Architecture

Learn how the Gx402 architecture connects x402 payments across Unity, Unreal, WebGL, and more using middleware and backend servers.

Architecture Overview

Gx402 acts as a unified payment integration layer built on top of x402 — designed to bring seamless Web3 payments into game engines and web apps like Unity, Unreal, WebGL, Telegram Mini Apps, and Farcaster Mini Apps.

Instead of building a new SDK, Gx402 currently uses existing x402 SDKs and connects them through a shared backend and middleware layer.
This ensures consistent payments, authentication, and transaction handling across every platform.

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Core Components

1. Platform Layer

Each platform (Unity, Unreal, WebGL, Telegram, etc.) integrates the x402 payment logic using custom wrappers or scripts.
These wrappers handle:

• Player authentication
• In-game purchases or bets
• Sending transaction requests to middleware

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2. Middleware Layer

A lightweight service that connects platform clients to the Gx402 backend.
It helps handle:

• Platform-specific API differences
• Request normalization
• Security checks before server calls

Example: Unity and WebGL both send payment intents to /api/payments/initiate, which the middleware reformats before passing to the server.

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3. Gx402 Server

Your main Express.js backend where:

• Payment requests are validated
• User sessions are managed
• Calls are made to the x402 API
• Transactions are finalized and confirmed

This is where you can easily plug in logging, analytics, or game-specific rules.

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4. x402 API

The foundation of all payment logic.
It handles:

• Smart contract interactions
• Token transfers
• Receipt validation on-chain

Gx402 relies on x402 APIs for actual transaction execution while abstracting all the complexity away from game developers.

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5. Blockchain Layer

Finally, the blockchain network (e.g., Solana, Base, or Polygon) records every transaction initiated through x402.
You don’t need to interact with it directly — Gx402 handles all the bridging and wallet logic for you.

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Example Flow

1. Player triggers a purchase in Unity (e.g., buys a game pass).
2. Unity SDK wrapper sends a request → Middleware.
3. Middleware validates and sends it to the Gx402 Server.
4. Server processes and forwards to x402 API.
5. x402 API finalizes the payment on-chain.
6. Confirmation flows back through the same layers to the game.

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Key Difference from x402

Feature	x402	Gx402
SDK Type	Direct integration SDK	Middleware + Server bridge
Platform Coverage	Mostly web-based	Game engines + mini apps
Payment Flow	App → x402 → Blockchain	Platform → Middleware → Server → x402 → Blockchain
Customization	Limited	Fully customizable middleware and server logic
Deployment	Developer handles	Gx402 handles backend

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Future Plans

• Native Gx402 SDKs (import { gx402 } from "gx402";)
• Developer dashboard for payment tracking
• Custom tokens and NFTs integration
• Webhooks and realtime event streams

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