BitGo · abhishekagrawal080 · Mar 23, 2026
@@ -172,9 +172,25 @@ export enum MethodNames {
    * @see https://github.com/MystenLabs/walrus-docs/blob/9307e66df0ea3f6555cdef78d46aefa62737e216/contracts/walrus/sources/staking/staked_wal.move#L143
    */
   WalrusSplitStakedWal = '::staked_wal::split',
+  /**
+   * Redeem funds from the address balance system into a Coin<T> object.
+   * Used with the BalanceWithdrawal CallArg to spend from address balance.
+   *
+   * @see https://docs.sui.io/concepts/sui-move-concepts/address-balance
+   */
+  RedeemFunds = '::coin::redeem_funds',
 }
 
 export interface SuiObjectInfo extends SuiObjectRef {
   /** balance */
   balance: BigNumber;
 }
+
+export interface SuiBalanceInfo {
+  /** Total balance combining coin object balance and address balance */
+  totalBalance: string;
+  /** Balance held in coin objects (UTXO-style Coin<T> objects) */
+  coinObjectBalance: string;
+  /** Balance held in the address balance system (not in coin objects) */
+  fundsInAddressBalance: string;
+}
@@ -1,5 +1,5 @@
-import { array, boolean, Infer, integer, object, string, union } from 'superstruct';
-import { normalizeSuiAddress, ObjectId, SharedObjectRef, SuiObjectRef } from '../types';
+import { any, array, boolean, Infer, integer, object, string, union } from 'superstruct';
+import { normalizeSuiAddress, ObjectId, SharedObjectRef, SuiObjectRef, TypeTag } from '../types';
 import { builder } from './bcs';
 
 const ObjectArg = union([
@@ -15,10 +15,17 @@ const ObjectArg = union([
 
 export const PureCallArg = object({ Pure: array(integer()) });
 export const ObjectCallArg = object({ Object: ObjectArg });
+export const BalanceWithdrawalCallArg = object({
+  BalanceWithdrawal: object({
+    amount: any(),
+    type_: any(),
+  }),
+});
 export type PureCallArg = Infer<typeof PureCallArg>;
 export type ObjectCallArg = Infer<typeof ObjectCallArg>;
+export type BalanceWithdrawalCallArg = Infer<typeof BalanceWithdrawalCallArg>;
 
-export const BuilderCallArg = union([PureCallArg, ObjectCallArg]);
+export const BuilderCallArg = union([PureCallArg, ObjectCallArg, BalanceWithdrawalCallArg]);
 export type BuilderCallArg = Infer<typeof BuilderCallArg>;
 
 export const Inputs = {
@@ -33,12 +40,27 @@ export const Inputs = {
   SharedObjectRef(ref: SharedObjectRef): ObjectCallArg {
     return { Object: { Shared: ref } };
   },
+  /**
+   * Create a BalanceWithdrawal CallArg that withdraws `amount` from the sender's
+   * address balance at execution time. Use with `0x2::coin::redeem_funds` to
+   * convert the withdrawal into a `Coin<T>` object.
+   *
+   * @param amount - amount in base units (MIST for SUI)
+   * @param type_ - the TypeTag of the coin (defaults to SUI)
+   */
+  BalanceWithdrawal(amount: bigint | number, type_: TypeTag): BalanceWithdrawalCallArg {
+    return { BalanceWithdrawal: { amount, type_ } };
+  },
 };
 
-export function getIdFromCallArg(arg: ObjectId | ObjectCallArg): string {
+export function getIdFromCallArg(arg: ObjectId | ObjectCallArg | BalanceWithdrawalCallArg): string {
   if (typeof arg === 'string') {
     return normalizeSuiAddress(arg);
   }
+  if ('BalanceWithdrawal' in arg) {
+    // BalanceWithdrawal inputs have no object ID; they cannot be deduplicated by ID
+    return '';
+  }
   if ('ImmOrOwned' in arg.Object) {
     return arg.Object.ImmOrOwned.objectId;
   }

@@ -4,6 +4,7 @@ import { ObjectId, SuiObjectRef } from '../types';
 import { Transactions, TransactionArgument, TransactionType, TransactionBlockInput } from './Transactions';
 import { BuilderCallArg, getIdFromCallArg, Inputs, ObjectCallArg } from './Inputs';
 import { TransactionBlockDataBuilder, TransactionExpiration } from './TransactionDataBlock';
+import { TypeTagSerializer } from '../txn-data-serializers/type-tag-serializer';
 import { create } from './utils';
 
 type TransactionResult = TransactionArgument & TransactionArgument[];
@@ -239,6 +240,28 @@ export class TransactionBlock {
 
