Updated on 2026-08-14

data/address-book/src/main/kotlin/com/tangem/data/addressbook/DefaultAddressBookRepository.kt

@@ -46,6 +46,8 @@ internal class DefaultAddressBookRepository(
 
     private val writeMutex = Mutex()
 
+    private val logger = TangemLogger.withTag(LOG_TAG)
+
     override fun getContacts(userWalletId: UserWalletId): Flow<List<Contact>> {
         return getContactsForWallet(userWalletId)
             .onStart { syncAddressBooks() }
@@ -124,6 +126,9 @@ internal class DefaultAddressBookRepository(
 
     override suspend fun syncAddressBooks(): Either<AddressBookSyncError, Unit> = withContext(dispatchers.default) {
         val wallets = userWalletsListRepository.userWalletsSync()
+        // Debug (Logcat only, dev builds) — the persisted prod log stays quiet on the happy path; only failures
+        // below are written at Error level.
+        logger.d("Syncing address books for ${wallets.size} wallet(s)")
         // The backend rejects more than MAX_SYNC_WALLETS per request, so sync in chunks and stop on the
         // first failed chunk.
         wallets.chunked(MAX_SYNC_WALLETS)
@@ -145,22 +150,38 @@ internal class DefaultAddressBookRepository(
             call = {
                 val response = withContext(dispatchers.io) { addressBookApi.syncAddressBooks(request).bind() }
                 // Only wallets whose etag changed are returned; the rest keep their local copy.
+                logger.d("Sync response: ${response.items.size} updated book(s) out of ${wallets.size} requested")
                 response.items.forEach { item ->
                     val userWalletId = UserWalletId(stringValue = item.walletId)
+                    // Metadata only — helps QA verify what the backend delivered (esp. for cross-platform books).
+                    // Debug (Logcat only) to keep the persisted prod log free of happy-path sync noise.
+                    logger.d(
+                        "Storing synced address book for wallet ${item.walletId}: version=${item.version}, " +
+                            "updatedAt=${item.updatedAt}, nonceLen=${item.nonce.length}, " +
+                            "ciphertextLen=${item.ciphertext.length}, authTagLen=${item.authTag.length}",
+                    )
                     blobStore.storeBlob(item.toBlob())
                     eTagsStore.store(userWalletId, ETagsStore.Key.AddressBook, item.etag)
                 }
                 Unit.right()
             },
             onError = { error ->
-                TangemLogger.e(messageString = "Failed to sync address books: $error")
+                logger.e("Failed to sync address books: $error")
                 error.toSyncError().left()
             },
         )
     }
 
     private fun decryptContacts(blob: AddressBookBlob, userWallet: UserWallet): List<Contact> {
-        return cipher.decrypt(blob, userWallet).getOrNull()?.contacts.orEmpty()
+        return cipher.decrypt(blob, userWallet).fold(
+            ifLeft = { error ->
+                // The cipher already logged the low-level cause; this ties the failure to the read path so QA
+                // can see that a stored/synced book (e.g. one created on iOS) could not be shown to the user.
+                logger.e("Skipping address book for wallet ${blob.walletId}: decrypt failed with $error")
+                emptyList()
+            },
+            ifRight = { it.contacts },
+        )
     }
 
     private suspend fun currentContacts(userWalletId: UserWalletId, userWallet: UserWallet): List<Contact> {
@@ -176,9 +197,7 @@ internal class DefaultAddressBookRepository(
         val updatedAt = DateTime.parse(timestampProvider.now())
         return cipher.encrypt(addressBook, userWallet, updatedAt)
             .mapLeft { error ->
-                TangemLogger.e(
+                logger.e("Failed to encrypt address book for wallet ${userWallet.walletId}: $error")
-                    messageString = "Failed to encrypt address book for wallet ${userWallet.walletId}: $error",
-                )
                 AddressBookSyncError.Unknown
             }
             .flatMap { blob -> pushBlob(userWallet.walletId, blob) }
@@ -209,7 +228,7 @@ internal class DefaultAddressBookRepository(
                 Unit.right()
             },
             onError = { error ->
-                TangemLogger.e(messageString = "Failed to push address book for wallet $userWalletId: $error")
+                logger.e("Failed to push address book for wallet $userWalletId: $error")
                 val syncError = error.toSyncError()
                 // A 412 means the local etag is stale relative to the backend. Refresh the local blob + etag so the
                 // next save attempt (user re-taps Save) starts from the current backend state. We do NOT re-push here
@@ -249,6 +268,7 @@ internal class DefaultAddressBookRepository(
         userWalletsListRepository.userWalletsSync().find { it.walletId.stringValue == walletId }
 
     private companion object {
+        const val LOG_TAG = "AddressBook"
         const val MAX_SYNC_WALLETS = 20
     }
 }

domain/address-book/src/main/kotlin/com/tangem/domain/addressbook/crypto/AddressBookCipher.kt

