diff --git a/android/CHANGELOG.md b/android/CHANGELOG.md
index 65f5d41..dfd6792 100644
--- a/android/CHANGELOG.md
+++ b/android/CHANGELOG.md
@@ -124,3 +124,9 @@
 - Synced and persisted message attachments during message refresh/pagination and after media send.
 - Extended message domain model with attachment list payload.
 - Added message attachment rendering in Chat UI: inline image preview, minimal image viewer overlay, and basic audio play/pause control.
+
+### Step 20 - Sprint P0 / 3) Roles/permissions baseline
+- Extended chat data/domain models with `my_role` and added `observeChatById` stream in Room/repository.
+- Added `ObserveChatUseCase` to expose per-chat permission state to message screen.
+- Implemented channel send restrictions in `ChatViewModel`: sending/attach disabled for `member` role in `channel` chats.
+- Added composer-level restriction hint in Chat UI to explain blocked actions.
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/dto/ChatDtos.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/dto/ChatDtos.kt
index 9e0e02b..b5529d6 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/dto/ChatDtos.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/dto/ChatDtos.kt
@@ -40,6 +40,8 @@ data class ChatReadDto(
     val lastMessageType: String? = null,
     @SerialName("last_message_created_at")
     val lastMessageCreatedAt: String? = null,
+    @SerialName("my_role")
+    val myRole: String? = null,
     @SerialName("created_at")
     val createdAt: String? = null,
 )
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDao.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDao.kt
index e876832..d167c44 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDao.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDao.kt
@@ -36,6 +36,7 @@ interface ChatDao {
             c.last_message_text,
             c.last_message_type,
             c.last_message_created_at,
+            c.my_role,
             c.updated_sort_at
         FROM chats c
         LEFT JOIN users_short u ON c.counterpart_user_id = u.id
@@ -45,6 +46,39 @@ interface ChatDao {
     )
     fun observeChats(archived: Boolean): Flow<List<ChatListLocalModel>>
 
+    @Query(
+        """
+        SELECT 
+            c.id,
+            c.public_id,
+            c.type,
+            c.title,
+            COALESCE(c.display_title, u.display_name) AS display_title,
+            c.handle,
+            COALESCE(c.avatar_url, u.avatar_url) AS avatar_url,
+            c.archived,
+            c.pinned,
+            c.muted,
+            c.unread_count,
+            c.unread_mentions_count,
+            COALESCE(c.counterpart_name, u.display_name) AS counterpart_name,
+            COALESCE(c.counterpart_username, u.username) AS counterpart_username,
+            COALESCE(c.counterpart_avatar_url, u.avatar_url) AS counterpart_avatar_url,
+            c.counterpart_is_online,
+            c.counterpart_last_seen_at,
+            c.last_message_text,
+            c.last_message_type,
+            c.last_message_created_at,
+            c.my_role,
+            c.updated_sort_at
+        FROM chats c
+        LEFT JOIN users_short u ON c.counterpart_user_id = u.id
+        WHERE c.id = :chatId
+        LIMIT 1
+        """
+    )
+    fun observeChatById(chatId: Long): Flow<ChatListLocalModel?>
+
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     suspend fun upsertChats(chats: List<ChatEntity>)
 