   // Method shorthands:
 
+  /**
+   * Create a BalanceWithdrawal argument that withdraws `amount` from the sender's
+   * address balance at execution time. Pass this as an argument to
+   * `0x2::coin::redeem_funds` to receive a `Coin<T>` object:
+   *
+   * ```typescript
+   * const [coin] = tx.moveCall({
+   *   target: '0x2::coin::redeem_funds',
+   *   typeArguments: ['0x2::sui::SUI'],
+   *   arguments: [tx.withdrawal({ amount: 1_000_000n })],
+   * });
+   * tx.transferObjects([coin], recipientAddress);
+   * ```
+   *
+   * @param amount - amount in base units (e.g. MIST for SUI)
+   * @param type   - coin type string, defaults to `'0x2::sui::SUI'`
+   */
+  withdrawal({ amount, type: coinType = '0x2::sui::SUI' }: { amount: bigint | number; type?: string }): TransactionArgument {
+    const typeTag = TypeTagSerializer.parseFromStr(coinType, true);
+    return this.input('object', Inputs.BalanceWithdrawal(amount, typeTag));
+  }
+
   splitCoins(...args: Parameters<(typeof Transactions)['SplitCoins']>) {
     return this.add(Transactions.SplitCoins(...args));
   }

@@ -25,6 +25,7 @@ export const CoinBalance = object({
   coinType: string(),
   coinObjectCount: number(),
   totalBalance: number(),
+  fundsInAddressBalance: optional(number()),
   lockedBalance: object({
     epochId: optional(number()),
     number: optional(number()),

@@ -66,7 +66,7 @@ export function isPureArg(arg: any): arg is PureArg {
  * For `Pure` arguments BCS is required. You must encode the values with BCS according
  * to the type required by the called function. Pure accepts only serialized values
  */
-export type CallArg = PureArg | { Object: ObjectArg };
+export type CallArg = PureArg | { Object: ObjectArg } | { BalanceWithdrawal: { amount: bigint | number; type_: TypeTag } };
 
 /**
  * Kind of a TypeTag which is represented by a Move type identifier.
@@ -144,6 +144,7 @@ const BCS_SPEC: TypeSchema = {
       Pure: [VECTOR, BCS.U8],
       Object: 'ObjectArg',
       ObjVec: [VECTOR, 'ObjectArg'],
+      BalanceWithdrawal: 'BalanceWithdrawal',
     },
     TypeTag: {
       bool: null,
@@ -175,6 +176,10 @@ const BCS_SPEC: TypeSchema = {
     },
   },
   structs: {
+    BalanceWithdrawal: {
+      amount: BCS.U64,
+      type_: 'TypeTag',
+    },
     SuiObjectRef: {
       objectId: BCS.ADDRESS,
       version: BCS.U64,

@@ -1,6 +1,6 @@
 import assert from 'assert';
 import { TransactionType, Recipient, BuildTransactionError, BaseKey } from '@bitgo/sdk-core';
-import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { BaseCoin as CoinConfig, SuiCoin } from '@bitgo/statics';
 import { SuiTransaction, SuiTransactionType, TokenTransferProgrammableTransaction } from './iface';
 import { Transaction } from './transaction';
 import { TransactionBuilder } from './transactionBuilder';
@@ -12,10 +12,19 @@ import {
   TransactionBlock as ProgrammingTransactionBlockBuilder,
   TransactionArgument,
 } from './mystenlab/builder';
+import BigNumber from 'bignumber.js';
 
 export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgrammableTransaction> {
   protected _recipients: Recipient[];
   protected _inputObjects: SuiObjectRef[];
+  /**
+   * Balance held in the address balance system for the token being transferred.
+   * When set, this amount is included in the total available balance.
+   * At execution time, tx.withdrawal() + 0x2::coin::redeem_funds converts it
+   * to a Coin<T> that is merged with any coin objects before splitting.
+   */
+  protected _fundsInAddressBalance: BigNumber = new BigNumber(0);
+
   constructor(_coinConfig: Readonly<CoinConfig>) {
     super(_coinConfig);
     this._transaction = new TokenTransferTransaction(_coinConfig);
@@ -25,6 +34,14 @@ export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgra
     return TransactionType.Send;
   }
 
