Reply Radar

Overview

Important emails go unanswered all the time, not because people don't care, but because following up requires remembering to follow up. Reply Radar exists to remove that memory step entirely.

Role: Designer and full-stack engineer. Started: 2026, still actively building.

The Problem

The usual fix is a reminder app or a note to "circle back Friday," which works until the week gets busy and Friday quietly becomes never. Nobody wants another inbox to manage just to manage their inbox.

The fix had to require zero new habits. If it needs you to open a dashboard and set a reminder, you've already lost the person it's meant to help.

Approach

CC Reply Radar on any email that needs a response. It watches the thread, and if no reply lands within your chosen window, it drafts a follow-up in your voice and gets it in front of you to send.

No new inbox, no dashboard to check daily, no manual reminders. The only new behavior is one extra address in the CC field.

Tech Stack

Next.js Supabase Resend Cursor Claude Code

Next.js and Supabase run the app and thread-tracking logic, Resend sends the drafted follow-ups, and Cursor and Claude Code did most of the heavy lifting getting it built fast.

What's Next

Thread tracking and drafting both work end to end. Next up is tone-matching follow-ups more closely to your own writing style, and support for shared team inboxes.