Production APIs,
one call away.
Focused, production-grade APIs — each built around a single problem, solved properly. No bloat, no bundled platforms. Clean endpoints, honest pricing, and documentation that tells you exactly what you're getting.
No credit card required
How it works
Browse the catalog
Find the API that fits your use case. Each one solves a single problem, properly — no bundled platforms, no bloat.
Get your key
Sign up on RapidAPI in seconds. A free tier is available on every API — no credit card required to start testing.
Call the endpoint
Add the key to your request header and make your first call. Clean JSON responses. Clear documentation. That's it.
API catalog
Available APIs
Each API is independently versioned and listed on RapidAPI. Try any endpoint directly from the listing — no setup required beyond a free key.
Phone Number Validator API
Validate, classify, and inspect phone numbers from any country. Built on Google's libphonenumber — the same engine used at scale in production. Pass a number in E.164 or national format with a region hint and get back structural validity, line type, carrier, geocoding, timezones, and every standard format representation.
POST /validate → 200 OK
{
"valid": true,
"type": "MOBILE",
"carrier": "EE",
"geocoding": "United Kingdom",
"e164": "+447700900123",
"intl": "+44 7700 900123",
"timezones": [
"Europe/London"
]
}Global Bank & Public Holiday API
Retrieve public and bank holidays for countries worldwide. Supports nationwide and subdivision-specific queries across 100+ countries using ISO 3166-1 alpha-2 country codes. Covers state, province, and regional holiday variations — so you're not flattening England, Scotland, and Wales into one result.
GET /holidays?country=DE&year=2024 → 200 OK
[
{
"date": "2024-01-01",
"name": "New Year's Day"
},
{
"date": "2024-04-01",
"name": "Easter Monday"
},
{
"date": "2024-10-03",
"name": "German Unity Day"
}
]Readability Analysis API
Analyse English text readability across ten established formulas including Flesch Reading Ease, SMOG Index, Gunning Fog, Coleman-Liau, ARI, Dale-Chall, and more. Returns per-formula scores with grade levels, text statistics, and a multi-formula consensus when all methods are run — giving you a defensible, aggregate reading level rather than one formula's opinion.
POST /analyse → 200 OK
{
"consensus": {
"grade": "7.4",
"level": "7th Grade",
"min": 6.1,
"max": 9.2
},
"flesch": {
"score": 68.2,
"grade": "7th"
},
"word_count": 312
}About the studio
Built to solve
real problems.
API Phase Studio exists because most developer tooling is either under-engineered or wrapped in too much product. We pick hard, specific infrastructure problems — the kind that come up in production and don't have a clean off-the-shelf answer — and we build a focused API around each one.
Every API we ship is built on a proven, battle-tested open-source engine. We don't reinvent the math or the data model. We do the hosting, the versioning, the documentation, and the edge cases — so you don't have to spin up and maintain a service yourself.
More APIs are in development. If you have a use case that fits this model, the best place to reach us is through our RapidAPI listings.