chore: refactor userOp builder to use generic implementation

advanced/wallets/react-wallet-v2/src/consts/smartAccounts.ts

@@ -1,5 +1,6 @@
 import { KernelSmartAccountLib } from '@/lib/smart-accounts/KernelSmartAccountLib'
 import { SafeSmartAccountLib } from '@/lib/smart-accounts/SafeSmartAccountLib'
+import { getAddress } from 'viem'
 import { goerli, polygonMumbai, sepolia } from 'viem/chains'
 
 // Types
@@ -15,3 +16,12 @@ export const availableSmartAccounts = {
   safe: SafeSmartAccountLib,
   kernel: KernelSmartAccountLib
 }
+
+export const SAFE_FALLBACK_HANDLER_STORAGE_SLOT =
+  '0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5'
+
+export const SAFE_4337_MODULE_ADDRESSES = [
+  getAddress('0xa581c4A4DB7175302464fF3C06380BC3270b4037'),
+  getAddress('0x75cf11467937ce3F2f357CE24ffc3DBF8fD5c226'),
+  getAddress('0x3Fdb5BC686e861480ef99A6E3FaAe03c0b9F32e2')
+]

advanced/wallets/react-wallet-v2/src/lib/smart-accounts/builders/SafeUserOpBuilder.ts

@@ -12,7 +12,6 @@ import {
   createPublicClient,
   GetStorageAtReturnType,
   Hex,
-  hexToString,
   http,
   parseAbi,
   PublicClient,
@@ -31,10 +30,9 @@ import {
 import { bundlerUrl, paymasterUrl, publicClientUrl } from '@/utils/SmartAccountUtil'
 
 import { getChainById } from '@/utils/ChainUtil'
+import { SAFE_FALLBACK_HANDLER_STORAGE_SLOT } from '@/consts/smartAccounts'
 
 const ERC_7579_LAUNCHPAD_ADDRESS: Address = '0xEBe001b3D534B9B6E2500FB78E67a1A137f561CE'
-const FALLBACK_HANDLER_STORAGE_SLOT =
-  '0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5'
 
 export class SafeUserOpBuilder implements UserOpBuilder {
   protected chain: Chain
@@ -147,15 +145,12 @@ export class SafeUserOpBuilder implements UserOpBuilder {
     }
     return false
   }
-  private async getStorageAt(slot: Hex): Promise<GetStorageAtReturnType> {
-    const result = await this.publicClient.getStorageAt({
+
+  private async getFallbackHandlerAddress(): Promise<Address> {
+    const value = await this.publicClient.getStorageAt({
       address: this.accountAddress,
-      slot: slot
+      slot: SAFE_FALLBACK_HANDLER_STORAGE_SLOT
     })
-    return result
-  }
-  private async getFallbackHandlerAddress(): Promise<Address> {
-    const storage = await this.getStorageAt(FALLBACK_HANDLER_STORAGE_SLOT)
-    return trim(storage as Hex)
+    return trim(value as Hex)
   }
 }

advanced/wallets/react-wallet-v2/src/lib/smart-accounts/builders/UserOpBuilder.ts

@@ -1,6 +1,5 @@
-import { publicClientUrl } from '@/utils/SmartAccountUtil'
 import { UserOperation } from 'permissionless'
-import { Address, Chain, createPublicClient, Hex, http, parseAbi, PublicClient } from 'viem'
+import { Address, Hex } from 'viem'
 
