REST API

Introduction

Welcome to OnnXpay’s API reference documentation. OnnXpay provides programmatically matched, peer-to-peer USDT deposit and automated payout infrastructure for platforms, merchants, and vendors.


HTTP / JSON API

We chose standard HTTP-over-JSON for convenience and ease of integration. Most users should be able to connect with our API without a major re-architecture of their existing backend systems.

Any standard HTTP client in Node.js, Python, Go, PHP, or cURL can make requests to our API.

POST-only Endpoints

If you look at the Payin reference and Payout reference, you’ll notice that all transactional requests to OnnXpay are HTTP POST requests.

Base URLs & Production Host

All API requests must be made over secure HTTPS:

Payin & Checkout Gateway Hosthttps://checkout.onnxpay.com
Payout Settlement Hosthttps://onnxpay.com

Authentication

Authentication is verified per request depending on the endpoint type:

Payin API: Pass your api key in the request header: x-api-key: YOUR_API_KEY
Payout API: Pass your api key in the request body payload: "api_key": "YOUR_API_KEY"

⚠️ Security Notice: Always keep your API keys confidential. Do not expose them in browser applications or frontend client repositories. All API calls should be executed from your server backend.

API Reference Guides