mattermost · larkox · Jun 6, 2026 · Jun 6, 2026 · Jun 8, 2026 · Jun 8, 2026
diff --git a/source/deployment-guide/mobile/mobile-troubleshooting.rst b/source/deployment-guide/mobile/mobile-troubleshooting.rst
@@ -166,3 +166,8 @@ If you did not receive a push notification when testing push notifications, use
   To conserve disk space, once your push notification issue is resolved, go to  **System Console > Environment > Logging > File Log Level**, then select **ERROR** to switch your logging detail level from **DEBUG** to **Errors Only**.
 
 If push notifications are not being delivered on the mobile device, confirm that you're logged in to the **Native** mobile app session through **Profile > Security > View and Log Out of Active Sessions**. Otherwise, the ``DeviceId`` won't get registered in the ``Sessions`` table and notifications won't be delivered.
+
+Integration posts (MM Blocks) do not render or respond
+-------------------------------------------------------
+
+If buttons, menus, or structured content from an integration post is missing or unresponsive on mobile, see the `MM Blocks reference <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_ in the developer documentation.
diff --git a/source/end-user-guide/access/client-availability.rst b/source/end-user-guide/access/client-availability.rst
@@ -147,6 +147,8 @@ Integrations
 +-----------------------------------------------------------------------------------------------------------------+-------------+-------------+-----------------+
 | `Outgoing webhooks <https://developers.mattermost.com/integrate/webhooks/outgoing/>`_                           | |checkmark| | |checkmark| | |checkmark|     |
 +-----------------------------------------------------------------------------------------------------------------+-------------+-------------+-----------------+
+| `MM Blocks <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_ [1]_                             | Conditional | Conditional | Conditional     |
++-----------------------------------------------------------------------------------------------------------------+-------------+-------------+-----------------+
 | `Message attachments <https://developers.mattermost.com/integrate/reference/message-attachments/>`_             | |checkmark| | |checkmark| | |checkmark|     |
 +-----------------------------------------------------------------------------------------------------------------+-------------+-------------+-----------------+
 | `Message buttons <https://developers.mattermost.com/integrate/plugins/interactive-messages/#message-buttons>`_  | |checkmark| | |checkmark| | |checkmark|     |
@@ -158,6 +160,8 @@ Integrations
 | `Right-hand sidebar <https://developers.mattermost.com/integrate/reference/server/server-reference/>`_          | |checkmark| | |checkmark| |                 |
 +-----------------------------------------------------------------------------------------------------------------+-------------+-------------+-----------------+
 
+.. [1] Requires ``MM_FEATUREFLAGS_MMBLOCKSENABLED`` to be enabled on the Mattermost server (defaults to ``true``). When set to ``false``, clients do not render native MM Blocks payloads and the server rejects MM Blocks action requests.
+
 Authentication
 ~~~~~~~~~~~~~~
 

diff --git a/source/end-user-guide/messaging-collaboration.rst b/source/end-user-guide/messaging-collaboration.rst
@@ -36,4 +36,4 @@ Getting Started
 * :doc:`Communicate with messages and threads </end-user-guide/collaborate/communicate-with-messages>` Learn how to get started collaborating within Mattermost channels.
 * :doc:`Collaborate within Microsoft Teams </end-user-guide/collaborate/collaborate-within-connected-microsoft-teams>` - Learn how to get started collaborating within Microsoft Teams.
 * :doc:`Keyboard shortcuts </end-user-guide/collaborate/keyboard-shortcuts>` - Make a more efficient use of your keyboard with keyboard shortcuts.
-* :doc:`Extend Mattermost with integrations </end-user-guide/collaborate/extend-mattermost-with-integrations>` - Find open source integrations to common tools in the Mattermost Marketplace.
+* :doc:`Extend Mattermost with integrations </end-user-guide/collaborate/extend-mattermost-with-integrations>` - Find open source integrations to common tools in the Mattermost Marketplace, and learn how to interact with rich integration messages.
diff --git a/source/integrations-guide/faq.rst b/source/integrations-guide/faq.rst
@@ -48,7 +48,18 @@ What are attachments?
 
 When "attachments" are mentioned in Mattermost integrations documentation, it refers to Slack's message attachments functionality. These "attachments" can be optionally added as an array in the data sent by an integration, and are used to customize the formatting of the message.
 
-Mattermost doesn't currently support the ability to attach files to a post made via webhook. You can use the API to attach files to a message if needed. 
+Mattermost doesn't currently support the ability to attach files to a post made via webhook. You can use the API to attach files to a message if needed.
+
+What are MM Blocks?
+--------------------
+
+MM Blocks are Mattermost's structured format for rich, interactive integration posts. Integrations can extend messages with text, images, buttons, menus, collapsible sections, and different layout options.
+
+Starting in Mattermost v11.10, MM Blocks are the recommended replacement for `message attachments <https://developers.mattermost.com/integrate/reference/message-attachments/>`_. They are the preferred way to create interactive messages for integrations such as :doc:`incoming webhooks </integrations-guide/incoming-webhooks>`, plugins, and bot accounts.
+
+Legacy message attachments and other interactive message formats continue to work; clients translate them into the MM Blocks format at render time. We encourage new and updated integrations to use MM Blocks instead.
