API

Build your own global telecom product. Live in two weeks.

FULL PLATFORM, ONE API

Every product in the Firsty suite through a single API, fully white-labeled with your brand, your pricing, and your experience. Most partners are live in two weeks. Building telecom infrastructure takes years. Firsty's API gives you the full platform in a fraction of the time.

For your users

BRANDED EXPERIENCE

A fully branded telecom experience inside your product.

FULL SUITE ACCESS

Access to the full Firsty suite under your brand.

GLOBAL CONNECTIVITY

High-performance connectivity globally.

For you as a partner

White-label

Full white-label customisation of every Firsty product, from interface to checkout.

Fast & Documented

Sub 1 second API response time, with full developer documentation at developers.firsty.app.

Sandbox ready

Full sandbox and testing environment to validate your integration before going live.

99% Uptime

99% uptime SLA backed by enterprise-grade telecom infrastructure.

Two-week launch

Two week integration timeline from kickoff to live in production.

BUILT FOR EVERY USER MOMENT

A new global telecom infrastructure, accessible through one API. Built from the ground up by ex Adyen lead engineers to handle data, eSIM, and calling at scale, with the reliability and performance of a modern platform.

How it works

Build telecom into your product. Live in two weeks.

Explore the documentation

Understand the API

Visit developers.firsty.app to understand the full API capability.

Recieve SANDBOX

Request access

Test your integration in a full sandbox environment before going live.

BUILD YOUR INTEGRATION

Connect everything

Connect eSIM, local plans, calling, network switching, and any other Firsty products you need.

Go live

Launch in weeks

Most partners complete integration within two weeks.

Proof points

Integrate the full Firsty suite through one API and ship telecom in your product within two weeks. Sub 1 second response time, a full sandbox environment, and 99% uptime, all on infrastructure built for scale.

Looking up at glass skyscrapers against a clear sky

Ornate stone office building beside a modern glass tower

4.8

Out of 5 on Trustpilot

1.2 M +

Users on the Firsty platform

Build once, scale globally. Trusted by Uber, Grab, Mastercard, Belfius, and Siemens.

“Amsterdam-based telecom startup Firsty raises €5.1M Seed funding”

"Potential telcomarketdisruptor Firsty immediately brings in €1.1 Million"

"Belfius partners with Dutch eSIM disruptor Firsty for free global app access"

"Five million in growth capital for a Dutch eSIM provider"

“Why We Invested in Firsty: Democratizing Global Mobile Data with eSims”

"Nifty eSIM provider offers free mobile data for life wherever you are"

“Amsterdam-based telecom startup Firsty raises €5.1M Seed funding”

"Potential telcomarketdisruptor Firsty immediately brings in €1.1 Million"

"Belfius partners with Dutch eSIM disruptor Firsty for free global app access"

"Five million in growth capital for a Dutch eSIM provider"

“Why We Invested in Firsty: Democratizing Global Mobile Data with eSims”

"Nifty eSIM provider offers free mobile data for life wherever you are"

join the revolution

Ready to build your own telecom product? Drop us a line at partners@firsty.app

ISO 27001, PCI DSS, and GDPR compliance badges

Questions about the api?

We know, it sounds too good to be true. But it’s real. Here’s how.

What is the Firsty API?

The Firsty API is a single integration that gives partners access to the full Firsty telecom suite, including eSIM provisioning, local plans, international calling, cloud phone numbers, real-time network switching, and the partner dashboard. It is fully white-labeled, runs on infrastructure built for scale, and most partners are live within two weeks.

How long does Firsty API integration take?

Most partners complete Firsty API integration within two weeks. Our technical team supports you throughout the process.

Does the Firsty API have a sandbox environment?

Yes. A full sandbox and testing environment is available before going live with the Firsty API.

Where is the Firsty API documentation?

Full Firsty API documentation is available at developers.firsty.app.

What support is available during Firsty integration?

Documentation, sandbox access, and direct engineering support from the Firsty team are all available throughout integration.

What is the Firsty API response time?

Sub 1 second for all standard Firsty API calls.

Is there a minimum volume commitment for the Firsty API?

Pricing for the Firsty API is based on usage and volume. Contact our team to discuss your specific situation.

Is the Firsty API GDPR compliant?

Yes. Firsty is GDPR compliant and operates under licensed telecom frameworks in all supported markets.