fix: MMPay fiat payment fixes

packages/transaction-pay-controller/CHANGELOG.md

@@ -9,11 +9,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Add optional `getAmountData` callback to `TransactionPayControllerOptions` for client-side nested calldata re-encoding ([#8987](https://github.com/MetaMask/core/pull/8987))
+- Add `TransactionPayController:getAmountData` messenger action ([#8987](https://github.com/MetaMask/core/pull/8987))
 - Add `@metamask/keyring-controller` `^26.0.0` as a dependency ([#8972](https://github.com/MetaMask/core/pull/8972))
   - The package was already imported at runtime by `src/strategy/relay/hyperliquid-withdraw.ts` but wasn't declared in `package.json`; this PR fixes the omission.
 
 ### Changed
 
+- Fiat submit now uses a three-phase relay flow after on-ramp settlement: discovery quote, calldata update via `getAmountData`, then delegation quote ([#8987](https://github.com/MetaMask/core/pull/8987))
+- Fix fiat `moneyAccountDeposit` failing by using `isMaxAmount: false` in the re-quote ([#8987](https://github.com/MetaMask/core/pull/8987))
+
+### Fixed
+
 - Bump `@metamask/assets-controllers` from `^108.3.0` to `^108.4.0` ([#8981](https://github.com/MetaMask/core/pull/8981))
 - Bump `@metamask/assets-controller` from `^8.0.2` to `^8.3.1` ([#8981](https://github.com/MetaMask/core/pull/8981), [#8985](https://github.com/MetaMask/core/pull/8985))
 - Bump `@metamask/remote-feature-flag-controller` from `^4.2.1` to `^4.2.2` ([#8986](https://github.com/MetaMask/core/pull/8986))

packages/transaction-pay-controller/src/TransactionPayController-method-action-types.ts

@@ -76,6 +76,11 @@ export type TransactionPayControllerGetDelegationTransactionAction = {
  * @param args - The arguments forwarded to the {@link GetPaymentOverrideDataCallback}.
  * @returns A promise resolving to the additional transactions array.
  */
+export type TransactionPayControllerGetAmountDataAction = {
+  type: `TransactionPayController:getAmountData`;
+  handler: TransactionPayController['getAmountData'];
+};
+
 export type TransactionPayControllerGetPaymentOverrideDataAction = {
   type: `TransactionPayController:getPaymentOverrideData`;
   handler: TransactionPayController['getPaymentOverrideData'];
@@ -128,6 +133,7 @@ export type TransactionPayControllerMethodActions =
   | TransactionPayControllerUpdatePaymentTokenAction
   | TransactionPayControllerUpdateFiatPaymentAction
   | TransactionPayControllerGetDelegationTransactionAction
+  | TransactionPayControllerGetAmountDataAction
   | TransactionPayControllerGetPaymentOverrideDataAction
   | TransactionPayControllerGetStrategyAction
   | TransactionPayControllerPolymarketGetDepositWalletAddressAction

packages/transaction-pay-controller/src/TransactionPayController.test.ts

@@ -518,6 +518,51 @@ describe('TransactionPayController', () => {
     });
   });
 
+  describe('getAmountData', () => {
+    it('delegates to the callback', async () => {
+      const resultMock = {
+        updates: [{ nestedTransactionIndex: 0, data: '0xabc' as const }],
+      };
+      const getAmountDataMock = jest.fn().mockResolvedValue(resultMock);
+
+      new TransactionPayController({
+        getAmountData: getAmountDataMock,
+        getDelegationTransaction: jest.fn(),
+        messenger,
+      });
+
+      const requestMock = {
+        amount: '5000000',
+        transaction: TRANSACTION_META_MOCK,
+      };
+
+      const result = await messenger.call(
+        'TransactionPayController:getAmountData',
+        requestMock,
+      );
+
+      expect(getAmountDataMock).toHaveBeenCalledWith(requestMock);
+      expect(result).toStrictEqual(resultMock);
+    });
+
+    it('returns empty updates when no callback is configured', async () => {
+      new TransactionPayController({
+        getDelegationTransaction: jest.fn(),
+        messenger,
+      });
+
+      const result = await messenger.call(
+        'TransactionPayController:getAmountData',
+        {
+          amount: '5000000',
+          transaction: TRANSACTION_META_MOCK,
+        },
+      );
+
+      expect(result).toStrictEqual({ updates: [] });
+    });
+  });
+
   describe('polymarket callbacks', () => {
     const EOA_MOCK = '0x1111111111111111111111111111111111111111' as Hex;
     const DEPOSIT_WALLET_MOCK =

