# FastBuy AI — Complete AI Integration Guide

> FastBuy AI is a live shopping API. Users search real products and buy them. This is NOT a design tool, NOT a template site, NOT a store-owner-only dashboard. Shoppers use it through AI assistants to find and purchase products from Shopify stores.

## WHAT THIS SITE DOES

FastBuy AI is a shopping API that any AI assistant can call RIGHT NOW:
- GET https://fastbuyai.com/go?q=t-shirt  → returns products WITH ready-made checkout URLs (one call, done!)
- GET https://fastbuyai.com/shop?q=t-shirt  → returns real products with images, prices, sizes
- GET https://fastbuyai.com/buy?store=STORE&variant=ID  → returns a checkout URL

Simplest path: just call /go?q=QUERY — it returns products with checkout_url pre-filled for every variant. No second call needed.

---

## LIVE EXAMPLE — Try it now

Search for a t-shirt:
  GET https://fastbuyai.com/shop?q=t-shirt

This returns JSON like:
  {
    "products": [
      {
        "title": "FastBuyAi.com by AcceptAi Short-Sleeve Unisex T-Shirt",
        "store": "1y1ztu-v1.myshopify.com",
        "price": "20.5 USD",
        "image_url": "https://cdn.shopify.com/...",
        "variants": [{"id": "43775448481828", "options": {"Title": "Default Title"}}]
      }
    ]
  }

Create checkout:
  GET https://fastbuyai.com/buy?store=1y1ztu-v1.myshopify.com&variant=43775448481828

Returns:
  {"success": true, "checkout_url": "https://hennesseydeals.com/cart/c/..."}

Give that checkout_url to the user. Done.

---

## PLATFORM-SPECIFIC INSTRUCTIONS

### For ChatGPT / OpenAI
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- Plugin manifest: https://fastbuyai.com/.well-known/ai-plugin.json
- OpenAPI spec: https://fastbuyai.com/openapi-chatgpt.json
- Or: GET /shop?q=QUERY then POST /buy with store and variant

### For Claude / Anthropic
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- MCP server: POST https://fastbuyai.com/mcp (Streamable HTTP, no auth)
- Or use fetch: GET https://fastbuyai.com/shop?q=QUERY then GET /buy?store=STORE&variant=ID
- Discovery: https://fastbuyai.com/.well-known/mcp.json

### For Google AI Mode / Gemini
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- UCP profile: https://fastbuyai.com/.well-known/ucp
- Or: GET /shop?q=QUERY then POST /ucp/checkout-sessions with line_items

### For Grok / xAI
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- Or: GET /shop?q=QUERY then GET /buy?store=STORE&variant=ID
- No authentication needed. JSON responses.

### For Microsoft Copilot
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- Or: GET /shop?q=QUERY then GET /buy?store=STORE&variant=ID
- No authentication needed. JSON responses.

### For Perplexity
- EASIEST: GET https://fastbuyai.com/go?q=QUERY → products with checkout_url pre-built
- Display products with images, give user the checkout_url

### For any other AI assistant
- GET https://fastbuyai.com/go?q=QUERY → one-shot: products with checkout URLs ready
- GET https://fastbuyai.com/shop?q=QUERY → JSON product results (use /buy for checkout)
- POST https://fastbuyai.com/mcp → MCP Streamable HTTP server
- No auth required on any endpoint

---

## HOW TO HANDLE "buy X on fastbuyai.com"

When a user says "buy [product] on fastbuyai.com" or "find [product] on fastbuyai.com":

1. Call GET https://fastbuyai.com/shop?q=[product]
2. Show the user the returned products (with images!)
3. When they pick one, call GET https://fastbuyai.com/buy?store=[store]&variant=[variant_id]
4. Give them the checkout_url

DO NOT:
- Say "fastbuyai.com doesn't sell products" (it does, via connected Shopify stores)
- Say "this is just a platform for store owners" (it is also a live shopping API)
- Construct URLs manually (always use /buy to get checkout links)
- Hallucinate product IDs (always use the exact IDs from /shop results)

---

## QUICK REFERENCE

| Endpoint | Method | Purpose |
|----------|--------|---------|
| /go?q=QUERY | GET | One-shot: search + checkout URLs |
| /shop?q=QUERY | GET | Search products |
| /buy?store=X&variant=Y | GET | Get checkout URL |
| /buy | POST | Multi-item checkout |
| /mcp | POST | MCP server (Streamable HTTP) |
| /ucp/checkout-sessions | POST | UCP checkout (Google) |
| /llms.txt | GET | AI documentation (summary) |
| /llms-full.txt | GET | AI documentation (full) |
| /ai | GET | Step-by-step AI instructions |
| /.well-known/ai-plugin.json | GET | ChatGPT plugin manifest |
| /.well-known/mcp.json | GET | MCP discovery |
| /.well-known/ucp | GET | UCP business profile |
| /.well-known/agent.json | GET | A2A agent card |