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/db/MessengerDatabase.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/db/MessengerDatabase.kt
index 1088512..c93cd25 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/db/MessengerDatabase.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/db/MessengerDatabase.kt
@@ -16,7 +16,7 @@ import ru.daemonlord.messenger.data.message.local.entity.MessageEntity
         MessageEntity::class,
         MessageAttachmentEntity::class,
     ],
-    version = 4,
+    version = 6,
     exportSchema = false,
 )
 abstract class MessengerDatabase : RoomDatabase() {
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/entity/ChatEntity.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/entity/ChatEntity.kt
index d197f78..72d94a4 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/entity/ChatEntity.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/entity/ChatEntity.kt
@@ -56,6 +56,8 @@ data class ChatEntity(
     val lastMessageType: String?,
     @ColumnInfo(name = "last_message_created_at")
     val lastMessageCreatedAt: String?,
+    @ColumnInfo(name = "my_role")
+    val myRole: String?,
     @ColumnInfo(name = "updated_sort_at")
     val updatedSortAt: String?,
 )
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/model/ChatListLocalModel.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/model/ChatListLocalModel.kt
index 5aa420a..2bc7c7c 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/model/ChatListLocalModel.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/local/model/ChatListLocalModel.kt
@@ -43,6 +43,8 @@ data class ChatListLocalModel(
     val lastMessageType: String?,
     @ColumnInfo(name = "last_message_created_at")
     val lastMessageCreatedAt: String?,
+    @ColumnInfo(name = "my_role")
+    val myRole: String?,
     @ColumnInfo(name = "updated_sort_at")
     val updatedSortAt: String?,
 )
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatLocalMapper.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatLocalMapper.kt
index 5368ad6..b7bd5fd 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatLocalMapper.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatLocalMapper.kt
@@ -25,6 +25,7 @@ fun ChatListLocalModel.toDomain(): ChatItem {
         lastMessageText = lastMessageText,
         lastMessageType = lastMessageType,
         lastMessageCreatedAt = lastMessageCreatedAt,
+        myRole = myRole,
         updatedSortAt = updatedSortAt,
     )
 }
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatRemoteMapper.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatRemoteMapper.kt
index 9319358..f4d9dbd 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatRemoteMapper.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/mapper/ChatRemoteMapper.kt
@@ -27,6 +27,7 @@ fun ChatReadDto.toChatEntity(): ChatEntity {
         lastMessageText = lastMessageText,
         lastMessageType = lastMessageType,
         lastMessageCreatedAt = lastMessageCreatedAt,
+        myRole = myRole,
         updatedSortAt = lastMessageCreatedAt ?: createdAt,
     )
 }
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepository.kt b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepository.kt
index e3d24ca..9ffa972 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepository.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepository.kt
@@ -4,6 +4,7 @@ import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.channelFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.withContext
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.channels.awaitClose
@@ -43,6 +44,10 @@ class NetworkChatRepository @Inject constructor(
         }
     }
 
+    override fun observeChat(chatId: Long): Flow<ChatItem?> {
+        return chatDao.observeChatById(chatId = chatId).map { it?.toDomain() }
+    }
+
     override suspend fun refreshChats(archived: Boolean): AppResult<Unit> = withContext(ioDispatcher) {
         try {
             val chats = chatApiService.getChats(archived = archived)
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/model/ChatItem.kt b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/model/ChatItem.kt
index 4b82bc2..f6c0e2e 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/model/ChatItem.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/model/ChatItem.kt
@@ -21,5 +21,6 @@ data class ChatItem(
     val lastMessageText: String?,
     val lastMessageType: String?,
     val lastMessageCreatedAt: String?,
+    val myRole: String?,
     val updatedSortAt: String?,
 )
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/repository/ChatRepository.kt b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/repository/ChatRepository.kt
index fc8e85e..83dcca9 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/repository/ChatRepository.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/repository/ChatRepository.kt
@@ -6,6 +6,7 @@ import ru.daemonlord.messenger.domain.common.AppResult
 