+  /**
+   * The full coin type string derived from the coin config (e.g. `0xabc::my_token::MY_TOKEN`).
+   */
+  private get tokenCoinType(): string {
+    const config = this._coinConfig as SuiCoin;
+    return `${config.packageId}::${config.module}::${config.symbol}`;
+  }
+
   /** @inheritdoc */
   validateTransaction(transaction: TokenTransferTransaction): void {
     if (!transaction.suiTransaction) {
@@ -78,8 +95,23 @@ export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgra
     this.gasData(txData.gasData);
     const recipients = utils.getRecipients(tx.suiTransaction);
     this.send(recipients);
-    assert(txData.inputObjects);
-    this.inputObjects(txData.inputObjects);
+
+    // Reconstruct fundsInAddressBalance from BalanceWithdrawal input if present.
+    // After BCS deserialization inputs are CallArg format: { BalanceWithdrawal: {...} }
+    // During building they are TransactionBlockInput format: { kind:'Input', value: { BalanceWithdrawal: {...} } }
+    const withdrawalInput = (tx.suiTransaction?.tx?.inputs as any[])?.find(
+      (input: any) =>
+        (input !== null && typeof input === 'object' && 'BalanceWithdrawal' in input) ||
+        (input?.value !== null && typeof input?.value === 'object' && 'BalanceWithdrawal' in (input.value ?? {}))
+    );
+    if (withdrawalInput) {
+      const bw = withdrawalInput.BalanceWithdrawal ?? withdrawalInput.value?.BalanceWithdrawal;
+      this._fundsInAddressBalance = new BigNumber(String(bw.amount));
+    }
+
+    if (txData.inputObjects && txData.inputObjects.length > 0) {
+      this.inputObjects(txData.inputObjects);
+    }
   }
 
   send(recipients: Recipient[]): this {
@@ -89,11 +121,21 @@ export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgra
   }
 
   inputObjects(inputObject: SuiObjectRef[]): this {
-    this.validateInputObjects(inputObject);
+    this.validateInputObjectRefs(inputObject);
     this._inputObjects = inputObject;
     return this;
   }
 
+  /**
+   * Set the amount of token funds held in the Sui address balance system for this sender.
+   *
+   * @param {string} amount - amount in base units held in address balance
+   */
+  fundsInAddressBalance(amount: string): this {
+    this._fundsInAddressBalance = new BigNumber(amount);
+    return this;
+  }
+
   /**
    * Validates all fields are defined correctly
    */
@@ -106,21 +148,37 @@ export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgra
     );
     assert(this._gasData, new BuildTransactionError('gasData is required before building'));
     this.validateGasData(this._gasData);
-    this.validateInputObjects(this._inputObjects);
-  }
 
-  private validateInputObjects(inputObjects: SuiObjectRef[]): void {
+    // Must have at least coin objects OR address balance
     assert(
-      inputObjects && inputObjects.length > 0,
-      new BuildTransactionError('input objects required before building')
+      (this._inputObjects && this._inputObjects.length > 0) || this._fundsInAddressBalance.gt(0),
+      new BuildTransactionError('input objects or fundsInAddressBalance required before building')
     );
-    inputObjects.forEach((inputObject) => {
-      this.validateSuiObjectRef(inputObject, 'input object');
-    });
+    if (this._inputObjects && this._inputObjects.length > 0) {
+      this.validateInputObjectRefs(this._inputObjects);
+    }
+  }
+
+  /** Validates the individual object refs (does not require non-empty array). */
+  private validateInputObjectRefs(inputObjects: SuiObjectRef[]): void {
+    if (inputObjects) {
+      inputObjects.forEach((inputObject) => {
+        this.validateSuiObjectRef(inputObject, 'input object');
+      });
+    }
   }
 
   /**
-   * Build SuiTransaction
+   * Build SuiTransaction.
+   *
+   * Two build paths:
+   *
+   * Path A — coin objects only (fundsInAddressBalance = 0):
+   *   MergeCoins(inputObject[0], [inputObject[1..]]) → SplitCoins → TransferObjects
+   *
+   * Path B — coin objects + address balance (or address balance only):
+   *   MoveCall(0x2::coin::redeem_funds, [withdrawal(amount, coinType)]) → Coin<T>
+   *   MergeCoins(inputObject[0] | addrCoin, [rest...]) → SplitCoins → TransferObjects
    *
    * @return {SuiTransaction<TokenTransferProgrammableTransaction>}
    * @protected
@@ -130,9 +188,27 @@ export class TokenTransferBuilder extends TransactionBuilder<TokenTransferProgra
 
     const programmableTxBuilder = new ProgrammingTransactionBlockBuilder();
 
