fix: walletconnect fee refresh (#3153)

* fix: refresh EIP-1559 fees before sign for walletconnect transactions

* fix: add missing data to configure file

---------

Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

cw_evm/lib/evm_chain_wallet.dart

@@ -99,7 +99,8 @@ abstract class EVMChainWalletBase
         _isTransactionUpdating = false,
         _client = client,
         selectedChainId = initialChainId ?? _getInitialChainId(walletInfo.type),
-        walletAddresses = EVMChainWalletAddresses(walletInfo, initialChainId ?? _getInitialChainId(walletInfo.type)),
+        walletAddresses = EVMChainWalletAddresses(
+            walletInfo, initialChainId ?? _getInitialChainId(walletInfo.type)),
         balance = ObservableMap<CryptoCurrency, EVMChainERC20Balance>.of(
           {
             nativeCurrency: initialBalance ?? EVMChainERC20Balance(BigInt.zero),
@@ -779,27 +780,13 @@ abstract class EVMChainWalletBase
         throw EVMChainTransactionFeesException('Failed to retrieve gas price from node');
       }
 
-      int maxFeePerGas;
-      int adjustedGasPrice;
-
-      if (gasBaseFee != null && gasBaseFee > 0) {
-        // For chains with base fee, add priority fee (if supported) and a buffer to account for base fee increases
-        // Base fee can increase between estimation and transaction submission
-        final baseFeeWithPriority = gasBaseFee + priorityFee;
-
-        // For chains without priority fees (e.g., Arbitrum), use a 5% buffer
-        // For chains with priority fees (e.g., Ethereum), use a 15% buffer to account for base fee volatility
-        // Base fee can increase significantly during high network activity
-        final bufferMultiplier = hasPriorityFee ? 115 : 105;
-        final bufferPercent = (baseFeeWithPriority * bufferMultiplier) ~/ 100;
-        final bufferMin = baseFeeWithPriority + (baseFeeWithPriority ~/ 100);
-        maxFeePerGas = bufferPercent > bufferMin ? bufferPercent : bufferMin;
-      } else {
-        // Fallback to gasPrice if baseFee is not available
-        maxFeePerGas = gasPrice + priorityFee;
-      }
-
-      adjustedGasPrice = maxFeePerGas;
+      final maxFeePerGas = EVMChainUtils.computeBufferedMaxFeePerGasWei(
+        gasBaseFee: gasBaseFee,
+        gasPrice: gasPrice,
+        priorityFeeWei: priorityFee,
+        chainHasPriorityFee: hasPriorityFee,
+      );
+      final adjustedGasPrice = maxFeePerGas;
 
       final estimatedGas = await _client.getEstimatedGasUnitsForTransaction(
         contractAddress: contractAddress,
@@ -829,6 +816,39 @@ abstract class EVMChainWalletBase
     }
   }
 
+  Future<WalletConnectBufferedFeeData?> getWCBufferedFeeQuote(TransactionPriority priority) async {
+    try {
+      final gasBaseFee = await _client.getGasBaseFee();
+      final gasPrice = await _client.getGasUnitPrice();
+
+      if (gasPrice <= 0) {
+        printV('WC fee quote: invalid gas price $gasPrice');
+        return null;
+      }
+
+      int priorityFee = 0;
+      if (hasPriorityFee && priority is EVMChainTransactionPriority) {
+        priorityFee = getTotalPriorityFee(priority);
+      }
+
+      final maxFee = EVMChainUtils.computeBufferedMaxFeePerGasWei(
+        gasBaseFee: gasBaseFee,
+        gasPrice: gasPrice,
+        priorityFeeWei: priorityFee,
+        chainHasPriorityFee: hasPriorityFee,
+      );
+
+      return WalletConnectBufferedFeeData(
+        maxFeePerGasWei: maxFee,
+        maxPriorityFeePerGasWei: priorityFee,
+        latestBaseFeeWei: gasBaseFee,
+      );
+    } catch (e, s) {
+      printV('getWalletConnectBufferedFeeQuote: $e\n$s');
+      return null;
+    }
+  }
+
   @override
   Future<void> changePassword(String password) {
     throw UnimplementedError("changePassword");
@@ -1048,15 +1068,14 @@ abstract class EVMChainWalletBase
   }
 