@@ -10,6 +10,7 @@ import com.tangem.domain.addressbook.model.AddressBookBlob
 import com.tangem.domain.models.wallet.UserWallet
 import com.tangem.utils.extensions.hexToBytesOrNull
 import com.tangem.utils.extensions.toHexString
+import com.tangem.utils.logging.TangemLogger
 import kotlinx.serialization.json.Json
 import org.joda.time.DateTime
 import org.joda.time.DateTimeZone
@@ -35,6 +36,7 @@ class AddressBookCipher {
 
     private val json = Json { ignoreUnknownKeys = true }
     private val secureRandom = SecureRandom()
+    private val logger = TangemLogger.withTag(LOG_TAG)
 
     fun encrypt(
         addressBook: AddressBook,
@@ -58,24 +60,97 @@ class AddressBookCipher {
             nonce = nonce.toHexString().lowercase(),
             ciphertext = ciphertext.toHexString().lowercase(),
             authTag = authTag.toHexString().lowercase(),
-        )
+        ).also { blob ->
+            // Metadata only — the plaintext (contact names/addresses/memos) is never logged.
+            logger.d(
+                "Encrypted address book for wallet ${blob.walletId}: contacts=${addressBook.contacts.size}, " +
+                    "plaintextBytes=${plaintext.size}, version=${blob.version}, " +
+                    "nonceLen=${blob.nonce.length}, ciphertextLen=${blob.ciphertext.length}, " +
+                    "authTagLen=${blob.authTag.length}",
+            )
+        }
     }
 
     fun decrypt(blob: AddressBookBlob, userWallet: UserWallet): Either<AddressBookCryptoError, AddressBook> = either {
-        ensure(blob.walletId == userWallet.walletId.stringValue) { AddressBookCryptoError.WalletMismatch }
+        // Metadata only — helps QA correlate a failing blob with what was received from the backend/other platform.
+        logger.d(
+            "Decrypting address book for wallet ${blob.walletId}: version=${blob.version}, " +
+                "updatedAt=${blob.updatedAt}, nonceLen=${blob.nonce.length}, " +
+                "ciphertextLen=${blob.ciphertext.length}, authTagLen=${blob.authTag.length}",
+        )
+
+        ensure(blob.walletId == userWallet.walletId.stringValue) {
+            logger.w(
+                "Wallet mismatch decrypting address book: blob wallet=${blob.walletId}, " +
+                    "target wallet=${userWallet.walletId.stringValue}",
+            )
+            AddressBookCryptoError.WalletMismatch
+        }
 
         val aesKey = deriveKey(userWallet)
-        val nonce = blob.nonce.hexToBytesOrNull() ?: raise(AddressBookCryptoError.DecryptionFailed)
+        val nonce = blob.nonce.hexToBytesOrNull() ?: raiseNonHex(blob, field = "nonce", value = blob.nonce)
-        val ciphertext = blob.ciphertext.hexToBytesOrNull() ?: raise(AddressBookCryptoError.DecryptionFailed)
+        val ciphertext = blob.ciphertext.hexToBytesOrNull() ?: raiseNonHex(
-        val authTag = blob.authTag.hexToBytesOrNull() ?: raise(AddressBookCryptoError.DecryptionFailed)
+            blob = blob,
+            field = "ciphertext",
+            value = blob.ciphertext,
+        )
+        val authTag = blob.authTag.hexToBytesOrNull() ?: raiseNonHex(blob, field = "authTag", value = blob.authTag)
 
