Substack Newsletter Summariser

Too much good content. Too little time.

I used to keep tabs on ~10 Substack newsletters, all focused on product strategy, tech policy, and AI. But every week, I’d fall behind and then forget what I’d read.

So I built a system.

🎯 Objective
To turn information overload into a structured daily insight loop — surfacing only what’s relevant to my work, without the inbox clutter.

🧠 What it does
• Pulls newsletter emails via Gmail API
• Scores each based on product-relevance using prompt logic
• Summarizes key insights with GPT
• Sends me a daily digest
• Marks the original emails as read

🛠️ Technical stack
n8n · Gmail API · OpenAI GPT · Conditional logic · Error fallback

N8N Flow

n8n workflow summarising Substack newsletters

Summary Email

Summary email sample
© 2025 Sena Lim