   Future<PendingTransaction> createCallDataTransaction(
-      String to,
-      String dataHex,
-      BigInt valueWei,
-      EVMChainTransactionPriority? priority,
-      String? sourceTokenAddress,
-      BigInt? sourceTokenAmount, {
-        bool useBlinkProtection = true,
-      }) async {
-
+    String to,
+    String dataHex,
+    BigInt valueWei,
+    EVMChainTransactionPriority? priority,
+    String? sourceTokenAddress,
+    BigInt? sourceTokenAmount, {
+    bool useBlinkProtection = true,
+  }) async {
     // Define Native Currency
     final nativeCurrency = switch (selectedChainId) {
       137 => CryptoCurrency.maticpoly,
@@ -1099,12 +1118,9 @@ abstract class EVMChainWalletBase
         cleanAddress == '0x0000000000000000000000000000000000000000';
 
     if (!isNativeSource && sourceTokenAmount != null && sourceTokenAmount > BigInt.zero) {
-
       // Filter list to find match.
-      final matchingTokens = balance.keys.where((k) =>
-      k is Erc20Token &&
-          k.contractAddress.toLowerCase() == cleanAddress
-      );
+      final matchingTokens = balance.keys
+          .where((k) => k is Erc20Token && k.contractAddress.toLowerCase() == cleanAddress);
 
       if (matchingTokens.isEmpty) {
         // Token is not in the wallet balance map -> Balance is 0
@@ -1262,9 +1278,7 @@ abstract class EVMChainWalletBase
 
       if (existingTxInfo == null) {
         result[transactionModel.hash] = newTxInfo;
-      }
-
-      else if (newTxInfo.direction == TransactionDirection.incoming &&
+      } else if (newTxInfo.direction == TransactionDirection.incoming &&
           existingTxInfo.direction == TransactionDirection.outgoing) {
         result[transactionModel.hash] = newTxInfo;
       }
@@ -1760,3 +1774,15 @@ class MoralisDiscoveryResult {
 
   static const MoralisDiscoveryResult empty = MoralisDiscoveryResult(newTokens: []);
 }
+
+class WalletConnectBufferedFeeData {
+  const WalletConnectBufferedFeeData({
+    required this.maxFeePerGasWei,
+    required this.maxPriorityFeePerGasWei,
+    this.latestBaseFeeWei,
+  });
+
+  final int maxFeePerGasWei;
+  final int maxPriorityFeePerGasWei;
+  final int? latestBaseFeeWei;
+}

cw_evm/lib/utils/evm_chain_utils.dart

@@ -22,6 +22,22 @@ class EVMChainUtils {
     };
   }
 
+  static int computeBufferedMaxFeePerGasWei({
+    required int? gasBaseFee,
+    required int gasPrice,
+    required int priorityFeeWei,
+    required bool chainHasPriorityFee,
+  }) {
+    if (gasBaseFee != null && gasBaseFee > 0) {
+      final baseFeeWithPriority = gasBaseFee + priorityFeeWei;
+      final bufferMultiplier = chainHasPriorityFee ? 115 : 105;
+      final bufferPercent = (baseFeeWithPriority * bufferMultiplier) ~/ 100;
+      final bufferMin = baseFeeWithPriority + (baseFeeWithPriority ~/ 100);
+      return bufferPercent > bufferMin ? bufferPercent : bufferMin;
+    }
+    return gasPrice + priorityFeeWei;
+  }
+
   static String getErc20TokensBoxName(String walletName, int chainId) {
     final sanitizedName = walletName.replaceAll(" ", "_");
 

lib/evm/cw_evm.dart

@@ -239,10 +239,7 @@ class CWEVM extends EVM {
       (wallet as EVMChainWallet).isApprovalRequired(tokenContract, spender, requiredAmount);
 
   @override
-  Future<BigInt?> getAllowance(
-      WalletBase wallet,
-      String tokenContract,
-      String spender) =>
+  Future<BigInt?> getAllowance(WalletBase wallet, String tokenContract, String spender) =>
       (wallet as EVMChainWallet).getAllowance(tokenContract, spender);
 
   @override
@@ -272,7 +269,7 @@ class CWEVM extends EVM {
     String to,
     String dataHex,
     BigInt valueWei,
-    TransactionPriority? priority,{
+    TransactionPriority? priority, {
     bool useBlinkProtection = true,
     String? sourceTokenAddress,
     BigInt? sourceTokenAmount,
@@ -481,7 +478,7 @@ class CWEVM extends EVM {
 
