Chat
Channels and direct messages are where you, your team, and your customers communicate.
Starter documentation. Features and account details may differ from this deployment.
Open Chat in the sidebar, or press g + c, to see your channels and direct messages.
The review notes are in the doc. Can someone take a look?
I'll take the checklist and post it here.
Let's keep the thread in #design.
Anyone can be added to a channel by entering their email, even if they're not on your team. People without a Mosaic account receive an email telling them about their channel notifications.
You can have an empty channel with just yourself, or add team members for a collaborative channel.
Channel types
Mosaic has two visibility levels for channels:
Team channels
Team channels are visible to everyone on your team. Any team member can discover and join them. When you create a team channel, you can enable Automatically add teammates to add all current and future team members to the channel.
Use team channels for company-wide announcements, department discussions, or any conversation the whole team should be able to find.
Private channels
Private channels are only visible to the people you add. They don't appear in search or discovery for non-members. Use private channels for sensitive discussions or conversations with people outside your team.
Message history
When someone joins a channel, they see the full message history from the beginning — not just messages sent after they joined. This applies to both team and private channels.
Agents in channels
You can also mention @Mosaic to call an agent into the channel. @Mosaic can summarize previous discussions, answer workspace questions, and more.
Mention an agent you created the same way, with its @tag. Open Settings → Agents and click Add agent. A Private agent can be mentioned inside of a team channel only by the owner. A Team agent can be mentioned by anyone on the team.
In Settings → Agents, Connect Cursor lets you mention @Cursor on your Cursor subscription. Bring your own agent pairs Claude Code, Codex, or another local agent through Mosaicd. See Bring your own agent.
@mention a coding agent in the channel and it opens a session in the thread. When that session opens a pull request, the message links to it.
@Cursor, the signup button is too small on mobile. Open a pull request.
Message Features
Rich Text Editing
Compose messages using Mosaic's unified rich text editor:
- Formatting: Bold, italic, code blocks, lists
- @mentions: Reference users, documents, tasks, files, and more
- Snippets: Type ; to insert a saved snippet
- Attachments: Add files, images, and media
- Markdown: Full markdown support for quick formatting
Message actions
Hover over any message on desktop to reveal its action menu. Alongside reactions and replies, you can:
- Task — create a task from the message
- Chat with Agent — start an agent chat with the message
- Copy Link — copy a link straight to that message so you can paste it into a doc, task, or another channel
- Copy Text — copy the message's text to your clipboard
- Edit — change a message you sent
- Delete — remove a message you sent, or a message from a bot
On mobile, long-press a message to open the same menu. Task is Create task, and Chat with Agent is Ask Mosaic.
Thread Replies
Keep conversations organized by replying in threads:
- Click on any message to view or start a thread
- Thread replies appear indented under the parent message
- Thread indicators show when new replies are added
Threads help keep channels clean by organizing side conversations and reducing notification noise.
@Linking System
Mention an entity in a channel and it is shared with the channel participants. The mention also leaves a link you can trace back: the entity shows where it was referenced.
Messages support bidirectional @links to everything in your workspace:
Type @
Start typing @ to open the mentions menu
Select an item
Choose from documents, tasks, emails, files, users, companies, calls or other channels. Mentioning one shares its permissions with the channel participants.
Create the link
The mention creates a bidirectional reference you can trace back later
What You Can @Mention
- Users: Notify team members (
@username) - Documents: Reference notes, wikis, and collaborative docs
- Tasks: Link to specific tasks or projects
- Files: Reference PDFs, images, videos, and other files
- Emails: Link to email threads
- Channels: Reference other channels or conversations
- Dates: Create date references (
@tomorrow,@next week) - Groups: Mention groups like
@hereor@team
Attachments
Share files and media in messages:
- Drag and drop: Drop files directly into the message composer
- File picker: Browse and select from your storage
- Inline previews: Images and supported files show inline previews
Attachments shared in channels are automatically imported to Mosaic's file storage, making them searchable and accessible from anywhere.
Participant Management
Manage channel membership:
- Add or remove participants
- View all channel members
- See participant status and presence
Best Practices
- Use channels to organize conversations by topic or project
- @mention documents and tasks to create traceable references
- Use threads for side conversations to keep the main channel clean
- React with emoji instead of sending "thanks" messages
- Edit messages to fix mistakes rather than sending corrections