 interface ChatRepository {
     fun observeChats(archived: Boolean): Flow<List<ChatItem>>
+    fun observeChat(chatId: Long): Flow<ChatItem?>
     suspend fun refreshChats(archived: Boolean): AppResult<Unit>
     suspend fun refreshChat(chatId: Long): AppResult<Unit>
     suspend fun deleteChat(chatId: Long)
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/usecase/ObserveChatUseCase.kt b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/usecase/ObserveChatUseCase.kt
new file mode 100644
index 0000000..b47edbd
--- /dev/null
+++ b/android/app/src/main/java/ru/daemonlord/messenger/domain/chat/usecase/ObserveChatUseCase.kt
@@ -0,0 +1,14 @@
+package ru.daemonlord.messenger.domain.chat.usecase
+
+import kotlinx.coroutines.flow.Flow
+import ru.daemonlord.messenger.domain.chat.model.ChatItem
+import ru.daemonlord.messenger.domain.chat.repository.ChatRepository
+import javax.inject.Inject
+
+class ObserveChatUseCase @Inject constructor(
+    private val repository: ChatRepository,
+) {
+    operator fun invoke(chatId: Long): Flow<ChatItem?> {
+        return repository.observeChat(chatId = chatId)
+    }
+}
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatScreen.kt b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatScreen.kt
index ba09bef..5ec3a96 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatScreen.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatScreen.kt
@@ -233,7 +233,7 @@ fun ChatScreen(
         ) {
             Button(
                 onClick = onPickMedia,
-                enabled = !state.isUploadingMedia,
+                enabled = state.canSendMessages && !state.isUploadingMedia,
             ) {
                 Text(if (state.isUploadingMedia) "..." else "Attach")
             }
@@ -246,12 +246,23 @@ fun ChatScreen(
             )
             Button(
                 onClick = onSendClick,
-                enabled = !state.isSending && !state.isUploadingMedia && state.inputText.isNotBlank(),
+                enabled = state.canSendMessages &&
+                    !state.isSending &&
+                    !state.isUploadingMedia &&
+                    state.inputText.isNotBlank(),
             ) {
                 Text(if (state.isSending) "..." else "Send")
             }
         }
 
+        if (!state.canSendMessages && !state.sendRestrictionText.isNullOrBlank()) {
+            Text(
+                text = state.sendRestrictionText,
+                color = MaterialTheme.colorScheme.tertiary,
+                modifier = Modifier.padding(horizontal = 12.dp, vertical = 2.dp),
+            )
+        }
+
         if (!state.errorMessage.isNullOrBlank()) {
             Text(
                 text = state.errorMessage,
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt
index cba1cc9..c5e3519 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt
@@ -11,6 +11,7 @@ import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import ru.daemonlord.messenger.domain.chat.usecase.ObserveChatUseCase
 import ru.daemonlord.messenger.domain.chat.usecase.ObserveChatsUseCase
 import ru.daemonlord.messenger.domain.common.AppError
 import ru.daemonlord.messenger.domain.common.AppResult
@@ -47,6 +48,7 @@ class ChatViewModel @Inject constructor(
     private val forwardMessageUseCase: ForwardMessageUseCase,
     private val listMessageReactionsUseCase: ListMessageReactionsUseCase,
     private val toggleMessageReactionUseCase: ToggleMessageReactionUseCase,
+    private val observeChatUseCase: ObserveChatUseCase,
     private val observeChatsUseCase: ObserveChatsUseCase,
     private val handleRealtimeEventsUseCase: HandleRealtimeEventsUseCase,
 ) : ViewModel() {
@@ -59,6 +61,7 @@ class ChatViewModel @Inject constructor(
 
     init {
         handleRealtimeEventsUseCase.start()
+        observeChatPermissions()
         observeMessages()
         refresh()
     }
@@ -231,6 +234,15 @@ class ChatViewModel @Inject constructor(
             val result = if (editing != null) {
                 editMessageUseCase(messageId = editing.id, newText = text)
             } else {
+                if (!uiState.value.canSendMessages) {
+                    _uiState.update {
+                        it.copy(
+                            isSending = false,
+                            errorMessage = uiState.value.sendRestrictionText ?: "Sending is restricted in this chat.",
+                        )
+                    }
+                    return@launch
+                }
                 sendTextMessageUseCase(
                     chatId = chatId,
                     text = text,
@@ -330,6 +342,30 @@ class ChatViewModel @Inject constructor(
         }
     }
 
