How I built a no-code AI agent that generates and manages personalized marketing content across channels—on autopilot.

🤖 GrowthLoop AI: My Autonomous Marketing Assistant Built with n8n + OpenRouter

How I built a no-code AI agent that generates and manages personalized marketing content across channels—on autopilot.

🧠 TL;DR

As a solo creator working on products like Mentorpedia, itsweekend.wtf, and Foreplay, I often found myself stuck in the content hamster wheel. Every new feature, update, or launch needed:

• A tweet thread

• A LinkedIn post

• An email to my list

• And sometimes… a Medium blog

The problem?
Manual content creation doesn’t scale when you're doing everything else solo.

So I built GrowthLoop AI — a fully automated marketing assistant using n8n, OpenRouter, and free LLMs like Mistral, Claude Instant, and Gemini Pro. Now, every time I log a product update in Notion, it writes, formats, queues, and sends marketing-ready content across my stack.

Let’s break it down.

🧩 The Problem

"I just shipped something cool. Now I need to promote it."

But that meant:

• Writing thoughtful content for 3–4 platforms

• Maintaining a consistent tone and CTA

• Managing tools like Buffer, Sheets, and Notion

• Losing hours every week doing repetitive creative work

Even AI tools like ChatGPT were manual and non-integrated into my workflow.
So I asked:
"What if I could automate my entire content loop with one prompt and a push?"

💡 Introducing: GrowthLoop AI

A solo marketer’s dream agent that turns product updates into distribution-ready content using:

✅ n8n → Orchestration
✅ OpenRouter → LLM-based generation
✅ Notion → Input & storage
✅ Google Sheets or Buffer → Output queue
✅ Slack/WhatsApp → Previews & approvals

⚙️ The Full Workflow

Here’s exactly how it works:

🔁 Step 1: Trigger Input via Notion or Form

• I log a product update in a Notion database:

  • Title

  • What’s new?

  • Target audience (PMs, Students, Couples, etc.)

  • Product (Mentorpedia / Trippo / etc.)

  • Intent (educational, announcement, engagement)

🧰 Tool Used:

• n8n Notion Trigger — watches for new pages or updates

🧠 Step 2: LLM-Based Content Generation

Once the new entry is detected, n8n sends the data to an LLM via OpenRouter API.

Prompt Template (in n8n):

plaintextCopyEditYou are a creative content strategist. Based on the following product update, generate:

1. A LinkedIn post (max 600 characters)
2. A Twitter/X post (max 280 characters)
3. An email subject line + body copy
4. Optional: blog post intro paragraph

Product Update:
{{Notion.fields.What'sNew}}

Audience:
{{Notion.fields.Audience}}

Product Name:
{{Notion.fields.Product}}

Tone: Clear, helpful, and action-driven

🧰 Tools Used:

• n8n HTTP Request node

• OpenRouter API Key

• Model Used: Mistral 7B (free tier) OR Claude Instant (when tone is key)

📥 Step 3: Output to Google Sheets or Buffer

The LLM-generated copy is:

• Parsed into individual outputs (LinkedIn, Twitter, Email, etc.)

• Appended to a Google Sheet or

• Sent directly to Buffer as a scheduled post

• (Optional) Saved back to Notion for future reference

🧰 Tools Used:

• n8n Google Sheets node

• n8n HTTP Request to Buffer API

🔔 Step 4: Preview Notification via Slack or WhatsApp

Once everything is generated, n8n sends me a preview:

plaintextCopyEdit✅ Growth Content Ready!

📌 Product: Mentorpedia
🗒 LinkedIn: "We just launched a smarter way to onboard mentors…"
🐦 Tweet: "Students deserve real guidance. That’s why we built…"

👉 Approve to schedule: [Link]

🧰 Tools Used:

• n8n Webhook to WhatsApp Cloud API OR

• n8n Slack node with Webhook URL

🔄 Step 5: Optional Edits & Loop

If I don’t like a post, I can just edit the Notion row, and n8n regenerates the content via webhook trigger.

📈 Why This Works

BenefitResult⚡ SpeedFull campaign content in 1–2 mins✍️ ConsistencyAlways on-brand, audience-specific tone🧠 StrategyForces me to think in content formats🛠 TechnicalProves AI + automation + product thinking🎯 Real-worldUsed in Trippo, Mentorpedia, Foreplay launches

🛠 Tech Stack Summary

ToolUse Casen8nWorkflow automation engineOpenRouterLLM API gateway for Claude, Gemini, MistralNotionInput database & CMS for product updatesGoogle SheetsOutput repository (queue-style or tracker)Buffer APISocial media publishingSlack/WhatsAppPreviews & approvals

🧠 Learnings & Challenges

✅ What Went Well:

• API chaining in n8n is super intuitive

• Mistral (via OpenRouter) provides fast, usable copy

• Content personalization improves when tied to “intent” tag

⚠️ Challenges:

• Claude Instant handles tone better than Mistral for emotional posts

• Managing post length constraints across formats takes tuning

• Buffer API scheduling requires exact date formatting

🔮 Next Steps

• Add automatic content tagging via AI (e.g., for SEO or audience match)

• Integrate with Beehiiv or Mailchimp for newsletter delivery

• Track CTR and post engagement back in Notion to close the loop

• Build a Framer front-end as a UI wrapper

🧠 Final Thoughts

You don’t need a team to grow. You need workflows that think.

GrowthLoop AI is my way of scaling what I already do well—ship → share → learn → repeat—with the help of open AI and no-code tools.

🧩 Want to try the workflow or fork it?

Check out: (coming soon)

• My Notion template

• Workflow screenshots

• LinkedIn Post: How I built a solo AI growth engine