         val plaintext = runCatching {
             cipher(Cipher.DECRYPT_MODE, aesKey, nonce).doFinal(ciphertext + authTag)
-        }.getOrElse { raise(AddressBookCryptoError.DecryptionFailed) }
+        }.getOrElse { error ->
+            logger.e(
+                "Failed to AES-GCM decrypt address book for wallet ${blob.walletId} " +
+                    "(nonceBytes=${nonce.size}, ciphertextBytes=${ciphertext.size}, authTagBytes=${authTag.size}): " +
+                    "${error.safeDescription()}. Usually a wrong key/nonce/tag or a corrupted blob.",
+                error,
+            )
+            raise(AddressBookCryptoError.DecryptionFailed)
+        }
 
         runCatching {
             json.decodeFromString(AddressBook.serializer(), plaintext.toString(Charsets.UTF_8))
-        }.getOrElse { raise(AddressBookCryptoError.MalformedBlob) }
+        }.getOrElse { error ->
+            // Decryption succeeded, so this is a payload schema/format mismatch — the prime suspect for a book
+
+            // reason (missing/extra field, wrong type, JSON path) but strips any raw plaintext the exception echoes.
+            logger.e(
+                "Failed to parse decrypted address book for wallet ${blob.walletId} " +
+                    "(plaintextBytes=${plaintext.size}, version=${blob.version}): ${error.safeDescription()}. " +
+                    "Decryption OK → cross-platform payload schema/format mismatch.",
+            )
+            raise(AddressBookCryptoError.MalformedBlob)
+        }.also { addressBook ->
+            logger.d(
+                messageString = "Decrypted address book for wallet ${blob.walletId}: " +
+                    "contacts=${addressBook.contacts.size}",
+            )
+        }
+    }
+
+    private fun Raise<AddressBookCryptoError>.raiseNonHex(
+        blob: AddressBookBlob,
+        field: String,
+        value: String,
+    ): Nothing {
+        logger.e(
+            "Address book blob has non-hex $field for wallet ${blob.walletId} " +
+                "(${field}Len=${value.length}, version=${blob.version}).",
+        )
+        raise(AddressBookCryptoError.DecryptionFailed)
+    }
+
+    /**
+     * A log-safe, one-line description of a failure: exception type + message, with any raw decrypted payload
+     * stripped. kotlinx.serialization appends the offending input after a `JSON input:` marker; everything before
+     * it (the reason and the `at path: …` location) is structural and safe to log.
+     */
+    private fun Throwable.safeDescription(): String {
+        val safeMessage = message.orEmpty().substringBefore("JSON input:").trim()
+        return buildString {
+            append(this@safeDescription::class.simpleName)
+            if (safeMessage.isNotEmpty()) append(": ").append(safeMessage)
+        }
     }
 
     private fun Raise<AddressBookCryptoError>.deriveKey(userWallet: UserWallet): ByteArray {
@@ -91,6 +166,7 @@ class AddressBookCipher {
     }
 
     private companion object {
+        const val LOG_TAG = "AddressBook"
         const val AES_GCM_TRANSFORMATION = "AES/GCM/NoPadding"
         const val AES_ALGORITHM = "AES"
         const val NONCE_SIZE_BYTES = 12

domain/address-book/src/main/kotlin/com/tangem/domain/addressbook/model/AddressEntry.kt

@@ -5,7 +5,6 @@ import com.tangem.domain.models.network.Network
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
-/** A single saved address belonging to a [Contact]. */
 @Serializable
 data class AddressEntry(
     @SerialName("id")
@@ -15,10 +14,8 @@ data class AddressEntry(
     @SerialName("networkId")
     @Serializable(with = NetworkRawIdAsStringSerializer::class)
     val networkId: Network.RawID,
-    @SerialName("networkName")
-    val networkName: String,
     @SerialName("memo")
-    val memo: String?,
+    val memo: String? = null,
     @SerialName("signature")
     val signature: String,
 )

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/crypto/AddressBookCipherTest.kt

@@ -266,7 +266,6 @@ internal class AddressBookCipherTest {
         networkId = Network.RawID("ethereum"),
         memo = memo,
         signature = "",
-        networkName = "Ethereum",
     )
 
     private fun String.flipFirstHexNibble(): String = (if (first() == '0') '1' else '0') + substring(1)

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/interactor/GetVerifiedContactsInteractorTest.kt

@@ -70,7 +70,6 @@ class GetVerifiedContactsInteractorTest {
                 id = AddressEntryId("addr-1"),
                 address = "0xabc",
                 networkId = Network.RawID("ethereum"),
-                networkName = "Ethereum",
                 memo = null,
                 signature = "AABB",
             ),

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/interactor/SaveContactInteractorTest.kt

