Threads

A thread is a set of replies to one message. Threads keep side conversations from crowding the main chat. For example, in a team channel, a question gets its answers in a thread instead of between unrelated messages.

Where this fits: your app already sends messages. A reply is just a normal message with replyTo set to the message it answers. There's nothing to create or set up first.

Reply and load a thread

In your app:

await chat.sendMessage({ text: 'This is a reply', replyTo: 'msg_3xR…' });
 
const thread = await chat.messages.thread('msg_3xR…'); // [root, reply, reply, ...] oldest first

const { send } = useMessages();
await send('This is a reply', { replyTo: 'msg_3xR…' });

await chat.send('This is a reply', replyTo: messageId);
final thread = await chat.thread(messageId); // oldest first

React Native uses the same chat.sendMessage() and chat.messages.thread() as web.

Thread replies are normal messages. They arrive as message events, and search, retention, moderation, and webhooks all work on them too. Check threadRootId on each message to decide where to show it: null means the main chat, anything else means "inside that thread".

Threads stay flat

A reply to a reply joins the same thread. Threads don't nest:

msg_A                    threadRootId: null
├── msg_B  replyTo: A    threadRootId: A
└── msg_C  replyTo: B    threadRootId: A     ← not B

• replyTo is the message you answered. threadRootId is the thread's first message.
• This keeps threads easy to follow and fast to load.
• chat.messages.thread() works with any message in the thread, not only the first one.

Long threads: paging

chat.messages.thread() returns the first page of a thread. For long threads, page through with threadPage() (at most 100 per page, oldest first):

let page = await chat.messages.threadPage('msg_3xR…', { limit: 50 });
render(page.data);
while (page.hasMore && page.nextCursor) {
  page = await chat.messages.threadPage('msg_3xR…', { cursor: page.nextCursor });
  render(page.data);
}

var page = await chat.threadPage(messageId, limit: 50);
while (page.hasMore) {
  page = await chat.threadPage(messageId, cursor: page.nextCursor);
}

In React, <Thread> pages for you. See UI components.

Reply counts

Root messages carry replyCount and lastReplyAt, so the main list can show "4 replies · last 2 min ago" without loading the thread:

if (message.replyCount) showThreadLink(message.id, message.replyCount, message.lastReplyAt);

Filtering history by thread

You can also use the threadRootId filter in Message History. chat.messages.thread() is a shortcut for that same filter.

Common mistakes

Next steps

• Message History
• Messages