UX Spec: Managed channel categories - Phase 1 MVF

1. Overview

1.1 Problem Statement

Mattermost's sidebar has no shared management over channel organization and categorization, forcing every user in command-and-control environments to self-organize channels—resulting in critical channels being buried in ad-hoc manual groupings.

Multiple defense deployments have resorted to fragile plugin workarounds that programmatically manipulate individual user sidebar preferences, creating maintenance burden and no enforcement of consistent organizational structure.

1.2 Feature Summary

Managed channel categories introduces a parallel, controlled category mechanism for Mattermost channels.

Channel Admins will be able to assign their channels to managed categories they are a part of and/or create new managed categories for their channels.
These managed categories appear at fixed positions at the top of every team member's sidebar (above favorites and personal categories), are visually distinguished by a differentiated icon, and are locked against user modification or drag-and-drop. End users cannot rename, reorder, delete, or drag channels out of their categories.
In order to see a managed category in the sidebar, you must be a member of a channel that is in the category
Users retain full control of their existing personal categories which show below the managed categories.
The feature is team-scoped, gated behind an Enterprise license and a system-level feature flag. A team-level toggle may follow in a subsequent version.
A channel maps to at most one managed category. Managed categories are visually and behaviorally distinct from personal categories.

1.3 Scope

In Scope (MVF):

Team admins do not have any special admin previleges beyond what their existing channel membership grants them
Channel Admins can:
- Create new managed categories via new channel modal or channel settings modal for existing channels
- Assign a channel to existing managed categories via new channel modal or channel settings modal
- Move channels they have ownership over to managed categories
- Only assign their channels to existing categories they already have in their sidebar or create new ones. This is to limit visibility of sensitive categories.
Sidebar rendering of managed categories with differentiated icon, alphabetical sort order, and locked behavior
Favorites: Channels in managed categories cannot be favorited in the MVF.
Unreads filter or unread grouping at top of LHS: behaves as it does today.
Per-category channel sort (Alphabetically, Recently created, Recent activity)
Team-level toggle + system-level feature flag
Enterprise license gating
Mobile parity for end-user sidebar and Channel Admin flows
Audit logging for all category and mapping operations
Plugin API for category management

Explicitly Out of Scope for MVF:

Team admin settings UI for channel categories to re-order, edit, delete – Reason: not important to initial requirements
Category ordering via drag-to-reorder - descoped due to implementation decision on categories as a simple string prop on a channel
Renaming a category - descoped due to implementation decision. Rename only by creating a new category.
Channel drag and drop in to and out of managed categories - descoped due to implementation decision on categories as a simple string prop on a channel
AllowOnlyAdminSidebarCategories -- deferred to later decision
Nested categories (sub-categories) -- Reason: Flat list confirmed for MVF
Bulk channel assignment to categories -- Reason: Fast-follow
System Console category management page -- Reason: not system admin managed
Cross-team category synchronization -- Reason: Categories are team-scoped
Category-level notification overrides (e.g. muting category) -- Reason: Not technically feasible due to implementation decision on categories as a simple string prop on a channel
ABAC-based category visibility restrictions -- Reason: Simplified model adopted
Mobile Team Admin management interface -- Reason: no team admin management in MVF

2. Configuration UX

2.1 Feature Flag

For the MVF, an experimental settings is required to enable this feature system wide. This config setting will be available initially in the System Console > Site Configuration > Users and Teams page.

< Enterprise

Additionally, this feature will only be available for licensed servers with Enterprise and above.

In subsequent releases, category management can be done in this view as well. See Section 4.

2.2 Channel Settings Modal

If this feature is enabled, a "Managed category" input field appears in the Info tab in the Channel Settings Modal.

The dropdown lists all managed categories that the channel admin has visibility of. In other words, we will only show categories the Channel Admin already has a channel in.

Adding a new category

In the same finput field, typing a new name (min. 2 characters) that doesn't match an existing category surfaces a "Create new category: [name]" option. Selecting it stages the new category — it's created on save, not immediately.

A clear (X) button removes the mapping. The channel returns to the user's personal CHANNELS section.

Removing from a category

When editing a channel, it can be removed from a Managed Category by clicking the clear button x on the right side of the input. This will move it out of the managed category and in to the default Channels category.

2.4 New Channel Modal

Users can also choose the managed category from the New Channel Modal. This field behaves the same in this context as it does in the Channel Settings modal described above.

3. End User: Managed Categories in Sidebar

3.1 Viewing Managed Categories in the Sidebar

Managed categories display at the top of the channel list (below Threads/Drafts) and are fixed in this position.

For the MVF, managed categories display in alphabetical order only.
Channels within each category are sorted alphabetically only.
Managed categories are indicated by a folder icon, existing personal categories do not have the folder.
Users only see a managed category if they can access at least one channel mapped to that category (read-only users). Otherwise, the category is hidden from their view.

3.2 Collapse/Expand Managed Category

Managed categories adopt the same collapsing/expanding behavior. The collapsed state is ephemeral for managed categories.

3.3 Favoriting a Channel from Managed Category

In the MVF, channels that are within a managed category cannot be favorited.

3.4 Blocking drag and drop for managed categories

Drag-and-drop:

Dragging a channel from managed to personal category: rejected and cannot be dragged. No valid drop zone highlights. Tooltip: "This channel is in a managed category, you do not have permission to move it out."
Dragging a managed category header: not initiated. No drag handle visible for non-admin users. A tooltip displays “This is a managed category. Drag and drop is not permitted.”

3.5 Sidebar Context menu for managed categories

Managed categories will not have a context menu.

3.6 Sidebar Context menu for channels within managed categories

For channels that are within a manged category, the context menu shows as follows:

The Favorite option is greyed out with a tooltip.
If user is a Channel Admin for the channel, the Move to option is available. If they chose this, they will be presented with a confirmation modal to warn them they will be moving it out of the managed category.
- In the Move to submenu, we group ‘Managed categories' and ‘Your categories’

If moving a channel out of a managed category in to a personal category, users are warned with a confirmation modal.
If the user is not a channel admin, the Move to option is disabled with a tooltip on hover.

3.7 Category ownership and permissions

Categories do not have any ownership or permission aspects. They are simply strings added as channels props. Renaming a category can only be done by removing the category and adding a newly named one.

Mobile UX

Display-only for MVF

For the MVF, we’ll start by only displaying managed categories with their differentiated icon on the home screen in the identical position as the web/desktop client. Managed categories can be collapsed/expanded on mobile as well.