@@ -321,7 +321,6 @@ internal class SaveContactInteractorTest {
         networkId = networkRawId,
         memo = memo,
         signature = "sig",
-        networkName = "Ethereum",
     )
 
     private fun expectedHash(contact: Contact, entry: AddressEntry): ByteArray {

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/model/AddressBookSerializationTest.kt

@@ -34,7 +34,6 @@ internal class AddressBookSerializationTest {
                     id = AddressEntryId("addr-1"),
                     address = "0xabc",
                     networkId = Network.RawID("ethereum"),
-                    networkName = "Ethereum",
                     memo = null,
                     signature = "",
                 ),
@@ -71,7 +70,6 @@ internal class AddressBookSerializationTest {
                             id = AddressEntryId("addr-1"),
                             address = "0xabc",
                             networkId = Network.RawID("ethereum"),
-                            networkName = "Ethereum",
                             memo = "memo",
                             signature = "sig",
                         ),
@@ -102,4 +100,23 @@ internal class AddressBookSerializationTest {
         // Assert
         assertThat(error).isNotNull()
     }
+
+    @Test
+    fun `GIVEN entry with null memo WHEN serialized THEN memo key is omitted`() {
+        // Arrange — kotlinx omits properties equal to their default, so a null memo must not appear in the JSON,
+        // matching iOS's encodeIfPresent for String? optionals.
+        val entry = AddressEntry(
+            id = AddressEntryId("a1"),
+            address = "0xabc",
+            networkId = Network.RawID("ethereum"),
+            memo = null,
+            signature = "sig",
+        )
+
+        // Act
+        val obj = json.parseToJsonElement(json.encodeToString(AddressEntry.serializer(), entry)).jsonObject
+
+        // Assert
+        assertThat(obj.keys).doesNotContain("memo")
+    }
 }

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/usecase/CheckAddressDuplicateUseCaseTest.kt

@@ -90,7 +90,6 @@ class CheckAddressDuplicateUseCaseTest {
                 networkId = Network.RawID(networkId),
                 memo = null,
                 signature = "sig",
-                networkName = "Ethereum",
             ),
         ),
     )

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/usecase/GetContactsUseCaseTest.kt

@@ -119,7 +119,6 @@ class GetContactsUseCaseTest {
                 networkId = Network.RawID("ethereum"),
                 memo = null,
                 signature = "sig",
-                networkName = "Ethereum",
             ),
         ),
     )

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/validation/ContactNameValidatorTest.kt

@@ -102,7 +102,6 @@ class ContactNameValidatorTest {
                 networkId = Network.RawID("ethereum"),
                 memo = null,
                 signature = "AABB",
-                networkName = "Ethereum",
             ),
         ),
     )

domain/address-book/src/test/kotlin/com/tangem/domain/addressbook/verification/ContactSignatureVerifierTest.kt

@@ -253,7 +253,6 @@ class ContactSignatureVerifierTest {
         id = AddressEntryId(id),
         address = address,
         networkId = Network.RawID("ethereum"),
-        networkName = "Ethereum",
         memo = memo,
         signature = signature,
     )

features/address-book/impl/src/main/kotlin/com/tangem/features/addressbook/common/ContactMatcher.kt

@@ -1,6 +1,9 @@
 package com.tangem.features.addressbook.common
 
+import com.tangem.blockchain.common.Blockchain
+import com.tangem.blockchainsdk.utils.fromNetworkId
 import com.tangem.common.ui.account.AccountIconUM
+import com.tangem.domain.addressbook.model.AddressEntry
 import com.tangem.domain.addressbook.model.Contact
 import com.tangem.domain.models.account.CryptoPortfolioIcon
 import com.tangem.features.addressbook.MatchedContact
@@ -27,7 +30,7 @@ internal object ContactMatcher {
                     MatchedContact.ContactAddress(
                         address = entry.address,
                         memo = entry.memo,
-                        networkName = entry.networkName,
+                        networkName = entry.displayNetworkName(),
                     )
                 }.toImmutableList(),
             )
@@ -40,4 +43,8 @@ internal object ContactMatcher {
         color = CryptoPortfolioIcon.Color.entries.firstOrNull { it.name == iconColor }
             ?: CryptoPortfolioIcon.Color.Azure,
     )
+
+    /** Display network name is derived from [AddressEntry.networkId] — it is not stored in the encrypted payload. */
+    private fun AddressEntry.displayNetworkName(): String =
+        Blockchain.fromNetworkId(networkId.value)?.fullName ?: networkId.value
 }

features/address-book/impl/src/main/kotlin/com/tangem/features/addressbook/editcontact/model/ContactAddressEntriesConverter.kt

