> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Reference

> GatePay API Reference grouping and endpoint index.

This page helps you locate endpoint groups and individual APIs quickly. If you are integrating GatePay for the first time, start with [Quickstart](/essentials/version/100/en/common/quickstart), [Merchant Access](/essentials/version/100/en/common/accessguide), and the relevant product guides before returning to the API reference.

Review the API Reference in the following order:

1. [Merchant Access](/api-reference/version/100/en/common/merchantAccess)
2. [Security and Signature](/api-reference/version/100/en/common/securityAndSignature)
3. [Async Notification](/api-reference/version/100/en/common/asyncNotification)
4. [Error Codes](/api-reference/version/100/en/common/errorCodes)
5. Balance: balance, fees, and fund records
6. Institution: accounts, fee settings, charge, transfer, callback, and merchant APIs
7. Payment: customer management, orders, checkout, address payment, static address, call payment, QR pay, web payment, and notification
8. OTC: quote, on-ramp, off-ramp, bank accounts, and notification
9. Convert: exchange, assets, and rates
10. Payout: withdraw, chains, balance and fees, records, and notification
11. Gift Card: cards, templates, and balance
12. Subscription: products, plans, orders, deductions, and notification

The left navigation already follows this structure. Continue drilling down within each product group to inspect request fields, response schemas, and examples for every endpoint.