Arc Merchant

A full end-to-end demo of agentic commerce on Arc blockchain.

An AI agent discovers paywalled content, pays 0.01 USDC via x402, and receives it — autonomously, on-chain, no human approval. The merchant dashboard updates in real time as payments land.

🏆 2nd Place — Agentic Commerce on Arc Hackathon (January 2026) 🌐 Live demo: https://arc-merchant-production.up.railway.app 📋 Roadmap: ROADMAP.md

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What This Is

What This Is

┌─────────────────────────────────────────────────────────────┐
│              AI Agent (e.g., Claude Code)                   │
│              with Circle wallet + MCP tools                 │
└─────────────────────────────┬───────────────────────────────┘
                              │ x402 payment ($0.01 USDC)
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                      Arc Merchant                           │
│  ┌─────────────────────┐    ┌────────────────────────────┐  │
│  │  x402 Paywall API   │───▶│   Merchant Dashboard       │  │
│  │  /api/article/:slug │    │   - Real-time payments     │  │
│  └─────────────────────┘    │   - Revenue tracking       │  │
│                             │   - On-chain balance       │  │
│                             └────────────────────────────┘  │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                      Arc Blockchain                         │
│              USDC settlement  •  Circle Wallets             │
└─────────────────────────────────────────────────────────────┘

The buyer side (your chosen autonomous AI agent framework) manages wallets and signs x402 payments.

The seller side (next.js) provides paywalled content endpoints and a real-time dashboard showing payments as they arrive.

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How It Works

1. Content behind x402 paywall — Articles at /api/article/:slug require payment
2. AI agent requests content — Gets HTTP 402 Payment Required with price
3. Agent pays via Circle wallet — Signs x402 payment, sends USDC
4. Facilitator server settles on-chain — Verifies signature, submits to Arc L1
5. Content delivered — Agent receives the article
6. Dashboard updates — Merchant sees payment in real-time, can track receipts, sales, autonomous treasury, etc

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Architecture: Buyer vs Seller

This project contains both sides of the x402 payment flow:

Buyer Side (AI Agent Tools)

The src/tools/ SDK lets AI agents manage wallets and pay for content:

src/tools/core.ts        → Tool definitions (Zod + execute functions)
src/tools/adapters/      → MCP, SDK adapters
src/servers/mcp.ts       → MCP server for Claude Code

Seller Side (Facilitator + API)

The facilitator settles payments on-chain when agents pay for your content:

src/servers/facilitator.ts   → Receives signed payments, settles on Arc blockchain
src/app/api/article/         → x402-protected content endpoints
src/app/page.tsx             → Merchant dashboard

Use this if: You're a merchant accepting x402 payments for content.

The facilitator is required — it's what actually moves USDC on-chain. Think of it like your own payment processor.

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Quick Start

1. Install dependencies

npm install

2. Configure environment variables

Copy .env.local.example to .env.local and fill in:

# Circle API credentials (https://console.circle.com)
CIRCLE_API_KEY=
CIRCLE_ENTITY_SECRET=

# Facilitator wallet (create via arc_create_wallet, then add ID here)
CIRCLE_FACILITATOR_WALLET_ID=

# Google AI (for Vercel AI SDK with Gemini)
GOOGLE_GENERATIVE_AI_API_KEY=

# Google AI (for @google/genai SDK)
GEMINI_API_KEY=

3. Set up Circle Entity Secret (one-time)

npm run setup-circle

This generates and registers your Entity Secret with Circle (updates CIRCLE_ENTITY_SECRET).

4. Configure facilitator wallet

Create a Circle wallet to use as your facilitator (settles payments on-chain):

npm run wallet create

This outputs a wallet ID. Add it to .env.local:

CIRCLE_FACILITATOR_WALLET_ID=<your-wallet-id>

5. Run both servers

# Terminal 1: Facilitator (settles payments)
npm run facilitator

# Terminal 2: Next.js (dashboard + paywalled API server)
npm run dev

Open http://localhost:3000 to see the merchant dashboard.

6. Test a payment

In Claude Code with the arc-agent-payments MCP server:

"Pay for http://localhost:3000/api/article/arc-blockchain-guide"

Watch the dashboard update in real-time.