   @override
   BigInt? getERC20AvailableBalance(Object balance) {
-    if(balance is EVMChainERC20Balance) {
+    if (balance is EVMChainERC20Balance) {
       return balance.balance;
     }
     return null;
@@ -544,6 +541,23 @@ class CWEVM extends EVM {
   @override
   bool hasPriorityFee(int chainId) => EVMChainUtils.hasPriorityFee(chainId);
 
+  @override
+  Future<EvmWalletConnectFeeQuote?> getWCBufferedFeeQuote(
+    WalletBase wallet,
+    TransactionPriority priority,
+  ) async {
+    if (wallet is! EVMChainWallet) return null;
+
+    final data = await wallet.getWCBufferedFeeQuote(priority);
+    if (data == null) return null;
+
+    return EvmWalletConnectFeeQuote(
+      maxFeePerGasWei: data.maxFeePerGasWei,
+      maxPriorityFeePerGasWei: data.maxPriorityFeePerGasWei,
+      latestBaseFeeWei: data.latestBaseFeeWei,
+    );
+  }
+
   Future<({double usdValue, bool hasValidFiatPrice})> _getTokenUsdValueAndFiatCheck(
     Erc20Token token,
     BigInt balanceWei,

lib/src/screens/wallet_connect/services/chain_service/eth/evm_chain_service.dart

@@ -432,43 +432,14 @@ class EvmChainServiceImpl {
       }
     }
 
-    // we need to check if dApp provides the gas values and if not, we need to estimate them
-    final hasGasLimit = transaction.maxGas != null && transaction.maxGas! > 0;
-    final hasGasPrice = transaction.gasPrice != null;
-    final hasMaxFeePerGas = transaction.maxFeePerGas != null;
-    final hasMaxPriorityFeePerGas = transaction.maxPriorityFeePerGas != null;
-
-    final needsGasEstimation = !hasGasLimit || (!hasGasPrice && !hasMaxFeePerGas);
-
-    if (needsGasEstimation) {
-      try {
-        final gasPrice = hasGasPrice ? transaction.gasPrice! : await ethClient.getGasPrice();
-
-        if (!hasGasLimit) {
-          final gasLimit = await ethClient.estimateGas(
-            sender: transaction.from,
-            to: transaction.to,
-            value: transaction.value,
-            data: transaction.data,
-            gasPrice: gasPrice,
-          );
-
-          if (hasMaxFeePerGas || hasMaxPriorityFeePerGas) {
-            transaction = transaction.copyWith(maxGas: gasLimit.toInt());
-          } else {
-            transaction = transaction.copyWith(
-              gasPrice: hasGasPrice ? transaction.gasPrice : gasPrice,
-              maxGas: gasLimit.toInt(),
-            );
-          }
-        } else if (!hasGasPrice && !hasMaxFeePerGas) {
-          transaction = transaction.copyWith(gasPrice: gasPrice);
-        }
-      } on RPCError catch (e) {
-        return JsonRpcError(code: e.errorCode, message: e.message);
-      }
+    try {
+      transaction = await _ensureWCTransactionHasGasLimit(transaction);
+    } on RPCError catch (e) {
+      return JsonRpcError(code: e.errorCode, message: e.message);
     }
 
+    transaction = await _applyWCBufferedFees(transaction);
+
     final gweiGasPrice =
         (transaction.gasPrice?.getInWei ?? transaction.maxFeePerGas?.getInWei ?? BigInt.zero) /
             BigInt.from(1000000000);
@@ -500,6 +471,90 @@ class EvmChainServiceImpl {
     return JsonRpcError(code: 5002, message: S.current.user_rejected_method);
   }
 
