Amazon MCP App

[!WARNING] Extremely experimental. This is a demo/spike to exercise the MCP Apps (interactive widget) surface. APIs, tool shapes, and the widget itself will change without notice. Not affiliated with Amazon.

Live endpoint: https://amazon-mcp-app.vercel.app/mcp (streamable-HTTP)

Claude Desktop config:

{
  "mcpServers": {
    "amazon-shopping": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://amazon-mcp-app.vercel.app/mcp", "--transport", "http-only"]
    }
  }
}

---

Demo MCP app that lets Claude deep-research Amazon products across many keyword searches, then present a curated set in an interactive, Amazon-flavored carousel widget the user can add-to-cart from — checkout hands off to the real amazon.com cart.

Built on the official TypeScript MCP SDK + @modelcontextprotocol/ext-apps. Headless aside from the one widget. Stateless streamable-HTTP transport, so it drops straight onto Vercel / any Node host.

┌──────────┐  search_amazon ×N   ┌────────────────┐
│  Claude  │────────────────────>│ amazon-mcp-app │──> SerpApi (Amazon engine)
│   host   │<─────── JSON ───────│  (remote HTTP) │    (swap for PA-API later)
│          │                     │                │
│          │ present_amazon_…    │                │
│          │────────────────────>│                │
│ ┌──────┐ │<── widget ref ──────│  widgets/      │
│ │iframe│ │<── resources/read ──│  carousel.html │
│ │ 🛒   │ │                     └────────────────┘
│ └──┬───┘ │
└────┼─────┘
     └─ "Go to cart" → https://www.amazon.com/gp/aws/cart/add.html?ASIN.1=…

---

Tools

Tool	Kind	What it does
search_amazon	headless, read-only	Keyword search via SerpApi's Amazon engine. Returns { asin, title, price, rating, reviews, prime, thumbnail, url }[]. Claude is instructed to call this multiple times with different phrasings to explore the option space.
present_amazon_products	MCP-app widget	Takes a curated products[] (from search results) and renders a sideways-scrolling carousel. Users toggle Add to cart per item; Go to cart opens amazon.com/gp/aws/cart/add.html?ASIN.1=…&Quantity.1=… in a new tab. Cart state is echoed back to Claude via updateModelContext.

The widget handles both same-category comparisons ("5 quiet mechanical keyboards") and cross-category bundles ("desk setup: keyboard + mat + lamp") — it's just a flat list of ASINs, heading is free-form.

---

Run locally

npm install
export SERPAPI_KEY=your_key_here   # https://serpapi.com/manage-api-key
npm run dev                        # → POST http://localhost:3000/mcp

Poke it with the MCP Inspector:

npx @modelcontextprotocol/inspector
# → Streamable HTTP → http://localhost:3000/mcp → Connect

Or connect from Claude Code:

claude mcp add --transport http amazon http://localhost:3000/mcp

---

Env

Var	Required	Notes
SERPAPI_KEY	✅	SerpApi key. Stand-in for the real Amazon Product Advertising API — src/serpapi.ts is the only file that needs swapping.
PORT	–	Defaults to 3000.

---

Layout

src/
  server.ts       MCP server: 2 tools + 1 UI resource, express /mcp endpoint
  serpapi.ts      Amazon search backend (SerpApi today, PA-API tomorrow)
widgets/
  amazon-carousel.html   iframe widget — vanilla JS, ext-apps App class,
                         Amazon-styled (orange/yellow, smile, star ratings,
                         prime badge, super-script price)

---

Deploy (Vercel)

The server exports its Express app as default and the transport is stateless (fresh StreamableHTTPServerTransport per request), so it maps cleanly to serverless. Add a vercel.json that routes POST /mcp to the build output and set SERPAPI_KEY in project env — details in the next step.

---

Swapping SerpApi → real Amazon API

src/serpapi.ts exports a single searchAmazon(query, opts) → AmazonProduct[] contract. Replace the fetch body with PA-API 5.0's SearchItems call and map its response into the same AmazonProduct shape. Nothing else changes.