Claude Duet: what Anthropic's proactive agent does, who can get it and what it means for apps

Claude Duet is a new app where Claude works as a proactive agent. Anthropic describes it as an agent that brings you what needs your attention, finishes the tasks you give it, keeps going while you are away and checks with you before it acts on your behalf. It launched on October 21, 2026 as a research preview, built for professionals and small business owners who have more on their plates than they can keep track of.

Duet runs on Claude Opus 5.5 on its own cloud computer with its own browser, so your laptop does not need to stay open. It uses the memory, skills and connected apps already on your Claude account, which leaves very little to set up, and you talk to it by text or voice in one ongoing thread rather than in separate chats.

Most of what Duet does happens in the background, and its work shows up in a few places.

During the research preview Duet is included with Claude Pro and Max at no extra cost. It is only open to US accounts, and you need an invitation from the waitlist, which Anthropic sends out in waves with no guaranteed date. Team and Enterprise plans are not included yet, though Anthropic says they will come later.

Duet draws on the same five-hour and weekly usage limits as your regular Claude chats, at the same rate. Its morning brief and check-ins count too, so you may hit your limits sooner, and big jobs such as financial models or decks use the most. To soften that, everyone admitted gets one full reset of their session and weekly limits, which can be used until November 30, 2026.

Joining takes a couple of minutes, but the email you use matters, because your access is tied to it.

Once you are in, Duet also works on the web at claude.ai. Joining the list does not guarantee access, and a Pro or Max subscription on its own does not skip the queue.

Duet can read and draft on its own, but before it sends a message, makes a payment, signs a document or deletes anything, it shows you what it plans to do and waits for your yes. If you cannot answer right away, it finishes the rest of the task and brings the approval back later. When it gives you a number or a summary, it tells you which email, file or spreadsheet it came from.

It can also shop. Purchases go through Stripe's Link or Shopify's Shop Pay, each one uses a one-time card that only works for that purchase, and Duet asks before every one. Some things stay off limits even with your approval, namely trading securities, moving money between accounts and getting into someone else's account.

On safety, a classifier checks every message and stops card numbers and government IDs from leaking. Passwords are typed into a separate form on your device and go straight to Duet's browser, so they never enter the chat. Anthropic also says the system was tested by its own security teams and an outside firm, and that a public bug bounty covers it.

Because this is a preview, there are limits worth knowing before you hand Duet real work.

Duet is the third big proactive agent in two months. Meta's Muse arrived on September 8 and, according to Sensor Tower, had passed 10.9 million downloads and 2.5 million daily users by mid-October, and OpenAI launched dots at DevDay on September 29. All three work in the background on their own cloud computer and ask before sensitive actions, but they are built for different people.

Duet's case is that it costs nothing extra if you already pay for Claude, runs on Opus 5.5 and asks before the widest set of actions. Its weak spots today are the waitlist, the US-only preview and the fact that you can only reach it in its own app.

Some of what comes next is confirmed and some is our own reading, and we will update this page as things change.

For a founder running a consumer app with a small team, Duet can work like a chief of staff. Connect Stripe, Gmail, your calendar and a CRM, and it can find unpaid invoices and draft the reminders, draft replies to the people who email you, put together a weekly revenue dashboard and build the forecast for your next investor update while you work on the product.

It also changes how people find apps. Duet browses the web on its own and can buy through Link and Shop Pay, and when an agent researches on someone's behalf, it reads your site, your store listing and your reviews, so clear pages that answer the obvious questions now matter to agents as much as to people. Anthropic also says Duet suggests plugins that fit a person's work, which makes a place in the Claude Marketplace worth having if your product can offer one.

What Duet does not do is grow your audience. It will not study what is getting views in your niche, make the videos people stop for on TikTok, Instagram and YouTube or post for you every day. That is the job of Viralway, the AI marketer built only for apps. It studies your app and your competitors, finds what is going viral, makes your videos, carousels and images, posts for you every day and learns from every view. Let Duet run the back office while Viralway brings in the users.