E-Commerce: Cart & Checkout

Problem Statement

Adding items to a cart and beginning checkout are high-intent, multi-step flows. Agents must be able to add items (write), view the cart (read), update quantities (write), remove items (write), and initiate checkout (write with side-effects).

Why Human-Only Semantics Fail

• "Add to Cart" buttons don't declare which product ID, variant, or quantity they affect
• Checkout flows are multi-step wizards with no declared state machine
• Shipping/payment forms don't expose their parameter schemas to machines
• "Place Order" has financial side-effects that no DOM attribute communicates

Why Scraping Fails Here

• Cart state is stored in cookies/session, not in the DOM
• Quantity controls use custom components with inconsistent selectors
• Checkout steps load dynamically via SPA navigation
• Payment forms are in iframes from third-party providers
• Anti-bot protections specifically target checkout scrapers

How AXAG Eliminates Scraping

AXAG annotates each cart and checkout operation with intent, parameters, preconditions, and risk level. The generated tools are safe, typed, and declare side-effects explicitly.

Annotated UI Example

Cart & Checkout actions

<!-- Add to Cart -->
<button
  axag-intent="cart.add_item"
  axag-entity="cart"
  axag-action-type="write"
  axag-required-parameters='["product_id","quantity"]'
  axag-optional-parameters='["variant_id"]'
  axag-preconditions='["product must be in stock"]'
  axag-postconditions='["cart updated with new item"]'
  axag-risk-level="low"
  axag-idempotent="false"
  axag-description="Add a product to the shopping cart"
>Add to Cart</button>

<!-- Begin Checkout -->
<button
  axag-intent="cart.begin_checkout"
  axag-entity="cart"
  axag-action-type="write"
  axag-required-parameters='["cart_id"]'
  axag-optional-parameters='["shipping_method","promo_code"]'
  axag-preconditions='["cart must have at least one item","user must be authenticated"]'
  axag-postconditions='["checkout session created","inventory reserved for 15 minutes"]'
  axag-risk-level="medium"
  axag-confirmation-required="true"
  axag-idempotent="false"
  axag-side-effects='["inventory_reservation","price_lock"]'
  axag-description="Begin the checkout process for the current cart"
>Proceed to Checkout</button>

Semantic Manifest Excerpt

axag-manifest.json — cart actions

{
  "actions": [
    {
      "intent": "cart.add_item",
      "entity": "cart",
      "action_type": "write",
      "parameters": {
        "product_id": { "type": "string", "required": true },
        "quantity": { "type": "integer", "required": true, "minimum": 1, "maximum": 99 },
        "variant_id": { "type": "string", "required": false }
      },
      "preconditions": ["product must be in stock"],
      "postconditions": ["cart updated with new item"],
      "risk_level": "low",
      "idempotent": false
    },
    {
      "intent": "cart.begin_checkout",
      "entity": "cart",
      "action_type": "write",
      "parameters": {
        "cart_id": { "type": "string", "required": true },
        "shipping_method": { "type": "string", "required": false },
        "promo_code": { "type": "string", "required": false }
      },
      "preconditions": ["cart must have at least one item", "user must be authenticated"],
      "postconditions": ["checkout session created", "inventory reserved for 15 minutes"],
      "risk_level": "medium",
      "confirmation_required": true,
      "idempotent": false,
      "side_effects": ["inventory_reservation", "price_lock"]
    }
  ]
}

Generated Tool Examples

{
  "tool_name": "cart_add_item",
  "description": "Add a product to the shopping cart",
  "input_schema": {
    "type": "object",
    "properties": {
      "product_id": { "type": "string" },
      "quantity": { "type": "integer", "minimum": 1, "maximum": 99 },
      "variant_id": { "type": "string" }
    },
    "required": ["product_id", "quantity"]
  },
  "safety": {
    "risk_level": "low",
    "idempotent": false,
    "preconditions": ["product must be in stock"]
  }
}

Constraints & Safety Notes

• cart.begin_checkout requires confirmation because it reserves inventory
• Quantity is bounded to 1–99 to prevent abuse
• Cart operations are NOT idempotent — adding twice doubles the quantity
• begin_checkout side-effects (inventory reservation, price lock) are time-bounded (15 min)