feat: implement wallet_getSubAccounts rpc

examples/testapp/src/pages/add-sub-account/components/GetSubAccounts.tsx

@@ -0,0 +1,89 @@
+import { Box, Button } from '@chakra-ui/react';
+import { createCoinbaseWalletSDK } from '@coinbase/wallet-sdk';
+import { useCallback, useState } from 'react';
+
+type GetSubAccountsProps = {
+  sdk: ReturnType<typeof createCoinbaseWalletSDK>;
+};
+
+export function GetSubAccounts({ sdk }: GetSubAccountsProps) {
+  const [subAccounts, setSubAccounts] = useState<{
+    subAccounts: {
+      address: string;
+      factory: string;
+      factoryCalldata: string;
+    }[];
+  }>();
+  const [error, setError] = useState<string>();
+  const [isLoading, setIsLoading] = useState(false);
+
+  const handleGetSubAccounts = useCallback(async () => {
+    if (!sdk) {
+      return;
+    }
+
+    setIsLoading(true);
+    try {
+      const provider = sdk.getProvider();
+      const accounts = await provider.request({
+        method: 'eth_requestAccounts',
+      }) as string[];
+      if (accounts.length < 2) {
+        throw new Error('Create a sub account first by clicking the Add Address button');
+      }
+      const response = await provider.request({
+        method: 'wallet_getSubAccounts',
+        params: [{
+          account: accounts[1],
+          domain: window.location.origin,
+        }],
+      });
+
+      console.info('getSubAccounts response', response);
+      setSubAccounts(response as { subAccounts: { address: string; factory: string; factoryCalldata: string; }[] });
+    } catch (error) {
+      console.error('Error getting sub accounts:', error);
+      setError(error instanceof Error ? error.message : 'Unknown error');
+    } finally {
+      setIsLoading(false);
+    }
+  }, [sdk]);
+
+  return (
+    <>
+      <Button w="full" onClick={handleGetSubAccounts} isLoading={isLoading} loadingText="Getting Sub Accounts...">
+        Get Sub Accounts
+      </Button>
+      {subAccounts && (
+        <Box
+          as="pre"
+          w="full"
+          p={2}
+          bg="gray.900"
+          borderRadius="md"
+          border="1px solid"
+          borderColor="gray.700"
+          overflow="auto"
+          whiteSpace="pre-wrap"
+        >
+          {JSON.stringify(subAccounts, null, 2)}
+        </Box>
+      )}
+      {error && (
+        <Box
+          as="pre"
+          w="full"
+          p={2}
+          bg="red.900"
+          borderRadius="md"
+          border="1px solid"
+          borderColor="red.700"
+          overflow="auto"
+          whiteSpace="pre-wrap"
+        >
+          {error}
+        </Box>
+      )}
+    </>
+  );
+}

examples/testapp/src/pages/add-sub-account/index.page.tsx

@@ -19,6 +19,7 @@ import { AddSubAccount } from './components/AddSubAccount';
 import { AddSubAccountWithoutKeys } from './components/AddSubAccountWithoutKeys';
 import { Connect } from './components/Connect';
 import { GenerateNewSigner } from './components/GenerateNewSigner';
+import { GetSubAccounts } from './components/GetSubAccounts';
 import { GrantSpendPermission } from './components/GrantSpendPermission';
 import { PersonalSign } from './components/PersonalSign';
 import { SendCalls } from './components/SendCalls';
@@ -81,6 +82,7 @@ export default function SubAccounts() {
           onAddSubAccount={setSubAccountAddress}
           signerFn={getSubAccountSigner}
         />
+        <GetSubAccounts sdk={sdk} />
         <AddSubAccountWithoutKeys
           sdk={sdk}
           onAddSubAccount={setSubAccountAddress}

