Hosted checkout in 2 minutes. Custom integration in a day.

A clean REST API, four official SDKs, and a sandbox with test cards. Built by developers, for developers.

Quickstart

Create a payment in 4 lines.

Pick your language. The same operation, in every supported SDK.

curl https://api.fyber.one/v1/charges \
  -u sk_test_...: \
  -d amount=25000 \
  -d currency=jmd \
  -d source=tok_visa \
  -d description="Charge for test@example.com"
What you can build

From drop-in to fully custom.

🛍️

Hosted checkout

Drop-in payment pages — no integration required.

🔗

Payment links

Shareable URLs, branded, with custom slugs.

🛒

Custom checkout

Build your own UI with our card capture endpoints.

🔁

Subscriptions

Recurring billing with proration and dunning.

🪜

BNPL / Installments

Schedule, cadence, retries — all configurable.

📨

Webhooks

Signed event delivery with retries.

API design

Predictable. Documented. Versioned.

Six principles every endpoint follows. No surprises in production.

REST + JSON

Predictable HTTP verbs, JSON in and out, ISO 8601 timestamps, ISO 4217 currencies.

Idempotency keys

Pass an Idempotency-Key header on POSTs. Safe to retry — same key returns same response.

Cursor pagination

List endpoints use cursor-based pagination. Use the next_cursor in the response to fetch the next page.

Signed webhooks

HMAC-SHA256 over the request body. Verify with your webhook signing secret before processing.

Versioning

API version is in the URL (/v1). Breaking changes ship as new versions; old versions are supported for 12 months.

Rate limits

Per-key, per-endpoint. 429s come with a Retry-After header. We email you well before you hit a limit.

SDKs

Four official SDKs.

Same API surface in every language. Type definitions included.

JavaScript / Node

Works in Node 18+ and modern browsers. TypeScript-first.

npm i @fyber.one/sdk-js

PHP

PHP 8.1+. Composer package on Packagist.

composer require fyber/sdk-php

.NET

.NET 8+. NuGet package, full async/await.

dotnet add package Fyber

Flutter

Dart 3+. Mobile and web. Hosted checkout WebView helper included.

flutter pub add fyber

Build your first integration in an afternoon.

Test API keys are free. The sandbox is always live.