# Gx402 SDK

## Docs

- [Erc 8004](https://docs.gx402.org/agent/erc-8004.md): Coming Soon
- [Authentication](https://docs.gx402.org/api-reference/authentication.md): Details on API authentication for the Gx402 SDK.
- [Core Functions API](https://docs.gx402.org/api-reference/core-functions.md): API reference for Gx402 SDK core functionality
- [Gx402 SDK API Reference](https://docs.gx402.org/api-reference/introduction.md): Complete API reference for the Gx402 SDK
- [Architecture](https://docs.gx402.org/architecture.md): Learn how the Gx402 architecture connects x402 payments across Unity, Unreal, WebGL, and more using middleware and backend servers.
- [Authentication](https://docs.gx402.org/backend/authentication.md): How to authenticate clients, secure server-to-provider calls, and verify wallet signatures.
- [Backend overview](https://docs.gx402.org/backend/backend-overview.md): High-level backend role for x402 and how Gx402 middleware ties platforms together.
- [Errors and status codes](https://docs.gx402.org/backend/errors-and-status-codes.md): Common HTTP error responses, provider error mapping, and best practices for returning structured errors.
- [Mock](https://docs.gx402.org/backend/mock.md): How to safely test Gx402 integrations locally and in staging using mocks and testnet.
- [Payment flow](https://docs.gx402.org/backend/payment-flow.md): Step-by-step payment lifecycle: create → sign → confirm → finalize and the responsibilities of each layer.
- [Webhooks](https://docs.gx402.org/backend/webhooks.md): How to receive, verify, and process Gx402 (or relay) webhooks and reconcile payment state.
- [Contributing to Gx402](https://docs.gx402.org/community/contributing.md): How to contribute to the Gx402 SDK and documentation
- [Community Showcase](https://docs.gx402.org/community/showcase.md): See projects built with Gx402 SDK
- [Community Support](https://docs.gx402.org/community/support.md): Get help and support for Gx402 SDK
- [Core Concepts](https://docs.gx402.org/core-concepts.md): This page explains the key terms used across our examples. Everything here assumes you are using **x402** directly; Gx402 examples show how to structure server middleware and client flows.
- [Facilitator](https://docs.gx402.org/facilitator.md): Comprehensive, production-ready documentation for the GX402 Facilitator architecture, endpoints, request/response schemas, examples, deployment, security, and troubleshooting.
- [Advanced Gaming Mechanics](https://docs.gx402.org/features/advanced-gaming-mechanics.md): Advanced monetization and game mechanics powered by Gx402.
- [Data Management](https://docs.gx402.org/features/data-management.md): Manage game data with Gx402 SDK
- [Genre Templates](https://docs.gx402.org/features/genre-templates.md): Pre-built payment logic for common game genres.
- [Real-time Sync](https://docs.gx402.org/features/real-time-sync.md): Synchronize game states across platforms with Gx402
- [Security](https://docs.gx402.org/features/security.md): Security architecture and features of the Gx402 SDK.
- [Glossary](https://docs.gx402.org/glossary.md): A glossary of terms related to the Gx402 SDK and the technologies it uses.
- [Installation](https://docs.gx402.org/installation.md): Gx402 provides example projects and server middleware, Use the templates to see how to call x402, then add your x402 credentials and wallet integration.
- [Overview](https://docs.gx402.org/overview.md): Get started with Gx402  in minutes
- [Base Mini-App Integration](https://docs.gx402.org/platforms/base.md): Use Gx402 patterns to integrate x402 payments into Base Mini-Apps and Unity/Unreal builds running on Base network.
- [Farcaster & Mobile Integration](https://docs.gx402.org/platforms/farcaster.md): Use Gx402 patterns to add x402 payments into Farcaster miniapps and in-game purchases using Unity or Unreal builds. This page adapts the x402 miniapp approach and extends it for engine-built miniapps and in-game flows.
- [Mobile Integration](https://docs.gx402.org/platforms/mobile.md): Integrate Gx402 SDK with mobile applications
- [Telegram Miniapp Integration](https://docs.gx402.org/platforms/telegram.md): Adapt the Gx402 x402 payment flow for Telegram Mini-Apps and Unity WebGL games running inside Telegram. Covers init-data auth, WebApp SDK, invoice vs on-chain flows, and example server + frontend snippets.
- [Unity Integration](https://docs.gx402.org/platforms/unity.md): How to integrate x402 payments in Unity using Gx402 middleware patterns.
- [Unreal Engine Integration](https://docs.gx402.org/platforms/unreal-engine.md): Blueprints and C++ examples to integrate Gx402 payments in Unreal Engine.
- [Pricing](https://docs.gx402.org/pricing.md): Information on the pricing and monetization strategy for the Gx402 SDK.
- [Quick Start](https://docs.gx402.org/quick-start.md): This page shows the fastest path to a working Gx402 payment: create a payment session, sign it with a wallet, and confirm it using the backend.
- [Basic Integration Tutorial](https://docs.gx402.org/tutorials/basic-integration.md): Step-by-step guide to integrating Gx402 SDK in your game
- [Custom Workflows](https://docs.gx402.org/tutorials/custom-workflows.md): Define your own logic and event triggers inside Gx402 — coming soon.
- [Hello World with Gx402](https://docs.gx402.org/tutorials/hello-world.md): Your first Gx402-powered game
- [Multi-Platform Sync](https://docs.gx402.org/tutorials/multi-platform-sync.md): Seamless sync between Unity, Unreal, Web, and Mobile — coming soon.
- [Performance Optimization](https://docs.gx402.org/tutorials/performance-optimization.md): Optimize runtime efficiency with Gx402 performance tools — coming soon.
- [What is Gx402?](https://docs.gx402.org/what-is-gx402.md): Gx402 is a practical collection of **x402 integration examples** tailored for games and mini-app platforms. It demonstrates how to integrate x402 payment flows (create → sign → confirm → finalize) across Unity, Unreal, WebGL, Telegram, Farcaster, and more — using small server middleware examples you…

## OpenAPI Specs

- [openapi](https://docs.gx402.org/api-reference/openapi.json)

## Optional

- [GitHub](https://github.com/0xDeepanshu/docs)
- [Discord](https://discord.gg/RSzdmPWQ)
- [Twitter](https://x.com/gx4O2)