Updated on 2026-08-14

core/datasource/src/main/java/com/tangem/datasource/di/NetworkModule.kt

@@ -39,7 +39,7 @@ class NetworkModule {
         appVersionProvider: AppVersionProvider,
     ): TangemExpressApi {
         val url = if (BuildConfig.ENVIRONMENT == "dev") {
-            DEV_EXPRESS_BASE_URL
+            STAGE_EXPRESS_BASE_URL
         } else {
             PROD_EXPRESS_BASE_URL
         }
@@ -162,6 +162,7 @@ class NetworkModule {
     private companion object {
         const val STAKEKIT_BASE_URL = "https://api.stakek.it/v1/"
         const val PROD_EXPRESS_BASE_URL = "https://express.tangem.com/v1/"
+        const val STAGE_EXPRESS_BASE_URL = "[REDACTED_ENV_URL]"
         const val DEV_EXPRESS_BASE_URL = "[REDACTED_ENV_URL]"
 
         const val DEV_V1_TANGEM_TECH_BASE_URL = "https://devapi.tangem-tech.com/v1/"

data/transaction/src/main/java/com/tangem/data/transaction/DefaultTransactionRepository.kt

@@ -35,6 +35,7 @@ internal class DefaultTransactionRepository(
         userWalletId: UserWalletId,
         network: Network,
         isSwap: Boolean,
+        txExtras: TransactionExtras?,
         hash: String?,
     ): TransactionData? = withContext(coroutineDispatcherProvider.io) {
         val blockchain = Blockchain.fromId(network.id.value)
@@ -51,6 +52,7 @@ internal class DefaultTransactionRepository(
             destination = destination,
             network = network,
             isSwap = isSwap,
+            txExtras = txExtras,
             hash = hash,
         )
     }
@@ -63,6 +65,7 @@ internal class DefaultTransactionRepository(
         userWalletId: UserWalletId,
         network: Network,
         isSwap: Boolean,
+        txExtras: TransactionExtras?,
         hash: String?,
     ): Result<Unit> {
         val blockchain = Blockchain.fromId(network.id.value)
@@ -82,6 +85,7 @@ internal class DefaultTransactionRepository(
                 destination = destination,
                 network = network,
                 isSwap = isSwap,
+                txExtras = txExtras,
                 hash = hash,
             )
 
@@ -115,17 +119,24 @@ internal class DefaultTransactionRepository(
         destination: String,
         network: Network,
         isSwap: Boolean,
+        txExtras: TransactionExtras?,
         hash: String?,
     ): TransactionData {
+        // TODO: refactor workaround to use general mechanism in bsdk for build tx for DEX
         val txAmount = if (isSwap) {
             createAmountForSwap(amount)
         } else {
             amount
         }
 
+        if (txExtras != null && memo != null) {
+            // throw error for now to avoid programmers errors when use extras
+            error("Both txExtras and memo provided, use only one of them")
+        }
+        val extras = txExtras ?: getMemoExtras(network.id.value, memo)
         return createTransaction(txAmount, fee, destination).copy(
             hash = hash,
-            extras = getMemoExtras(network.id.value, memo),
+            extras = extras,
         )
     }
 

domain/transaction/src/main/java/com/tangem/domain/transaction/TransactionRepository.kt

@@ -3,6 +3,7 @@ package com.tangem.domain.transaction
 import com.tangem.blockchain.common.Amount
 import com.tangem.blockchain.common.CommonSigner
 import com.tangem.blockchain.common.TransactionData
+import com.tangem.blockchain.common.TransactionExtras
 import com.tangem.blockchain.common.transaction.Fee
 import com.tangem.blockchain.extensions.SimpleResult
 import com.tangem.domain.tokens.model.Network
@@ -19,6 +20,7 @@ interface TransactionRepository {
         userWalletId: UserWalletId,
         network: Network,
         isSwap: Boolean,
+        txExtras: TransactionExtras?,
         hash: String?,
     ): TransactionData?
 
