Architecture Overview

CloudBank is a decentralized prediction market platform on BNB Smart Chain (BSC). The system enables users to trade on the outcomes of real-world events using binary (YES/NO) and multi-outcome markets, with AI-powered settlement and gasless transactions.

System Architecture

┌─────────────────────────────────────────────────────────────┐
│                      Frontend Layer                         │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐   │
│  │  Web App  │  │  Admin   │  │ Presale  │  │   Docs   │   │
│  │ React 19  │  │ Ant Dsn  │  │ Next.js  │  │VitePress │   │
│  └────┬─────┘  └────┬─────┘  └────┬─────┘  └──────────┘   │
│       │              │              │                        │
├───────┼──────────────┼──────────────┼────────────────────────┤
│       │         Backend Layer       │                        │
│       ▼              ▼              ▼                        │
│  ┌──────────────────────────────────────┐                   │
│  │       Custodial Wallet Service       │                   │
│  │        Go + Gin + GORM + JWT         │                   │
│  │   ┌─────────┐  ┌────────────────┐    │                   │
│  │   │Orderbook│  │  Signing/Auth  │    │                   │
│  │   │ Engine  │  │  EIP-191/712   │    │                   │
│  │   └─────────┘  └────────────────┘    │                   │
│  └──────────┬───────────────────────────┘                   │
│             │                                                │
├─────────────┼────────────────────────────────────────────────┤
│             │        Smart Contract Layer                    │
│             ▼                                                │
│  ┌──────────────────────────────────────┐                   │
│  │         BSC (BNB Smart Chain)        │                   │
│  │  ┌──────────┐  ┌────────────────┐    │                   │
│  │  │ Factory  │  │  Optimistic    │    │                   │
│  │  │ Registry │  │  Controller    │    │                   │
│  │  └──────────┘  └────────────────┘    │                   │
│  │  ┌──────────┐  ┌────────────────┐    │                   │
│  │  │ Binary   │  │  Sora Oracle   │    │                   │
│  │  │  CPMM    │  │  + Adapters    │    │                   │
│  │  └──────────┘  └────────────────┘    │                   │
│  │  ┌──────────┐  ┌────────────────┐    │                   │
│  │  │  Gnosis  │  │  Verifying     │    │                   │
│  │  │   CTF    │  │  Paymaster     │    │                   │
│  │  └──────────┘  └────────────────┘    │                   │
│  └──────────────────────────────────────┘                   │
│                                                              │
├──────────────────────────────────────────────────────────────┤
│                    Indexing Layer                             │
│  ┌──────────────────────────────────────┐                   │
│  │    The Graph (Goldsky hosted)        │                   │
│  │    AssemblyScript mappings           │                   │
│  │    GraphQL API                       │                   │
│  └──────────────────────────────────────┘                   │
└──────────────────────────────────────────────────────────────┘

Technology Stack

Layer	Technology	Purpose
Smart Contracts	Solidity ^0.8.19, Foundry	Market logic, AMM, oracle, paymaster
Backend	Go 1.23, Gin, GORM	Custodial wallet, orderbook engine, signing
Frontend	React 19, Vite, TanStack	Trading UI, admin panel
Presale	Next.js 16, wagmi	Node presale application
Database	MySQL (GORM), Redis	User data, sessions, rate limiting
Indexing	The Graph, Goldsky, AssemblyScript	On-chain event indexing, GraphQL API
Infrastructure	GitHub Actions, Cloudflare Pages, EC2	CI/CD, static hosting, backend deployment
Wallet	wagmi, viem, EIP-191/712	Wallet connection, signing
AA	ERC-4337, EntryPoint v0.6	Account Abstraction for gasless transactions

Module Map

• Smart Contracts — Solidity contracts, market lifecycle, CTF integration
• Orderbook & AMM — CPMM formula, orderbook engine, hybrid routing
• Settlement — Optimistic oracle, AI auto-settlement, dispute flow
• Gas Sponsorship — ERC-4337 AA, Paymaster, gasless transactions
• Backend Services — Go API, custodial wallet, authentication
• Frontend — React apps, wallet integration, state management
• Indexing — The Graph subgraph, GraphQL schema, event handlers
• Infrastructure — CI/CD, deployment, monorepo structure
• API Reference — REST API, contract ABI, GraphQL queries

Data Flow

A complete trading flow from user action to settlement:

User Action                    Backend                     Blockchain
────────────                   ───────                     ──────────
1. Connect Wallet         →
2. Sign EIP-191 message   →  Verify signature
3. Receive JWT            ←  Issue JWT token
4. Place order            →  Validate + match
5. Submit transaction     →  Sign with custodial key  →  Execute on BSC
6. Confirm                ←                           ←  Tx receipt
7. Position updated       ←  Subgraph indexes event
                              ...
8. Market expires                                     →  Oracle resolves
9. AI verifies result     →  Sora Keeper proposes     →  OptimisticController
10. Settlement            ←                           ←  CTF reports payouts
11. Redeem positions      →                           →  CTF.redeemPositions

External Dependencies

Dependency	Purpose	Integration
Gnosis CTF	ERC-1155 conditional tokens	Position minting, splitting, merging, redemption
ERC-4337 EntryPoint v0.6	Account Abstraction	UserOperation validation, gas sponsorship
Goldsky	Subgraph hosting	GraphQL API for indexed on-chain data
Alchemy	RPC provider	BSC node access (primary)
Cloudflare Pages	Static hosting	Frontend deployment