LinkedIn Post Automation with AI Generation (Gpt-4o) & Slack Approval

How it Works

This workflow automates the creation and publishing of LinkedIn posts with AI-generated content and human approval via Slack, using Google Sheets, OpenAI (GPT-4), Slack Interactive Messages, and the LinkedIn API.

Whether you're a social media manager, content creator, or marketing professional, this workflow helps you maintain consistent LinkedIn presence and scale content creation while keeping human oversight — all managed from a simple spreadsheet.

🎯 Use Case

Ideal for:

• Content Marketers managing multiple LinkedIn accounts
• Personal Brand Builders maintaining regular posting schedule
• Agencies handling client social media presence
• Teams requiring content approval workflows

Setup Instructions

1. Prepare the Spreadsheet

• File name: Linkedin Post
• Main sheet structure: | ID | Linkedin Post Title | Status | Image URL |
• Groups sheet structure: | GroupIds |
• Add post topics and set their Status as Pending

2. Configure Google Sheets Nodes

Connect your Google account to:

• Linkedin-Post-Topic (Trigger node)
• Update-Status
• Get-Group-id

3. Add API Credentials

• OpenAI API Key → for GPT-4 content generation
• Slack OAuth Token → for approval messages
• LinkedIn Access Token → for posting content
• HTTP Header Auth → Bearer token for LinkedIn API

4. Configure Webhooks

• Set up Slack Interactive Components webhook
• Point Request URL to your N8N webhook endpoint
• Enable interactive messages in Slack app

5. Activate the Workflow

Once live, the workflow will:

1. Monitor spreadsheet for new topics every minute
2. Generate LinkedIn post using GPT-4
3. Send to Slack for approval/editing
4. Upload image to LinkedIn
5. Publish to profile and groups
6. Update spreadsheet status to Posted

🔁 Workflow Logic

1. Trigger: New/updated row with Pending status
2. Generate: AI creates engaging LinkedIn post
3. Approve: Slack message for review/edit
4. Process: Handle approval response
5. Upload: Register and upload image
6. Publish: Post to LinkedIn profile & groups
7. Update: Mark as Posted in sheet

🧩 Node Descriptions

| Node Name | Description | |-----------|-------------| | Linkedin-Post-Topic | Monitors spreadsheet for new post topics | | Validate-Status | Filters only 'Pending' items | | Limit | Processes one item at a time | | Linedin-Post-Creator | Generates post content using GPT-4 | | Format-Content | Prepares content for Slack display | | Approval-on-Slack | Sends interactive approval message | | Webhook | Receives Slack button responses | | Format-Response | Extracts edited content from Slack | | Set-Final-Message | Prepares approved content | | Linkedin-User-Detail | Fetches LinkedIn user info | | Register Image | Initiates LinkedIn image upload | | Upload Image | Uploads image to LinkedIn | | Linkedin-post | Publishes to personal profile | | Get-Group-id | Retrieves LinkedIn group IDs | | Post-Linkedin-Groups | Posts to multiple groups | | Update-Status | Marks as completed in sheet |

🛠️ Customization Tips

• Adjust AI prompt for brand voice and hashtags
• Change Slack approver or add multiple reviewers
• Modify posting schedule with delay nodes
• Add analytics tracking with additional API calls
• Filter groups based on specific criteria
• Include URL shortening for tracking

📒 Suggested Sticky Notes for Workflow

| Node/Section | Sticky Note Content | |--------------|---------------------| | Linkedin-Post-Topic | "Triggers every minute for new posts in your spreadsheet" | | Validate-Status | "Filters to process only 'Pending' items - prevents duplicates" | | Linedin-Post-Creator | "Uses GPT-4 to generate LinkedIn content - customize prompt for your brand voice" | | Approval-on-Slack | "Sends for human review - edit the Slack user to change approver" | | Webhook | "Receives approval responses - ensure URL is configured in Slack app" | | Register Image | "Initiates LinkedIn media upload - requires valid image URL from sheet" | | Linkedin-post | "Publishes to your profile - update with your LinkedIn credentials" | | Post-Linkedin-Groups | "Posts to multiple groups - add group IDs in Groups sheet" | | Update-Status | "Marks as 'Posted' to prevent reprocessing" |

💡 AI Prompt Configuration

The workflow uses a sophisticated prompt that:

• Creates compelling hooks
• Includes 3-4 informative paragraphs
• Adds engagement questions
• Inserts relevant emojis
• Generates 4-6 hashtags
• Formats with proper spacing

🔒 Security & Permissions

LinkedIn App Requirements:

• r_liteprofile - Read profile data
• r_emailaddress - Access email
• w_member_social - Post content
• rw_organization_admin - Group posting

Slack Bot Permissions:

• chat:write - Send messages
• im:write - Direct messages
• users:read - User information

📎 Required Components

| Component | Purpose | |-----------|---------| | Google Sheet | Store post topics and status | | LinkedIn App | API access for posting | | Slack App | Interactive approval flow | | OpenAI Account | GPT-4 content generation | | N8N Instance | Workflow execution |

🧪 Testing Tips

• Start with one test topic marked as Pending
• Verify Slack message appears correctly
• Test both "Approve" and "Edit" buttons
• Check image upload completes
• Confirm post appears on LinkedIn
• Verify status updates to Posted

⚠️ Common Issues & Solutions

LinkedIn API Errors:

• Token expiration → Refresh access token
• Rate limits → Add delays between posts
• Group restrictions → Check posting permissions

Slack Integration:

• Missing responses → Verify webhook URL
• Button not working → Check interactive components
• User not found → Confirm Slack user ID

Image Upload Failures:

• Invalid URL → Validate image accessibility
• Size limits → Compress images under 10MB
• Format issues → Use JPEG or PNG only

📊 Workflow Benefits

• Time Savings: 80% reduction in content publishing time
• Consistency: Regular posting schedule maintained
• Quality Control: Human review ensures brand standards
• Scalability: Handle multiple accounts and groups
• Flexibility: Easy to modify and extend

📎 Required Files

| File Name | Purpose | |-----------|---------| | Linkedin Post | Google Sheet to hold post topics and status |

🏷 Suggested Tags & Categories

• #LinkedIn
• #AI
• #ContentAutomation
• #SocialMedia
• #Slack
• #GPT4
• #Marketing
• #WorkflowAutomation