Component

ItemSummary

Quantity and money stay visible and editable until confirm.

Rows, a quantity stepper, and a subtotal. Also exported as the Cart alias in A2UI messages.

Plan

Group fare to Lisbon
Per seat, mid May
12
€3,720
Rooms in Alfama
Per room, 4 nights
6
€5,040
Group dinner
Per person
12
€660

Subtotal

€9,420

Do

Keep quantity editable until the person confirms.
Show the subtotal in the same surface.
Leave a removed line visible, at zero.

Don't

Lock the plan before it has been reviewed.
Round away a number the person needs.
Start a second checkout somewhere else on the page.

Props

Prop	Type	Description
items	SummaryItem[]	Name, detail, quantity, and unit price.
currency	string	ISO currency. Defaults to EUR.
onQuantityChange	(id, quantity) => void	Stepper callback. Zero removes the line from the subtotal.

A2UI message

v0.9.1 envelope. catalogId is latch://catalog/v1. The preview under the message is rendered by the adapter, not hand-built.

JSON

[
  {
    "version": "v0.9.1",
    "createSurface": {
      "surfaceId": "plan",
      "catalogId": "latch://catalog/v1"
    }
  },
  {
    "version": "v0.9.1",
    "updateDataModel": {
      "surfaceId": "plan",
      "path": "/dinner",
      "value": 55
    }
  },
  {
    "version": "v0.9.1",
    "updateComponents": {
      "surfaceId": "plan",
      "components": [
        {
          "id": "root",
          "component": "ItemSummary",
          "currency": "EUR",
          "items": [
            {
              "id": "flights",
              "name": "Group fare to Lisbon",
              "detail": "Per seat",
              "quantity": 12,
              "unitPrice": 310
            },
            {
              "id": "rooms",
              "name": "Rooms in Alfama",
              "detail": "Per room, 4 nights",
              "quantity": 6,
              "unitPrice": 840
            },
            {
              "id": "dinner",
              "name": "Group dinner",
              "detail": "Per person",
              "quantity": 12,
              "unitPrice": {
                "path": "/dinner"
              }
            }
          ]
        }
      ]
    }
  }
]

Plan

Group fare to Lisbon
Per seat
12
€3,720
Rooms in Alfama
Per room, 4 nights
6
€5,040
Group dinner
Per person
12
€660

Subtotal

€9,420