+
+For payload structure, block types, action handling, migration guidance, and troubleshooting, see the `MM Blocks reference <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_ in the developer documentation.
 
 Where can I find existing integrations?
 ---------------------------------------

diff --git a/source/integrations-guide/incoming-webhooks.rst b/source/integrations-guide/incoming-webhooks.rst
@@ -8,6 +8,8 @@ Incoming Webhooks
 
 Send or receive real-time data from external tools. Webhooks require minimal coding and are easy to set up with virtually any tool or platform because they use lightweight HTTP POST requests with JSON payloads.
 
+For richly formatted interactive posts with buttons and menus, see :ref:`What are MM Blocks? <integrations-guide/faq:what are mm blocks?>`.
+
 Using incoming webhooks in Mattermost requires only basic setup. You generate a webhook URL using the Mattermost interface, then point another service to send data to that address. No coding is required if your external service triggering the events is able to send data via webhooks or HTTP POST requests, which most modern applications and platforms support. Setting this up usually involves pasting the Mattermost webhook URL into the service’s settings and selecting what type of events you want it to send. 
 
 Example Use Cases
@@ -107,7 +109,7 @@ The JSON payload can contain the following parameters:
      - Required
      - Description
    * - ``text``
-     - Yes (if ``attachments`` is not set)
+     - Yes (if ``props.mm_blocks`` is not set)
      - :doc:`Markdown-formatted </end-user-guide/collaborate/format-messages>` message. Use ``@<username>``, ``@channel``, and ``@here`` for notifications.
    * - ``channel``
      - No
@@ -121,15 +123,12 @@ The JSON payload can contain the following parameters:
    * - ``icon_emoji``
      - No
      - Overrides the ``icon_url`` with an emoji. Use the emoji name (e.g., ``:tada:``). The :ref:`Enable integrations to override profile picture icons <administration-guide/configure/integrations-configuration-settings:enable integrations to override profile picture icons>` setting must be enabled.
-   * - ``attachments``
-     - Yes (if ``text`` is not set)
-     - An array of `message attachment <https://developers.mattermost.com/integrate/reference/message-attachments/>`_ objects for richer formatting.
    * - ``type``
      - No
      - Sets the post type, mainly for use by plugins. If set, must begin with ``custom_``.
    * - ``props``
      - No
-     - A JSON object for storing metadata. The ``card`` property can be used to display extra Markdown-formatted text in the post's info panel (RHS). This is available in Mattermost v5.14 and later, and is not yet supported on mobile.
+     - A JSON object for storing metadata. Use `MM Blocks <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_ for rich, interactive content. The ``card`` property can be used to display extra Markdown-formatted text in the post's info panel (RHS). This is available in Mattermost v5.14 and later, and is not yet supported on mobile.
    * - ``priority``
      - No
      - Sets the priority of the message. See `message priorities <https://developers.mattermost.com/integrate/reference/message-priority/>`_.
@@ -224,8 +223,7 @@ Do More with Incoming Webhooks
 
 Transform basic message posts into rich, interactive notifications by including buttons, menus, and other interactive elements in your webhook messages, making them more engaging and useful for your team.
 
-- `Message Attachments <https://developers.mattermost.com/integrate/reference/message-attachments/>`_: Present rich, structured summaries such as status, priority, fields, links, or images for faster triage and comprehension. (Slack‑compatible schema.)
-- `Interactive Messages <https://developers.mattermost.com/integrate/plugins/interactive-messages>`_: Make notifications actionable with buttons or menus such as Acknowledge, Assign, or Escalate that enable an immediate user response without switching tools or context.
+- `MM Blocks <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_: Create structured, interactive posts with text, images, buttons, and menus.
 - `Interactive Dialogs <https://developers.mattermost.com/integrate/plugins/interactive-dialogs/>`_: Guide users to successful outcomes when interactions need structured input or confirmation (for example, “Acknowledge with note” or “Assign to user”). Improve data quality with required fields, minimum/maximum input lengths, server‑driven user/channel pickers, validated defaults, inline field errors, placeholders, and help text that help users enter the right data the first time.
 - `Message Priority <https://developers.mattermost.com/integrate/reference/message-priority/>`_: Set ``priority`` to elevate critical posts and optionally request acknowledgements or persistent notifications.
 

diff --git a/source/integrations-guide/integrations-guide-index.rst b/source/integrations-guide/integrations-guide-index.rst
@@ -88,7 +88,7 @@ Incoming Webhooks
 
 :doc:`Incoming webhooks </integrations-guide/incoming-webhooks>` allow external applications to post messages into Mattermost channels and direct messages. They are a simple way to receive notifications and data from other services in real-time and require only basic setup.
 
-Additionally, Mattermost webhook payloads are :ref:`fully compatible <integrations-guide/incoming-webhooks:slack compatibility>` with Slack’s webhook format to make migration easier.
+Additionally, Mattermost webhook payloads are :ref:`fully compatible <integrations-guide/incoming-webhooks:slack compatibility>` with Slack’s webhook format to make migration easier. For new interactive content, use `MM Blocks <https://developers.mattermost.com/integrate/reference/mm-blocks/>`_ instead of message attachments.
 
 Outgoing Webhooks
 ^^^^^^^^^^^^^^^^^^