You've got an email you starred last week, a client who never replied, an invoice nobody's paid. You know someone should chase it, and every day you push it to tomorrow. That's exactly the gap Anthropic built Claude Duet, its new personal agent, to fill, but two people who tested it over the past few weeks found that how you set it up on day one decides whether it works, or becomes one more tool you forget to open.
Here's what you get: what Duet actually does with your email and calendar, four steps to set it up so it chases quiet emails without sending anything without you, a prompt based on Anthropic's own official example, and what two real tests found.
Start with the basics. Duet is currently a waitlist research preview, open only to Claude Pro and Max subscribers in the US. It checks your connected accounts every few hours, sends a short morning brief with what needs attention, and reads your email and calendar to build it. Anything that costs money or sends something on your behalf, an email, a payment, a signature, a deletion, waits for your approval. That's not a setting you have to find, it's the default Anthropic built in.
Step 1: give it one narrow job, not "manage my inbox"
Anthropic's own example is: check Stripe for unpaid invoices and draft reminder emails for me to approve. That's the right shape to start with, one task with a clear edge, not a general request to run your whole inbox. Duet also checks on its own which email threads have gone quiet without a reply and proposes a follow up, so that can be your second narrow job.
Step 2: keep the default, it drafts, you approve
Sending, paying, signing and deleting all wait for your approval before they happen, by default, not a setting you have to dig for. Keep it that way for at least the first few weeks, even if it feels slow. That's the difference between an agent that helps and one that surprises you on your account statement.
Step 3: set your own reminder frequency, don't trust the default
Claire Vo tested Duet on her inbox, Slack, sales pipeline and a Google Docs deck, and wrote about it for Lenny's Newsletter. She loved the design and how fast it pulled in her connected data, but after the first few tasks it stopped nudging her, and its quiet notifications weren't enough to keep it in her routine. She said she still forgot to use it. Tell it explicitly how many times a day to flag you about the narrow task you picked, and where, don't settle for the general morning brief.
Step 4: give it two weeks on the narrow job before you expand
Dan Shipper, at Every, used Duet for about two weeks and called it the first personal agent he'd call a pro tool. He found it good at sorting recurring topics into their own channels, tracking its own tasks, and keeping docs and dashboards updated. But he said its email drafts were weaker than a competing agent's. The lesson: trust it for sorting and follow up tracking, and read every email draft twice before you approve it, at least for the first two weeks.
That phrasing matters, because it gives Duet a clear edge, what to check, what to write, and when to stop and ask, instead of leaving it open territory it has to interpret on its own.
Wait, before you join the waitlist. Duet is only open in the US right now, to Pro and Max subscribers, and by design it never touches passwords or sign in tokens, with health or financial data sharing needing your explicit instruction. If you don't have access yet, these same four steps work on any AI agent already connected to your inbox, pick one narrow job, keep manual approval on every send, set your own reminder cadence, and give it two weeks before you expand it.
Next ten minutes: write down the one narrow job you'd want someone to chase for you this week, an invoice, a quiet thread, and open either the settings of whatever agent you already have connected, or Duet's waitlist, and write that instruction down before you open the tool.