Updated on 2026-08-14

core/datasource/src/main/java/com/tangem/datasource/api/express/TangemExpressApi.kt

@@ -50,6 +50,8 @@ interface TangemExpressApi {
         @Query("rateType") rateType: String,
         @Query("toAddress") toAddress: String,
         @Query("requestId") requestId: String,
+        @Query("refundAddress") refundAddress: String?, // for cex only
+        @Query("refundExtraId") refundExtraId: String?, // for cex only
     ): ApiResponse<ExchangeDataResponse>
 
     @GET("exchange-status")

features/swap/data/src/main/java/com/tangem/feature/swap/DefaultSwapRepository.kt

@@ -256,6 +256,8 @@ internal class DefaultSwapRepository @Inject constructor(
         providerId: String,
         rateType: RateType,
         toAddress: String,
+        refundAddress: String?, // for cex only
+        refundExtraId: String?, // for cex only
     ): Either<DataError, SwapDataModel> {
         return withContext(coroutineDispatcher.io) {
             try {
@@ -272,6 +274,8 @@ internal class DefaultSwapRepository @Inject constructor(
                     rateType = rateType.name.lowercase(),
                     toAddress = toAddress,
                     requestId = requestId,
+                    refundAddress = refundAddress,
+                    refundExtraId = refundExtraId,
                 ).getOrThrow()
                 if (dataSignatureVerifier.verifySignature(response.signature, response.txDetailsJson)) {
                     val txDetails = parseTxDetails(response.txDetailsJson)

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

@@ -65,6 +65,8 @@ interface SwapRepository {
         providerId: String,
         rateType: RateType,
         toAddress: String,
+        refundAddress: String? = null, // for cex only
+        refundExtraId: String? = null, // for cex only
     ): Either<DataError, SwapDataModel>
 
     fun getNativeTokenForNetwork(networkId: String): CryptoCurrency

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

@@ -589,6 +589,8 @@ internal class SwapInteractorImpl @Inject constructor(
             providerId = swapProvider.providerId,
             rateType = RateType.FLOAT,
             toAddress = currencyToGet.value.networkAddress?.defaultAddress?.value ?: "",
+            refundAddress = currencyToSend.value.networkAddress?.defaultAddress?.value,
+            refundExtraId = null, // currently always null
         ).getOrElse { return SwapTransactionState.ExpressError(it) }
 
         val exchangeDataCex =