Anthropic opened a research preview of Claude Duet on October 21, 2026, placing a proactive agent built on Opus 5.5 inside Gmail, HubSpot, QuickBooks, Stripe, Shopify, Gusto, DocuSign, and the roughly 6,000-plus connectors already published in the Claude Marketplace. Access is waitlisted, US-only, and limited at launch to Pro and Max subscribers.

The product is being positioned as a direct response to Meta Muse and OpenAI Dots, both of which arrived with heavier distribution. Per CNBC, Mark Zuckerberg told investors in third-quarter remarks that more than 10 million people in the US and Canada have set up Muse in roughly six weeks. Anthropic has no comparable footprint and isn't pretending to. Duet enters as a Pro-and-Max tier feature with no general-availability date for the $20/month Pro plan Engadget flagged as the eventual on-ramp.

What Duet actually does is run quietly against a user's connected stack and prepare the work. "Each morning, it sends you a short brief on the most important items across your connected apps," Anthropic told The Verge. Behind the brief, the agent checks accounts every few hours rather than continuously, "because checking nonstop would use up your plan's limits much faster," the company told Engadget. Background activity meters against the same Pro and Max budgets that already fund Claude and Code sessions, which is the fine print worth reading twice.

The approval model is the actual product. Duet shows intended actions before executing them, blocks securities trading and inter-account money movement outright, and runs a classifier that keeps credit cards, government IDs, and health or financial details from leaving the thread. For a founder running sales alone, the practical shape is familiar: a HubSpot deal gone cold, drafted into a follow-up overnight; a Stripe invoice past due, ready to resend; a thread flagged as urgent, waiting for a tap. The work that used to require opening the CRM arrives pre-staged.

Anthropic concedes the obvious. The agent "can still misread a thread or miscalibrate what is urgent," per its own announcement, and personal errands like booking tickets remain weak. Team and Enterprise access is, in the company's phrasing, expected later.

The structural read is simpler than the launch suggests. Muse and Dots are competing on reach; Duet is competing on the surface area it already owns inside Claude's installed base of paying subscribers. The question isn't whether proactive agents work. It's whether owners will tolerate one that bills against the same meter running everything else.

Anthropic opens Claude Duet to a US waitlist, putting Opus 5.5 inside the apps owners already run

Sources