ScuttlePay

ScuttlePay lets AI agents buy things online - no humans (or credit cards) required.

• For merchants: Allow AI agents to discover and purchase products from your store.

  1. A Shopify plugin that exposes your store's products to AI agents via an API.
  2. An admin dashboard for merchants to see purchases made by AI agents on their store.

• For agents: Browse items and buy products - without a human in the loop!

  1. A User dashboard where you can add funds and set spending limits for your AI agents.
  2. An agent skill to teach agents how to autonomously purchase products.

How It Works

Architecture

┌─────────────┐     REST API      ┌──────────────────────────────────────────────┐
│  AI Agent   │◄────(sk_* key)───►│              ScuttlePay                      │
│  (Claude)   │                   │                                              │
└─────────────┘                   │  ┌──────────┐  ┌──────────┐  ┌───────────┐  │
                                  │  │  Spending │  │  Wallet   │  │  Payment  │  │
                                  │  │  Policies │  │  Service  │  │  Service  │  │
                                  │  └────┬─────┘  └────┬──────┘  └─────┬─────┘  │
                                  │       │             │               │         │
                                  │       ▼             ▼               ▼         │
                                  │  ┌─────────┐  ┌──────────┐  ┌───────────┐   │
                                  │  │ Postgres │  │ thirdweb │  │  Stripe   │   │
                                  │  │          │  │ Engine   │  │  x402     │   │
                                  │  └──────────┘  └────┬─────┘  └─────┬─────┘  │
                                  └─────────────────────┼──────────────┼────────┘
                                                        │              │
                                                        ▼              ▼
                                                   ┌─────────┐  ┌───────────┐
                                                   │  Base    │  │  Shopify  │
                                                   │  (USDC)  │  │  Admin    │
                                                   └─────────┘  └───────────┘

ScuttlePay is a Next.js 15 app backed by PostgreSQL, thirdweb Engine for wallet management, and Stripe x402 for settlement. Agents authenticate with API keys (sk_*) and interact through a REST API — no MCP server or separate process needed.

Agent wallets and API keys

When a user signs up, ScuttlePay creates a server-side wallet on Base via thirdweb Engine. The user funds it with USDC, then creates API keys from the dashboard — each key is bound to a spending policy with per-transaction and daily limits (in USDC). The raw key is shown once; only a SHA-256 hash is stored.

Purchase flow

When an agent calls POST /api/mcp/purchase:

1. Product lookup — Fetch the product (and optional variant) from the merchant's Shopify Storefront API. Resolve the USDC price.
2. Serializable transaction — Inside a single Postgres SERIALIZABLE transaction:
   • Read the wallet's on-chain USDC balance
   • Evaluate spending limits (per-tx max, daily cap with UTC window)
   • Insert a PENDING transaction row
3. Settlement — Transfer USDC on Base to Stripe's x402 crypto deposit address (or directly to a settlement address in testnet mode). thirdweb Engine signs and submits the transaction.
4. Order creation — Create an order in Shopify Admin marked as PAID with the blockchain tx hash as payment proof. This step is non-fatal — if Shopify is down, the agent's payment still settles.

All USDC math uses bigint arithmetic (never floating point) to preserve 6-decimal precision.

Merchant onboarding

Merchants install the Shopify app, which stores their Storefront API token (for product browsing) and Admin API token (for order creation). They connect a Stripe account to receive settlement payouts. The merchant dashboard shows orders placed by agents and sales stats.

Agent-facing API

Method	Endpoint	Purpose
GET	/api/mcp/wallet	Balance and wallet info
GET	/api/mcp/merchants	List available stores
GET	/api/mcp/products	Search or get product details
POST	/api/mcp/purchase	Execute a purchase
GET	/api/mcp/transactions	Transaction history

Stack

Layer	Tech
Frontend	Next.js 15 (App Router), React 19, Tailwind 4, shadcn/ui
API	tRPC 11 + TanStack Query 5, Next.js route handlers
Database	PostgreSQL (Drizzle ORM)
Wallets	thirdweb Engine (server-side wallets on Base)
Payments	Stripe x402 crypto mode (USDC on Base)
Validation	Zod (shared schemas in packages/shared)
Auth	thirdweb wallet signatures (JWT) + API keys

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Configuration

Two environment variables are required:

Variable	Description
SCUTTLEPAY_API_KEY	Your API key (starts with sk_) — get it from the dashboard
SCUTTLEPAY_API_URL	ScuttlePay instance URL (e.g. https://scuttlepay.com)

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Safety

The plugin instructs Claude to always confirm purchases with you before executing. Your agent will show the product, price, and merchant before spending any USDC.

Spending limits (per-transaction and daily) are configured when you create your API key in the dashboard. Limits are enforced server-side inside a serializable database transaction — agents cannot circumvent them.

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License

MIT — see LICENSE