feat: Support BatchV1_1

packages/ripple-binary-codec/HISTORY.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+### Changed
+* Add XLS-56 Batch V1_1 support to `signingBatchData` / `encodeForSigningBatch` ([XRPLF/rippled#6446](https://github.com/XRPLF/rippled/pull/6446)). Tracks an unmerged rippled PR; the wire format may still change.
+
 ## 2.8.0 (2026-06-04)
 
 ### Fixed

packages/ripple-binary-codec/package.json

@@ -1,6 +1,6 @@
 {
   "name": "ripple-binary-codec",
-  "version": "2.8.0",
+  "version": "2.9.0-batch.1",
   "description": "XRP Ledger binary codec",
   "files": [
     "dist/*",

packages/ripple-binary-codec/src/binary.ts

@@ -178,41 +178,77 @@ function multiSigningData(
 }
 
 /**
- * Interface describing fields required for a Batch signer
- * @property flags - Flags indicating Batch transaction properties
- * @property txIDs - Array of transaction IDs included in the Batch
+ * Fields required to serialize an XLS-56 Batch V1_1 signing payload.
+ *
+ * @property account - The outer Batch transaction's `Account`.
+ * @property sequence - The outer Batch's sequence value (`Sequence`, or the
+ *   `TicketSequence` value when a ticket is used).
+ * @property flags - Flags indicating Batch transaction properties.
+ * @property txIDs - Array of inner transaction IDs included in the Batch.
+ * @property batchAccount - The `BatchSigner.Account` the signature binds to.
+ * @property signerAccount - For a multi-signed `BatchSigner`, the inner
+ *   `Signers` entry account, appended after `batchAccount`.
  */
 interface BatchObject extends JsonObject {
+  account: string
+  sequence: number
   flags: number
   txIDs: string[]
+  batchAccount?: string
+  signerAccount?: string
 }
 
 /**
- * Serialize a signingClaim
+ * Serialize an XLS-56 Batch V1_1 signing payload:
+ *   HashPrefix.batch | account | sequence | flags | txIDCount | txIDs[]
+ *   [ | batchAccount [ | signerAccount ] ]
  *
  * @param batch A Batch object to serialize.
  * @returns the serialized object with appropriate prefix
  */
 function signingBatchData(batch: BatchObject): Uint8Array {
+  if (batch.account == null) {
+    throw Error('No field `account`')
+  }
+  if (batch.sequence == null) {
+    throw Error('No field `sequence`')
+  }
   if (batch.flags == null) {
-    throw Error("No field `flags'")
+    throw Error('No field `flags`')
   }
   if (batch.txIDs == null) {
     throw Error('No field `txIDs`')
   }
   const prefix = HashPrefix.batch
+  const account = coreTypes.AccountID.from(batch.account).toBytes()
+  const sequence = coreTypes.UInt32.from(batch.sequence).toBytes()
   const flags = coreTypes.UInt32.from(batch.flags).toBytes()
   const txIDsLength = coreTypes.UInt32.from(batch.txIDs.length).toBytes()
 
   const bytesList = new BytesList()
 
   bytesList.put(prefix)
+  bytesList.put(account)
+  bytesList.put(sequence)
   bytesList.put(flags)
   bytesList.put(txIDsLength)
   batch.txIDs.forEach((txID: string) => {
     bytesList.put(coreTypes.Hash256.from(txID).toBytes())
   })
 
+  if (batch.batchAccount != null) {
+    bytesList.put(coreTypes.AccountID.from(batch.batchAccount).toBytes())
+  }
+  // The wire format is positional, so `signerAccount` must follow `batchAccount`.
+  // Reject `signerAccount` without `batchAccount` to avoid binding the signature
+  // to the wrong account.
+  if (batch.signerAccount != null) {
+    if (batch.batchAccount == null) {
+      throw Error('Field `signerAccount` requires `batchAccount`')
+    }
+    bytesList.put(coreTypes.AccountID.from(batch.signerAccount).toBytes())
+  }
+
   return bytesList.toBytes()
 }
 

packages/ripple-binary-codec/test/signing-data-encoding.test.ts

@@ -306,25 +306,74 @@ describe('Signing data', function () {
     )
   })
 
