Auto-Generate Platform-Specific Social Media Posts from YouTube Videos using n8n, Dumpling AI, and GPT

This tutorial explains how to set up an automation in n8n that takes a topic from Google Sheets, finds a relevant YouTube video, extracts its transcript, generates platform-specific posts for Instagram, Facebook, and LinkedIn, creates matching AI images, and saves everything back to Google Sheets.

This system is perfect for content creators, marketers, and agencies that want to repurpose YouTube videos without spending hours writing captions and designing posts manually.

🌟 Key Benefits of this Automation

Saves hours of manual work by automating search, writing, and design
Keeps content fresh and consistent through scheduled runs
Maintains platform authenticity with posts tailored for each social media channel
Ensures accuracy and quality by using GPT and Dumpling AI for smart selection and creation
Organizes everything neatly inside Google Sheets for review and scheduling

🧭 Workflow Overview

Below is the full sequence of the automation:

Trigger the workflow on a set schedule
Get an unsearched topic from Google Sheets
Search YouTube for relevant videos with Dumpling AI
Filter and sort the videos by date
Aggregate the top videos into one structured dataset
Use GPT to select the most relevant video
Retrieve the transcript of that video
Generate platform-specific posts with GPT
Create matching AI images for each post
Format and save everything back into Google Sheets
Mark the topic as completed

Step 1: Scheduled Trigger

Node: Trigger Search Schedule
This node determines when the workflow will run automatically. You can configure it to run daily or multiple times a week depending on your content pipeline.

Why it matters: This ensures you never have to manually start the process, keeping your content creation consistent and timely.

Step 2: Fetch Unsearched Topic from Google Sheets

Node: Get Unsearched Topic from Google Sheet
This node connects to your Google Sheet that contains a list of YouTube content topics. It pulls the first topic that has not yet been marked as “Searched? = Yes”.

Sheet required:

YouTube Topics sheet with columns Youtube Topics and Searched?.

Step 3: Search YouTube using Dumpling AI

Node: Search YouTube via Dumpling AI
The selected topic is sent to Dumpling AI’s YouTube search API, which returns relevant video results. The HTTP Request is authenticated using your Dumpling API key.

Why Dumpling AI: Dumpling AI handles structured video search better than standard APIs, making it easier to filter for the most relevant results.

Step 4: Filter and Sort YouTube Videos

Node: Filter + Sort YouTube Videos
This Code node parses the search results, filters for valid videos, sorts them by published date, and selects the top 3 most recent.

Why it matters: Picking fresh videos ensures your posts are timely and engaging.

Step 5: Aggregate Video Data

Node: Prepare Video List for AI
Type: Aggregate Node

This is an important step. The aggregate node takes the top three filtered videos and combines them into a single structured JSON object. This structure allows GPT to see all candidate videos at once and make a smarter selection.

Without this node, GPT would receive one video per input, which reduces the quality of its decision.

Example aggregated output:

{

“videos”: [

{

“id”: “abc123”,

“title”: “How to Automate Content Creation”,

“url”: “https://youtube.com/watch?v=abc123”,

“publishedTime”: “2025-09-25T10:00:00Z”

{

“id”: “def456”,

“title”: “Content Repurposing with AI”,

“url”: “https://youtube.com/watch?v=def456”,

“publishedTime”: “2025-09-23T08:30:00Z”

{

“id”: “ghi789”,

“title”: “YouTube Automation Tips”,

“url”: “https://youtube.com/watch?v=ghi789”,

“publishedTime”: “2025-09-20T14:00:00Z”

}

]

}

Step 6: Select Best Video with GPT

Node: Select Best Video with GPT-4o

GPT receives the aggregated data and the original topic. It analyzes all the video options and picks the one that matches the topic best and is closest to the current date.

Using GPT here allows the selection to go beyond simple keyword matching. It considers context and relevance, which gives you higher quality content sources.

Step 7: Get Transcript

Node: Get Transcript (Dumpling AI)

Once the best video is selected, this step retrieves its transcript through Dumpling AI’s transcript API. The transcript will serve as the base for generating posts.

Step 8: Generate Social Media Posts

Node: Generate Posts with GPT-4o

GPT takes the transcript and creates three posts:

Instagram post: short, punchy, with emojis and hashtags
Facebook post: warm, conversational, with a clear takeaway
LinkedIn post: professional, insightful, and thought-provoking

It also creates a unique image prompt for each platform, describing what the image should look like.

Step 9: Generate Platform-Specific Images

Nodes:

Generate Instagram Image (Dumpling AI)
Generate Facebook Image (Dumpling AI)
Generate LinkedIn Image (Dumpling AI)

Each of these nodes uses Dumpling AI to create a matching image based on the prompts from GPT. This ensures your posts have strong visuals without the need for manual design work.

Step 10: Format and Save Posts to Google Sheets

Nodes:

Format Instagram Post
Format Facebook Post
Format LinkedIn Post
Save Instagram Post to Sheet
Save Facebook Post to Sheet
Save LinkedIn Post to Sheet

This section formats the generated posts and images, then appends them to a Social Media Post sheet.
The sheet should have the following columns:

platform
Content
Image

This creates a clean database of ready-to-use posts for your social media scheduler.

Step 11: Mark Topic as Completed

Node: Update Topic Status in Sheet

The workflow finally updates the original YouTube Topics sheet and marks the used topic as Searched = Yes, ensuring the same topic is not processed twice.

Final Outcome

When the workflow finishes, your Social Media Post sheet will be filled with Instagram, Facebook, and LinkedIn posts that are:

Based on real YouTube videos
Accurately written for each platform
Paired with AI-generated visuals
Ready for publishing or scheduling

This turns what used to take hours into a fully automated, repeatable process.

Conclusion

This automation is a practical way to build a content engine that never runs dry. It saves time, improves quality, and keeps your social media calendar full of engaging, platform-specific posts. By combining Google Sheets, Dumpling AI, and GPT inside n8n, you create a system that works reliably in the background while you focus on strategy and growth.

Download the blueprint used in this blog post

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