@@ -37,7 +37,6 @@ internal class ContactAddressEntriesConverter {
             id = AddressEntryId(UUID.randomUUID().toString()),
             address = address,
             networkId = Network.RawID(rawId),
-            networkName = blockchain?.fullName ?: rawId,
             memo = memo?.takeIf { hasExtrasSupport },
             signature = "",
         )

features/address-book/impl/src/main/kotlin/com/tangem/features/addressbook/list/DefaultAddressBookListComponent.kt

@@ -63,7 +63,7 @@ internal class DefaultAddressBookListComponent(
             is AddressBookListUM.Content -> AddressBookListScreen(
                 state = addressBookListUM,
                 onBackClick = router::pop,
-                modifier = modifier.background(TangemTheme.colors3.bg.primary),
+                modifier = Modifier.background(TangemTheme.colors3.bg.primary),
             )
         }
         selector.child?.instance?.BottomSheet()

features/address-book/impl/src/main/kotlin/com/tangem/features/addressbook/list/ui/AddressBookListScreen.kt

@@ -43,7 +43,7 @@ internal fun AddressBookListScreen(
 ) {
     val density = LocalDensity.current
     val bottomBarHeight = with(density) { WindowInsets.systemBars.getBottom(this).toDp() }
-    Column(modifier = modifier) {
+    Column(modifier = modifier.fillMaxSize()) {
         TangemTopBar(
             modifier = Modifier.statusBarsPadding(),
             title = resourceReference(R.string.address_book_title),

features/address-book/impl/src/test/kotlin/com/tangem/features/addressbook/common/ContactMatcherTest.kt

@@ -90,7 +90,6 @@ internal class ContactMatcherTest {
         networkId = Network.RawID(networkId),
         memo = memo,
         signature = "sig",
-        networkName = "Ethereum",
     )
 
     private companion object {

features/address-book/impl/src/test/kotlin/com/tangem/features/addressbook/editcontact/model/EditContactModelTest.kt

@@ -808,7 +808,6 @@ internal class EditContactModelTest {
                         id = AddressEntryId("e-1"),
                         address = "0xAAA",
                         networkId = Network.RawID("ethereum"),
-                        networkName = "Ethereum",
                         memo = null,
                         signature = "sig",
                     ),
@@ -816,7 +815,6 @@ internal class EditContactModelTest {
                         id = AddressEntryId("e-2"),
                         address = "0xBBB",
                         networkId = Network.RawID("bsc"),
-                        networkName = "BSC",
                         memo = null,
                         signature = "sig",
                     ),
@@ -1016,7 +1014,6 @@ internal class EditContactModelTest {
                 id = AddressEntryId("e-1"),
                 address = address,
                 networkId = Network.RawID("ethereum"),
-                networkName = "Ethereum",
                 memo = null,
                 signature = "sig",
             ),

features/address-book/impl/src/test/kotlin/com/tangem/features/addressbook/list/model/AddressBookListModelTest.kt

@@ -186,7 +186,6 @@ internal class AddressBookListModelTest {
                     id = AddressEntryId("e-$id"),
                     address = "0xABC",
                     networkId = Network.RawID("ethereum"),
-                    networkName = "Ethereum",
                     memo = null,
                     signature = "sig",
                 ),

features/address-book/impl/src/test/kotlin/com/tangem/features/addressbook/list/state/transformers/UpdateAddressBookListContentTransformerTest.kt

@@ -172,7 +172,6 @@ internal class UpdateAddressBookListContentTransformerTest {
                     networkId = Network.RawID("ethereum"),
                     memo = null,
                     signature = "sig",
-                    networkName = "Ethereum",
                 ),
             ),
         ),

features/send/impl/src/test/java/com/tangem/features/send/subcomponents/destination/model/SendDestinationModelTest.kt

@@ -589,7 +589,6 @@ internal class SendDestinationModelTest {
                 id = AddressEntryId("e1"),
                 address = address,
                 networkId = Network.RawID(networkRawId),
-                networkName = "Ethereum",
                 memo = null,
                 signature = "",
             ),