fix(walletconnect): scope EVM message signing

.changeset/siwx-walletconnect-routing.md

@@ -0,0 +1,10 @@
+---
+'@reown/appkit': patch
+'@reown/appkit-controllers': patch
+---
+
+Route EVM WalletConnect signatures through the shared connector.
+
+The shared WalletConnect connector now passes the captured CAIP network to UniversalProvider
+instead of relying on mutable provider state. This applies consistently across EVM adapters, and
+provider errors retain their original cause.

packages/appkit/src/client/appkit-base-client.ts

@@ -78,6 +78,7 @@ import {
   SnackController,
   StorageUtil,
   ThemeController,
+  WalletConnectConnector,
   WalletUtil,
   WcHelpersUtil,
   getPreferredAccountType,
@@ -769,12 +770,37 @@ export abstract class AppKitBaseClient {
           throw new Error('signMessage: connector changed before the request was sent')
         }
 
+        const connectorId = context?.connectorId || activeConnectorId
+        if (
+          connectorId === ConstantsUtil.CONNECTOR_ID.WALLET_CONNECT &&
+          namespace === ConstantsUtil.CHAIN.EVM
+        ) {
+          const connector = ConnectorController.getConnector({
+            id: connectorId,
+            namespace
+          }) as WalletConnectConnector | undefined
+
+          if (!connector || typeof connector.signEvmMessage !== 'function') {
+            throw new Error(
+              'signMessage: WalletConnect connector does not support EVM message signing'
+            )
+          }
+
+          const result = await connector.signEvmMessage({
+            message,
+            address,
+            caipNetworkId: caipNetwork.caipNetworkId
+          })
+
+          return result.signature
+        }
+
         const result = await adapter.signMessage({
           message,
           address,
           provider: ProviderController.getProvider(namespace),
           caipNetwork,
-          connectorId: context?.connectorId || activeConnectorId
+          connectorId
         })
 
         return result?.signature || ''

packages/appkit/tests/client/sign-message.test.ts

@@ -5,7 +5,8 @@ import {
   ChainController,
   ConnectorController,
   ProviderController,
-  type SignMessageContext
+  type SignMessageContext,
+  type WalletConnectConnector
 } from '@reown/appkit-controllers'
 import { mockChainControllerState } from '@reown/appkit-controllers/testing'
 
@@ -41,8 +42,8 @@ describe('AppKit message signing', () => {
     appKit = new TestAppKit(mockOptions)
   })
 
-  it('uses the captured SIWX chain and account when the active namespace changes', async () => {
-    const provider = { request: vi.fn() }
+  it('routes WalletConnect signing through the captured EVM connector', async () => {
+    const signEvmMessage = vi.fn().mockResolvedValue({ signature: '0xsignature' })
     const context: SignMessageContext = {
       chainId: mainnet.caipNetworkId,
       accountAddress: '0x1234567890123456789012345678901234567890',
@@ -55,6 +56,41 @@ describe('AppKit message signing', () => {
     })
     vi.spyOn(ChainController, 'getCaipNetworkById').mockReturnValue(mainnet)
     vi.spyOn(ConnectorController, 'getConnectorId').mockReturnValue('walletConnect')
+    vi.spyOn(ConnectorController, 'getConnector').mockReturnValue({
+      signEvmMessage
+    } as unknown as WalletConnectConnector)
+    const getProviderSpy = vi.spyOn(ProviderController, 'getProvider')
+
+    const result = await appKit.testConnectionControllerClient?.signMessage('Sign in', context)
+
+    expect(ConnectorController.getConnector).toHaveBeenCalledWith({
+      id: context.connectorId,
+      namespace: ConstantsUtil.CHAIN.EVM
+    })
+    expect(signEvmMessage).toHaveBeenCalledWith({
+      message: 'Sign in',
+      address: context.accountAddress,
+      caipNetworkId: context.chainId
+    })
+    expect(getProviderSpy).not.toHaveBeenCalled()
+    expect(mockEvmAdapter.signMessage).not.toHaveBeenCalled()
+    expect(result).toBe('0xsignature')
+  })
+
+  it('keeps adapter signing for non-WalletConnect connectors', async () => {
+    const provider = { request: vi.fn() }
+    const context: SignMessageContext = {
+      chainId: mainnet.caipNetworkId,
+      accountAddress: '0x1234567890123456789012345678901234567890',
+      connectorId: 'injected'
+    }
+
+    mockChainControllerState({
+      activeChain: ConstantsUtil.CHAIN.SOLANA,
+      activeCaipNetwork: solana
+    })
+    vi.spyOn(ChainController, 'getCaipNetworkById').mockReturnValue(mainnet)
+    vi.spyOn(ConnectorController, 'getConnectorId').mockReturnValue('injected')
     vi.spyOn(ProviderController, 'getProvider').mockReturnValue(provider)
     vi.spyOn(mockEvmAdapter, 'signMessage').mockResolvedValue({ signature: '0xsignature' })
 

