I Turned 8 Blog Posts into 120 Social Posts with n8n. The Naive Version Forgot the Link 93 Times

Description and use

Automating blog‑to‑social posts with n8n and an LLM revealed that a single‑prompt approach fails to meet platform rules, while a validated workflow yields 77/120 compliant posts.

Problem

Generating compliant social media posts from a single blog post using an LLM often fails to meet platform constraints and link inclusion.

Outcome

The validated workflow achieved 77/120 compliant posts, eliminating the 93‑post link omission issue and reducing other rule violations.

Workflow

• Webhook receives {title,url,body}
• Config node builds prompt
• LLM node generates post per platform
• Code node validates length, hashtags, link, uniqueness, numbers
• If validation fails, retry prompt sent to LLM
• Final check node marks post as ready or flags for human
• Respond node returns ready posts

Evidence

The one‑prompt version produced 118 bad posts out of 120.

Source

The validated version got 77 posts clean enough to mark "ready"

Source

The model never sees "280 characters". It sees the space that's actually left after the link and hashtags.

Source