Claude Duet: Anthropic's proactive agent built on Opus 5.5

On October 21, Anthropic unveiled Claude Duet, a proactive AI agent that reaches out to you on its own instead of waiting for a question. Duet runs on Opus 5.5, is in research preview, and for now is rolling out through a waitlist to Claude Pro and Max subscribers in the US.

What is Claude Duet?

The product page calls it “a proactive agent that understands what needs your attention”. The difference from regular Claude is simple: Claude waits for you to open a chat, while Duet comes to you with a morning brief and alerts.

According to the announcement, Duet:

1. sends a short brief every morning with the most important items from your connected apps,
2. checks them every few hours during the day (according to MacRumors) and only speaks up when something needs a response,
3. takes tasks by message, text or voice: from scheduling a meeting to building a dashboard, a forecast, a prototype or a web app,
4. flags important emails and calendar events, drafts replies, finds unpaid invoices and prepares payroll for review.

Interestingly, it all happens in one continuous thread rather than in separate chats. Duet uses the memory, skills and connectors you already have set up in your Claude account, so there’s very little to configure.

How does an agent work on its own cloud computer?

Duet works on its own cloud computer, so it keeps going after you close the app. According to 9to5Mac, it also has its own browser for sites that don’t have a connector, and it hands over finished files (presentations, financial models, dashboards) in the Make tab. Ongoing work shows up in the Tasks tab, and only you can mark a task as done.

Anthropic says there are more than 6,000 connectors and plugins. The page lists, among others, Gmail, Google Calendar, Slack, Notion, Stripe, QuickBooks, Docusign, HubSpot and Microsoft 365.

Will Duet do anything behind your back?

It shouldn’t. Before sending a message, making a payment, signing a document or deleting anything, Duet asks for permission. According to MacRumors, the agent can’t see passwords or account credentials, and every message is checked by a separate classifier and an extra system prompt that guards against leaking sensitive data.

Anthropic itself admits what doesn’t work well yet: Duet “may misread a thread or miscalibrate what’s urgent”, and it can miss something that arrives between checks.

Why is everyone talking about it?

Because it’s the third player in the race for proactive agents. Meta launched Muse on September 8, and OpenAI showed its Dots agent a few weeks before Duet (according to 9to5Google). The Duet page made the Hacker News front page, where it collected almost 300 points in a few hours.

Still, an agent with access to your email, calendar and payments is also a risk. I recently wrote about the Meta Muse leak, where shared conversations turned out to be the problem, and about the AI cyberattack on more than 100 companies. Duet’s permission model looks sensible, but the real test will come with actual users.

How to try Claude Duet

1. You need a Pro or Max plan and to be in the US. Team and Enterprise plans aren’t included for now.
2. Join the waitlist on the product page. Invites go out in waves.
3. Duet works as a separate iOS and Android app and in the browser at claude.ai.

You don’t pay extra for Duet. It draws on the same usage limits as the rest of Claude, and background checks and bigger tasks count against them too (9to5Mac quotes a warning that limits may run out “sooner than with chat alone”). If you already hit your Opus 5.5 limits now and then, keep that in mind ;)

FAQ

Is Claude Duet available outside the US?

Not yet. The research preview covers only Pro and Max subscribers in the US, and access is through a waitlist.

How much does Claude Duet cost?

There’s no separate price. Duet comes with the Pro and Max plans, but it uses up your plan’s limits, including while it works in the background.

How is Claude Duet different from regular Claude?

Regular Claude answers when you open a chat. Duet sends a morning brief and alerts on its own, works on its own cloud computer and keeps one continuous thread.

What model does Claude Duet run on?

Claude Opus 5.5.