--- updatedAt: 2026-06-27T12:05:30.000Z agentTools: projectIndex: https://foxentry.dev/llms.txt --- # FAQ

Quick answers for developers integrating the Foxentry REST API. Can't find what you need? Reach us at dev@foxentry.com.

🚀 Getting started

How do I create an API project?

Sign in to our app and create a new project from your dashboard. Name it, choose whether it's for you or for a client, and pick the Application project type — that's the one for REST API integrations.

💡 Building a website or e-shop instead of an app? Consider a Web project (script) — you drop a snippet into your site (or GTM) and get ready-made autocomplete, validation and the Fix autocomplete feature without writing any frontend code.
Where do I get my API key?

In the app, open your project → Settings → API keys → Create API key. A project can have any number of keys, so you can separate e.g. production from testing, or per-developer access.

When creating a key you can set a name, an optional expiration, and an IP restriction.

🔐 The full key is shown only once, right after it's created — afterwards you'll see just part of it. Store it somewhere safe (e.g. a password manager). If you lose it, you'll need to generate a new one.
Can I try it for free?

Yes! Every new API project comes with a 14-day free trial — currently 50 requests for each of our services — so you can test everything end to end.

New here? Just sign up. Already a client? Simply create a new project in the app.

🔌 Using the API

How do I authenticate and make my first call?

Send your key as a Bearer token in the request header, and specify the API version:

Authorization: Bearer YOUR_API_KEY
Api-Version: 2.1

Full details, headers and a "Try it" console are on the Authentication and API call pages.

Which API version should I use, and how do I pin it?

The latest version is 2.1. If you don't send the Api-Version header, the API uses the latest version automatically. To pin a specific version, send e.g. Api-Version: 2.1.

Upgrading from 2.0? See the Migrating from 2.0 guide — it lists the breaking changes for names and phone numbers.

Do you have SDKs?

Yes — official open-source SDKs handle request/response formatting for you and cut integration time significantly:

LanguageRequirementRepo
PHP8.1+php-sdk
JavaScript / TSNode 18+js-sdk
C#.NET 8.0+c-sharp-sdk
Swift5.0+swift-sdk
KotlinJava 17+kotlin-sdk
What can the API validate?

Five data categories, each with validation, autocomplete and detailed lookups where applicable:

  • 📍 Addresses — validation, autocomplete, localization, detailed info
  • 💼 Companies — validation, autocomplete, detailed registry info
  • ✉️ Emails — validation, domain autocomplete
  • 📞 Phone numbers — validation, prefix suggestions
  • 👤 Names — validation, correction, vocative & gender, name days

Browse all endpoints on the API Reference.

Which countries do you support?

Coverage keeps growing. Emails and phone numbers work worldwide; addresses, companies and names depend on the country. See the always-current list on the Supported countries page.

💳 Credit & billing

I'm getting a 402 / "No credit available" error

That means your project has run out of credit — authentication is fine, there's just nothing to draw from. Top up in your project administration at app.foxentry.com and the calls will go through again.

💡 To avoid this in production, enable automatic top-up — the system re-buys your package when credit drops below a threshold (available with card payment).
How do I top up credit?

In the app, open Tariff / credit packages → Choose tariff, then pick a model:

  • Monthly tariffs — a set number of requests that resets each period; best for stable, high-volume projects.
  • Credit packages — a bundle of credits valid for 2 years, drawn down as you use them; best for smaller or seasonal projects.

You configure services per category (addresses, companies, emails, phones, names) and pay by card (Braintree) or bank transfer.

What's the pricing?

You pay only for what you use — each request deducts its value from your credit. See the full price list here. Pay as you go (or pay as you grow).

🔐 Security & keys

How do I keep my API key secure?
  • Store it in a password manager — it's shown in full only once.
  • Set an expiration date so a leaked key stops working after a while.
  • Add an IP restriction so the key only works from your servers.
  • If you suspect a key was exposed, use Regenerate key in the app — the old one stops working immediately.
Do API keys expire?

Only if you want them to. Expiration is optional — set it when creating a key, or add it later via the key's … → Edit menu. Leave it empty for an unlimited key. Rotating keys regularly is good practice for security.

How is my data protected?

Personal data is sacred to us — we never store it. Every entry is anonymized and encrypted, with no decryption key, so even in the event of an attack your data can't be stolen.

More in our privacy policy, GDPR information and data code.

🆘 Support

Need more help?

If you can't find the answer in the documentation, reach out — Monday to Friday, 9:30–17:00:

E-mail: dev@foxentry.com
Helpline: +420 277 278 678