The assistant

A thread is a conversation with an agent. Matter runs agents on your Macs through your own ChatGPT or Claude subscription. Threads are private; a teammate can only open one read-only, when it’s linked to a task they can see.

Start a thread

• On Home, type in the box under the greeting and send.
• In the sidebar, click New thread (the pen) in a Threads header, or the + beside a space and choose Thread.
• Anywhere, press ⌘N.

Before you send, the space chip under the composer sets the thread’s space. Choose None for a thread of your own; it’s listed under Threads at the top of the sidebar. Right-click a thread in the sidebar to Pin, Rename, Archive or Delete it.

Connect ChatGPT or Claude

Matter has two backends, ChatGPT (OpenAI) and Claude (Anthropic). Connect one during setup or from the composer: until a backend is ready, the send button shows the next step, such as Connect a model provider, Install Claude Code or Sign in to Claude. You finish signing in in your browser. If you already use Claude Code or Codex on your Mac, the button may read Connect Claude or Connect ChatGPT, which reuses that sign-in.

You can add more than one account per backend. Settings > Devices lists each Mac’s backends and accounts, with Use for chats, Sign out and Remove account.

Choose a model

The menu beside the send button shows the model and effort. It has Device, Model, Account, Effort (how much the model reasons) and, for models that offer it, Speed (Standard or Fast).

A change applies from your next message, even mid-thread. Choosing a model for a new thread also sets your Default model in Settings > General. Hover the ring beside the menu to see how full the context window is.

Write a message

• Attach files with the paperclip, or paste or drop them: images, PDFs and text files up to 20 MB.
• Type @ to mention a doc, task, table, row or person.
• Type / at the start for the backend’s commands and skills.
• Click Dictate (the microphone) or hold Caps Lock to talk.

While the agent works, a new message steers the current turn or waits in a queue, as Follow-up behavior in Settings > General says; ⌘↵ does the other, by default. Stop ends the turn.

Hover a message to Copy it. Edit on your message rewinds the thread to it and runs it again. Fork on a reply starts a new thread from that point.

Device and folder

Each thread runs on one Mac, its host, picked in Device. If the host goes offline, messages wait for it, or you can Move to this device. The conversation moves; the agent’s earlier internal reasoning doesn’t.

A thread starts in its space’s folder on the host, set from the space chip with Choose folder. Without one, it uses your Default folder from Settings > General, then your home folder.

When the folder is a git repository, a branch chip appears. Before you send, pick a branch, Create branch, or turn on New worktree to work in a separate checkout. Once the thread starts, the chip shows its changes. Commit and Create pull request hand the job to the agent, which writes the message; Sync pulls and pushes the branch.

Side chats

To ask about a thread without adding to it, type /btw and a question, or press ⌘;. The agent answers in a Side chat card, seeing the conversation so far. Side chats aren’t saved; they last until you Clear them or close the window. They work on the Mac that runs the thread, after its first reply.

Subagents

An agent can hand parts of a job to subagents. Each shows as a card in the reply, and a bar above the composer counts the ones running. Click one to read its work in the side panel. To redirect a subagent, message the main thread.

When the agent needs you

A blocked agent asks you. The ask replaces the composer and shows on Home under Action Requested. It can be a question with suggested answers (the first is Recommended), a confirmation (Done), an app to connect, or files to upload (Choose files). You can also write your own answer, Skip, or dismiss it.

Agents can suggest follow-up tasks above the composer: Save creates the task, and Start creates it and starts it in a new thread. Docs, tasks and routines a turn creates appear as cards at the end of the reply.

What agents can do in Matter

Agents work in Matter with its own tools, and with your access. They can:

• find their way around the workspace and its spaces, and search anything in it;
• create, update, plan and delete tasks, edit boards’ fields, and post progress notes on tasks;
• build tables, and read and write their rows;
• read, write, move, upload and download docs and files, and draw on canvases;
• start other threads, message and watch them, and stop the ones they started;
• create and change your routines;
• keep your brief current;
• read and write your notes, and keep their memory of your work (see Notes and memory);
• use your connected apps, such as email;
• look after Matter apps: list their versions, roll back, rename, move and archive them;
• ask you questions, and suggest tasks.

With browser or computer use on, agents can also drive a browser and Mac apps. See Browser and computer use.