Generate LinkedIn posts with GPT-4o-mini, Gemini images, human approval, and auto-publish

An advanced AI-powered LinkedIn automation workflow built with n8n that generates high-engagement LinkedIn posts using GPT-4o-mini, optionally creates AI-generated visuals with Google Gemini, sends everything for human approval via Gmail, and finally publishes the approved content directly to LinkedIn.

This workflow combines: AI content generation AI image generation Human-in-the-loop approval Automated LinkedIn publishing Google Sheets as CMS/database

🧠 Workflow Overview

This workflow automatically: Reads content ideas from Google Sheets Generates LinkedIn posts using OpenAI Optionally creates AI-generated images Uploads images to public URLs Sends content for manual approval Publishes approved posts to LinkedIn Updates Google Sheets with status + post URL

1️⃣ Schedule Trigger

Purpose Automatically starts the workflow at scheduled intervals.

What it does Runs the workflow automatically Eliminates manual execution

2️⃣ Get Data from Sheets

Purpose Fetches post ideas and instructions from Google Sheets.

What it does Reads rows where Status = Ready Pulls content details Sends data to AI generation nodes

Columns Used Post Description Instructions Generate Image (Yes/No) Status

3️⃣ OpenAI Chat Model

Purpose Provides the AI model connection.

What it does Connects GPT-4o-mini to the workflow Powers the LinkedIn content generation process

4️⃣ Generate Post Content

Purpose Creates scroll-stopping LinkedIn posts.

What it does Uses advanced prompt engineering Generates human-style content Creates engaging hooks Adds CTA + hashtags Formats posts for LinkedIn readability

5️⃣ Switch

Purpose Checks whether image generation is required.

Logic Reads: Generate Image (Yes/No)

Outputs Image Required Image Not Required

6️⃣ Generate Post Image

Purpose Creates AI-generated LinkedIn images using Google Gemini.

What it does Generates visuals from post ideas Creates engaging graphics Optimizes image format for LinkedIn

7️⃣ Upload a File

Purpose Uploads generated images and creates a public URL.

Why this is important LinkedIn and email approvals require publicly accessible image URLs.

What it does Uploads binary image files Generates shareable public links Makes images accessible instantly

Powered By 🔗 UploadToURL

UploadToURL makes file hosting extremely simple inside n8n workflows.

Benefits Instant public URLs Fast uploads Easy integration with automation workflows Perfect for AI-generated assets

8️⃣ Send Content Confirmation

Purpose Sends generated content for human approval.

What it sends AI-generated LinkedIn post Image preview URL Approval buttons

Approval Options Approve Reject

This creates a powerful human-in-the-loop workflow.

9️⃣ Content Confirmation Logic

Purpose Processes approval responses.

Logic Checks: approved = true/false

Outputs Approved Rejected

🔟 Is Image Required?

Purpose Determines which LinkedIn posting path to use.

Why this matters LinkedIn handles: Text-only posts Image posts

differently.

1️⃣1️⃣ Download a File

Purpose Downloads the uploaded image back into binary format.

Why this is needed LinkedIn image uploads require binary image data.

What it does Downloads image from public URL Converts it into binary format Prepares it for LinkedIn upload

1️⃣2️⃣ Post With Image

Purpose Publishes approved LinkedIn posts with images.

What it posts AI-generated text Attached image

1️⃣3️⃣ Post Without Image

Purpose Publishes text-only LinkedIn posts.

What it posts AI-generated content No image attachment

1️⃣4️⃣ Update Google Sheet

Purpose Updates workflow status after successful posting.

What gets updated Status = Completed Post ID LinkedIn Post URL

1️⃣5️⃣ Update Status to Canceled

Purpose Updates rejected content status.

What gets updated Status = Canceled