MetaMask · matthewwalsh0 · Jun 13, 2026 · Jun 13, 2026 · Jun 16, 2026 · Jun 16, 2026
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Export `generateEIP7702BatchTransaction` for building EIP-7702 batch transaction calldata from nested calls ([#9143](https://github.com/MetaMask/core/pull/9143))
+
 ### Fixed
 
 - Set `isExternalSign` to `true` when `isGasFeeSponsored` is confirmed by simulation, so gas-sponsored transactions from accounts that cannot locally sign (e.g. Money Account keyring) skip `KeyringController:signTransaction` ([#9148](https://github.com/MetaMask/core/pull/9148))

@@ -128,7 +128,10 @@ export {
   WalletDevice,
 } from './types';
 export { mergeGasFeeEstimates } from './utils/gas-flow';
-export { decodeAuthorizationSignature } from './utils/eip7702';
+export {
+  decodeAuthorizationSignature,
+  generateEIP7702BatchTransaction,
+} from './utils/eip7702';
 export {
   isEIP1559Transaction,
   normalizeTransactionParams,

@@ -108,6 +108,17 @@ type IsAtomicBatchSupportedRequestInternal = {
   publicKeyEIP7702?: Hex;
 };
 
+type PrepareEIP7702BatchTransactionRequest = {
+  messenger: TransactionControllerMessenger;
+  publicKeyEIP7702?: Hex;
+  request: TransactionBatchRequest;
+};
+
+type EIP7702BatchTransaction = {
+  nestedTransactions: NestedTransactionMetadata[];
+  txParams: TransactionParams;
+};
+
 const log = createModuleLogger(projectLogger, 'batch');
 
 export const ERROR_MESSAGE_NO_UPGRADE_CONTRACT =
@@ -238,79 +249,19 @@ export function generateBatchId(): Hex {
   return bytesToHex(idBytes);
 }
 
-/**
- * Generate the metadata for a nested transaction.
- *
- * @param request - The batch request.
- * @param singleRequest - The request for a single transaction.
- * @param messenger - The transaction controller messenger.
- * @param networkClientId - The network client ID.
- * @returns The metadata for the nested transaction.
- */
-async function getNestedTransactionMeta(
-  request: TransactionBatchRequest,
-  singleRequest: TransactionBatchSingleRequest,
-  messenger: TransactionControllerMessenger,
-  networkClientId: NetworkClientId,
-): Promise<NestedTransactionMetadata> {
-  const { from } = request;
-  const { params, type: requestedType } = singleRequest;
-
-  if (requestedType) {
-    return {
-      ...params,
-      type: requestedType,
-    };
-  }
-
-  const { type: determinedType } = await determineTransactionType(
-    { from, ...params },
-    { messenger, networkClientId },
-  );
-
-  return {
-    ...params,
-    type: determinedType,
-  };
-}
-
-/**
- * Process a batch transaction using an EIP-7702 transaction.
- *
- * @param request - The request object including the user request and necessary callbacks.
- * @returns The batch result object including the batch ID.
- */
-async function addTransactionBatchWith7702(
-  request: AddTransactionBatchRequest,
-): Promise<TransactionBatchResult> {
-  const {
-    addTransaction,
-    messenger,
-    publicKeyEIP7702,
-    request: userRequest,
-  } = request;
+async function prepareEIP7702BatchTransaction(
+  request: PrepareEIP7702BatchTransactionRequest,
+): Promise<EIP7702BatchTransaction> {
+  const { messenger, publicKeyEIP7702, request: userRequest } = request;
 
   const {
     atomic,
-    batchId: batchIdOverride,
     disableUpgrade,
     from,
-    gasFeeToken,
     gasLimit7702,
-    isInternal,
     networkClientId,
-    origin,
     overwriteUpgrade,
-    requestId,
-    requiredAssets,
-    requireApproval,
-    securityAlertId,
-    skipInitialGasEstimate,
     transactions,
-    excludeNativeTokenForFee,
-    isGasFeeIncluded,
-    isGasFeeSponsored,
-    validateSecurity,
   } = userRequest;
 
   const chainId = getChainId({ messenger, networkClientId });
@@ -389,6 +340,89 @@ async function addTransactionBatchWith7702(
     txParams.authorizationList = [{ address: upgradeContractAddress }];
   }
 