-  it('can create batch blob', function () {
-    const flags = 1
-    const txIDs = [
-      'ABE4871E9083DF66727045D49DEEDD3A6F166EB7F8D1E92FE868F02E76B2C5CA',
-      '795AAC88B59E95C3497609749127E69F12958BC016C600C770AEEB1474C840B4',
-    ]
-    const json = { flags, txIDs }
+  it('can create batch blob for a single-signed BatchSigner', function () {
+    const json = {
+      account: 'rNCFjv8Ek5oDrNiMJ3pw6eLLFtMjZLJnf2',
+      sequence: 5,
+      flags: 1,
+      txIDs: [
+        'ABE4871E9083DF66727045D49DEEDD3A6F166EB7F8D1E92FE868F02E76B2C5CA',
+        '795AAC88B59E95C3497609749127E69F12958BC016C600C770AEEB1474C840B4',
+      ],
+      // The BatchSigner.Account the signature is bound to (XLS-56 V1_1).
+      batchAccount: 'rJCxK2hX9tDMzbnn3cg1GU2g19Kfmhzxkp',
+    }
+    const actual = encodeForSigningBatch(json)
+    expect(actual).toBe(
+      [
+        // hash prefix
+        '42434800',
+        // outer account
+        '95F14B0E44F78A264E41713C64B5F89242540EE2',
+        // outer sequence
+        '00000005',
+        // flags
+        '00000001',
+        // txIds length
+        '00000002',
+        // txIds
+        'ABE4871E9083DF66727045D49DEEDD3A6F166EB7F8D1E92FE868F02E76B2C5CA',
+        '795AAC88B59E95C3497609749127E69F12958BC016C600C770AEEB1474C840B4',
+        // batch signer account
+        'C1D81FB31C42392BA1570431F1CBCBEEBBEF50E1',
+      ].join(''),
+    )
+  })
+
+  it('can create batch blob for a multi-signed BatchSigner', function () {
+    const json = {
+      account: 'rNCFjv8Ek5oDrNiMJ3pw6eLLFtMjZLJnf2',
+      sequence: 5,
+      flags: 1,
+      txIDs: [
+        'ABE4871E9083DF66727045D49DEEDD3A6F166EB7F8D1E92FE868F02E76B2C5CA',
+        '795AAC88B59E95C3497609749127E69F12958BC016C600C770AEEB1474C840B4',
+      ],
+      // The BatchSigner.Account the signature is bound to.
+      batchAccount: 'rJCxK2hX9tDMzbnn3cg1GU2g19Kfmhzxkp',
+      // The inner Signers entry account for a multi-signed BatchSigner.
+      signerAccount: 'rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh',
+    }
     const actual = encodeForSigningBatch(json)
     expect(actual).toBe(
       [
         // hash prefix
         '42434800',
+        // outer account
+        '95F14B0E44F78A264E41713C64B5F89242540EE2',
+        // outer sequence
+        '00000005',
         // flags
         '00000001',
         // txIds length
         '00000002',
         // txIds
         'ABE4871E9083DF66727045D49DEEDD3A6F166EB7F8D1E92FE868F02E76B2C5CA',
         '795AAC88B59E95C3497609749127E69F12958BC016C600C770AEEB1474C840B4',
+        // batch signer account
+        'C1D81FB31C42392BA1570431F1CBCBEEBBEF50E1',
+        // inner signer account
+        'B5F762798A53D543A014CAF8B297CFF8F2F937E8',
       ].join(''),
     )
   })

packages/xrpl/HISTORY.md

@@ -4,6 +4,9 @@ Subscribe to [the **xrpl-announce** mailing list](https://groups.google.com/g/xr
 
 ## Unreleased
 
+### Changed
+* Add XLS-56 Batch V1_1 support to `signMultiBatch` and `combineBatchSigners` ([XRPLF/rippled#6446](https://github.com/XRPLF/rippled/pull/6446)).
+
 ## 5.0.0 (2026-06-05)
 
