How It Works • Architecture • Features • Contracts • Quick Start

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Gambit is a native iOS + Apple Watch app for trading 5-minute crypto prediction markets. Swipe right for UP, swipe left for DOWN — trade executes in ~3 seconds. No seed phrases, no browser extensions, no complex DeFi interfaces. Just your watch and a market opinion.

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⌚ GAMBIT — Prediction Markets on Your Wrist

🔴 The Problem

Prediction markets are powerful tools for price discovery and hedging, but they're trapped behind desktop-only interfaces that require technical crypto knowledge. Polymarket — the largest prediction market — has no mobile trading, no watch app, and requires manual wallet management.

Meanwhile, millions of people check their Apple Watch dozens of times a day. What if they could act on a market view in 2 seconds?

💡 The Solution

Gambit brings prediction markets to the most personal device you own. Real-time crypto charts on your wrist, instant swipe-to-trade, and automatic settlement — all powered by an embedded MPC wallet that requires zero crypto knowledge from the user.

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⚡ How It Works

1. 📱 Open iPhone app → tap "Get Started" → sign in with email (no seed phrase)
2. 🔐 Wallet is created automatically and configured for trading (one-time, ~10 seconds)
3. 💰 Deposit USDC to your wallet address
4. ⌚ Open Apple Watch → see live crypto charts → swipe to trade
5. 🏆 Watch positions resolve → claim winnings from iPhone

🔧 Under the Hood (~3 seconds)

Watch swipe
  → WatchConnectivity message to iPhone
  → iPhone asks backend to prepare EIP-712 order data
  → Dynamic embedded wallet silently signs (no user prompt)
  → Backend submits signed order to Polymarket CLOB
  → Polymarket matches the order (Fill-or-Kill)
  → Result flows back to Watch with haptic feedback

The user never sees a transaction, never approves a popup, never deals with gas.

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🏗️ Architecture

┌─────────────┐     WatchConnectivity     ┌─────────────┐
│ Apple Watch │ ◄──────────────────────► │   iPhone    │
│  SwiftUI    │    price data + trades    │  SwiftUI    │
│  Charts     │                           │  Dynamic SDK│
└─────────────┘                           └──────┬──────┘
                                                  │ HTTPS
                                                  ▼
                                          ┌──────────────┐
                                          │   Backend    │
                                          │  Fastify+TS  │
                                          │  PostgreSQL  │
                                          │    Redis     │
                                          └──┬───┬───┬──┘
                                             │   │   │
                              ┌──────────────┘   │   └──────────────┐
                              ▼                  ▼                  ▼
                      ┌──────────────┐  ┌──────────────┐  ┌──────────────┐
                      │  Polymarket  │  │   Binance    │  │   Polygon    │
                      │  CLOB API   │  │  WebSocket   │  │     RPC      │
                      │  Orders     │  │  BTC/ETH/XRP │  │   USDC/CT    │
                      └──────────────┘  └──────────────┘  └──────────────┘

🛠️ Tech Stack

Layer	Technology	Purpose
📱 iOS App	SwiftUI, Combine, Dynamic SDK	Native UI + embedded MPC wallet
⌚ watchOS App	SwiftUI, WatchConnectivity	Swipe-to-bet + live charts
⚙️ Backend	Node.js, TypeScript, Fastify	Order orchestration + market discovery
🗄️ Database	PostgreSQL + Drizzle ORM	Users, wallets, orders, audit log
⚡ Cache	Redis	Market data, L2 creds, price history
⛓️ Blockchain	Polygon PoS, Arc Testnet	Polymarket settlement + custom markets
📈 Market Data	Binance WebSocket, Polymarket CLOB	Real-time spot prices + odds
🔗 Oracle	Chainlink CRE	Decentralized market settlement
🔐 Wallet	Dynamic.xyz	Embedded MPC wallet, no seed phrases
🌐 Deployment	Hetzner Helsinki, Caddy	Auto SSL, no VPN needed

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✨ Key Features

⌚ Swipe-to-Bet on Apple Watch — See a 60-second live price chart, swipe right for UP or left for DOWN. Digital Crown selects bet amount. Trade executes in ~3 seconds with haptic feedback.

🔐 Zero-Friction Onboarding — Sign in with email, wallet is created automatically. No seed phrases, no browser extensions, no MetaMask popups. Dynamic's MPC wallet handles everything.

✍️ Client-Side Signing — All blockchain transactions are signed on the iPhone using Dynamic's embedded wallet SDK. The backend never has access to private keys. Custodial-level UX with self-custodial security.

🔄 Dual Settlement Layer — Trade on Polymarket (Polygon) for deep liquidity, or switch to Arc Testnet for custom prediction markets with Chainlink CRE settlement. Toggle between networks from settings.

📡 Real-Time Price Pipeline — Binance WebSocket → Redis → SSE → iPhone → WatchConnectivity → Watch. Sub-second price updates across the entire stack.

