safe batch transactions

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.1.0-r3
+
+* Add mutisend address to constants
+* Add support for Safe account batch transactions
+
 ## 0.1.0-r2
 
 * Fix safe transaction encoding

README.md

@@ -88,14 +88,14 @@ The smart wallet factory handles the creation of smart wallet instances. Make su
 final SmartWalletFactory smartWalletFactory = SmartWalletFactory(chain, signer);
 ```
 
-#### To Create a Simple Account Smart Wallet
+#### To Create a Simple Smart Account
 
 ```dart
 final Smartwallet wallet = await smartWalletFactory.createSimpleAccount(salt);
 print("simple wallet address: ${wallet.address.hex}");
 ```
 
-#### To create a P256 Smart Account
+#### To create a P256 Smart Account (Secure Enclave/Keystore)
 
 ```dart
 final Smartwallet wallet = await smartWalletFactory.createP256Account(keypair, salt);
@@ -110,7 +110,7 @@ final Smartwallet wallet = await smartWalletFactory.createP256Account(keypair, s
 print("p256 wallet address: ${wallet.address.hex}");
 ```
 
-#### To create a Safe Smart Account
+#### To create a [Safe](https://safe.global) Smart Account
 
 ```dart
 final Smartwallet wallet = await smartWalletFactory

example/lib/providers/wallet_provider.dart

@@ -29,7 +29,8 @@ class WalletProvider extends ChangeNotifier {
       : _chain = Chains.getChain(Network.baseTestnet)
           ..accountFactory = EthereumAddress.fromHex(
               "0x402A266e92993EbF04a5B3fd6F0e2b21bFC83070")
-          ..bundlerUrl = "https://api.pimlico.io/v2/84532/rpc?apikey="
+          ..bundlerUrl =
+              "https://api.pimlico.io/v2/84532/rpc?apikey=YOUR_API_KEY"
           ..paymasterUrl = "https://paymaster.optimism.io/v1/84532/rpc";
 
   Future<void> registerWithPassKey(String name,
@@ -137,23 +138,6 @@ class WalletProvider extends ChangeNotifier {
             ContractAbis.get("ERC721_SafeMint"), [_wallet?.address]));
     await tx1?.wait();
 
-    // mints erc20 tokens
-    final tx2 = await _wallet?.sendTransaction(
-        erc20,
-        Contract.encodeFunctionCall(
-            "mint", erc20, ContractAbis.get("ERC20_Mint"), [
-          _wallet?.address,
-          w3d.EtherAmount.fromInt(w3d.EtherUnit.ether, 20).getInWei
-        ]));
-    await tx2?.wait();
-
-    // transfers the tokens
-    final tx3 = await _wallet?.sendTransaction(
-        erc20,
-        Contract.encodeERC20TransferCall(
-            erc20, deployer, w3d.EtherAmount.fromInt(w3d.EtherUnit.ether, 18)));
-    await tx3?.wait();
-    log("trying batched transaction");
     await sendBatchedTransaction();
   }
 

lib/src/4337/chains.dart

@@ -176,6 +176,8 @@ class Constants {
       EthereumAddress.fromHex("0x41675C099F32341bf84BFc5382aF534df5C7461a");
   static final EthereumAddress safeModuleSetupAddress =
       EthereumAddress.fromHex("0x8EcD4ec46D4D2a6B64fE960B3D64e8B94B2234eb");
+  static final EthereumAddress safeMultiSendaddress =
+      EthereumAddress.fromHex("0x38869bf66a61cF6bDB996A6aE40D5853Fd43B526");
 
   Constants._();
 }

lib/src/4337/safe.dart

@@ -64,4 +64,42 @@ class _SafePlugin extends Safe4337Module implements Safe4337ModuleBase {
         op.paymasterAndData,
         hexToBytes(getSafeSignature(op.signature, blockInfo))
       ]);
+
+  Uint8List getSafeMultisendCallData(List<EthereumAddress> recipients,
+      List<EtherAmount>? amounts, List<Uint8List>? innerCalls) {
+    Uint8List packedCallData = Uint8List(0);
+
+    for (int i = 0; i < recipients.length; i++) {
+      Uint8List operation = Uint8List.fromList([0]);
+      assert(operation.length == 1);
+      Uint8List to = recipients[i].addressBytes;
+      assert(to.length == 20);
+      Uint8List value = amounts != null
+          ? padTo32Bytes(amounts[i].getInWei)
+          : padTo32Bytes(BigInt.zero);
+      assert(value.length == 32);
+      Uint8List dataLength = innerCalls != null
+          ? padTo32Bytes(BigInt.from(innerCalls[i].length))
+          : padTo32Bytes(BigInt.zero);
+      assert(dataLength.length == 32);
+      Uint8List data =
+          innerCalls != null ? innerCalls[i] : Uint8List.fromList([]);
+      Uint8List encodedCall = Uint8List.fromList(
+          [...operation, ...to, ...value, ...dataLength, ...data]);
+      packedCallData = Uint8List.fromList([...packedCallData, ...encodedCall]);
+    }
+
+    return Contract.encodeFunctionCall(
+        "multiSend",
+        Constants.safeMultiSendaddress,
+        ContractAbis.get("multiSend"),
+        [packedCallData]);
+  }
+
+  Uint8List padTo32Bytes(BigInt number) {
+    final bytes = intToBytes(number);
+    return bytes.length < 32
+        ? Uint8List.fromList([...Uint8List(32 - bytes.length), ...bytes])
+        : bytes;
+  }
 }

lib/src/4337/wallet.dart

@@ -111,15 +111,28 @@ class SmartWallet with _PluginManager, _GasSettings implements SmartWalletBase {
 