packages/wallet-sdk/src/core/rpc/wallet_getSubAccount.test.ts

@@ -0,0 +1,70 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  GetSubAccountsRequest,
+  GetSubAccountsResponse,
+  GetSubAccountsResponseItem,
+} from './wallet_getSubAccount.js';
+
+describe('wallet_getSubAccounts schema', () => {
+  it('should have correct request type structure', () => {
+    const request: GetSubAccountsRequest = {
+      account: '0x742C4d6c2B4ABE65a3A3B0A4B2Ed8B6a67c2E3f1',
+      domain: 'example.com',
+    };
+
+    expect(request.account).toBeDefined();
+    expect(request.domain).toBeDefined();
+    expect(typeof request.account).toBe('string');
+    expect(typeof request.domain).toBe('string');
+  });
+
+  it('should have correct response item type structure', () => {
+    const responseItem: GetSubAccountsResponseItem = {
+      address: '0x742C4d6c2B4ABE65a3A3B0A4B2Ed8B6a67c2E3f1',
+      factory: '0x4e59b44847b379578588920cA78FbF26c0B4956C',
+      factoryData: '0x1234567890abcdef',
+    };
+
+    expect(responseItem.address).toBeDefined();
+    expect(responseItem.factory).toBeDefined();
+    expect(responseItem.factoryData).toBeDefined();
+    expect(typeof responseItem.address).toBe('string');
+    expect(typeof responseItem.factory).toBe('string');
+    expect(typeof responseItem.factoryData).toBe('string');
+  });
+
+  it('should have correct response type structure', () => {
+    const response: GetSubAccountsResponse = {
+      subAccounts: [
+        {
+          address: '0x742C4d6c2B4ABE65a3A3B0A4B2Ed8B6a67c2E3f1',
+          factory: '0x4e59b44847b379578588920cA78FbF26c0B4956C',
+          factoryData: '0x1234567890abcdef',
+        },
+        {
+          address: '0x8ba1f109551bD432803012645Hac136c5e84F31D',
+          factory: '0x5FbDB2315678afecb367f032d93F642f64180aa3',
+          factoryData: '0xabcdef1234567890',
+        },
+      ],
+    };
+
+    expect(response.subAccounts).toBeDefined();
+    expect(Array.isArray(response.subAccounts)).toBe(true);
+    expect(response.subAccounts.length).toBe(2);
+    expect(response.subAccounts[0]).toHaveProperty('address');
+    expect(response.subAccounts[0]).toHaveProperty('factory');
+    expect(response.subAccounts[0]).toHaveProperty('factoryData');
+  });
+
+  it('should allow empty subAccounts array', () => {
+    const response: GetSubAccountsResponse = {
+      subAccounts: [],
+    };
+
+    expect(response.subAccounts).toBeDefined();
+    expect(Array.isArray(response.subAccounts)).toBe(true);
+    expect(response.subAccounts.length).toBe(0);
+  });
+});

packages/wallet-sdk/src/core/rpc/wallet_getSubAccount.ts

@@ -0,0 +1,16 @@
+import { Address, Hex } from 'viem';
+
+export type GetSubAccountsRequest = {
+  account: Address;
+  domain: string;
+};
+
+export type GetSubAccountsResponseItem = {
+  address: Address;
+  factory: Address;
+  factoryData: Hex;
+};
+
+export type GetSubAccountsResponse = {
+  subAccounts: GetSubAccountsResponseItem[];
+};

packages/wallet-sdk/src/sign/scw/SCWSigner.ts

@@ -8,6 +8,7 @@ import { RPCResponse } from ':core/message/RPCResponse.js';
 import { AppMetadata, ProviderEventCallback, RequestArguments } from ':core/provider/interface.js';
 import { FetchPermissionsResponse } from ':core/rpc/coinbase_fetchSpendPermissions.js';
 import { WalletConnectRequest, WalletConnectResponse } from ':core/rpc/wallet_connect.js';
+import { GetSubAccountsResponse } from ':core/rpc/wallet_getSubAccount.js';
 import {
   logHandshakeCompleted,
   logHandshakeError,
@@ -179,7 +180,7 @@ export class SCWSigner implements Signer {
           this.callback?.('connect', { chainId: numberToHex(this.chain.id) });
           return this.accounts;
         }
-        case 'wallet_switchEthereumChain': {
+        case 'wallet_switchEthereumChain': { 
           assertParamsChainId(request.params);
           this.chain.id = Number(request.params[0].chainId);
           return;
@@ -280,6 +281,31 @@ export class SCWSigner implements Signer {
         return this.sendRequestToPopup(modifiedRequest);
       }
       // Sub Account Support
+      case 'wallet_getSubAccounts': {
+        const subAccount = store.subAccounts.get();
+        if (subAccount?.address) {
+          return {
+            subAccounts: [subAccount],
+          };
+        }
+
+        if (!this.chain.rpcUrl) {
+          throw standardErrors.rpc.internal('No RPC URL set for chain');
+        }
+        const response = await fetchRPCRequest(request, this.chain.rpcUrl) as GetSubAccountsResponse;
+        assertArrayPresence(response.subAccounts, 'subAccounts');
+        if (response.subAccounts.length > 0) {
+          // cache the sub account
+          assertSubAccount(response.subAccounts[0]);
+          const subAccount = response.subAccounts[0];
+          store.subAccounts.set({
+            address: subAccount.address,
+            factory: subAccount.factory,
+            factoryData: subAccount.factoryData,
+          });
+        }
+        return response;
+      }
       case 'wallet_addSubAccount':
         return this.addSubAccount(request);
       case 'coinbase_fetchPermissions': {