Generate and schedule LinkedIn, X, and Instagram posts with OpenAI agents

Description

This workflow orchestrates three specialized AI agents in sequence to research trends, generate platform-specific content (captions + images), and schedule posts across LinkedIn, X (Twitter), and Instagram.

Who's it for
• Social media managers handling multiple brands
• Marketing teams needing consistent content pipelines
• Creators automating their content calendar
• Agencies managing high-volume posting schedules

How it works
A topic/industry keyword is submitted via webhook or schedule
Agent 1 (Research): Searches current trends, extracts insights & hashtags
Agent 2 (Content Gen): Produces platform-specific captions + image prompts
Agent 3 (Scheduling): Posts to LinkedIn, X, and Instagram via their APIs
All activity is logged to a Google Sheet tracker

How to set up
Import this workflow into n8n
Set credentials: OpenAI, LinkedIn OAuth2, Twitter OAuth2, Instagram Graph API, Google Sheets OAuth2, SendGrid (optional alerts)
Replace YOUR_SHEET_ID placeholder in the Google Sheet node
Replace YOUR_INSTAGRAM_ACCOUNT_ID, YOUR_LINKEDIN_PERSON_URN placeholders
Activate the workflow

Requirements
• OpenAI API key (GPT-4.1 mini or better)
• LinkedIn OAuth2 credentials
• Twitter/X OAuth2 credentials
• Instagram Graph API credentials (Business account)
• Google Sheets OAuth2
• Optional: Stable Diffusion / DALL-E for image generation

How to customize
• Swap OpenAI model in all AI nodes
• Adjust character limits per platform in Agent 2 prompt
• Modify posting schedule in the Schedule Trigger node
• Add Slack/email notifications on post confirmation
• Extend the Google Sheet columns for additional metadata