fix(sdk-coin-xrp): route MPT token enablement to enableMpt type via coin config

Add getEnableTokenType to TokenEnablementConfig so coins can return the
correct transaction type. XRP uses this to return 'enableMpt' for XrpMptCoin
tokens instead of hardcoded 'enabletoken', avoiding the IOU TrustSet path
that throws for MPT tokens. Remove redundant xrpl.decode fallbacks in
ripple.ts and xrp.ts since binary/rippleBinaryCodec are aliased to xrpl
which supports all tx types including MPTokenAuthorize. Simplify express
handleV2EnableTokens by removing the offline MPT/IOU split. Add unit tests
for getTokenEnablementConfig and MPTokenAuthorize explainTransaction paths.

TICKET: CGD-2013

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 0xPrabh

modules/sdk-coin-xrp/src/ripple.ts

@@ -50,7 +50,7 @@ const signWithPrivateKey = function (txHex, privateKey, options) {
   } catch (e) {
     try {
       tx = JSON.parse(txHex);
-    } catch (e) {
+    } catch (e2) {
       throw new Error('txHex needs to be either hex or JSON string for XRP');
     }
   }

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

@@ -25,7 +25,7 @@ import {
   UnexpectedAddressError,
   VerifyTransactionOptions,
 } from '@bitgo/sdk-core';
-import { coins, BaseCoin as StaticsBaseCoin, XrpCoin } from '@bitgo/statics';
+import { coins, BaseCoin as StaticsBaseCoin, XrpCoin, XrpMptCoin } from '@bitgo/statics';
 import * as rippleKeypairs from 'ripple-keypairs';
 import * as xrpl from 'xrpl';
 
@@ -132,6 +132,8 @@ export class Xrp extends BaseCoin {
     return {
       requiresTokenEnablement: true,
       supportsMultipleTokenEnablements: false,
+      getEnableTokenType: (tokenName: string) =>
+        coins.has(tokenName) && coins.get(tokenName) instanceof XrpMptCoin ? 'enableMpt' : 'enabletoken',
     };
   }
 
@@ -219,7 +221,7 @@ export class Xrp extends BaseCoin {
       try {
         transaction = JSON.parse(txHex);
         txHex = rippleBinaryCodec.encode(transaction);
-      } catch (e) {
+      } catch (e2) {
         throw new Error('txHex needs to be either hex or JSON string for XRP');
       }
     }
@@ -329,18 +331,25 @@ export class Xrp extends BaseCoin {
     } catch (e) {
       try {
         transaction = JSON.parse(txHex);
-      } catch (e) {
+      } catch (e2) {
         throw new Error('txHex needs to be either hex or JSON string for XRP');
       }
     }
 
     return transaction.TransactionType;
   }
 
-  verifyTxType(txPrebuildDecoded: TransactionExplanation, txHexPrebuild: string | undefined): void {
+  verifyTxType(txPrebuildDecoded: TransactionExplanation, txHexPrebuild: string | undefined, isMpt = false): void {
     if (!txHexPrebuild) throw new Error('Missing txHexPrebuild to verify token type for enabletoken tx');
     const transactionType = this.getTransactionTypeRawTxHex(txHexPrebuild);
     if (transactionType === undefined) throw new Error('Missing TransactionType on token enablement tx');
+
+    if (isMpt) {
+      if (transactionType !== XrpTransactionType.MPTokenAuthorize)
+        throw new Error(`tx type ${transactionType} does not match expected type MPTokenAuthorize`);
+      return;
+    }
+
     if (transactionType !== XrpTransactionType.TrustSet)
       throw new Error(`tx type ${transactionType} does not match expected type TrustSet`);
     // decoded payload type could come as undefined or any of the enabletoken like types but never as something else like Send, etc
@@ -438,6 +447,13 @@ export class Xrp extends BaseCoin {
 
