Skip to main content

Create curated newsletters from Reddit discussions with GPT-4o Mini and Gmail

Workflow preview

Create curated newsletters from Reddit discussions with GPT-4o Mini and Gmail preview
Open on n8n.io

Important notice

This workflow is provided as-is. Please review and test before using in production.

Overview

πŸ“° Reddit to Newsletter (Automated Curation with Open AI 4o Mini )

Turn the best posts from a subreddit into a ready-to-send HTML newsletter β€” no copy-pasting, no wasted time.
This workflow fetches new posts, filters by topic of interest, analyzes comments, summarizes insights, and composes a clean HTML email delivered straight to your inbox with Gmail.


πŸ’‘ What this workflow does

  • βœ… Fetches posts from your chosen subreddit (default: r/microsaas, sorted by β€œnew”)
  • πŸ† Selects the Top 10 by upvotes, comments, and recency
  • 🧭 Defines a topic of interest and runs a lightweight AI filter (true/false) without altering the original JSON
  • πŸ’¬ Pulls and flattens comments into a clean, structured list
  • 🧠 Summarizes each post + comments into main_post_summary, comment_insights, and key_learnings
  • ✍️ Generates a newsletter in HTML (not Markdown) with headline, outline, sections per post, quotes, and β€œby the numbers”
  • πŸ“€ Sends the HTML email via Gmail with subject β€œReddit Digest” (editable)

πŸ›  What you’ll need

  • πŸ”‘ Reddit OAuth2 connected in n8n
  • πŸ”‘ OpenAI API key (e.g., gpt-4o-mini) for filtering and summarization
  • πŸ”‘ Gmail OAuth2 to deliver the newsletter
  • 🧡 A target subreddit and a clearly defined topic of interest

🧩 How it works (high-level)

  1. Manual Trigger β†’ Get many posts (from subreddit)
  2. Select Top 10 (Code node, ranking by ups + comments + date)
  3. Set topic of interest β†’ AI filter β†’ String to JSON β†’ If topic of interest
  4. Loop Over Items for each valid post
  5. Fetch post comments β†’ Clean comments (Code) β†’ Merge comments β†’ Merge with post
  6. Summarize post + comments (AI) β†’ Merge summaries β†’ Create newsletter HTML
  7. Send Gmail message with the generated HTML

βš™οΈ Key fields to adjust

  • Subreddit name and β€œnew” filter in Get many posts
  • Ranking logic inside Top 10 Code node
  • Text inside Set topic of interest
  • Prompts for AI filter, Summarize, and Create newsletter (tone & structure)
  • Recipient & subject line in Send Gmail message

✨ Use cases

  • Weekly digest of your niche community
  • Podcast or newsletter prep with community insights
  • Monitoring specific themes (e.g., β€œhow to get first customers”) and delivering insights to a team or client

🧠 Tips & gotchas

  • ⏱️ Reddit API limits: tune batch size and rate if the subreddit is very active
  • 🧹 Robust JSON parsing: the String to JSON node handles clean, fenced, or escaped JSON; failures return error + raw for debugging
  • πŸ“¨ Email client quirks: test long newsletters; some clients clip lengthy HTML
  • πŸ’Έ AI cost: the two-step (summarization + HTML generation) improves quality but can be merged to reduce cost

🧭 Quick customization

  • Change microsaas to your target subreddit
  • Rewrite the topic of interest (e.g., β€œgrowth strategies”, β€œfundraising”, etc.)
  • Adapt the newsletter outline prompt for a different tone/format
  • Schedule with a Cron node for daily or weekly digests

πŸ“¬ Contact & Feedback

Need help tailoring this workflow to your stack?

πŸ“© [email protected]
🐦 @guanchehacker

If you’re building something more advanced with curation + AI (like turning the digest into a podcast or video), let’s connect β€” I may have the missing piece you need.