diff --git a/android/CHANGELOG.md b/android/CHANGELOG.md
index d34df5b..1835df3 100644
--- a/android/CHANGELOG.md
+++ b/android/CHANGELOG.md
@@ -91,3 +91,9 @@
 - Added input composer with send flow, reply/edit modes, and inline action cancellation.
 - Added long-press actions (`reply`, `edit`, `delete`) for baseline message operations.
 - Added manual "load older" pagination trigger and chat back navigation integration.
+
+### Step 15 - Sprint A / 5) Message tests and docs
+- Added unit tests for `NetworkMessageRepository` sync/send flows.
+- Added DAO test for message scoped replace behavior in Room.
+- Expanded realtime parser tests with rich `receive_message` mapping coverage.
+- Updated `docs/android-checklist.md` for completed message-core items.
diff --git a/android/app/src/test/java/ru/daemonlord/messenger/data/message/local/dao/MessageDaoTest.kt b/android/app/src/test/java/ru/daemonlord/messenger/data/message/local/dao/MessageDaoTest.kt
new file mode 100644
index 0000000..0ed3351
--- /dev/null
+++ b/android/app/src/test/java/ru/daemonlord/messenger/data/message/local/dao/MessageDaoTest.kt
@@ -0,0 +1,79 @@
+package ru.daemonlord.messenger.data.message.local.dao
+
+import androidx.room.Room
+import androidx.test.core.app.ApplicationProvider
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.test.runTest
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import ru.daemonlord.messenger.data.chat.local.db.MessengerDatabase
+import ru.daemonlord.messenger.data.message.local.entity.MessageEntity
+
+@RunWith(RobolectricTestRunner::class)
+@OptIn(ExperimentalCoroutinesApi::class)
+class MessageDaoTest {
+
+    private lateinit var db: MessengerDatabase
+    private lateinit var dao: MessageDao
+
+    @Before
+    fun setUp() {
+        db = Room.inMemoryDatabaseBuilder(
+            ApplicationProvider.getApplicationContext(),
+            MessengerDatabase::class.java,
+        ).allowMainThreadQueries()
+            .build()
+        dao = db.messageDao()
+    }
+
+    @After
+    fun tearDown() {
+        db.close()
+    }
+
+    @Test
+    fun clearAndReplaceMessages_replacesOnlyTargetChatMessages() = runTest {
+        dao.upsertMessages(
+            listOf(
+                message(id = 1, chatId = 10, text = "old-10"),
+                message(id = 2, chatId = 20, text = "keep-20"),
+            )
+        )
+
+        dao.clearAndReplaceMessages(
+            chatId = 10,
+            messages = listOf(message(id = 3, chatId = 10, text = "new-10")),
+            attachments = emptyList(),
+        )
+
+        val chat10 = dao.observeRecentMessages(chatId = 10).first()
+        val chat20 = dao.observeRecentMessages(chatId = 20).first()
+
+        assertEquals(1, chat10.size)
+        assertEquals(3L, chat10.first().id)
+        assertEquals(1, chat20.size)
+        assertEquals(2L, chat20.first().id)
+    }
+
+    private fun message(id: Long, chatId: Long, text: String): MessageEntity {
+        return MessageEntity(
+            id = id,
+            chatId = chatId,
+            senderId = 1,
+            senderDisplayName = "User",
+            senderUsername = "user",
+            senderAvatarUrl = null,
+            replyToMessageId = null,
+            type = "text",
+            text = text,
+            status = null,
+            createdAt = "2026-03-08T12:00:00Z",
+            updatedAt = null,
+        )
+    }
+}
diff --git a/android/app/src/test/java/ru/daemonlord/messenger/data/message/repository/NetworkMessageRepositoryTest.kt b/android/app/src/test/java/ru/daemonlord/messenger/data/message/repository/NetworkMessageRepositoryTest.kt
new file mode 100644
index 0000000..857fd35
--- /dev/null
+++ b/android/app/src/test/java/ru/daemonlord/messenger/data/message/repository/NetworkMessageRepositoryTest.kt
@@ -0,0 +1,124 @@
+package ru.daemonlord.messenger.data.message.repository
+
+import androidx.room.Room
+import androidx.test.core.app.ApplicationProvider
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.runTest
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import ru.daemonlord.messenger.data.chat.local.db.MessengerDatabase
+import ru.daemonlord.messenger.data.message.api.MessageApiService
+import ru.daemonlord.messenger.data.message.dto.MessageCreateRequestDto
+import ru.daemonlord.messenger.data.message.dto.MessageReadDto
+import ru.daemonlord.messenger.data.message.dto.MessageUpdateRequestDto
+
+@RunWith(RobolectricTestRunner::class)
+@OptIn(ExperimentalCoroutinesApi::class)
+class NetworkMessageRepositoryTest {
+
+    private lateinit var db: MessengerDatabase
+    private lateinit var fakeApi: FakeMessageApiService
+    private val dispatcher = StandardTestDispatcher()
+
+    @Before
+    fun setUp() {
+        db = Room.inMemoryDatabaseBuilder(
+            ApplicationProvider.getApplicationContext(),
+            MessengerDatabase::class.java,
+        ).allowMainThreadQueries().build()
+        fakeApi = FakeMessageApiService()
+    }
+
+    @After
+    fun tearDown() {