     // Explaining a tx strips out certain data, for extra measurement we're checking vs the explained tx
     // but also vs the tx pre explained.
+    if (txParams.type === 'enableMpt') {
+      if (verification?.verifyTokenEnablement) {
+        this.verifyTxType(explanation, txPrebuild.txHex, true);
+      }
+      return true;
+    }
+
     if (txParams.type === 'enabletoken' && verification?.verifyTokenEnablement) {
       this.verifyTxType(explanation, txPrebuild.txHex);
       this.verifyActivationAddress(txParams, explanation);

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

@@ -158,6 +158,38 @@ describe('XRP:', function () {
     unsignedExplanation.fee.fee.should.equal('45');
   });
 
+  it('should explain an MPTokenAuthorize transaction from hex', async function () {
+    const factory = getMptBuilderFactory(testData.MPT_ISSUANCE_ID);
+    const sender = testData.TEST_MULTI_SIG_ACCOUNT.address.split('?')[0];
+
+    const builder = factory.getMPTokenAuthorizeBuilder();
+    builder.sender(sender);
+    builder.mptIssuanceId(testData.MPT_ISSUANCE_ID);
+    builder.sequence(1600000);
+    builder.fee('12');
+    builder.flags(2147483648);
+
+    const txHex = (await builder.build()).toBroadcastFormat();
+    const explanation = await basecoin.explainTransaction({ txHex });
+
+    explanation.id.should.be.a.String();
+    explanation.fee.fee.should.equal('12');
+  });
+
+  it('should explain an MPTokenAuthorize transaction from JSON string', async function () {
+    const txJson = JSON.stringify({
+      TransactionType: 'MPTokenAuthorize',
+      Account: 'rBSpCz8PafXTJHppDcNnex7dYnbe3tSuFG',
+      MPTokenIssuanceID: testData.MPT_ISSUANCE_ID,
+      Fee: '12',
+      Sequence: 1600000,
+      Flags: 2147483648,
+    });
+    const explanation = await basecoin.explainTransaction({ txHex: txJson });
+
+    explanation.fee.fee.should.equal('12');
+  });
+
   it('should be able to sign an XRP transaction', async function () {
     const txPrebuild = {
       txHex:
@@ -1038,4 +1070,27 @@ describe('XRP:', function () {
       );
     });
   });
+
+  describe('getTokenEnablementConfig', function () {
+    it('should return enableMpt for a registered MPT token', function () {
+      const config = basecoin.getTokenEnablementConfig();
+      config.getEnableTokenType('txrp:feesec').should.equal('enableMpt');
+    });
+
+    it('should return enabletoken for a registered IOU token', function () {
+      const config = basecoin.getTokenEnablementConfig();
+      config.getEnableTokenType('txrp:rlusd').should.equal('enabletoken');
+    });
+
+    it('should return enabletoken for an unknown token name', function () {
+      const config = basecoin.getTokenEnablementConfig();
+      config.getEnableTokenType('txrp:unknown-token').should.equal('enabletoken');
+    });
+
+    it('should require token enablement and not support multiple enablements in one tx', function () {
+      const config = basecoin.getTokenEnablementConfig();
+      config.requiresTokenEnablement.should.equal(true);
+      config.supportsMultipleTokenEnablements.should.equal(false);
+    });
+  });
 });

modules/sdk-core/src/bitgo/baseCoin/iBaseCoin.ts

@@ -608,6 +608,7 @@ export interface TokenEnablementConfig {
   requiresTokenEnablement: boolean;
   supportsMultipleTokenEnablements: boolean;
   validateWallet?: (walletType: string) => void;
+  getEnableTokenType?: (tokenName: string) => string;
 }
 
 export interface MessagePrep {

modules/sdk-core/src/bitgo/wallet/wallet.ts

@@ -3975,7 +3975,8 @@ export class Wallet implements IWallet {
 
     const buildParams: PrebuildTransactionOptions = _.pick(params, this.prebuildWhitelistedParams());
     if (!buildParams.type) {
-      buildParams.type = 'enabletoken';
+      const tokenName = params.enableTokens[0]?.name;
+      buildParams.type = (tokenName && teConfig.getEnableTokenType?.(tokenName)) ?? 'enabletoken';
     }
     // Check if we build with intent
     if (this._wallet.multisigType === 'tss') {