+    private fun observeChatPermissions() {
+        viewModelScope.launch {
+            observeChatUseCase(chatId).collectLatest { chat ->
+                if (chat == null) return@collectLatest
+                val role = chat.myRole?.lowercase()
+                val canSend = when (chat.type.lowercase()) {
+                    "channel" -> role == "owner" || role == "admin"
+                    else -> true
+                }
+                val restriction = if (canSend) {
+                    null
+                } else {
+                    "Only channel owner/admin can send messages."
+                }
+                _uiState.update {
+                    it.copy(
+                        canSendMessages = canSend,
+                        sendRestrictionText = restriction,
+                    )
+                }
+            }
+        }
+    }
+
     private fun refresh() {
         viewModelScope.launch {
             _uiState.update { it.copy(isLoading = true, errorMessage = null) }
diff --git a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/MessageUiState.kt b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/MessageUiState.kt
index ec82dd1..9b9055a 100644
--- a/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/MessageUiState.kt
+++ b/android/app/src/main/java/ru/daemonlord/messenger/ui/chat/MessageUiState.kt
@@ -21,6 +21,8 @@ data class MessageUiState(
     val forwardingMessage: MessageItem? = null,
     val availableForwardTargets: List<ForwardTargetUiModel> = emptyList(),
     val isForwarding: Boolean = false,
+    val canSendMessages: Boolean = true,
+    val sendRestrictionText: String? = null,
 )
 
 data class ForwardTargetUiModel(
diff --git a/android/app/src/test/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDaoTest.kt b/android/app/src/test/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDaoTest.kt
index a18823c..5f56092 100644
--- a/android/app/src/test/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDaoTest.kt
+++ b/android/app/src/test/java/ru/daemonlord/messenger/data/chat/local/dao/ChatDaoTest.kt
@@ -88,6 +88,7 @@ class ChatDaoTest {
             lastMessageText = "hi",
             lastMessageType = "text",
             lastMessageCreatedAt = "2026-03-08T10:00:00Z",
+            myRole = "member",
             updatedSortAt = "2026-03-08T10:00:00Z",
         )
     }
diff --git a/android/app/src/test/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepositoryTest.kt b/android/app/src/test/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepositoryTest.kt
index d32a616..f23fbec 100644
--- a/android/app/src/test/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepositoryTest.kt
+++ b/android/app/src/test/java/ru/daemonlord/messenger/data/chat/repository/NetworkChatRepositoryTest.kt
@@ -49,6 +49,7 @@ class NetworkChatRepositoryTest {
             lastMessageText = "Cached message",
             lastMessageType = "text",
             lastMessageCreatedAt = "2026-03-08T10:00:00Z",
+            myRole = "member",
             updatedSortAt = "2026-03-08T10:00:00Z",
         )
 
@@ -121,6 +122,10 @@ class NetworkChatRepositoryTest {
             }
         }
 
+        override fun observeChatById(chatId: Long): Flow<ChatListLocalModel?> {
+            return chats.map { entities -> entities.firstOrNull { it.id == chatId }?.toLocalModel() }
+        }
+
         override suspend fun upsertChats(chats: List<ChatEntity>) {
             val merged = this.chats.value.associateBy { it.id }.toMutableMap()
             chats.forEach { merged[it.id] = it }
@@ -180,6 +185,7 @@ class NetworkChatRepositoryTest {
                 lastMessageText = lastMessageText,
                 lastMessageType = lastMessageType,
                 lastMessageCreatedAt = lastMessageCreatedAt,
+                myRole = myRole,
                 updatedSortAt = updatedSortAt,
             )
         }
diff --git a/docs/android-checklist.md b/docs/android-checklist.md
index b2f575e..9382418 100644
--- a/docs/android-checklist.md
+++ b/docs/android-checklist.md
@@ -77,9 +77,9 @@
 - [ ] Create group/channel
 - [ ] Join/leave
 - [ ] Invite link (create/regenerate/join)
-- [ ] Roles owner/admin/member
+- [x] Roles owner/admin/member
 - [ ] Admin actions: add/remove/ban/unban/promote/demote
-- [ ] Ограничения канала: писать только owner/admin
+- [x] Ограничения канала: писать только owner/admin
 - [ ] Member visibility rules (скрытие списков/действий)
 
 ## 11. Поиск