Updated on 2026-08-14

data/common/src/main/kotlin/com/tangem/data/common/currency/UserTokensSaver.kt

@@ -41,7 +41,9 @@ class UserTokensSaver(
             return@withContext
         }
 
-        val enrichedResponse = response.enrichIf(userWalletId = userWalletId, condition = useEnricher)
+        val enrichedResponse = response
+            .withoutDuplicates()
+            .enrichIf(userWalletId = userWalletId, condition = useEnricher)
 
         push(userWallet = userWallet, response = enrichedResponse, onFailSend = onFailSend)
     }
@@ -85,7 +87,46 @@ class UserTokensSaver(
                     apiResponse.bind()
                 }
             },
-            onError = { onFailSend() },
+            onError = { error ->
+                TangemLogger.e("Failed to push ${response.tokens.size} user tokens", error)
+                onFailSend()
+            },
+        )
+    }
+
+    /**
+     * Drops fully identical tokens from the list.
+     *
+     * The API rejects the whole list with `400 All tokens's elements must be unique` if it contains two equal
+     * elements, so a single duplicate discards the update of the entire wallet's token list. Duplicates are not
+     * expected here, hence the error log.
+     *
+     * Tokens are compared by every field of the request instead of [UserTokensResponse.Token.equals], which
+     * deliberately ignores most of them: dropping an element that differs in any way would silently change what the
+     * user has saved.
+     */
+    private fun UserTokensResponse.withoutDuplicates(): UserTokensResponse {
+        val uniqueTokens = tokens.distinctBy { it.toRequestKey() }
+
+        if (uniqueTokens.size == tokens.size) return this
+
+        TangemLogger.e("Dropped ${tokens.size - uniqueTokens.size} duplicated tokens before pushing them")
+
+        return copy(tokens = uniqueTokens)
+    }
+
+    private fun UserTokensResponse.Token.toRequestKey(): List<Any?> {
+        return listOf(
+            id,
+            accountId,
+            networkId,
+            derivationPath,
+            name,
+            symbol,
+            decimals,
+            contractAddress,
+            addresses,
+            dynamicAddressesEnabled,
         )
     }
 

data/common/src/test/kotlin/com/tangem/data/common/currency/UserTokensSaverTest.kt

@@ -95,4 +95,75 @@ class UserTokensSaverTest {
 
             assert(onFailSendCalled) { "onFailSend callback should be called when API call fails" }
         }
+
+    @Test
+    fun `GIVEN response with duplicated tokens WHEN push THEN duplicates are dropped before the api call`() = runTest {
+        // GIVEN
+        val userWalletId = UserWalletId("1234567890abcdef")
+        val userWallet = mockk<UserWallet.Cold> {
+            every { this@mockk.walletId } returns userWalletId
+            every { this@mockk.name } returns ""
+        }
+
+        val token = createToken()
+        val response = createResponse(tokens = listOf(token, token))
+        val uniqueResponse = createResponse(tokens = listOf(token))
+
+        every { userWalletsListRepository.userWallets } returns MutableStateFlow(listOf(userWallet))
+        coEvery { enricher(userWalletId, uniqueResponse) } returns uniqueResponse
+        coEvery { tangemTechApi.saveTokens(any(), any()) } returns ApiResponse.Success(Unit)
+
+        // WHEN
+        userTokensSaver.push(userWalletId = userWalletId, response = response)
+
+        // THEN
+        coVerify(exactly = 1) { tangemTechApi.saveTokens(userWalletId.stringValue, uniqueResponse) }
+    }
+
+    @Test
+    fun `GIVEN tokens differing in account id only WHEN push THEN both of them are pushed`() = runTest {
+        // GIVEN
+        val userWalletId = UserWalletId("1234567890abcdef")
+        val userWallet = mockk<UserWallet.Cold> {
+            every { this@mockk.walletId } returns userWalletId
+            every { this@mockk.name } returns ""
+        }
+
+        val token = createToken()
+        val response = createResponse(tokens = listOf(token, token.copy(accountId = "other-account")))
+
+        every { userWalletsListRepository.userWallets } returns MutableStateFlow(listOf(userWallet))
+        coEvery { enricher(userWalletId, response) } returns response
+        coEvery { tangemTechApi.saveTokens(any(), any()) } returns ApiResponse.Success(Unit)
+
+        // WHEN
+        userTokensSaver.push(userWalletId = userWalletId, response = response)
+
+        // THEN
+        coVerify(exactly = 1) { tangemTechApi.saveTokens(userWalletId.stringValue, response) }
+    }
+
+    private fun createResponse(tokens: List<UserTokensResponse.Token>): UserTokensResponse {
+        return UserTokensResponse(
+            version = 0,
+            group = UserTokensResponse.GroupType.NETWORK,
+            sort = UserTokensResponse.SortType.BALANCE,
+            tokens = tokens,
+            walletName = null,
+            walletType = WalletType.COLD,
+        )
+    }
+
+    private fun createToken(): UserTokensResponse.Token {
+        return UserTokensResponse.Token(
+            id = "ethereum",
+            accountId = "account",
+            networkId = "ethereum",
+            derivationPath = "m/44'/60'/0'/0/1",
+            name = "Ethereum",
+            symbol = "ETH",
+            decimals = 18,
+            contractAddress = null,
+        )
+    }
 }