Anthropic Launches Claude Duet: A Proactive AI Agent Preview for US Pro/Max Users

Anthropic launched a research preview of its new application, Claude Duet, on October 21, 2026. Unlike traditional passive chatbots, Claude Duet is designed as a "proactive agent" capable of initiating contact with users based on data from connected calendars, emails, and apps. It sends daily briefings and continues working on tasks even when the user steps away. Currently, access is limited to US Pro and Max subscribers who join a waitlist.

The core functionality of Claude Duet lies in its judgment. Built on the Claude Opus 5.5 model, it aims to help users prioritize what needs immediate attention versus what can wait. For instance, it sends a morning briefing across connected apps and proactively notifies users of urgent events like schedule conflicts or unpaid invoices. Users can delegate complex tasks ranging from scheduling meetings to building dashboards and creating financial forecasts.

To address the security and privacy risks inherent in proactive agents, Anthropic implemented multiple layers of protection. First, Claude Duet uses a dedicated classifier and safety system prompt to prevent the leakage of sensitive information such as credit card numbers and government IDs. Second, all critical actions—including sending messages, making payments, or signing documents—require explicit user approval before execution. Additionally, the system integrates defenses against prompt injection attacks and has undergone red teaming and external penetration testing.

Technically, Claude Duet operates within its own virtual machine and browser environment, allowing it to work continuously without relying on the user's device being online. It checks connected account statuses to trigger actions, though these checks occur every few hours rather than continuously to conserve resources. This design balances responsiveness with computational cost.