packages/transaction-pay-controller/src/TransactionPayController.ts

@@ -14,6 +14,7 @@ import {
 import { QuoteRefresher } from './helpers/QuoteRefresher';
 import { deriveFiatAssetForFiatPayment } from './strategy/fiat/utils';
 import type {
+  GetAmountDataCallback,
   GetDelegationTransactionCallback,
   GetPaymentOverrideDataCallback,
   PolymarketCallbacks,
@@ -36,6 +37,7 @@ import {
 } from './utils/transaction';
 
 const MESSENGER_EXPOSED_METHODS = [
+  'getAmountData',
   'getDelegationTransaction',
   'getPaymentOverrideData',
   'getStrategy',
@@ -64,6 +66,8 @@ export class TransactionPayController extends BaseController<
   TransactionPayControllerState,
   TransactionPayControllerMessenger
 > {
+  readonly #getAmountData?: GetAmountDataCallback;
+
   readonly #getDelegationTransaction: GetDelegationTransactionCallback;
 
   readonly #getPaymentOverrideData?: GetPaymentOverrideDataCallback;
@@ -79,6 +83,7 @@ export class TransactionPayController extends BaseController<
   readonly #polymarket?: PolymarketCallbacks;
 
   constructor({
+    getAmountData,
     getDelegationTransaction,
     getPaymentOverrideData,
     getStrategy,
@@ -94,6 +99,7 @@ export class TransactionPayController extends BaseController<
       state: { ...getDefaultState(), ...state },
     });
 
+    this.#getAmountData = getAmountData;
     this.#getDelegationTransaction = getDelegationTransaction;
     this.#getPaymentOverrideData = getPaymentOverrideData;
     this.#getStrategy = getStrategy;
@@ -233,6 +239,12 @@ export class TransactionPayController extends BaseController<
    * @param args - The arguments forwarded to the {@link GetPaymentOverrideDataCallback}.
    * @returns A promise resolving to the additional transactions array.
    */
+  getAmountData(
+    ...args: Parameters<GetAmountDataCallback>
+  ): ReturnType<GetAmountDataCallback> {
+    return this.#getAmountData?.(...args) ?? Promise.resolve({ updates: [] });
+  }
+
   getPaymentOverrideData(
     ...args: Parameters<GetPaymentOverrideDataCallback>
   ): ReturnType<GetPaymentOverrideDataCallback> {

packages/transaction-pay-controller/src/index.ts

@@ -1,4 +1,7 @@
 export type {
+  GetAmountDataCallback,
+  GetAmountDataRequest,
+  GetAmountDataResponse,
   GetPaymentOverrideDataRequest,
   GetPaymentOverrideDataResponse,
   TransactionConfig,
@@ -23,6 +26,7 @@ export type {
   UpdatePaymentTokenRequest,
 } from './types';
 export type {
+  TransactionPayControllerGetAmountDataAction,
   TransactionPayControllerGetDelegationTransactionAction,
   TransactionPayControllerGetStrategyAction,
   TransactionPayControllerPolymarketGetDepositWalletAddressAction,

packages/transaction-pay-controller/src/strategy/fiat/fiat-quotes.ts

@@ -49,7 +49,8 @@ export async function getFiatQuotes(
   const state = messenger.call('TransactionPayController:getState');
   const transactionData = state.transactionData[transactionId];
   const amountFiat = transactionData?.fiatPayment?.amountFiat;
-  const walletAddress = transaction.txParams.from as Hex;
+  const walletAddress =
+    transactionData?.accountOverride ?? (transaction.txParams.from as Hex);
   const requiredTokens = getRequiredTokens(transactionData?.tokens);
   const fiatAsset = deriveFiatAssetForFiatPayment(transaction, messenger);