Draft follow-up email reminders in Gmail with Anthropic Claude

Quick overview

This workflow runs every weekday morning to find Gmail threads where your last sent message has not been replied to, generates short follow-up drafts with Anthropic Claude, saves each as a Gmail draft in the original thread, and emails you a digest of the queued follow-ups.

How it works

1. Runs every weekday morning on a schedule.
2. Fetches messages you sent in Gmail and messages you received over the same look-back window.
3. Compares messages by Gmail thread to keep only threads where the newest message is still yours, excluding automated senders by keyword and limiting the list to a maximum count.
4. Filters the remaining threads to only those silent for between the configured minimum and maximum number of days.
5. Sends the thread context (recipient, subject, and last-sent snippet) to the Anthropic Messages API (Claude) to generate a prioritized follow-up draft for each thread.
6. Saves each generated follow-up as a Gmail draft reply on the original thread and sends you a plain-text digest email listing the drafts sorted by priority.

Setup

1. Connect your Gmail credentials for reading sent/received messages, creating drafts, and sending the digest email.
2. Provide an Anthropic API key (set ANTHROPIC_API_KEY in your n8n environment) to allow the HTTP request to Claude.
3. Update the configuration values for look-back days, silence window (min/max), excluded sender keywords, your name, tone, digest recipient, and maximum threads to process.