packages/appkit/tests/connectors/WalletConnectConnector.test.ts

@@ -19,6 +19,7 @@ describe('WalletConnectConnector', () => {
   let provider: typeof mockProvider
 
   beforeEach(() => {
+    vi.clearAllMocks()
     caipNetworks = [
       { ...mainnet, caipNetworkId: 'eip155:1', chainNamespace: 'eip155' },
       solana,
@@ -79,6 +80,43 @@ describe('WalletConnectConnector', () => {
     })
   })
 
+  describe('signEvmMessage', () => {
+    it('routes personal_sign to the supplied CAIP network', async () => {
+      vi.mocked(provider.request).mockResolvedValueOnce('0xsignature')
+
+      const result = await connector.signEvmMessage({
+        message: 'Sign in',
+        address: '0x1234567890123456789012345678901234567890',
+        caipNetworkId: 'eip155:1'
+      })
+
+      expect(provider.request).toHaveBeenCalledWith(
+        {
+          method: 'personal_sign',
+          params: ['0x5369676e20696e', '0x1234567890123456789012345678901234567890']
+        },
+        'eip155:1'
+      )
+      expect(result).toEqual({ signature: '0xsignature' })
+    })
+
+    it('preserves the provider error as the cause', async () => {
+      const cause = new Error('Wallet request failed')
+      vi.mocked(provider.request).mockRejectedValueOnce(cause)
+
+      await expect(
+        connector.signEvmMessage({
+          message: 'Sign in',
+          address: '0x1234567890123456789012345678901234567890',
+          caipNetworkId: 'eip155:1'
+        })
+      ).rejects.toMatchObject({
+        message: 'WalletConnectConnector:signEvmMessage - Sign message failed',
+        cause
+      })
+    })
+  })
+
   describe('disconnect', () => {
     it('should disconnect from the provider', async () => {
       await connector.disconnect()

packages/controllers/src/controllers/AdapterController/WalletConnectConnector.ts

@@ -1,7 +1,14 @@
 import type { SessionTypes } from '@walletconnect/types'
 import UniversalProvider from '@walletconnect/universal-provider'
+import { isHex, stringToHex } from 'viem'
 
-import { type CaipNetwork, type ChainNamespace, ConstantsUtil } from '@reown/appkit-common'
+import {
+  type CaipNetwork,
+  type CaipNetworkId,
+  type ChainNamespace,
+  ConstantsUtil,
+  type Hex
+} from '@reown/appkit-common'
 
 import { SIWXUtil } from '../../utils/SIWXUtil.js'
 import { WcHelpersUtil } from '../../utils/WalletConnectUtil.js'
@@ -55,6 +62,29 @@ export class WalletConnectConnector<Namespace extends ChainNamespace = ChainName
     await this.provider.disconnect()
   }
 
+  async signEvmMessage({
+    message,
+    address,
+    caipNetworkId
+  }: WalletConnectConnector.SignEvmMessageParams): Promise<WalletConnectConnector.SignEvmMessageResult> {
+    try {
+      const hexMessage = isHex(message) ? message : stringToHex(message)
+      const signature = await this.provider.request<Hex>(
+        {
+          method: 'personal_sign',
+          params: [hexMessage, address]
+        },
+        caipNetworkId
+      )
+
+      return { signature }
+    } catch (error) {
+      throw new Error('WalletConnectConnector:signEvmMessage - Sign message failed', {
+        cause: error
+      })
+    }
+  }
+
   async authenticate(): Promise<boolean> {
     const chains = this.chains.map(network => network.caipNetworkId)
 
@@ -77,6 +107,16 @@ export namespace WalletConnectConnector {
     clientId: string | null
     session: SessionTypes.Struct
   }
+
+  export type SignEvmMessageParams = {
+    message: string
+    address: string
+    caipNetworkId: CaipNetworkId
+  }
+
+  export type SignEvmMessageResult = {
+    signature: Hex
+  }
 }
 
 const OPTIONAL_METHODS = [