Delta — Visual Flow Automation on Arc Testnet

Delta is a visual node-based money-flow automation platform built for the Circle Arc Hackathon. Users can design, test, and run automated payment workflows (Swaps, CCTP Bridges to Solana, EVM Sends, Notifications) on Arc Testnet (#5042002) using Circle Developer-Controlled Wallets and Circle App Kit.

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Core Features

• Privy Passwordless Authentication: Seamless email OTP authentication powered by Privy (Circle/Arc ecosystem partner with 499 free MAU / 50k signatures / $1M volume free).
• Circle Custodial Developer-Controlled Wallets: Automatic user wallet provisioning on Arc Testnet ("ARC-TESTNET") bound to a single application-wide Wallet Set.
• Circle App Kit Multi-Chain Integration: Token swaps (USDC $\rightarrow$ EURC), multi-chain CCTP forwarder bridges (Arc_Testnet $\rightarrow$ Solana Devnet, Arbitrum Sepolia, Base Sepolia, Ethereum Sepolia, OP Sepolia, Polygon Amoy, etc.), and EVM USDC transfers.
• Arc Multi-Node Provider RPC Fallback: Built using viem fallback transport across official Arc node provider partners (Arc Public RPC, Blockdaemon, dRPC).
• Durable Background Execution & Live Audit Trail: Sequential workflow automation steps managed via Inngest with real-time granular log state updates (RUNNING $\rightarrow$ PARTIAL $\rightarrow$ COMPLETE).
• Cryptographic Webhook Verification: Runtime Circle Webhook signature verification using ECDSA + SHA-256 and dynamic public key caching.
• Visual Flow Editor (@xyflow/react): Node palette supporting Trigger (USDC Received), Swap, Bridge, Send, Notify, and Hold nodes with strict $\le 100%$ allocation validation.

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Getting Started & Setup

1. Installation

git clone https://github.com/keoyle52/Delta.git
cd Delta
npm install --legacy-peer-deps

2. Environment Configuration

Copy .env.example to .env and fill in your credentials:

cp .env.example .env

3. Database Synchronization (Neon PostgreSQL)

npx prisma db push

4. Configure Privy App & Register Circle Entity Secret

1. Create a free app at dashboard.privy.io and obtain your NEXT_PUBLIC_PRIVY_APP_ID and PRIVY_APP_SECRET.
2. Run the one-time Circle setup scripts:

# Register Entity Secret on Circle Developer Console
npx tsx scripts/register-entity-secret-sdk.ts

# Create single application-wide Wallet Set
npm run setup:wallet-set

5. Running Locally

Local development requires running two terminal windows concurrently:

# Terminal 1: Next.js App Router Server
npm run dev

# Terminal 2: Inngest Background Job Runner
npm run inngest:dev

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Built on Arc Attribution Note & Simulation Mode

Delta is purpose-built for the Circle Arc Hackathon. All native gas fees and transaction settlements on Arc Testnet use USDC with sub-second deterministic finality.

Demo & Jury Access: Demo access uses an isolated Simulation Mode that runs entirely within the database and memory. Demo visitors can test full workflow automation with simulated deposits and execution steps without touching real custodial wallets or incurring any real platform gas or fund risk.

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Production Security Checklist

Before deploying Delta to production environments, complete the following security verifications:

1. Rotate NEXTAUTH_SECRET: Replace default secret with a strong random 32+ character key (openssl rand -hex 32).
2. Rotate RPC & Provider API Keys: Replace any test Alchemy keys (ARC_RPC_PRIMARY) and Circle API keys (CIRCLE_API_KEY) with production-scoped tokens.
3. Enforce Rate Limiting & Webhook Validation: Verify that SSRF protection (validateWebhookUrl) and rate limiting middleware (checkRateLimit) remain active across all endpoint handlers.
4. Dedicated Arc RPC Notice:

   Important: For production/demo use, ARC_RPC_PRIMARY must be set to a dedicated RPC endpoint (e.g. Alchemy) in Vercel environment variables — the public fallback RPC may have stricter rate limits and could cause getTransactionReceipt calls to fail silently (resulting in null fee data).

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Internal Development Scripts

The scripts/ directory contains internal setup and maintenance scripts (create-wallet-set.ts, register-entity-secret-sdk.ts, clean-old-executions.ts). These are internal developer tooling scripts and not part of the runtime web application bundle.