@@ -31,6 +33,7 @@ interface TransactionRepository {
         userWalletId: UserWalletId,
         network: Network,
         isSwap: Boolean = false,
+        txExtras: TransactionExtras?,
         hash: String? = null,
     ): Result<Unit>
 

domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/CreateTransactionUseCase.kt

@@ -2,6 +2,7 @@ package com.tangem.domain.transaction.usecase
 
 import arrow.core.Either
 import com.tangem.blockchain.common.Amount
+import com.tangem.blockchain.common.TransactionExtras
 import com.tangem.blockchain.common.transaction.Fee
 import com.tangem.domain.tokens.model.Network
 import com.tangem.domain.transaction.TransactionRepository
@@ -22,6 +23,7 @@ class CreateTransactionUseCase(
         destination: String,
         userWalletId: UserWalletId,
         network: Network,
+        txExtras: TransactionExtras? = null,
         isSwap: Boolean = false,
         hash: String? = null,
     ) = Either.catch {
@@ -34,6 +36,7 @@ class CreateTransactionUseCase(
                 userWalletId = userWalletId,
                 network = network,
                 isSwap = isSwap,
+                txExtras = txExtras,
                 hash = hash,
             ),
         ) { "Failed to create transaction" }

domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/ValidateTransactionUseCase.kt

@@ -32,6 +32,7 @@ class ValidateTransactionUseCase(
             userWalletId = userWalletId,
             network = network,
             isSwap = isSwap,
+            txExtras = null,
             hash = hash,
         )
             .fold(onSuccess = { Unit.right() }, onFailure = { it.left() })

features/swap/domain/src/main/java/com/tangem/feature/swap/domain/SwapInteractorImpl.kt

@@ -2,13 +2,12 @@ package com.tangem.feature.swap.domain
 
 import arrow.core.Either
 import arrow.core.getOrElse
-import com.tangem.blockchain.common.Amount
-import com.tangem.blockchain.common.AmountType
-import com.tangem.blockchain.common.Blockchain
-import com.tangem.blockchain.common.BlockchainSdkError
+import com.tangem.blockchain.blockchains.ethereum.EthereumTransactionExtras
+import com.tangem.blockchain.common.*
 import com.tangem.blockchain.common.transaction.Fee
 import com.tangem.blockchain.common.transaction.TransactionFee
 import com.tangem.blockchainsdk.utils.minimalAmount
+import com.tangem.common.extensions.hexToBytes
 import com.tangem.core.ui.utils.BigDecimalFormatter
 import com.tangem.core.ui.utils.parseBigDecimal
 import com.tangem.domain.appcurrency.GetSelectedAppCurrencyUseCase
@@ -479,6 +478,7 @@ internal class SwapInteractorImpl @Inject constructor(
             amount = amount.value.convertToAmount(fromToken),
             fee = null,
             memo = null,
+            txExtras = null,
             destination = getTokenAddress(fromToken),
             userWalletId = userWalletId,
             network = fromToken.network,
@@ -625,6 +625,7 @@ internal class SwapInteractorImpl @Inject constructor(
         val amountDecimal = requireNotNull(toBigDecimalOrNull(amountToSwap)) { "wrong amount format" }
         val amount = SwapAmount(amountDecimal, currencyToSend.decimals)
         val derivationPath = currencyToSend.network.derivationPath.value
+        val dataToSign = (swapData.transaction as ExpressTransactionModel.DEX).txData
         val txData = createTransactionUseCase(
             amount = amount.value.convertToAmount(currencyToSend),
             fee = getFeeForTransaction(
@@ -635,7 +636,8 @@ internal class SwapInteractorImpl @Inject constructor(
             destination = swapData.transaction.txTo,
             userWalletId = userWalletId,
             network = currencyToSend.network,
-            hash = (swapData.transaction as ExpressTransactionModel.DEX).txData,
+            txExtras = createDexTxExtras(fee.gasLimit, dataToSign),
+            hash = dataToSign,
             isSwap = true,
         ).getOrElse {
             Timber.e(it)
@@ -678,6 +680,15 @@ internal class SwapInteractorImpl @Inject constructor(
         )
     }
 
+    private fun createDexTxExtras(gasLimit: Int, data: String): TransactionExtras {
+        // for now we support only Ethereum like DEX
+        // need to be extended if we support other blockchains in DEX
+        return EthereumTransactionExtras(
+            gasLimit = gasLimit.toBigInteger(),
+            data = data.removePrefix(HEX_PREFIX).hexToBytes(),
+        )
+    }
+
     @Suppress("LongMethod")
     private suspend fun onSwapCex(
         currencyToSend: CryptoCurrencyStatus,