   @override
   Future<UserOperationResponse> sendBatchedTransaction(
-          List<EthereumAddress> recipients, List<Uint8List> calls,
-          {List<EtherAmount>? amounts}) =>
-      sendUserOperation(buildUserOperation(
+      List<EthereumAddress> recipients, List<Uint8List> calls,
+      {List<EtherAmount>? amounts}) {
+    final isSafe = hasPlugin("safe");
+    if (isSafe) {
+      final innerCall = plugin<_SafePlugin>('safe')
+          .getSafeMultisendCallData(recipients, amounts, calls);
+      return sendUserOperation(buildUserOperation(
+          callData: Contract.executeBatch(
+              walletAddress: _walletAddress,
+              recipients: [Constants.safeMultiSendaddress],
+              amounts: [],
+              innerCalls: [innerCall],
+              isSafe: true)));
+    } else {
+      return sendUserOperation(buildUserOperation(
           callData: Contract.executeBatch(
               walletAddress: _walletAddress,
               recipients: recipients,
               amounts: amounts,
-              innerCalls: calls,
-              isSafe: hasPlugin("safe"))));
+              innerCalls: calls)));
+    }
+  }
 
   @override
   Future<UserOperationResponse> sendSignedUserOperation(UserOperation op) =>

lib/src/abis/contract_abis.dart

@@ -82,6 +82,10 @@ class ContractAbis {
         abi =
             '[{"type":"function","name":"setup","inputs":[{"name":"_owners","type":"address[]","internalType":"address[]"},{"name":"_threshold","type":"uint256","internalType":"uint256"},{"name":"to","type":"address","internalType":"address"},{"name":"data","type":"bytes","internalType":"bytes"},{"name":"fallbackHandler","type":"address","internalType":"address"},{"name":"paymentToken","type":"address","internalType":"address"},{"name":"payment","type":"uint256","internalType":"uint256"},{"name":"paymentReceiver","type":"address","internalType":"address payable"}],"outputs":[],"stateMutability":"nonpayable"}]';
         break;
+      case 'multiSend':
+        abi =
+            '[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[{"internalType":"bytes","name":"transactions","type":"bytes"}],"name":"multiSend","outputs":[],"stateMutability":"payable","type":"function"}]';
+        break;
       default:
         throw 'ABI of $name is not available by default. Please provide the ABI manually.';
     }

lib/src/common/contract.dart

@@ -286,8 +286,12 @@ class Contract {
       innerCallData ?? Uint8List.fromList([])
     ];
 
-    if (isSafe) params.add(BigInt.zero);
-    final method = isSafe ? 'executeUserOpWithErrorString' : 'execute';
+    String method = 'execute';
+
+    if (isSafe) {
+      method = 'executeUserOpWithErrorString';
+      params.add(BigInt.zero);
+    }
 
     return encodeFunctionCall(
       method,
@@ -331,24 +335,32 @@ class Contract {
       List<EtherAmount>? amounts,
       List<Uint8List>? innerCalls,
       bool isSafe = false}) {
-    if (isSafe) {
-      throw UnimplementedError(
-          "Batch Transactions with Safe are not yet implemented.");
-    }
-
-    final params = [
+    List params = [
       recipients,
       amounts?.map<BigInt>((e) => e.getInWei) ?? [],
       innerCalls ?? Uint8List.fromList([]),
     ];
+
     if (innerCalls == null || innerCalls.isEmpty) {
       require(amounts != null && amounts.isNotEmpty, "malformed batch request");
     }
 
+    String method = 'executeBatch';
+
+    if (isSafe) {
+      method = 'executeUserOpWithErrorString';
+      params = [
+        recipients[0], // multisend contract
+        EtherAmount.zero().getInWei, // 0 value to be passed
+        innerCalls?[0], // the encoded multisend calldata
+        BigInt.one // specifying delegate call operation
+      ];
+    }
+
     return encodeFunctionCall(
-      'executeBatch',
+      method,
       walletAddress,
-      ContractAbis.get('executeBatch'),
+      ContractAbis.get(method),
       params,
     );
   }

pubspec.yaml

@@ -1,6 +1,6 @@
 name: variance_dart
 description: An Account Abstraction (4337) Development kit, for quickly building mobile web3 apps and smart wallets.
-version: 0.1.0-r2
+version: 0.1.0-r3
 documentation: https://docs.variance.space
 homepage: https://variance.space
 repository: https://github.com/vaariance/variance-dart