End-to-end Ai blog research and writer with Gemini AI, Supabase and Nano-Banana

Blog Research and Writer n8n Workflow - Ai Blog Writer Fully automated blog creation system using n8n + AI Agents + Image Generation Example Blog Overview This workflow automates the entire blog creation pipeline—from topic research to final publication. Three specialized AI agents collaborate to produce publication-ready blog posts with custom images, all saved directly to your Supabase database. How It Works 1. Research Agent (Topic Discovery) - Triggers: Runs on schedule (default: daily at 4 AM) - Process: - Fetches existing blog titles from Supabase to avoid duplicates - Uses Google Search + RSS feeds to identify trending topics in your niche - Scrapes competitor content to find content gaps - Generates detailed topic briefs with SEO keywords, search intent, and differentiation angles - Output: Comprehensive research document with SERP analysis and content strategy 2. Writer Agent (Content Creation) - Triggers: Receives research from Agent 1 - Process: - Writes full blog article based on research brief - Follows strict SEO and readability guidelines (no AI fluff, natural tone, actionable content) - Structures content with proper HTML markup - Includes key sections: hook, takeaways, frameworks, FAQs, CTAs - Places image placeholders with mock URLs ( etc.) - Output: Complete JSON object with title, slug, excerpt, tags, category, and full HTML content 3. Image Prompt Writer (Visual Generation) - Triggers: Receives blog content from Agent 2 - Process: - Analyzes blog content to determine number and type of images needed - Generates detailed 150-word prompts for each image (feature image + content images) - Creates prompts optimized for Nano-Banana image model - Names each image descriptively for SEO - Output: Structured prompts for 3-6 images per blog post 4. Image Generation Pipeline - Process: - Loops through each image prompt - Generates images via Nano-Banana API (Wavespeed.ai) - Downloads and converts images to PNG - Uploads to Supabase storage bucket - Generates permanent signed URLs - Replaces mock URLs in HTML with real image URLs - Output: Blog HTML with all images embedded 5. Publication - Final blog post saved to Supabase blogs table as draft - Ready for immediate publishing or review Key Features ✅ Duplicate Prevention: Checks existing blogs before researching new topics ✅ SEO Optimized: Natural language, proper heading structure, keyword integration ✅ Human-Like Writing: No robotic phrases, varied sentence structure, actionable advice ✅ Custom Images: Generated specifically for each blog's content ✅ Fully Structured: JSON output with all metadata (tags, category, excerpt, etc.) ✅ Error Handling: Automatic retries with wait periods between agent calls ✅ Tool Integration: Google Search, URL scraping, RSS feeds for research Setup Requirements 1. API Keys Needed - Google Gemini API: For Gemini 2.5 Pro/Flash models (content generation/writing) - Groq API (optional): For Kimi-K2-Instruct model (research/writing) - Serper.dev API: For Google Search (2,500 free searches/month) - Wavespeed.ai API: For Nano-Banana image generation - Supabase Account: For database and image storage 2. Supabase Setup - Create blogs table with fields: - title, slug, excerpt, category, tags, featuredimage, status, featured, content - Create storage bucket for blog images - Configure bucket as public or use signed URLs 3. Workflow Configuration Update these placeholders: - RSS Feed URLs: Replace [your website's rss.xml] with your site's RSS feed - Storage URLs: Update Supabase storage paths in "Upload object" and "Generate presigned URL" nodes - API Keys: Add your credentials to all HTTP Request nodes - Niche/Brand: Customize Research Agent system prompt with your industry keywords - Writing Style: Adjust Writer Agent prompt for your brand voice Customization Options Change Image Provider Replace the "nano banana" node with: - Gemini Imagen 3/4 - DALL-E 3 - Midjourney API - Any Wavespeed.ai model Adjust Schedule Modify "Schedule Trigger" to run: - Multiple times daily - Specific days of week - On-demand via webhook Alternative Research Tools Replace Serper.dev with: - Perplexity API (included as alternative node) - Custom web scraping - Different search providers Output Format Performance Notes - Average runtime: 15-25 minutes per blog post - Cost per post: $0.10-0.30 (depending on API usage) - Image generation: 10-15 seconds per image with Nano-Banana - Retry logic: Automatically handles API timeouts with 5-15 minute wait periods Best Practices 1. Review Before Publishing: Workflow saves as "draft" status for human review 2. Monitor API Limits: Track Serper.dev searches and image generation quotas 3. Test Custom Prompts: Adjust Research/Writer prompts to match your brand 4. Image Quality: Review generated images; regenerate if needed 5. SEO Validation: Check slugs and meta descriptions before going live Workflow Architecture 3 Main Phases: 1. Research → Writer → Image Prompts (Sequential AI Agent chain) 2. Image Generation → Upload → URL Replacement (Loop-based processing) 3. Final Assembly → Database Insert (Single save operation) Error Handling: - Wait nodes between agents prevent rate limiting - Retry logic on agent failures (max 2 retries) - Conditional checks ensure content quality before proceeding --- Result: Hands-free blog publishing that maintains quality while saving 3-5 hours per post.