Updated on 2026-08-14

libs/crypto/src/main/java/com/tangem/lib/crypto/TransactionManager.kt

@@ -1,6 +1,7 @@
 package com.tangem.lib.crypto
 
 import com.tangem.lib.crypto.models.Currency
+import com.tangem.lib.crypto.models.ProxyAmount
 import com.tangem.lib.crypto.models.transactions.SendTxResult
 import java.math.BigDecimal
 
@@ -14,4 +15,13 @@ interface TransactionManager {
         destinationAddress: String,
         dataToSign: String,
     ): SendTxResult
+
+    suspend fun getFee(
+        networkId: String,
+        amountToSend: BigDecimal,
+        currencyToSend: Currency,
+        destinationAddress: String,
+    ): ProxyAmount
+
+    fun getNativeAddress(networkId: String): String
 }

libs/crypto/src/main/java/com/tangem/lib/crypto/models/Currency.kt

@@ -9,20 +9,21 @@ sealed class Currency(
     open val name: String,
     open val symbol: String,
     open val networkId: String,
-)
+) {
 
-data class NativeToken(
-    override val id: String,
-    override val name: String,
-    override val symbol: String,
-    override val networkId: String,
-) : Currency(id, name, symbol, networkId)
+    data class NativeToken(
+        override val id: String,
+        override val name: String,
+        override val symbol: String,
+        override val networkId: String,
+    ) : Currency(id, name, symbol, networkId)
 
-class NonNativeToken(
-    override val id: String,
-    override val name: String,
-    override val symbol: String,
-    override val networkId: String,
-    val contractAddress: String,
-    val decimalCount: Int,
-) : Currency(id, name, symbol, networkId)
+    class NonNativeToken(
+        override val id: String,
+        override val name: String,
+        override val symbol: String,
+        override val networkId: String,
+        val contractAddress: String,
+        val decimalCount: Int,
+    ) : Currency(id, name, symbol, networkId)
+}

libs/crypto/src/main/java/com/tangem/lib/crypto/models/ProxyAmount.kt

@@ -0,0 +1,16 @@
+package com.tangem.lib.crypto.models
+
+import java.math.BigDecimal
+
+/**
+ * Proxy amount is always has a Coin type
+ *
+ * @property currencySymbol
+ * @property value amount in [BigDecimal]
+ * @property decimals count for token
+ */
+data class ProxyAmount(
+    val currencySymbol: String,
+    var value: BigDecimal,
+    val decimals: Int,
+)