Onizuka

Posted on Jul 17

5 Free APIs I Built with Cursor - No Coding Skills Required - Now on RapidAPI

#api #sideprojects #python #tutorial

The Problem

Every developer needs data: WHOIS records, company info, email validation, IP geolocation, compliance screening. But existing APIs are either expensive, rate-limited, or require API keys to third-party services.

I wanted to solve this — without knowing how to code.

The Solution: 5 Free APIs Built with Cursor

I used Cursor IDE (AI-powered code editor) to build 5 production-ready APIs. Cursor wrote 100% of the code — I just described what I wanted in plain English. Each API is:

Free tier: 100 requests/month, no credit card
Live on RapidAPI: Available to 4M+ developers instantly
Open source: Full code on GitHub
Zero infrastructure cost: Deployed on Render free tier

The 5 APIs

1. Domain WHOIS API

Get registration data for any domain via RDAP protocol.

curl "https://domain-whois.p.rapidapi.com/whois?domain=google.com" \
  -H "X-RapidAPI-Host: domain-whois.p.rapidapi.com" \
  -H "X-RapidAPI-Key: YOUR_API_KEY"

Returns: domain, registrar, registration date, expiration, status, nameservers.

RapidAPI: https://rapidapi.com/On13uka/api/domain-whois2
GitHub: https://github.com/On13uka/domain-whois-api

2. Company Info API

Get company profiles from Wikipedia + Wikidata: description, industry, founded date, HQ, employees, revenue, stock ticker.

curl "https://company-info.p.rapidapi.com/company?name=Microsoft" \
  -H "X-RapidAPI-Host: company-info.p.rapidapi.com" \
  -H "X-RapidAPI-Key: YOUR_API_KEY"

RapidAPI: https://rapidapi.com/On13uka/api/company-info1
GitHub: https://github.com/On13uka/company-info-api

3. Email Validator API

3-stage validation: RFC 5322 syntax, DNS MX lookup, optional SMTP mailbox verification.

curl "https://email-validator.p.rapidapi.com/validate?email=test@gmail.com" \
  -H "X-RapidAPI-Host: email-validator.p.rapidapi.com" \
  -H "X-RapidAPI-Key: YOUR_API_KEY"

RapidAPI: https://rapidapi.com/On13uka/api/email-validator112
GitHub: https://github.com/On13uka/email-validator-api

4. IP Geolocation API

Geolocate any IP: country, city, lat/lon, timezone, ISP, ASN. Dual-source fallback for reliability.

curl "https://ip-geolocation.p.rapidapi.com/geo?ip=8.8.8.8" \
  -H "X-RapidAPI-Host: ip-geolocation.p.rapidapi.com" \
  -H "X-RapidAPI-Key: YOUR_API_KEY"

RapidAPI: https://rapidapi.com/On13uka/api/ip-geolocation44
GitHub: https://github.com/On13uka/ip-geolocation-api

5. Sanctions Screener API

Screen names against OFAC SDN (19,000+ entities) and UN Consolidated (1,000+ entities) sanctions lists with match scoring.

curl "https://sanctions-screener.p.rapidapi.com/screen?name=Al+Qaeda&threshold=0.7" \
  -H "X-RapidAPI-Host: sanctions-screener.p.rapidapi.com" \
  -H "X-RapidAPI-Key: YOUR_API_KEY"

RapidAPI: https://rapidapi.com/On13uka/api/sanctions-screener
GitHub: https://github.com/On13uka/sanctions-screener-api

How I Built Them (No Coding Skills)

Each API took about 30 minutes to build:

Describe to Cursor what the API should do
Cursor wrote FastAPI Python code, error handling, and tests
Git init and push to GitHub
Deploy to Render (free tier, auto-detects from render.yaml)
List on RapidAPI (upload OpenAPI spec, set pricing, make public)

Pricing

All APIs follow the same model:

Plan	Price	Requests/month
Basic	Free	100
Pro	$19/mo	5,000
Ultra	$49/mo	25,000
Mega	$149/mo	100,000

Stack

IDE: Cursor (AI code generation)
Framework: FastAPI + Python
Hosting: Render free tier ($0/month)
Marketplace: RapidAPI (20% commission, 4M+ developers)
Data sources: RDAP, Wikipedia, Wikidata, DNS, ipapi.co, OFAC, UN

Try Them Out

All 5 APIs have free tiers — no credit card required. Get a RapidAPI key and start testing in 30 seconds.

My RapidAPI profile: https://rapidapi.com/user/On13uka

Built with Cursor IDE. No coding skills required. 100% AI-generated code.

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