Suggestion On social media automation

Hi everyone, I am building an AI-powered social media advertisement automation workflow using n8n (running locally through Docker), Python ML, OpenAI APIs, Google Sheets, Instagram, and Facebook APIs. I want feedback and suggestions regarding the architecture, best practices, and especially the ML + image generation part.

Workflow Summary

1. Daily Trigger

A Cron trigger in n8n runs every day at 12 PM.


2. ML Prediction Engine

The workflow accesses an Instagram engagement dataset stored in either:

  • Google Drive CSV

  • Airtable

A Python ML script then:

  • Cleans and preprocesses the dataset

  • Uses rolling engagement windows

    • Example:

      • Day 1 → May 1–30

      • Day 2 → May 2–31

  • Analyzes:

    • Likes

    • Comments

    • Shares

    • Saves

    • Reach

    • Engagement rates

The ML model predicts the best time to post an advertisement for the current day.

The predicted posting time is stored in a Google Sheet (Sheet1).


3. AI Advertisement Generation

After prediction:

  • An AI agent/LLM generates advertisement prompts

  • An image generation model creates the advertisement image

  • The generated image URL/path is stored in the same Google Sheet row along with the predicted posting time


4. Caption + Hashtag Generator

Another AI agent:

  • Generates multiple caption options

  • Generates hashtags

  • Performs trend-aware captioning/prompt engineering

The generated captions are stored in Google Sheets and one caption is manually selected.

The final selected caption + hashtags are saved in the same row.


5. Automated Posting System

At the predicted posting time:

  • The workflow reads the row from Google Sheets

  • Posts the advertisement automatically to:

    • Instagram

    • Facebook

Likely using:

  • Facebook Graph API

  • Instagram Graph API

Then:

  • IF nodes check whether posting succeeded or failed

  • Notifications are sent through:

    • Telegram

    • WhatsApp

    • Email


Current Stack

  • n8n (Docker local installation)

  • Python ML

  • Google Sheets

  • OpenAI API

  • Instagram/Facebook APIs

  • Possible Hugging Face image generation APIs


Questions

1. ML Integration in n8n

What is the best way to integrate the ML part into n8n?

Should I use:

  • Python Code node

  • Execute Command node

  • External FastAPI/Flask ML service

  • Dockerized ML microservice

Also, what would be the best ML approach for predicting optimal posting times from Instagram engagement data?


2. Free AI Image Generation

What are the best free or low-cost options for AI image generation inside n8n?

I am considering:

  • Hugging Face Inference API

  • Stable Diffusion

  • FLUX

  • Pollinations AI

  • Local ComfyUI / AUTOMATIC1111

I need something scalable and preferably free/self-hosted.


3. Instagram + Facebook Integration

What is the best way to connect n8n with Instagram and Facebook posting?

Should I directly use:

  • Facebook Graph API

  • HTTP Request nodes

  • Webhooks

  • Third-party schedulers

Also:

  • Do I need Instagram Business account only?

  • How does media publishing work for Instagram through Meta APIs?


4. Workflow Architecture

Is splitting the automation into separate workflows the correct approach?

Current architecture:

  1. ML prediction workflow

  2. Ad generation workflow

  3. Caption generation workflow

  4. Scheduled posting workflow

All connected through Google Sheets.

Would queues/databases be better than Google Sheets?


5. Human Approval Layer

What is the best way to manually approve/select one caption from multiple AI-generated captions?

Possible options:

  • Google Sheet manual selection

  • Telegram buttons

  • Custom webhook dashboard

Which is most practical in production?


6. Scaling + Reliability

Any recommendations for:

  • Error handling

  • Retry systems

  • Logging

  • Preventing duplicate posting

  • Managing API limits

  • Production deployment of n8n + ML

Would appreciate architecture suggestions, especially from people already using AI + n8n + Meta APIs together.