# TopPay - OpenAPI Integration Documentation
Welcome to use the TopPay OpenAPI documentation.
# Project Introduction
This document will provide you with effective assistance in using our products. Please read it carefully before starting the integration. If you have any questions, please consult via Telegram Messenger 👨💻 Devin (opens new window).
- API Common Parameters & Merchant Key Configuration
- API Signature Generation
- Fiat (Rupee) Proxy Loan Order Creation
- Fiat (Rupee) Proxy Loan Order Query
- Fiat (Rupee) Proxy Pay Order Creation
- Fiat (Rupee) Proxy Pay Order Query
- Fiat (Rupee) Proxy Pay Order UTR Replenishment
- Fiat (Rupee) Balance Query
- Order Status Callback Interface Specification