# Read state and unread counts > **Info:** This is release candidate documentation for **Stream Chat React Native SDK v10**. For the latest stable version, see the [latest version (v9)](https://getstream.io/chat/docs/sdk/react-native/). Every channel and every thread keeps a read state for each of its members: when they last read it, and how many messages they haven't read since. > > **Info:** **Example** > > The user last read "Design" on Monday at 9:00. Since then Bob and Cara posted 12 messages, so the user's read state says 12 unread. Bob's says 0, because posting a message counts as reading the channel. > Channel lists, unread badges, unread separators and "jump to first unread" all build on this state. Channels and threads keep it in different shapes, so this page covers channels first, then threads. ## Read state per user A channel's read state is the `read` field of `channel.state`, one entry per user id: | Field | What it holds | | ------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------ | | `last_read` | When the user last read the channel, in nanoseconds. | | `unread_messages` | How many messages the user hasn't read. | | `last_read_message_id` | The last message the user read. | | `first_unread_message_id` | The message the user marked the channel unread from. | | `user` | The user. | | `last_delivered_at`, `last_delivered_message_id` | Delivery receipts, explained in [Read state, unread and receipts](https://getstream.io/chat/docs/sdk/react-native/v10/features/messaging/read-state-unread-and-receipts/). | The current user's count is also `channel.state.unreadCount`, and `Channel.countUnread()` returns the same. Both read the current value without subscribing. To follow it, subscribe to `channel.state` and select the current user's entry: ```ts import { nsToDate } from "stream-chat"; import type { Channel } from "stream-chat"; export const followOwnReadState = (channel: Channel) => { const ownUserId = channel.getClient().userId; return channel.state.subscribeWithSelector( ({ read }) => ({ ownRead: ownUserId ? read[ownUserId] : undefined }), ({ ownRead }) => { if (!ownRead) return; const lastRead = nsToDate(ownRead.last_read).toLocaleString(); console.log(`${ownRead.unread_messages} unread since ${lastRead}`); }, ); }; ``` Timestamps are nanosecond numbers. `nsToDate` turns them into a `Date`, as [Data conventions](https://getstream.io/chat/docs/sdk/react-native/v10/state/state-and-entities/data-conventions/) explains. In a component, select `read` with `useStateStore`, as the unread badge on [Reading state in components](https://getstream.io/chat/docs/sdk/react-native/v10/ui/reading-state-in-components/) does. A few more reads: - `Channel.lastRead()` is the current user's `last_read`, or `null` if they never read the channel. - `Channel.countUnread(lastRead)` counts the loaded newest messages after `lastRead` that count as unread. - `Channel.countUnreadMentions()` counts the unread messages that mention the current user. ## What changes the read state - **The state changes on its own, through events.** That includes changes the user makes on another device. - **Other members' entries in `channel.state.read` update too.** When someone posts, their entry becomes read and everyone else's count goes up. Read receipts depend on this. - **Channels the client doesn't watch still get the user's own read changes.** They don't get other members' read changes. - **The server's count wins.** The client's count is an estimate, and each time the channel loads, the server's count replaces it. Each event changes it this way: | What happens | What changes | | ------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | The channel loads, from a query or a channel list | Every entry comes from the server. If the server sends none for the current user, they get one with nothing unread. | | `message.new` from Bob | Bob's entry: read at the message's time, 0 unread. Every other entry: 1 more unread. The current user's count goes up only if the message counts as unread (next section). | | `message.read` from Bob | Bob's entry: read at the event's time, 0 unread, `first_unread_message_id` cleared. Only watched channels receive it. | | `notification.mark_read` | The same, for the current user, also in channels the client doesn't watch. Marking every channel read sets every loaded channel's count to 0. | | `message.read_locally` | The same, for the current user, without a request. `Channel.markReadLocally()` dispatches it. | | `notification.mark_unread` | The current user's entry takes its read time, unread count, first unread message and last read message from the event. | | `channel.truncated` | The current user's count only includes the messages after the truncation, or goes to 0. | A message the current user sends, a reply that stays in its thread, and `message.read` or `notification.mark_read` for a thread don't change the channel's read state. `message.read_locally` carries the newest loaded message as `last_read_message_id` only while