can be used for the reposted Ledger Entry. To do so, simply use the addLedgerEntry or reconcileTx mutation.

mutation AddLedgerEntry(
  $ik: SafeString!
  $entry: LedgerEntryInput!
) {
  addLedgerEntry(
    ik: $ik,
    entry: $entry
  ) {
    __typename
    ... on AddLedgerEntryResult {
      entry {
        type
        created
        posted
        reversalPosition
      }
      lines {
        amount
        key
        description
        account {
          path
        }
      }
    }
    ... on Error {
      code
      message
    }
  }
}

{
  "ik": "add-ledger-entry",
  "entry": {
    "ledger": {
      "ik": "quickstart-ledger"
    },
    "type": "user_funds_account",
    "posted": "1234-01-01T01:01:01",
    "parameters": {
      "user_id": "testing-user",
      "funding_amount": "400"
    }
  }
}

mutation ReconcileTx(
  $entry: LedgerEntryInput!
) {
  reconcileTx(
    entry: $entry
  ) {
    ... on ReconcileTxResult {
      entry {
        type
        created
        posted
        reversalPosition
      }
      lines {
        amount
        key
        description
        account {
          path
        }
      }
    }
    ... on Error {
      code
      message
    }
  }
}

{
  "entry": {
    "type": "user_funding",
    "ledger": {
      "ik": "quickstart-ledger"
    },
    "parameters": {
      "txId": "tx_12345",
      "customerId": "customer-1"
    }
  }
}

The newly posted Ledger Entry will have a reversalPosition value of one greater than the previous reversal Ledger Entry.

Use the ledgerEntryHistory query to get the full history of a Ledger Entry with reversals. Lookups by IK for a reversing or reversed Ledger Entry will return a ledger_entry_not_found BadRequestError.

Additionally, Ledger Entries have a reversalHistory field that returns a list of all Ledger Entries and their reversals that share an ik.

Once a Ledger Entry has been reversed it is hidden from your list of Ledger Entries. For debugging, you can query hidden Ledger Entries.