-    const inputObjects = this._inputObjects.map((object) => programmableTxBuilder.object(Inputs.ObjectRef(object)));
-    const mergedObject = inputObjects.shift() as TransactionArgument;
+    const inputObjects: TransactionArgument[] = (this._inputObjects ?? []).map((object) =>
+      programmableTxBuilder.object(Inputs.ObjectRef(object))
+    );
+
+    // If address balance is available, withdraw it as Coin<T> and add to the pool
+    if (this._fundsInAddressBalance.gt(0)) {
+      const coinType = this.tokenCoinType;
+      const [addrCoin] = programmableTxBuilder.moveCall({
+        target: '0x2::coin::redeem_funds',
+        typeArguments: [coinType],
+        arguments: [
+          programmableTxBuilder.withdrawal({
+            amount: BigInt(this._fundsInAddressBalance.toFixed()),
+            type: coinType,
+          }),
+        ],
+      });
+      inputObjects.push(addrCoin);
+    }
 
+    const mergedObject = inputObjects.shift() as TransactionArgument;
     if (inputObjects.length > 0) {
       programmableTxBuilder.mergeCoins(mergedObject, inputObjects);
     }

@@ -181,7 +181,15 @@ export class TokenTransferTransaction extends Transaction<TokenTransferProgramma
           return Inputs.Pure(amount, BCS.U64);
         }
       }
-      if (input.kind === 'Input' && (input.value.hasOwnProperty('Object') || input.value.hasOwnProperty('Pure'))) {
+      if (input.hasOwnProperty('BalanceWithdrawal')) {
+        return input;
+      }
+      if (
+        input.kind === 'Input' &&
+        (input.value.hasOwnProperty('Object') ||
+          input.value.hasOwnProperty('Pure') ||
+          input.value.hasOwnProperty('BalanceWithdrawal'))
+      ) {
         return input.value;
       }
       return Inputs.Pure(input.value, input.type === 'pure' ? BCS.U64 : BCS.ADDRESS);
@@ -221,20 +229,28 @@ export class TokenTransferTransaction extends Transaction<TokenTransferProgramma
   }
 
   /**
-   * Extracts the objects that were provided as inputs while building the transaction
+   * Extracts the objects that were provided as inputs while building the transaction.
+   * Handles both the simple case (MergeCoins/SplitCoins first) and the address-balance
+   * case where MoveCall(redeem_funds) may precede MergeCoins/SplitCoins.
    * @param tx
    * @returns {SuiObjectRef[]} Objects that are inputs for the transaction
    */
   private getInputObjectsFromTx(tx: TokenTransferProgrammableTransaction): SuiObjectRef[] {
     const inputs = tx.inputs;
-    const transaction = tx.transactions[0] as SuiTransactionBlockType;
 
+    // Scan all transactions to find the first MergeCoins or SplitCoins,
+    // which holds references to the coin object inputs.
     let args: TransactionArgument[] = [];
-    if (transaction.kind === 'MergeCoins') {
-      const { destination, sources } = transaction;
-      args = [destination, ...sources];
-    } else if (transaction.kind === 'SplitCoins') {
-      args = [transaction.coin];
+    for (const txn of tx.transactions) {
+      const transaction = txn as SuiTransactionBlockType;
+      if (transaction.kind === 'MergeCoins') {
+        const { destination, sources } = transaction;
+        args = [destination, ...sources];
+        break;
+      } else if (transaction.kind === 'SplitCoins') {
+        args = [transaction.coin];
+        break;
+      }
     }
 
     const inputObjects: SuiObjectRef[] = [];

@@ -149,7 +149,15 @@ export abstract class TransactionBuilder<T = SuiProgrammableTransaction> extends
   }
 
   validateGasPayment(payments: SuiObjectRef[]): void {
-    assert(payments && payments.length > 0, new BuildTransactionError('gas payment is required before building'));
+    assert(
+      payments !== undefined && payments !== null,
+      new BuildTransactionError('gas payment is required before building')
+    );
+    // Empty array is valid: Sui allows setGasPayment([]) when gas is paid from
+    // address balance (sender or fee payer has sufficient fundsInAddressBalance).
+    if (payments.length === 0) {
+      return;
+    }
     payments.forEach((payment) => {
       this.validateSuiObjectRef(payment, 'payment');
     });