fix(sdk-coin-flrp): handle missing txParams.type in verifyTransaction…

modules/sdk-coin-flrp/src/flrp.ts

@@ -96,7 +96,11 @@ export class Flrp extends BaseCoin {
     // so the TransactionType enum lookup succeeds.
     const normalizedType = type === 'stake' ? 'AddPermissionlessDelegator' : type;
 
-    if (!normalizedType || (normalizedType !== 'ImportToC' && explainedTx.type !== TransactionType[normalizedType])) {
+    // When type is provided, verify it matches the parsed transaction.
+    // When type is not provided (MPC/TSS intent flow where buildParams are unavailable),
+    // skip the type match check and rely on explainedTx.type from the parsed hex —
+    // the transaction was built by wallet-platform and the hex is the source of truth.
+    if (normalizedType && normalizedType !== 'ImportToC' && explainedTx.type !== TransactionType[normalizedType]) {
       throw new Error('Tx type does not match with expected txParams type');
     }
 
@@ -126,8 +130,9 @@ export class Flrp extends BaseCoin {
         }
         break;
       case TransactionType.AddPermissionlessDelegator:
-        // Validate delegation transaction against both txParams and explainedTx
-        this.validateDelegationTx(params.txParams, explainedTx);
+        if (params.txParams.stakingOptions) {
+          this.validateDelegationTx(params.txParams, explainedTx);
+        }
         break;
       default:
         throw new Error('Tx type is not supported yet');

modules/sdk-coin-flrp/test/resources/transactionData/multisigDelegationTx.ts

@@ -98,3 +98,12 @@ export const MULTISIG_ADDRESS_SORTING = {
     { role: 'bitgo', originalIndex: 1, sortedIndex: 1 },
   ],
 };
+
+/**
+ * MPC/TSS delegation transaction hex (single signer, built by wallet-platform via buildTransactionWithIntent).
+ * From txRequest b5f89e8b-2273-4e29-80bd-60bd488e172f on Coston2 testnet.
+ * This is the serializedTxHex that verifyTransaction receives during MPC signing,
+ * where txParams has no type and no stakingOptions (only { recipients: [] }).
+ */
+export const MPC_DELEGATION_UNSIGNED_TX_HEX =
+  '00000000001a0000007200000000000000000000000000000000000000000000000000000000000000000000000158734f94af871c3d131b56131b6fb7a0291eacadd261e69dfb42a9cdf6f7fddd000000070000000253e0efe80000000000000000000000010000000184fa441f981fce7cd63189d5071802376ad6676e000000022ebd7484b5704be67db0344abd9d2223d5c7100795f68c7a6a4a77888dccb9820000000158734f94af871c3d131b56131b6fb7a0291eacadd261e69dfb42a9cdf6f7fddd0000000500002d79883d20000000000100000000933f844e2d35c52963abd7912ec39faa71ed5994a52c584d9bf1f6bd480c976c0000000058734f94af871c3d131b56131b6fb7a0291eacadd261e69dfb42a9cdf6f7fddd0000000500000002540be400000000010000000000000000664b4924a25af8be5f07052b2c2e582f7c10a654000000006a1192a4000000006a2407a400002d79883d200000000000000000000000000000000000000000000000000000000000000000000000000158734f94af871c3d131b56131b6fb7a0291eacadd261e69dfb42a9cdf6f7fddd0000000700002d79883d20000000000000000000000000010000000184fa441f981fce7cd63189d5071802376ad6676e0000000b00000000000000000000000100000001243f65fbcc8458492e09d7693c3966a734c0a30f00000002000000090000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000084fa441f981fce7cd63189d5071802376ad6676e000000090000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000084fa441f981fce7cd63189d5071802376ad6676ee5e72aa5';

modules/sdk-coin-flrp/test/unit/flrp.ts

@@ -12,6 +12,7 @@ import { IMPORT_IN_C } from '../resources/transactionData/importInC';
 import {
   MULTISIG_DELEGATION_FULLY_SIGNED_TX_HEX,
   MULTISIG_DELEGATION_PARAMS,
+  MPC_DELEGATION_UNSIGNED_TX_HEX,
 } from '../resources/transactionData/multisigDelegationTx';
 import { HalfSignedAccountTransaction, TransactionType, MPCAlgorithm } from '@bitgo/sdk-core';
 import { secp256k1 } from '@flarenetwork/flarejs';
@@ -978,6 +979,22 @@ describe('Flrp test cases', function () {
         const isVerified = await basecoin.verifyTransaction({ txParams, txPrebuild });
         isVerified.should.equal(true);
       });
+
+      it('should verify delegation transaction when txParams.type is undefined (MPC intent flow)', async () => {
+        // In the MPC/TSS staking flow, the txRequest is created by staking-service (not the UI).
+        // The UI only has txRequestId — no buildParams. The SDK falls back to { recipients: [] }
+        // with no type and no stakingOptions. verifyTransaction must still pass because the
+        // parsed hex (explainedTx.type) is the source of truth built by wallet-platform.
+        const txPrebuild = { txHex: MPC_DELEGATION_UNSIGNED_TX_HEX, txInfo: {} };
+        const txParams = {
+          recipients: [],
+          // no type — simulates MPC staking flow where buildParams is unavailable
+          // no stakingOptions — not passed through in the MPC intent flow
+        };
+
+        const isVerified = await basecoin.verifyTransaction({ txParams, txPrebuild });
+        isVerified.should.equal(true);
+      });
     });
 
     describe('verifyTransaction with TSS wallet (Avalanche atomic)', () => {