⚡ Kowhai API Hub

Fast, reliable developer tool APIs. AI prompt optimization, JSON validation, and text analysis — built for production use.

99.9% Uptime Sub-50ms Response Free Tier Available No Signup Required
Get API Key → View Docs

APIs

Three production-ready APIs, each with a free tier. Available on RapidAPI.

🤖

AI Prompt Optimizer

Takes a raw AI prompt and returns an optimized version with expert role definition, structured constraints, and output format guidance. Improves AI response quality by 40-60%.

POST/prompt-optimizer/optimize
GET/prompt-optimizer/health
Free: 100 req/mo • Pro: $9/mo (1K) • Business: $29/mo (10K)
📋

JSON Schema Validator

Validate JSON against schemas, format/prettify, and convert between JSON, CSV, and YAML. Returns all validation errors with field paths, not just the first.

POST/json-tools/validate
POST/json-tools/format
POST/json-tools/convert
Free: 500 req/mo • Pro: $5/mo (5K) • Business: $19/mo (50K)
📝

Text Readability & SEO Analyzer

Analyze text or HTML for readability scores (Flesch-Kincaid, Gunning Fog, SMOG), keyword density, heading structure, meta tags, image alt coverage, and get actionable SEO suggestions.

POST/text-analyzer/analyze
GET/text-analyzer/health
Free: 100 req/mo • Pro: $9/mo (1K) • Business: $29/mo (10K)

Quick Start

Test any API in under 30 seconds.

# AI Prompt Optimizer
curl -X POST https://api.kowhaigoods.com/prompt-optimizer/optimize \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "write code to sort a list",
    "goal": "write a Python function",
    "format": "structured"
  }'

# JSON Schema Validator
curl -X POST https://api.kowhaigoods.com/json-tools/validate \
  -H "Content-Type: application/json" \
  -d '{
    "data": {"name": "test", "age": 25},
    "schema": {"type": "object", "required": ["name"]}
  }'

# Text Readability & SEO Analyzer
curl -X POST https://api.kowhaigoods.com/text-analyzer/analyze \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Your content here...",
    "is_html": false,
    "target_keywords": ["your", "keywords"]
  }'

Why Kowhai API Hub?

⚡ Fast

Sub-50ms response times. All processing happens on dedicated infrastructure — no cold starts, no queuing.

🔒 Secure

No data is stored. All requests are processed in-memory and discarded. No external URL fetching — zero SSRF risk.

📦 Simple Pricing

Free tier for testing. Pro plans start at $5/mo. No hidden fees, no per-request charges beyond your plan.

📚 Well-Documented

Interactive Swagger/OpenAPI docs at /docs. Every endpoint has request/response examples and error codes.

🔄 Rate Limited

Built-in rate limiting protects your quota. RapidAPI handles authentication and billing automatically.

🌐 Global CDN

Served via Cloudflare's global edge network. Low latency from anywhere in the world.