+  Future<Transaction> _ensureWCTransactionHasGasLimit(Transaction transaction) async {
+    final hasGasLimit = transaction.maxGas != null && transaction.maxGas! > 0;
+    if (hasGasLimit) return transaction;
+
+    final hint = transaction.gasPrice ?? transaction.maxFeePerGas ?? await ethClient.getGasPrice();
+
+    final gasLimit = await ethClient.estimateGas(
+      sender: transaction.from,
+      to: transaction.to,
+      value: transaction.value,
+      data: transaction.data,
+      gasPrice: hint,
+    );
+
+    if (transaction.isEIP1559) {
+      return transaction.copyWith(maxGas: gasLimit.toInt());
+    }
+
+    return transaction.copyWith(
+      maxGas: gasLimit.toInt(),
+      gasPrice: transaction.gasPrice ?? hint,
+    );
+  }
+
+  Future<Transaction> _applyWCBufferedFees(Transaction transaction) async {
+    try {
+      final storedPriority =
+          appStore.settingsStore.getPriority(appStore.wallet!.type, chainId: reference.chainId);
+      final priority = storedPriority ?? evm!.getDefaultTransactionPriority();
+
+      final quote = await evm!.getWCBufferedFeeQuote(appStore.wallet!, priority);
+      if (quote != null) {
+        return _mergeWCBufferedFees(transaction, quote);
+      }
+    } catch (e) {
+      debugPrint('WalletConnect fee refresh failed: $e');
+    }
+
+    if (!transaction.isEIP1559 && transaction.gasPrice == null) {
+      return transaction.copyWith(gasPrice: await ethClient.getGasPrice());
+    }
+
+    return transaction;
+  }
+
+  Transaction _mergeWCBufferedFees(Transaction transaction, EvmWalletConnectFeeQuote quote) {
+    if (transaction.isEIP1559) {
+      // the fees coming from the dApp
+      final dAppMax = transaction.maxFeePerGas?.getInWei ?? BigInt.zero;
+      final dAppPri = transaction.maxPriorityFeePerGas?.getInWei ?? BigInt.zero;
+
+      // the updated fees coming from the wallet, handles buffered fees
+      final quoteMax = BigInt.from(quote.maxFeePerGasWei);
+      final quotePri = BigInt.from(quote.maxPriorityFeePerGasWei);
+
+      // we'll just use the higher of the two
+      var newMaxFeePerGasWei = dAppMax > quoteMax ? dAppMax : quoteMax;
+      var newPriorityFeePerGasWei = dAppPri > quotePri ? dAppPri : quotePri;
+
+      final base = quote.latestBaseFeeWei;
+      if (base != null) {
+        final baseB = BigInt.from(base);
+        final maxPriAllowed = newMaxFeePerGasWei - baseB;
+        if (newPriorityFeePerGasWei > maxPriAllowed) {
+          if (maxPriAllowed > BigInt.zero) {
+            newPriorityFeePerGasWei = maxPriAllowed;
+          } else {
+            newMaxFeePerGasWei = baseB + newPriorityFeePerGasWei;
+          }
+        }
+      }
+
+      return transaction.copyWith(
+        maxFeePerGas: EtherAmount.inWei(newMaxFeePerGasWei),
+        maxPriorityFeePerGas: EtherAmount.inWei(newPriorityFeePerGasWei),
+      );
+    }
+
+    final dPrice = transaction.gasPrice?.getInWei ?? BigInt.zero;
+    final floor = BigInt.from(quote.maxFeePerGasWei);
+    final newPriceWei = dPrice > floor ? dPrice : floor;
+    return transaction.copyWith(gasPrice: EtherAmount.inWei(newPriceWei));
+  }
+
   void _onSessionRequest(SessionRequestEvent? args) async {
     if (args != null && args.chainId == getChainId()) {
       debugPrint('_onSessionRequest ${args.toString()}');

tool/configure.dart

@@ -1555,6 +1555,12 @@ abstract class EVM {
   
   bool hasPriorityFee(int chainId);
 
+
+  Future<EvmWalletConnectFeeQuote?> getWCBufferedFeeQuote(
+    WalletBase wallet,
+    TransactionPriority priority,
+  );
+
   Future<void> discoverAndAddWalletTokens(WalletBase wallet);
 }
 
@@ -1577,6 +1583,18 @@ class ChainInfo {
   @override
   int get hashCode => chainId.hashCode;
 }
+
+class EvmWalletConnectFeeQuote {
+  const EvmWalletConnectFeeQuote({
+    required this.maxFeePerGasWei,
+    required this.maxPriorityFeePerGasWei,
+    this.latestBaseFeeWei,
+  });
+
+  final int maxFeePerGasWei;
+  final int maxPriorityFeePerGasWei;
+  final int? latestBaseFeeWei;
+}
   """;
 
   const evmEmptyDefinition = 'EVM? evm;\n';