Send and read messages

This article shows how to send messages to a room and read its history with the client SDK. From your server, you can also read, edit, and delete messages with the REST API.

The client SDK snippets assume you already have a connected client. See Get started for how to connect.

Subscribe to messages

Handle the message event to receive messages in real time. It fires for new messages in the rooms you belong to, including the ones you send.

client.on("message", (event) => {
  const message = event.message;
  console.log(`[${event.roomId}] ${message.createdBy}: ${message.content.text}`);
});

The handler only delivers messages that arrive after you subscribe, so register it before you send. It doesn't replay earlier messages; to load those, read the message history.

Send a message

Send a text message to a room with sendToRoom. It returns the new message's ID. The max size of the message content is 64KB.

const result = await client.sendToRoom(room.roomId, "Hello, team!");
console.log(`Sent message ${result.messageId}`);

Read message history

Read a room's past messages with listRoomMessages. It returns an async iterator that pages through the room's history for you.

for await (const message of client.listRoomMessages(room.roomId)) {
  console.log(`${message.createdBy}: ${message.content.text}`);
}

To control paging yourself, for example to load more messages as the user scrolls, use byPage. Each page is an array of messages.

const pages = client.listRoomMessages(room.roomId).byPage({ maxPageSize: 50 });
for await (const page of pages) {
  for (const message of page) {
    console.log(`${message.createdBy}: ${message.content.text}`);
  }
}

To read a range, pass startId or endId. Both are message IDs.

const messages = client.listRoomMessages(room.roomId, { startId: "<message-id>" });

Manage messages from your server

Your server can work with message history through the Chat REST API, for moderation, auditing, and other backend tasks. It can read, edit, and delete messages.

Note

Messages belong to a conversation (each room has a default one), so the message endpoints take a conversation ID rather than a room ID. Get a room's default conversation from its defaultConversation property, returned when you get the room through the REST API.

For the endpoints, request formats, and authentication, see Chat SDKs and REST API.

Next steps

Chat SDKs and REST API