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Project Structure

arc-merchant/
├── src/tools/                    # Framework-agnostic AI tools (SDK core)
│   ├── core.ts                   # Tool definitions (Zod schemas + execute)
│   └── adapters/
│       ├── mcp.ts                # MCP adapter (Claude Code)
│       ├── vercel.ts             # Vercel AI SDK adapter
│       └── google-genai.ts       # Google GenAI SDK adapter
├── src/app/
│   ├── page.tsx                  # Merchant dashboard
│   └── api/
│       ├── article/[slug]/       # x402-protected content
│       └── stats/                # Dashboard data
├── src/lib/
│   ├── arc.ts                    # Arc chain config
│   ├── circle-wallet.ts          # Circle SDK
│   ├── x402.ts                   # x402 facilitator
│   └── stats.ts                  # Payment tracking
├── src/servers/
│   ├── facilitator.ts            # Payment settlement server
│   └── mcp.ts                    # MCP server for AI agents
├── src/agents/
│   ├── vercel-agent.ts           # AI agent using Vercel AI SDK
│   └── google-agent.ts           # AI agent using Google GenAI SDK (Gemini 3)
└── scripts/
    ├── setup-circle-entity.ts    # Circle entity secret setup
    ├── wallet-cli.ts             # Wallet management CLI
    ├── agent-vercel-demo.ts      # Demo: Vercel AI SDK agent
    └── agent-google-demo.ts      # Demo: Google GenAI agent

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Wallet CLI

Manage Circle wallets without AI:

npm run wallet create          # Create a new wallet
npm run wallet list            # List all wallets
npm run wallet balance <id>    # Get wallet balance
npm run wallet fund <address>  # Request testnet tokens

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AI Payment Tools (SDK)

Framework-agnostic tools for AI agents to manage Circle wallets and pay for content via x402.

Tools Available

Tool	Description
arc_list_wallets	List all Circle wallets
arc_get_wallet	Get details for a specific wallet
arc_create_wallet	Create a new Circle wallet
arc_get_balance	Check USDC/EURC balances
arc_pay_for_content	Pay for x402 paywalled content
arc_transfer	Direct USDC transfer
arc_request_testnet_tokens	Fund wallet from Circle faucet
arc_get_transaction	Get transaction details

Usage with MCP (Claude Code)

claude mcp add arc-mcp-server -- npm run mcp

Usage with Other Frameworks

The core tools are framework-agnostic. Import from src/tools/core.ts and create your own adapter:

import { arcTools } from './src/tools/core';

// Each tool has: name, description, inputSchema (Zod), execute (async function)
const result = await arcTools.arc_list_wallets.execute({});

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Pre-built AI Agents

Two ready-to-use agents for autonomous payments:

Google GenAI Agent (Gemini 3)

Uses Google's official @google/genai SDK with the latest gemini-3-flash-preview model:

npm run agent:google "Pay for http://localhost:3000/api/article/arc-blockchain-guide"

import { runGoogleAgent } from './src/agents/google-agent';

const result = await runGoogleAgent("List my wallets and pay for the article");
console.log(result.text);

Vercel AI Agent

Uses Vercel AI SDK (works with Gemini, OpenAI, Anthropic, etc.):

npm run agent:vercel "Check my wallet balance"

import { runAgent } from './src/agents/vercel-agent';
import { openai } from '@ai-sdk/openai';

// Default: Gemini 2.5 Flash
const result = await runAgent("Pay for the article");

// Or use any Vercel AI SDK model
const result = await runAgent("Pay for the article", {
  model: openai('gpt-4o')
});

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Tech Stack

• Arc — Circle's L1 blockchain with native USDC gas
• Circle Developer-Controlled Wallets — Secure wallet infrastructure
• x402 — Web-native micropayment protocol (HTTP 402)
• Zod — Schema validation (with native JSON Schema conversion for MCP)
• Next.js — Dashboard and API
• Vercel AI SDK — Model-agnostic (Gemini, OpenAI, Anthropic, etc.)
• MCP — Model Context Protocol for Claude Code integration
• USDC — Stablecoin payments

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Built for the Agentic Commerce on Arc Hackathon (January 2026)