+        db.close()
+    }
+
+    @Test
+    fun syncRecentMessages_writesRemoteItemsToRoom() = runTest(dispatcher) {
+        fakeApi.messages = listOf(
+            MessageReadDto(
+                id = 101,
+                chatId = 5,
+                senderId = 7,
+                type = "text",
+                text = "hello",
+                createdAt = "2026-03-08T10:00:00Z",
+                updatedAt = null,
+            )
+        )
+        val repository = createRepository()
+
+        val sync = repository.syncRecentMessages(chatId = 5)
+        assertTrue(sync is ru.daemonlord.messenger.domain.common.AppResult.Success)
+
+        val items = repository.observeMessages(chatId = 5).first()
+        assertEquals(1, items.size)
+        assertEquals(101L, items.first().id)
+        assertEquals("hello", items.first().text)
+    }
+
+    @Test
+    fun sendTextMessage_optimisticThenServerReplace() = runTest(dispatcher) {
+        fakeApi.sendResponse = MessageReadDto(
+            id = 202,
+            chatId = 8,
+            senderId = 1,
+            type = "text",
+            text = "from server",
+            createdAt = "2026-03-08T11:00:00Z",
+            updatedAt = null,
+        )
+        val repository = createRepository()
+
+        val result = repository.sendTextMessage(chatId = 8, text = "from client")
+        assertTrue(result is ru.daemonlord.messenger.domain.common.AppResult.Success)
+
+        val items = repository.observeMessages(chatId = 8).first()
+        assertEquals(1, items.size)
+        assertEquals(202L, items.first().id)
+        assertEquals("from server", items.first().text)
+    }
+
+    private fun createRepository(): NetworkMessageRepository {
+        return NetworkMessageRepository(
+            messageApiService = fakeApi,
+            messageDao = db.messageDao(),
+            chatDao = db.chatDao(),
+            ioDispatcher = dispatcher,
+        )
+    }
+
+    private class FakeMessageApiService : MessageApiService {
+        var messages: List<MessageReadDto> = emptyList()
+        var sendResponse: MessageReadDto = MessageReadDto(
+            id = 1,
+            chatId = 1,
+            senderId = 1,
+            type = "text",
+            text = "ok",
+            createdAt = "2026-03-08T10:00:00Z",
+        )
+
+        override suspend fun getMessages(chatId: Long, limit: Int, beforeId: Long?): List<MessageReadDto> {
+            return messages
+        }
+
+        override suspend fun sendMessage(request: MessageCreateRequestDto): MessageReadDto {
+            return sendResponse
+        }
+
+        override suspend fun editMessage(messageId: Long, request: MessageUpdateRequestDto): MessageReadDto {
+            return sendResponse.copy(id = messageId, text = request.text)
+        }
+
+        override suspend fun deleteMessage(messageId: Long, forAll: Boolean) = Unit
+    }
+}
diff --git a/android/app/src/test/java/ru/daemonlord/messenger/data/realtime/RealtimeEventParserTest.kt b/android/app/src/test/java/ru/daemonlord/messenger/data/realtime/RealtimeEventParserTest.kt
index aaf8eff..fe8ab0f 100644
--- a/android/app/src/test/java/ru/daemonlord/messenger/data/realtime/RealtimeEventParserTest.kt
+++ b/android/app/src/test/java/ru/daemonlord/messenger/data/realtime/RealtimeEventParserTest.kt
@@ -41,4 +41,34 @@ class RealtimeEventParserTest {
         assertTrue(event is RealtimeEvent.ChatDeleted)
         assertEquals(77L, (event as RealtimeEvent.ChatDeleted).chatId)
     }
+
+    @Test
+    fun parseReceiveMessage_returnsRichMappedEvent() {
+        val payload = """
+            {
+              "event": "receive_message",
+              "payload": {
+                "chat_id": 88,
+                "message": {
+                  "id": 9001,
+                  "chat_id": 88,
+                  "sender_id": 5,
+                  "reply_to_message_id": 100,
+                  "type": "text",
+                  "text": "hi",
+                  "created_at": "2026-03-08T12:00:00Z"
+                }
+              }
+            }
+        """.trimIndent()
+
+        val event = parser.parse(payload)
+        assertTrue(event is RealtimeEvent.ReceiveMessage)
+        val mapped = event as RealtimeEvent.ReceiveMessage
+        assertEquals(88L, mapped.chatId)
+        assertEquals(9001L, mapped.messageId)
+        assertEquals(5L, mapped.senderId)
+        assertEquals(100L, mapped.replyToMessageId)
+        assertEquals("hi", mapped.text)
+    }
 }
diff --git a/docs/android-checklist.md b/docs/android-checklist.md
index eb27652..3d1684e 100644
--- a/docs/android-checklist.md
+++ b/docs/android-checklist.md
@@ -49,10 +49,10 @@
 - [x] Online indicator в private чатах
 
 ## 7. Сообщения
-- [ ] Отправка текста
-- [ ] Reply/quote
-- [ ] Edit (<=7 дней)
-- [ ] Delete for me / for all (по правам)
+- [x] Отправка текста
+- [x] Reply/quote
+- [x] Edit (<=7 дней)
+- [x] Delete for me / for all (по правам)
 - [ ] Forward в 1+ чатов
 - [ ] Reactions
 - [ ] Delivery/read states