+  return { nestedTransactions, txParams };
+}
+
+/**
+ * Generate the metadata for a nested transaction.
+ *
+ * @param request - The batch request.
+ * @param singleRequest - The request for a single transaction.
+ * @param messenger - The transaction controller messenger.
+ * @param networkClientId - The network client ID.
+ * @returns The metadata for the nested transaction.
+ */
+async function getNestedTransactionMeta(
+  request: TransactionBatchRequest,
+  singleRequest: TransactionBatchSingleRequest,
+  messenger: TransactionControllerMessenger,
+  networkClientId: NetworkClientId,
+): Promise<NestedTransactionMetadata> {
+  const { from } = request;
+  const { params, type: requestedType } = singleRequest;
+
+  if (requestedType) {
+    return {
+      ...params,
+      type: requestedType,
+    };
+  }
+
+  const { type: determinedType } = await determineTransactionType(
+    { from, ...params },
+    { messenger, networkClientId },
+  );
+
+  return {
+    ...params,
+    type: determinedType,
+  };
+}
+
+/**
+ * Process a batch transaction using an EIP-7702 transaction.
+ *
+ * @param request - The request object including the user request and necessary callbacks.
+ * @returns The batch result object including the batch ID.
+ */
+async function addTransactionBatchWith7702(
+  request: AddTransactionBatchRequest,
+): Promise<TransactionBatchResult> {
+  const {
+    addTransaction,
+    messenger,
+    publicKeyEIP7702,
+    request: userRequest,
+  } = request;
+
+  const {
+    batchId: batchIdOverride,
+    gasFeeToken,
+    isInternal,
+    networkClientId,
+    origin,
+    requestId,
+    requiredAssets,
+    requireApproval,
+    securityAlertId,
+    skipInitialGasEstimate,
+    transactions,
+    excludeNativeTokenForFee,
+    isGasFeeIncluded,
+    isGasFeeSponsored,
+    validateSecurity,
+  } = userRequest;
+
+  const { nestedTransactions, txParams } = await prepareEIP7702BatchTransaction(
+    {
+      messenger,
+      publicKeyEIP7702,
+      request: userRequest,
+    },
+  );
+
+  const chainId = getChainId({ messenger, networkClientId });
+
   if (validateSecurity) {
     const securityRequest: ValidateSecurityRequest = {
       method: 'eth_sendTransaction',

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Add Relay quote validation and transaction simulation before Transaction Pay quotes are surfaced ([#9143](https://github.com/MetaMask/core/pull/9143))
 - Add test-only fiat execution options to bypass fiat on-ramp settlement during local QA by funding the expected fiat asset from a configured account before continuing the normal MM Pay fiat submit flow ([#9161](https://github.com/MetaMask/core/pull/9161))
 
 ### Fixed

@@ -368,7 +368,7 @@ describe('AcrossStrategy', () => {
       transaction: TRANSACTION_META_MOCK,
     });
 
-    expect(result).toBe(false);
+    expect(result).toStrictEqual({ isSupported: false });
   });
 
   it('supports source 7702 authorization lists for Predict withdraw post-quote quotes without Across actions', () => {
@@ -390,7 +390,9 @@ describe('AcrossStrategy', () => {
       } as TransactionMeta,
     } as PayStrategyCheckQuoteSupportRequest<AcrossQuote>;
 
-    expect(strategy.checkQuoteSupport(request)).toBe(true);
+    expect(strategy.checkQuoteSupport(request)).toStrictEqual({
+      isSupported: true,
+    });
   });
 
   it('does not support first-time 7702 authorization lists for non-post-quote Across quotes', () => {
@@ -404,7 +406,9 @@ describe('AcrossStrategy', () => {
       } as TransactionMeta,
     } as PayStrategyCheckQuoteSupportRequest<AcrossQuote>;
 
-    expect(strategy.checkQuoteSupport(request)).toBe(false);
+    expect(strategy.checkQuoteSupport(request)).toStrictEqual({
+      isSupported: false,
+    });
   });
 
   it('does not support first-time 7702 authorization lists when the Across quote has embedded destination actions', () => {
@@ -441,7 +445,9 @@ describe('AcrossStrategy', () => {
       } as TransactionMeta,
     } as PayStrategyCheckQuoteSupportRequest<AcrossQuote>;
 