🤖 Automatic Settlement — 5-minute markets resolve automatically. Chainlink CRE fetches final price, achieves DON consensus, and calls settleMarket() on-chain. Winners receive USDC automatically.

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📜 Smart Contracts

GambitMarket.sol — Arc Testnet

Deployed at 0xfE3dd8F80051B2F3da054F8657BaF016478697bD

Function	Description
createMarket(asset, strikePrice, duration)	Creates a new 5-min prediction market
placeBet(marketId, direction, amount)	Places a USDC bet on UP or DOWN
settleMarket(marketId, finalPrice)	Resolves market with final price (CRE or operator)
claim(marketId)	Winners withdraw proportional USDC payout
requestSettlement(marketId)	Emits SettlementRequested event for CRE

Polymarket Contracts — Polygon

Contract	Address	Usage
CTF Exchange	0x4bFb41d5...982E	Order matching engine
Neg Risk Exchange	0xC5d563A3...f80a	Negative risk markets
Conditional Tokens	0x4D97DCd9...0045	ERC-1155 outcome tokens
USDC.e	0x2791Bca1...4174	Settlement token

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🔗 Chainlink CRE Integration

The CRE workflow provides decentralized, trustless market settlement:

1. 📋 Contract emits SettlementRequested(marketId, asset, strikePrice, endTime)
2. 👁️ CRE DON nodes detect the event via LogTrigger
3. 🌐 Each node fetches price from Binance API via HTTPClient
4. 🤝 Nodes reach consensus on the price (identical aggregation)
5. 📝 Workflow generates a signed report with encoded settlement data
6. ⛓️ Report is written on-chain → settleMarket() executes
7. 💸 Winners receive proportional USDC payout

Compiled to WASM. Backend provides an operator fallback for demo.

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🛡️ Security Model

Layer	Approach
🔑 Key Management	Dynamic MPC — key shares split between infra and device
✍️ Signing	Client-side EIP-712 on iPhone — backend never touches keys
🎫 Sessions	JWT tokens stored in iOS Keychain
🔒 API Auth	HMAC L2 signatures on every Polymarket call
🌐 RPC	Custom Polygon endpoint — no rate-limited defaults

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📁 Project Structure

gambit/
├── backend/                    # ⚙️ Node.js Fastify server (Polymarket)
│   ├── src/
│   │   ├── modules/            # auth, orders, markets, wallet, prices
│   │   ├── lib/                # polymarket client, dynamic SDK, errors
│   │   ├── plugins/            # postgres, redis, auth, websocket
│   │   └── db/                 # schema + migrations (Drizzle)
│   └── package.json
├── ios/
│   ├── Gambit/                 # 📱 iPhone app (SwiftUI)
│   │   ├── Auth/               # AuthManager, DelegationManager, Keychain
│   │   ├── Views/              # LoginView, DashboardView, OnboardingView
│   │   ├── Networking/         # APIClient, WebSocketManager
│   │   └── WatchBridge/        # WatchSessionManager
│   ├── GambitWatch/            # ⌚ Apple Watch app (SwiftUI)
│   │   ├── Views/              # MarketView, ActivePositionView, Charts
│   │   └── Connectivity/       # PhoneConnector, HTTPFallback
│   └── Shared/                 # SharedModels, MessageKeys
├── arc/
│   ├── contracts/              # 📜 GambitMarket.sol (Foundry)
│   ├── cre-workflow/           # 🔗 Chainlink CRE TypeScript workflow
│   └── backend/                # ⚙️ Arc-specific Fastify server
└── README.md

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🚀 Quick Start

Prerequisites

• Node.js v22+, npm
• PostgreSQL, Redis
• Xcode 16+ (for iOS/watchOS)
• Foundry (for smart contracts)

Backend

cd backend
cp .env.example .env  # fill in credentials
npm install
npx drizzle-kit migrate
npm run dev

iOS App

cd ios
open Gambit.xcodeproj
# Select Gambit scheme → Build & Run on iPhone
# Select GambitWatch scheme → Build & Run on Watch

Arc Contracts

cd arc/contracts
forge build
forge script script/Deploy.s.sol --rpc-url https://rpc.testnet.arc.network --broadcast

CRE Workflow

cd arc/cre-workflow
bun install
bunx cre-compile main.ts gambit-workflow.wasm --skip-type-checks

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👥 Team

Built by ITU Blockchain at ETHGlobal Cannes 2026.

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🏆 Bounty Submissions

🔐 Dynamic — Embedded Wallet SDK

Native iOS embedded MPC wallet with client-side EIP-712 signing. Zero seed phrases, silent transaction signing, custom Polygon RPC configuration via evmNetworks.

🌐 Arc/Circle — Best Prediction Markets on Arc

GambitMarket.sol deployed on Arc Testnet. USDC-native settlement, 5-minute binary options on BTC/ETH/XRP. Stablecoin gas model.

🔗 Chainlink — Best CRE Workflow

TypeScript CRE workflow for decentralized market settlement. Fetches price from Binance via HTTPClient, DON consensus, signed report settles markets on-chain. Compiled to WASM.