> ## 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. # GatePay Product Docs > Explore the latest GatePay guides and API references ## Quick Entry These entry cards cover the full merchant documentation path from onboarding and payments to OTC, convert, payout, and institution capabilities. Start with Overview, Quickstart, and Merchant Access, then continue into the product line you need. Review the documentation structure, integration prerequisites, base URL, credentials, and reading order. Run the first signing, order creation, callback, and order confirmation flow as quickly as possible. Check app creation, credential retrieval, callback setup, and pre-go-live requirements. Review signing, request headers, callback verification, and core security rules. Review callback handling rules, event types, terminal-state judgment, and processing order. See account balance, fees, fund records, and reconciliation guidance. Review collection/payout order list pulling, end-of-day reconciliation, and discrepancy investigation. Cover order payment, hosted checkout, address payment, web payment, and related callbacks. Review fiat on-ramp and off-ramp quotes, order creation, confirmation, queries, and callbacks. Review balance-based conversion, quote preview, order placement, and rate lookup. Review crypto withdrawals and fiat payouts, including initiation, queries, statuses, and callbacks. Review gift card creation, templates, queries, and balance usage scenarios. Review products, plans, subscription orders, deductions, and related notifications. Review the GatePay integration path for AI Agent and HTTP 402 payment scenarios. Review sub-accounts, charge, transfer, and the institution-side merchant APIs. Review Merchant MCP capabilities, target scenarios, and integration notes. Browse the full endpoint catalog, field definitions, and response structures by product module.