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miccho27
miccho27

Posted on • Originally published at listing-ai-ten.vercel.app

I Built an AI Product Description Generator with Compliance Checking for Japanese E-commerce

#ai #saas #ecommerce #nextjs

The Problem

If you're an e-commerce seller in Japan, you face two massive challenges:

  1. Writing product descriptions is painfully slow — 30 minutes per product × 1,000 SKUs = 500 hours
  2. Japanese regulations are strict — The Pharmaceutical and Medical Device Act (薬機法) and Act against Unjustifiable Premiums and Misleading Representations (景品表示法) can shut down your listings with a single violation

ChatGPT can help with #1, but it knows nothing about #2.

The Solution: ListingAI

I built ListingAI — an AI-powered product description generator specifically designed for Japanese e-commerce sellers.

What makes it different from ChatGPT?

Feature ChatGPT ListingAI
Single product description ✅ ✅
Bulk generation (1,000+ products) ❌ Manual copy-paste ✅ CSV upload
Platform optimization (Amazon/Rakuten/Shopify) ❌ Generic ✅ Algorithm-specific
Japanese regulatory compliance check ❌ ✅ Automatic
Direct push to Shopify/BASE ❌ ✅ API integration

Regulatory Compliance: The Killer Feature

Japanese e-commerce has unique legal requirements:

  • Pharmaceutical Affairs Act (薬機法): You can't claim cosmetics "cure" anything or supplements have "anti-aging effects"
  • Premiums and Representations Act (景品表示法): "No.1 in the industry" requires documented proof from a research organization
  • Food Labeling Act (食品表示法): "Additive-free" now requires specifying which additive since April 2025

ListingAI automatically scans generated descriptions for 17+ violation patterns and suggests safe alternatives.

Tech Stack

  • Frontend: Next.js 15 + Tailwind CSS
  • Backend: Next.js API Routes
  • AI: Claude API (Sonnet 4)
  • Database: Supabase (PostgreSQL + Auth)
  • Hosting: Vercel
  • Monthly cost: ~$10-50 (scales with usage)

Programmatic SEO Strategy

I generated 78 static pages targeting long-tail keywords:

  • Platform × Category pages: tools/amazon/beauty, tools/rakuten/supplements (60 pages)
  • Law × Category pages: compliance-guide/yakujihou/beauty (18 pages)

These pages target searches like:

  • "Amazon beauty product description template"
  • "Pharmaceutical Affairs Act cosmetics NG expressions"

All generated at build time via Next.js generateStaticParams().

Results So Far

  • 84 URLs indexed via Google Indexing API
  • 78 pSEO pages targeting long-tail keywords
  • 17 compliance rules for 4 Japanese laws
  • Free tier: 5 generations/month (no credit card required)

Try It

🔗 https://listing-ai-ten.vercel.app

Free to try — 5 product descriptions per month, including compliance checking.

Built with Claude Code in a single session. The entire MVP (AI generation, compliance checking, auth, payments placeholder, pSEO) was built and deployed in one day.

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