I Built an AI Content API with 8 Endpoints for $0 - Here's How
# sideprojects# webdev# ai# api
Breno MiguezI wanted a simple API for AI content tasks that returns clean JSON - not a chatbot, not a complex...
I wanted a simple API for AI content tasks that returns clean JSON - not a chatbot, not a complex SDK. So I built ContentCraft AI and listed it on RapidAPI.
Here's what it does, how I built it, and what I learned.
What It Does
ContentCraft AI provides 8 POST endpoints for content creation:
| Endpoint | What it does |
|---|---|
| /rewrite | Paraphrase text in 5 tones |
| /seo-analyze | SEO score, keyword density, suggestions |
| /headline-generate | Headlines in 5 styles |
| /summarize | Short/medium/long summaries |
| /email-generate | Marketing emails with subject + CTA |
| /social-post | Platform-optimized social posts |
| /extract-keywords | Keywords with relevance scores |
| /content-improve | Grammar, clarity, tone fixes |
Every response is structured JSON. No markdown, no chat format.
Quick Example
curl -X POST "https://contentcraft-ai-green.vercel.app/api/v1/rewrite" \
-H "X-RapidAPI-Key: YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"text": "Your text here", "tone": "professional"}'
Response:
{
"original_length": 60,
"rewritten_text": "Your professionally rewritten text...",
"tone": "professional"
}
The Stack
- Next.js 16 (App Router) on Vercel free tier
- Google Gemini AI (free tier)
- RapidAPI for auth, billing, and rate limiting
- Zero database, zero Stripe, zero custom auth
Total cost: $0/month.
Why RapidAPI
RapidAPI handles the boring stuff - API keys, rate limiting, billing, and discovery. Developers already search for APIs there. I just build the endpoints and set the pricing.
Pricing
- Free: 50 requests/month
- Pro: $9.99/mo (1,000 requests)
- Ultra: $29.99/mo (5,000 requests)
- Mega: $79.99/mo (20,000 requests)
Try It
Would love to hear your feedback!