thread.

What thread. is

thread. is a browser extension that reads an open email conversation and drafts a reply for Gmail or Outlook. It uses the messages in the full thread as context, and you can provide three to five past emails to help shape the draft to your writing style. The site describes seven drafting modes, including quick replies, follow-ups, difficult conversations, cold outreach, meeting recaps, and versions with three alternatives. You can also use tone controls and custom instructions. With Reply & insert, the extension opens the reply box, places the draft above your signature, and leaves the cursor ready for review. Draft text appears as it is generated, one word at a time.

The extension is free, with no subscription from thread.; you bring an OpenAI API key and pay OpenAI directly for AI use. Email content, prompts, and an optional voice profile are sent from your browser to OpenAI when you request a draft. The maker says there is no server, user account, usage analytics, or telemetry. Your key, voice profile, templates, and panel preferences are stored in browser local storage.