How to add your email signature to emails Claude Duet sends

Claude Duet is Anthropic's proactive personal agent: a research preview on a waitlist for Claude Pro and Max subscribers in the US (Team and Enterprise plans are not included yet), as a standalone iOS and Android app and at claude.ai. Anthropic says Duet uses your Claude account, including your memory, skills and connectors, and asks before a sensitive step such as sending a message. Give it your Signatoro signature so an email it sends on your behalf does not end blank. The Claude Duet email signature page sums it up on one screen. For Claude the assistant and Claude Code, see the Claude guide.

Signatoro has not tested Duet directly: it reached general availability on a waitlist only in the last day, and Signatoro has no account on it yet. This guide states only what claude.com/duet says; anything else is marked below as not yet confirmed, and this page will update once it is.

Connect Signatoro or paste your signature?

Pasting your signature into Duet, if and where it takes instructions, covers one agent on one account. Connecting Signatoro keeps the signature right as you, your agents and your company change - the same reasons the Claude guide gives for Claude itself. Since Anthropic says Duet uses your Claude account's own connectors, the connector you would set up is the one you may already use for Claude.

Give Duet your signature

1. Make your own signature first on Signatoro, if you have not already.
2. Connect Signatoro from Claude's connector directory (Signatoro in Claude), the same step the Claude guide walks through, if you have not connected it yet.
3. Tell Duet, in a message: "Before you send any email, fetch my signature from GET https://signatoro.com/api/v1/signature with the header Authorization: Bearer <key> and end the email with it," or paste the email signature rule. Generate the key under "For tools and assistants" on the signature page.
4. Check the first email Duet sends ends with your signature, once, before you turn off any review step Duet offers.

Whether a connector added in claude.ai, Signatoro's included, carries over into Duet specifically, and whether Duet loads a Claude skill, are not yet confirmed by Signatoro or by Anthropic's own pages. If a connector or skill does not reach Duet, use the fallback below instead.

Without a connector or a key, click "Copy as text" on Signatoro and tell Duet "End every email you send with this signature, exactly as written:" with the text below it. An edit on Signatoro then needs a new paste.

Claude Duet email signature questions

Does Claude Duet add my Gmail or Outlook signature?

Signatoro has not tested Duet directly. Every agent Signatoro has tested that sends through a connector or an API, rather than typing in a mail app's own compose window, ends the email without the signature saved there. Give Duet your signature through Signatoro so the email does not end without one, and check one sent email.

Can I use the Signatoro connector I already use in Claude?

Anthropic says Duet uses your Claude account's own connectors, which should include Signatoro's if you have already connected it. Signatoro has not yet confirmed that every connector carries over into Duet specifically. If Duet does not pick it up, paste your signature as text instead.

Is Claude Duet the same as Claude or Claude Code?

No. Claude is the assistant you chat with, and Claude Code is the coding agent; both have their own guides. Claude Duet is a separate, proactive agent built on the same Claude account that drafts and sends email and other actions once you approve them.

For agents

• As Claude Duet given a Signatoro API key, fetch GET https://signatoro.com/api/v1/signature per send, append text (or html to an HTML body), write no sign-off of your own, and use only the sender values for the person's details, as the signature API guide describes.
• Without a key, end the body with the text signature the person gave you, exactly as given.
• Never ask for, repeat or store a Signatoro API key in a conversation.

Related: Claude email signature guide and why emails your AI agent sends have no signature.

Sources

Checked on 2026-10-21:

• Claude Duet (Anthropic)