 ### BREAKING CHANGES:

packages/xrpl/package.json

@@ -30,7 +30,7 @@
     "eventemitter3": "^5.0.1",
     "fast-json-stable-stringify": "^2.1.0",
     "ripple-address-codec": "^5.0.1",
-    "ripple-binary-codec": "^2.8.0",
+    "ripple-binary-codec": "^2.9.0-batch.1",
     "ripple-keypairs": "^3.0.0"
   },
   "devDependencies": {

packages/xrpl/src/Wallet/batchSigner.ts

@@ -45,6 +45,21 @@ function constructBatchSignerObject(
   return batchSigner
 }
 
+/**
+ * Resolve the sequence value bound into a Batch signature: the `Sequence` when
+ * non-zero, otherwise the `TicketSequence` value (or 0).
+ *
+ * @param transaction - The Batch transaction being signed.
+ * @returns The sequence value to bind into the signature.
+ */
+function getBatchSeqValue(transaction: Batch): number {
+  const sequence = transaction.Sequence ?? 0
+  if (sequence !== 0) {
+    return sequence
+  }
+  return transaction.TicketSequence ?? 0
+}
+
 /**
  * Sign a multi-account Batch transaction.
  *
@@ -56,6 +71,7 @@ function constructBatchSignerObject(
  *                       The actual address is only needed in the case of regular key usage.
  * @throws ValidationError if the transaction is malformed.
  */
+// eslint-disable-next-line max-lines-per-function -- cohesive signing routine
 export function signMultiBatch(
   wallet: Wallet,
   transaction: Batch,
@@ -79,19 +95,33 @@ export function signMultiBatch(
   // eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- validate does not accept Transaction type
   validate(transaction as unknown as Record<string, unknown>)
 
-  const involvedAccounts = new Set(
-    transaction.RawTransactions.map((raw) => raw.RawTransaction.Account),
-  )
+  // An account must sign the Batch if it submits an inner transaction or is the
+  // `Counterparty` of one.
+  const involvedAccounts = new Set<string>()
+  transaction.RawTransactions.forEach((raw) => {
+    involvedAccounts.add(raw.RawTransaction.Account)
+    // eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- Counterparty only exists on some inner tx types
+    const counterparty = (raw.RawTransaction as Record<string, unknown>)
+      .Counterparty
+    if (typeof counterparty === 'string') {
+      involvedAccounts.add(counterparty)
+    }
+  })
   if (!involvedAccounts.has(batchAccount)) {
     throw new ValidationError(
       'Must be signing for an address submitting a transaction in the Batch.',
     )
   }
   const fieldsToSign = {
+    account: transaction.Account,
+    sequence: getBatchSeqValue(transaction),
     flags: transaction.Flags,
     txIDs: transaction.RawTransactions.map((rawTx) =>
       hashSignedTx(rawTx.RawTransaction),
     ),
+    batchAccount,
+    // Multi-signed batch signers also bind the inner signer account.
+    ...(multisignAddress ? { signerAccount: multisignAddress } : {}),
   }
   const signature = sign(encodeForSigningBatch(fieldsToSign), wallet.privateKey)
 
@@ -186,13 +216,28 @@ function validateBatchTransactionEquivalence(transactions: Batch[]): void {
 }
 
 function getTransactionWithAllBatchSigners(transactions: Batch[]): Batch {
+  const outerAccount = transactions[0].Account
+
   // Signers must be sorted in the combined transaction - See compareSigners' documentation for more details
   const sortedSigners: BatchSigner[] = transactions
     .flatMap((tx) => tx.BatchSigners ?? [])
-    .filter((signer) => signer.BatchSigner.Account !== transactions[0].Account)
+    // A batch signer cannot be the outer account (rippled: temBAD_SIGNER).
+    .filter((signer) => signer.BatchSigner.Account !== outerAccount)
     .sort((signer1, signer2) =>
       compareSigners(signer1.BatchSigner, signer2.BatchSigner),
     )
 
-  return { ...transactions[0], BatchSigners: sortedSigners }
+  // BatchSigners must be strictly ascending and unique by account, so
+  // de-duplicate when combining fragments that share a signer.
+  const dedupedSigners: BatchSigner[] = []
+  let lastAccount = ''
+  for (const signer of sortedSigners) {
+    const account = signer.BatchSigner.Account
+    if (account !== lastAccount) {
+      dedupedSigners.push(signer)
+      lastAccount = account
+    }
+  }
+
+  return { ...transactions[0], BatchSigners: dedupedSigners }
 }