API documentation

Merchant REST API for ULX Pay (signed merchant + sign headers). Live base URL: /api/v1

Quick start

How to obtain the payment API key and the payout API key.

Authentication, headers, and signature generation.

Create invoices, poll status, and receive payment webhooks.

Basic information about payment methods.

How to create a payment invoice via API.

Withdrawals, payout webhooks, and balance endpoints.

Basic information about payout methods.

How to send funds via API.