How I Built a Daily AI Trends Publisher That Runs for $1.40/Month
February 2026
The Idea
Keeping up with AI news is a full-time job. New models, research papers, product launches, regulatory changes — the landscape moves daily. I wanted a system that would automatically research the latest AI trends, write an engaging social media post, generate a matching image, and publish it to Facebook. Every single day. Without me lifting a finger.
The twist: I wanted a human-in-the-loop approval gate. The system does the heavy lifting, but I get to review and approve before anything goes live. Full automation with a safety net.
The Stack
- n8n — workflow orchestration engine, self-hosted on Railway
- Claude Sonnet 4.5 — AI content generation (Anthropic API)
- Claude Haiku 3.5 — lightweight formatting tasks
- Tavily Search API — real-time web research for trending AI topics
- Pollinations.ai — free AI image generation
- imgbb — image hosting
- Gmail — approval gate via OAuth (Send & Wait)
- IFTTT — bridge to Facebook posting
The Workflow Architecture
The workflow runs 14 functional nodes in a linear pipeline, triggered daily at 6AM (Asia/Manila timezone):
Daily 6AM Trigger
→ Social Media Content Factory (Claude Sonnet 4.5 + Tavily Search)
→ Keep First Result
→ Generate Post Image (Pollinations API)
→ Upload to imgbb
→ Collect Post Data
→ Prepare Content Review Email
→ Gmail: Send Approval Email (12hr timeout)
→ Is Content Approved?
→ Merge Approval with Data
→ Sanitize Text for IFTTT
→ IFTTT Facebook Post (HTTP Request)
→ Prepare Results Email
→ Gmail: Send Results Summary
The "Social Media Content Factory" is an n8n AI Agent node that uses Claude Sonnet 4.5 with a Tavily Search tool and a Structured Output Parser. It searches the web for the day's biggest AI story, then generates a structured JSON response with the post content, hashtags, and a call-to-action — all in one shot.
Key Features
AI-Powered Research
Tavily Search API (advanced depth mode) scans the web for the latest AI developments. The AI agent picks the most compelling story and writes a hook-style post — short, punchy, optimized for social media engagement. The structured output parser ensures consistent JSON format every time.
Automated Image Generation
Each post gets a unique AI-generated image from Pollinations.ai. The image prompt is derived from the post content, creating visually relevant artwork. Images are uploaded to imgbb for persistent hosting with a stable URL.
Human-in-the-Loop Approval
Before anything publishes, I get an email with the full post preview — text, image, hashtags, and CTA. I can approve or reject with a single click. The workflow waits up to 12 hours for a response. This ensures quality control while keeping the process nearly hands-free.
Facebook Publishing via IFTTT
Once approved, a Code node sanitizes the text (escaping special characters for IFTTT's webhook format), then triggers an IFTTT applet that posts to a Facebook page. A results summary email confirms the publish status.
Cost Analysis
One of the most surprising aspects: the entire pipeline costs about $1.40/month to run daily.
| Component | Per Run | Monthly |
|---|---|---|
| Content Factory (Claude Sonnet 4.5) | ~$0.02 | ~$0.60 |
| Email Formatter (Claude Sonnet 4.5) | ~$0.014 | ~$0.42 |
| Results Formatter (Claude Haiku 3.5) | ~$0.003 | ~$0.08 |
| Tavily Search (advanced) | ~$0.01 | ~$0.30 |
| Pollinations / imgbb / IFTTT | Free | $0 |
| Total | ~$0.047 | ~$1.40 |
With optimization (replacing LLM email formatters with Code nodes, downgrading to Haiku for content generation, switching to basic Tavily search), this could drop to ~$0.30/month — a 79% reduction.
Problems & Solutions
No Rejection Handling
Problem: If content was rejected or the 12-hour approval timeout expired, the workflow silently died. No notification, no logging, no retry.
Fix: Connected the FALSE output of the approval check to a notification node that emails a rejection/timeout summary with the original content for reference.
API Keys Hardcoded in Workflow
Problem: Tavily, imgbb, Pollinations, and IFTTT keys were hardcoded directly in node parameters — visible in exports and workflow JSON.
Fix: Migrated all keys to n8n credentials and environment variables. Redacted keys from snapshot files.
Gmail OAuth Token Expiry
Problem: OAuth tokens expire periodically. When they do, both the approval gate AND results notification break silently. The workflow fails every day until manually refreshed.
Fix: Added error handling around Gmail nodes with alerting on auth failures.
Image Generation Has No Fallback
Problem: Pollinations is a free service with no SLA. If it fails, the imgbb upload gets empty data, which breaks the entire downstream chain.
Fix: Added an IF node after image generation to check for binary data. On failure, it falls back to a static placeholder image URL.
Optimization Opportunities
The workflow works, but there's significant room for optimization:
- 1.Replace LLM email formatters with Code nodes — the email templates are deterministic HTML. Using Claude Sonnet for string interpolation is wasteful ($0.50/month saved).
- 2.Downgrade Content Factory to Haiku — writing a 50-80 word hook post doesn't require Sonnet-level reasoning ($0.45/month saved).
- 3.Switch Tavily to basic search — advanced depth is overkill for finding trending AI news ($0.15/month saved).
- 4.Cap max tokens — the content factory has a 4,096 token limit but outputs ~150 tokens. Reducing prevents runaway costs if the LLM goes off-script.
What I Learned
- -Human-in-the-loop is non-negotiable for public content — AI-generated posts can be subtly wrong, tone-deaf, or reference outdated information. The approval gate catches these before they go live.
- -Free-tier services need fallbacks — Pollinations and imgbb have no SLA. Build your pipeline assuming they'll fail sometimes.
- -LLMs are overkill for deterministic tasks — if the output format is always the same, use a Code node. LLMs add cost, latency, and non-determinism where none is needed.
- -Token costs are predictable — once you measure a few runs, monthly costs become very accurate. This workflow costs less than a cup of coffee per month.
The Takeaway
This project shows that sophisticated content automation doesn't have to be expensive or complex. A 14-node n8n workflow, a few API integrations, and a human approval gate create a daily content machine that runs for less than the cost of a monthly parking meter.
The n8n + AI combination is powerful: you get visual workflow design, built-in error handling, credential management, and seamless LLM integration — all without writing a traditional backend. This is automation that feels like building with Lego blocks.
Built with n8n, Claude AI (Anthropic API), Tavily, Pollinations.ai, and IFTTT. Orchestrated by Claude Code.