the newest messages are loaded. When only an older interval is loaded, for example after a jump, the event carries none, and the read covers everything up to the event's time. ## What counts as unread in a channel When a new message arrives in a channel, it raises the current user's count unless: - the current user sent it; - it's silent (`silent: true`) or shadowed by moderation; - it's a thread reply that isn't shown in the channel; - the current user muted its author; - the current user muted the channel; - the user is looking at the newest messages, as [Message paginators](https://getstream.io/chat/docs/sdk/react-native/v10/state/loading-data/message-paginators/#live-view-and-unread) explains; - the user doesn't have the `read-events` capability in the channel, unless the app counts unread messages locally (see [Turning read events off](#turning-read-events-off)). The SDK's message lists report that the user is looking at the newest messages while the app is in the foreground and the newest message is on screen. `Channel.countUnread(lastRead)` and `Channel.countUnreadMentions()` follow the same rules, except the one about looking at the newest messages. ## Marking read and unread Marking read or unread usually sends a request, and the read state changes when the server's event comes back, not when the call returns. Marking read locally changes it at once. - **`Channel.markReadViaReporter()`** marks the channel read the way the SDK does on its own, through `client.messageDeliveryReporter`. It calls your `markReadRequest` handler if you registered one, resets the count locally when read events are off and local counting is on, and calls `Channel.markRead()` otherwise. Use it when your UI marks a channel read. - **`Channel.markRead()`** always sends the request, even when you registered a handler. With `{ message_id }`, it marks the channel read up to that message. Use it inside a `markReadRequest` handler. It throws unless the channel is loaded, or restored from the offline database, and read events are on. - **`Channel.markReadLocally()`** resets the current user's count without a request, for channels whose unread messages are only counted locally. - **`Channel.markUnread({ message_id })`** marks the channel unread from that message. It takes `message_timestamp` instead of `message_id` too. Like `Channel.markRead()`, it throws when the channel isn't loaded or read events are off. ```ts await channel.markUnread({ message_id: messageId }); // read[ownUserId].first_unread_message_id is set when notification.mark_unread arrives ``` To change how the SDK marks a channel read, register a `markReadRequest` handler. `Channel.markReadViaReporter()` and the SDK's own marking use it. The handler receives the channel and the options, and returns the response, or `null` when it sent nothing: ```ts client.config.set({ channel: { requestHandlers: { markReadRequest: async ({ channel, options }) => { // Livestream channels are never marked read. if (channel.type === "livestream") return null; return await channel.markRead(options); }, }, }, }); ``` [Message operations](https://getstream.io/chat/docs/sdk/react-native/v10/state/writing-messages/message-operations/) explains request handlers. [What's optimistic and what isn't](https://getstream.io/chat/docs/sdk/react-native/v10/state/writing-messages/whats-optimistic-and-what-isnt/) lists when each read action shows. ## When the SDK marks a channel read `stream-chat` doesn't mark a channel read by itself. The SDK's components do, at these moments: - **`` mounts.** When the current user had unread messages in the channel as it mounted, `` marks it read once the channel has loaded. The list keeps showing where the unread messages start. Pass `markReadOnMount={false}` to leave the read state alone. - **A message arrives while the user is at the newest messages.** The channel's message list marks the channel read when a new message arrives while the app is in the foreground and the newest message is on screen, unless the user marked the channel unread. - **The user goes to the newest messages.** Pressing the scroll-to-bottom button in a channel, or closing the unread messages notification, marks the channel read. - **The connection recovers.** When `connection.recovered` arrives and the channel's list is at the newest messages, `` marks it read. A list that shows an older interval, with the newest messages not loaded, is left alone. [Connection](https://getstream.io/chat/docs/sdk/react-native/v10/state/connection/) explains the event. Each time, the SDK goes through `client.messageDeliveryReporter`, which uses your `markReadRequest` handler and sends at most one request a second per channel. When read events are off, it calls `Channel.markReadLocally()` instead, but only with `localUnreadCountEnabled` on (see below), and otherwise does nothing. The `markReadRequest` handler isn't called then. A thread list doesn't mark the channel read. `` activates its thread, and an active thread marks itself read, as [Read state in threads](#read-state-in-threads) explains. `useMarkRead(channel)` returns the function the SDK uses, for a component of your own that should mark the channel read the same way. By default it also clears the list's unread boundary, so the unread separator and the unread notification go away. Pass `{ updateChannelUnreadState: false }` to keep them: ```tsx import { Pressable, Text } from "react-native"; import { useChannel, useMarkRead } from "stream-chat-react-native"; export const MarkReadButton = () => { const channel = useChannel(); const markRead = useMarkRead(channel); return ( markRead()}> Mark as read ); }; ``` ## Turning read events off To turn read events off, turn off the channel type's `read_events` setting on the server. The user can then no longer mark the channel read, and nothing counts unread messages. `readEvents.enabled: false` in `client.config` does less. It only stops this client from marking channels read, and `Channel.markRead()` and `Channel.markUnread()` throw. The server and the client still count unread messages, so the user's count keeps going up. The client counts in channels where the current user has the `read-events` capability, which the server derives from the channel type, and the client setting doesn't remove it. Use it for a client that shouldn't mark anything read, such as a moderation tool: ```ts client.config.set({ channel: { readEvents: { enabled: false } } }); ``` `channel.config.readEvents.enabled` is `false` when the channel type's `read_events` is off on the server, or `readEvents.enabled` is `false` in `client.config`. A livestream channel type usually has `read_events` off on the server, so nothing counts unread messages. To count them anyway, turn on `localUnreadCountEnabled`. The client then counts new messages itself, and `Channel.markReadLocally()` resets the count. While read events are off, `Channel.markReadViaReporter()` and the SDK's own marking call it for you: ```ts client.config.set({ channel: { readEvents: { localUnreadCountEnabled: true } }, }); // The user has seen the newest messages. channel.markReadLocally(); ``` With offline support, the reset is saved in the offline database too. ## Read state in threads A thread keeps its own read state, in the `read` field of `thread.state`, one entry per participant. Its fields are named differently from a channel's: | Field | What it holds | | ---------------------- | --------------------------------------------------- | | `lastReadAt` | When the user last read the thread, in nanoseconds. | | `unreadMessageCount` | How many replies the user hasn't read. | | `lastReadMessageId` | The last reply the user read. | | `firstUnreadMessageId` | The reply the user marked the thread unread from. | | `user` | The user. | `thread.ownUnreadCount` is the current user's count. ```ts const ownUserId = client.userId; const unsubscribe = thread.state.subscribeWithSelector( ({ read }) => ({ unread: ownUserId ? (read[ownUserId]?.unreadMessageCount ?? 0) : 0, }), ({ unread }) => { console.log(`${unread} unread replies`); }, ); ``` What changes it: - a new reply: the author's entry goes to 0 unread, and every other entry gets 1 more, except the current user's while the thread is active; - `message.read` for the thread: that user's entry goes to 0 unread; - `notification.mark_unread` for the thread: the current user's entry takes the event's values. A thread counts every new reply from someone else as unread, except while the thread is active. The channel's other rules (silent, shadowed, muted author or channel, read events off) don't apply to threads. `Thread.markRead()` marks the thread read. It sends nothing when the current user has nothing unread, unless you pass `{ force: true }`. An active thread marks itself read whenever it has unread replies, at most once a second, through the thread's `markReadRequest` handler if one is registered. To mark a thread unread, call `Channel.markUnread({ thread_id: thread.id })`. Thread replies don't count toward the channel's unread count, and reading a thread doesn't change the channel's read state. The number of threads with unread replies is `unreadThreadCount` in `client.threads.state`, explained in [What channels and threads hold](https://getstream.io/chat/docs/sdk/react-native/v10/state/channels-and-threads/what-channels-and-threads-hold/#the-users-threads). ## Used in - [Read state, unread and receipts](https://getstream.io/chat/docs/sdk/react-native/v10/features/messaging/read-state-unread-and-receipts/) - [Channel lists](https://getstream.io/chat/docs/sdk/react-native/v10/features/channels/channel-lists/) - [Replies and threads](https://getstream.io/chat/docs/sdk/react-native/v10/features/messaging/replies-and-threads/) --- For the most recent version of this documentation, visit [https://getstream.io/chat/docs/sdk/react-native/v10/state/channels-and-threads/read-state-and-unread-counts/](https://getstream.io/chat/docs/sdk/react-native/v10/state/channels-and-threads/read-state-and-unread-counts/).