feat(sdk-coin-flrp): add createPairedWallet method to Flrp

Add CreatePairedWalletParams and CreatePairedWalletResponse interfaces
to iface.ts. Add createPairedWallet() method to the Flrp class that
POSTs to /api/v2/flrp/wallet/:walletId/create-paired-wallet. Add
unit tests covering label/no-label and error cases.

Closes #8578

Author: ashutoshkumar-6

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

@@ -22,6 +22,8 @@ import {
 } from '@bitgo/sdk-core';
 import * as FlrpLib from './lib';
 import {
+  CreatePairedWalletParams,
+  CreatePairedWalletResponse,
   FlrpEntry,
   FlrpExplainTransactionOptions,
   FlrpSignTransactionOptions,
@@ -436,4 +438,12 @@ export class Flrp extends BaseCoin {
   auditDecryptedKey(params: AuditDecryptedKeyParams): void {
     throw new MethodNotImplementedError();
   }
+
+  async createPairedWallet(params: CreatePairedWalletParams): Promise<CreatePairedWalletResponse> {
+    const { walletId, label } = params;
+    return this.bitgo
+      .post(this.url(`/wallet/${walletId}/create-paired-wallet`))
+      .send(label ? { label } : {})
+      .result();
+  }
 }

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

@@ -176,3 +176,34 @@ export interface ExportEVMOptions {
   threshold: number;
   locktime: bigint;
 }
+
+/**
+ * Parameters for creating a paired FLR C-chain wallet from an FLR P-chain wallet.
+ */
+export interface CreatePairedWalletParams {
+  /** The ID of the source FLRP (FLR P-chain) MPC wallet. */
+  walletId: string;
+  /** Optional label for the new FLR C-chain wallet. */
+  label?: string;
+}
+
+/**
+ * Response from the create-paired-wallet endpoint.
+ */
+export interface CreatePairedWalletResponse {
+  id: string;
+  coin: string;
+  label: string;
+  keys: string[];
+  keySignatures: Record<string, string>;
+  m: number;
+  n: number;
+  type: string;
+  multisigType: string;
+  coinSpecific: {
+    pairedWalletId?: string;
+    baseAddress?: string;
+    [key: string]: unknown;
+  };
+  [key: string]: unknown;
+}

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

@@ -13,6 +13,9 @@ import { HalfSignedAccountTransaction, TransactionType, MPCAlgorithm } from '@bi
 import { secp256k1 } from '@flarenetwork/flarejs';
 import { FlrpContext } from '@bitgo/public-types';
 import assert from 'assert';
+import nock from 'nock';
+import { common } from '@bitgo/sdk-core';
+import { CreatePairedWalletResponse } from '../../src/lib/iface';
 
 describe('Flrp test cases', function () {
   const coinName = 'flrp';
@@ -960,4 +963,75 @@ describe('Flrp test cases', function () {
       });
     });
   });
+
+  describe('createPairedWallet', function () {
+    const walletId = 'abc123def456abc123def456abc123de';
+
+    afterEach(function () {
+      nock.cleanAll();
+    });
+
+    it('should POST to create-paired-wallet and return new wallet', async function () {
+      const bgUrl = common.Environments[bitgo.getEnv()].uri;
+      const expectedResponse: CreatePairedWalletResponse = {
+        id: 'newwalletid000000000000000000001',
+        coin: 'tflr',
+        label: 'My FLR C Wallet',
+        keys: ['key1', 'key2', 'key3'],
+        keySignatures: { backupPub: 'sig1', bitgoPub: 'sig2' },
+        m: 2,
+        n: 3,
+        type: 'hot',
+        multisigType: 'tss',
+        coinSpecific: {
+          pairedWalletId: walletId,
+          baseAddress: '0x627306090abaB3A6e1400e9345bC60c78a8BEf57',
+        },
+      };
+
+      nock(bgUrl)
+        .post(`/api/v2/tflrp/wallet/${walletId}/create-paired-wallet`, { label: 'My FLR C Wallet' })
+        .reply(200, expectedResponse);
+
+      const result = await basecoin.createPairedWallet({ walletId, label: 'My FLR C Wallet' });
+      result.should.deepEqual(expectedResponse);
+      result.coin.should.equal('tflr');
+      result.coinSpecific.pairedWalletId.should.equal(walletId);
+    });
+
+    it('should POST without body when label is not provided', async function () {
+      const bgUrl = common.Environments[bitgo.getEnv()].uri;
+      const expectedResponse: CreatePairedWalletResponse = {
+        id: 'newwalletid000000000000000000002',
+        coin: 'tflr',
+        label: 'FLR C wallet (from tflrp wallet abc123def456abc123def456abc123de)',
+        keys: ['key1', 'key2', 'key3'],
+        keySignatures: {},
+        m: 2,
+        n: 3,
+        type: 'hot',
+        multisigType: 'tss',
+        coinSpecific: { pairedWalletId: walletId },
+      };
+
+      nock(bgUrl)
+        .post(`/api/v2/tflrp/wallet/${walletId}/create-paired-wallet`, {})
+        .reply(200, expectedResponse);
+
+      const result = await basecoin.createPairedWallet({ walletId });
+      result.should.deepEqual(expectedResponse);
+    });
+
+    it('should propagate HTTP errors from the server', async function () {
+      const bgUrl = common.Environments[bitgo.getEnv()].uri;
+
+      nock(bgUrl)
+        .post(`/api/v2/tflrp/wallet/${walletId}/create-paired-wallet`)
+        .reply(400, { error: 'Source FLR P wallet is not MPC (multisigType: onchain)' });
+
+      await basecoin
+        .createPairedWallet({ walletId })
+        .should.be.rejectedWith('Source FLR P wallet is not MPC');
+    });
+  });
 });