 type Call = { to: Address; value: bigint; data: Hex }
 
@@ -41,43 +40,3 @@ export interface UserOpBuilder {
     params: SendUserOpWithSigantureParams
   ): Promise<SendUserOpWithSigantureResponse>
 }
-
-export enum ImplementationType {
-  Safe = 'safe'
-}
-
-export type AccountImplementation = {
-  type: ImplementationType
-}
-type GetAccountImplementationParams = {
-  account: Address
-  chain?: Chain
-  publicClient?: PublicClient
-}
-export async function getAccountImplementation(
-  params: GetAccountImplementationParams
-): Promise<AccountImplementation> {
-  let publicClient = params.publicClient
-  if (!publicClient) {
-    if (!params.chain) {
-      throw new Error('publicClient or chain must be provided')
-    }
-    publicClient = createPublicClient({
-      transport: http(publicClientUrl({ chain: params.chain }))
-    })
-  }
-  const accountImplementation = await publicClient.readContract({
-    address: params.account,
-    abi: parseAbi([
-      'function accountId() external view returns (string memory accountImplementationId)'
-    ]),
-    functionName: 'accountId',
-    args: []
-  })
-  if (accountImplementation.includes('safe')) {
-    return {
-      type: ImplementationType.Safe
-    }
-  }
-  throw new Error('Unsupported implementation type')
-}

advanced/wallets/react-wallet-v2/src/pages/api/build.ts

@@ -1,12 +1,6 @@
-import { SafeUserOpBuilder } from '@/lib/smart-accounts/builders/SafeUserOpBuilder'
-import {
-  ErrorResponse,
-  FillUserOpResponse,
-  getAccountImplementation,
-  ImplementationType,
-  UserOpBuilder
-} from '@/lib/smart-accounts/builders/UserOpBuilder'
+import { ErrorResponse, FillUserOpResponse } from '@/lib/smart-accounts/builders/UserOpBuilder'
 import { getChainById } from '@/utils/ChainUtil'
+import { getUserOpBuilder } from '@/utils/UserOpBuilderUtil'
 import { NextApiRequest, NextApiResponse } from 'next'
 
 export default async function handler(
@@ -17,19 +11,11 @@ export default async function handler(
   const account = req.body.account
   const chain = getChainById(chainId)
   try {
-    const accountImplementation = await getAccountImplementation({
+    const builder = await getUserOpBuilder({
       account,
       chain
     })
 
-    let builder: UserOpBuilder
-
-    switch (accountImplementation.type) {
-      case ImplementationType.Safe:
-        builder = new SafeUserOpBuilder(account, chainId)
-        break
-    }
-
     const response = await builder.fillUserOp(req.body)
 
     res.status(200).json(response)

advanced/wallets/react-wallet-v2/src/utils/UserOpBuilderUtil.ts

@@ -0,0 +1,48 @@
+import { SafeUserOpBuilder } from '@/lib/smart-accounts/builders/SafeUserOpBuilder'
+import { UserOpBuilder } from '@/lib/smart-accounts/builders/UserOpBuilder'
+import {
+  Address,
+  Chain,
+  createPublicClient,
+  getAddress,
+  http,
+  PublicClient,
+  size,
+  slice
+} from 'viem'
+import { publicClientUrl } from './SmartAccountUtil'
+import {
+  SAFE_4337_MODULE_ADDRESSES,
+  SAFE_FALLBACK_HANDLER_STORAGE_SLOT
+} from '@/consts/smartAccounts'
+
+type GetUserOpBuilderParams = {
+  account: Address
+  chain: Chain
+  publicClient?: PublicClient
+}
+
+export async function getUserOpBuilder(params: GetUserOpBuilderParams): Promise<UserOpBuilder> {
+  let publicClient = params.publicClient
+  if (!publicClient) {
+    publicClient = createPublicClient({
+      transport: http(publicClientUrl({ chain: params.chain }))
+    })
+  }
+  if (await isSafeAccount(publicClient, params.account)) {
+    return new SafeUserOpBuilder(params.account, params.chain.id)
+  }
+  throw new Error('Unsupported implementation type')
+}
+
+async function isSafeAccount(publicClient: PublicClient, address: Address): Promise<Boolean> {
+  const storageValue = await publicClient.getStorageAt({
+    address,
+    slot: SAFE_FALLBACK_HANDLER_STORAGE_SLOT
+  })
+  if (!storageValue) {
+    return false
+  }
+  const safe4337ModuleAddress = getAddress(slice(storageValue, size(storageValue) - 20))
+  return SAFE_4337_MODULE_ADDRESSES.includes(safe4337ModuleAddress)
+}