Automated Email Digest from Gmail to Slack with GPT-4o Summary
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Yusei Miyakoshi
Description
Who’s it for
Teams that start their day in Slack and want a concise, automated summary of yesterday’s emails—ops leads, PMs, founders, and anyone handling busy inboxes without writing code.
What it does / How it works
Runs every morning at 08:00 (cron 0 0 8 * * ), fetches all emails received *yesterday, and routes the result: if none were found, it posts a polite “no emails” notice; if emails exist, it aggregates them and asks an AI agent to produce a structured digest, then formats and posts to your chosen Slack channel. The flow uses **Gmail → If → Aggregate (Item Lists) → AI Agent (OpenRouter model with structured output) → Code (Slack formatter) → Slack. A set of sticky notes on the canvas explains each step and required inputs.
How to set up
Connect Gmail (OAuth2) and keep the default date window (yesterday → today at 00:00).
Connect Slack (OAuth2) and select your target channel.
Add OpenRouter credentials and pick a compact model (e.g., gpt-4o-mini).
Keep the provided structured-output schema and formatter code.
Adjust the schedule/timezone if needed (the fallback message includes an Asia/Tokyo example).
Paste this description into the yellow sticky note at the top of the canvas.
Requirements
Gmail & Slack accounts with appropriate scopes
OpenRouter API key stored in Credentials (no hard-coded keys)
n8n Cloud or self-host with LangChain agent nodes enabled
How to customize the workflow
Narrow Gmail results with label/search filters (e.g., from:, subject:).
Change the digest sections or tone in the AI Agent system prompt.
Swap the model for cost/quality needs and tweak temperature/max tokens.
Localize dates/timezones in the formatter code and Slack messages.
Branch the output to email, Google Docs, or Sheets for archival.
Security & publishing tips
Rename all nodes clearly, do not hardcode API keys, remove real channel IDs/emails before sharing, and group end-user variables in a Set (Fields) node. Keep the sticky notes—they’re mandatory for reviewers.