--- a/doc/index.rst	Tue May 06 00:40:07 2025 +0200
+++ b/doc/index.rst	Tue May 06 00:40:53 2025 +0200
@@ -22,6 +22,7 @@
    :caption: Contents:
 
    installation.rst
+   user/chat.rst
    user/calls.rst
    web_framework/quick_start.rst
    web_framework/css_framework.rst

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/user/chat.rst	Tue May 06 00:40:53 2025 +0200
@@ -0,0 +1,36 @@
+=================
+Instant Messaging
+=================
+
+You can find the instant messaging feature on the **Chat** tab. Libervia's chat
+functionality supports a wide range of use cases, from professional collaboration to
+personal communication.
+
+Accessing the Chat Feature
+--------------------------
+
+1. Navigate to the main menu.
+2. Select the **Chat** option.
+
+Panels
+------
+
+There are three main panels for managing chats (not all may be visible simultaneously):
+
+- **Left panel**: Displays current group chats and direct conversations. You can also
+  start a new chat from this panel.
+- **Main panel**: Shows the active conversation.
+- **Right panel**: Provides information about the current discussion, such as participants
+  in a chat room.
+
+Threads and Replies
+-------------------
+
+In a message, you'll see a **"Reply"** button represented by a left-pointing arrow. Click
+it to reply to a specific message. This action creates a thread, which functions as a
+focused discussion within the main conversation or a series of replies on the same topic.
+
+When a thread exists, a chat bubble icon with three dots will appear in the message
+header, next to the timestamp. Hovering over this icon highlights all messages in the
+thread. Clicking it opens a **thread panel** containing all messages from that thread.
+Messages written in this panel will be posted as replies to the thread.