-    expect(strategy.checkQuoteSupport(request)).toBe(false);
+    expect(strategy.checkQuoteSupport(request)).toStrictEqual({
+      isSupported: false,
+    });
   });
 
   it('supports 7702 quotes that do not require an authorization list', () => {
@@ -461,7 +467,7 @@ describe('AcrossStrategy', () => {
         quotes: [quote],
         transaction: TRANSACTION_META_MOCK,
       }),
-    ).toBe(true);
+    ).toStrictEqual({ isSupported: true });
   });
 
   it('returns false for unsupported destination actions', () => {

@@ -5,6 +5,7 @@ import type {
   PayStrategyCheckQuoteSupportRequest,
   PayStrategyExecuteRequest,
   PayStrategyGetQuotesRequest,
+  PayStrategyQuoteSupportResult,
   TransactionPayQuote,
 } from '../../types';
 import { getPayStrategiesConfig } from '../../utils/feature-flags';
@@ -79,7 +80,7 @@ export class AcrossStrategy implements PayStrategy<AcrossQuote> {
 
   checkQuoteSupport(
     request: PayStrategyCheckQuoteSupportRequest<AcrossQuote>,
-  ): boolean {
+  ): PayStrategyQuoteSupportResult {
     // Gas planning can discover that TransactionController would add an
     // authorization list for a first-time 7702 upgrade. `is7702` alone is not a
     // blocker because it also covers already-upgraded accounts.
@@ -88,21 +89,23 @@ export class AcrossStrategy implements PayStrategy<AcrossQuote> {
     );
 
     if (!requiresAuthorizationList) {
-      return true;
+      return { isSupported: true };
     }
 
     if (!isPredictWithdrawTransaction(request.transaction)) {
-      return false;
+      return { isSupported: false };
     }
 
     // A first-time 7702 authorization list is acceptable here only because it is
     // attached to MetaMask's source-chain batch transaction. It must not be
     // smuggled into Across destination post-swap actions.
-    return request.quotes.every(
-      (quote) =>
-        quote.request.isPostQuote === true &&
-        quote.original.request.actions.length === 0,
-    );
+    return {
+      isSupported: request.quotes.every(
+        (quote) =>
+          quote.request.isPostQuote === true &&
+          quote.original.request.actions.length === 0,
+      ),
+    };
   }
 
   async getQuotes(

@@ -1,5 +1,6 @@
 import type { Hex } from '@metamask/utils';
 
+import { TransactionPayStrategy } from '../../constants';
 import type {
   PayStrategyExecuteRequest,
   PayStrategyGetQuotesRequest,
@@ -8,17 +9,20 @@ import type {
 import { getPayStrategiesConfig } from '../../utils/feature-flags';
 import { getRelayQuotes } from './relay-quotes';
 import { submitRelayQuotes } from './relay-submit';
+import { validateRelayQuoteSupport } from './relay-validation';
 import { RelayStrategy } from './RelayStrategy';
 import type { RelayQuote } from './types';
 
 jest.mock('./relay-quotes');
 jest.mock('./relay-submit');
+jest.mock('./relay-validation');
 jest.mock('../../utils/feature-flags');
 
 describe('RelayStrategy', () => {
   const getRelayQuotesMock = jest.mocked(getRelayQuotes);
   const submitRelayQuotesMock = jest.mocked(submitRelayQuotes);
   const getPayStrategiesConfigMock = jest.mocked(getPayStrategiesConfig);
+  const validateRelayQuoteSupportMock = jest.mocked(validateRelayQuoteSupport);
 
   const messenger = {} as never;
 
@@ -57,6 +61,7 @@ describe('RelayStrategy', () => {
         enabled: true,
       },
     });
+    validateRelayQuoteSupportMock.mockResolvedValue({ isSupported: true });
   });
 
   it('returns true from supports when relay is enabled', () => {
@@ -92,6 +97,40 @@ describe('RelayStrategy', () => {
     expect(getRelayQuotesMock).toHaveBeenCalledWith(request);
   });
 
+  it('delegates checkQuoteSupport', async () => {
+    const quote = buildQuote();
+    const supportResult = {
+      isSupported: false,
+      validationError: 'RPC down',
+    };
+
+    validateRelayQuoteSupportMock.mockResolvedValue(supportResult);
+
+    const strategy = new RelayStrategy();
+    const checkRequest = {
+      messenger,
+      quotes: [quote],
+      transaction: request.transaction,
+    };
+    const result = await strategy.checkQuoteSupport(checkRequest);
+
+    expect(result).toStrictEqual(supportResult);
+    expect(validateRelayQuoteSupportMock).toHaveBeenCalledWith(checkRequest);
+  });
+
+  function buildQuote(
+    requestOverrides: Partial<TransactionPayQuote<RelayQuote>['request']> = {},
+  ): TransactionPayQuote<RelayQuote> {
+    return {
+      request: {
+        sourceChainId: '0x1' as Hex,
+        sourceTokenAddress: '0xabc' as Hex,
+        ...requestOverrides,
+      },
+      strategy: TransactionPayStrategy.Relay,
+    } as TransactionPayQuote<RelayQuote>;
+  }
+
   it('delegates execute', async () => {
     const executeRequest = {
       messenger,