> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mercurjs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Complete Cart

> Complete the cart and split it into per-seller orders under an order group.

Completes the cart with Mercur's split-order workflow: items are grouped by seller, one order is created per seller, and all orders are attached to a single order group returned to the shopper.

<Note>
  On payment errors that need customer action (authorization failed or requires more), the route still returns `200` with `type: "cart"`, the refreshed cart, and an `error` object; any other failure is thrown as an error response.
</Note>

## Path parameters

<ParamField path="id" type="string" required>
  The cart's ID.
</ParamField>

## Query parameters

<ParamField query="fields" type="string">
  Comma-separated fields to include on the returned order group; prefix with `+`/`-` to add to or remove from the defaults.
</ParamField>

## Response

<ResponseField name="type" type="string">
  `order_group` on success, `cart` when payment requires further action.
</ResponseField>

<ResponseField name="order_group" type="object">
  Present when `type` is `order_group`.

  <Expandable title="properties">
    <ResponseField name="id" type="string">The order group's ID.</ResponseField>
    <ResponseField name="customer_id" type="string">ID of the purchasing customer.</ResponseField>
    <ResponseField name="cart_id" type="string">ID of the completed cart.</ResponseField>
    <ResponseField name="seller_count" type="number">Number of per-seller orders created.</ResponseField>
    <ResponseField name="total" type="number">Combined total across all child orders.</ResponseField>
    <ResponseField name="created_at" type="string">Creation timestamp.</ResponseField>
    <ResponseField name="updated_at" type="string">Last update timestamp.</ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="cart" type="object">
  Present when `type` is `cart`; the refreshed cart with items, totals, and payment collection.
</ResponseField>

<ResponseField name="error" type="object">
  Present when `type` is `cart`.

  <Expandable title="properties">
    <ResponseField name="message" type="string">The payment error message.</ResponseField>
    <ResponseField name="name" type="string">The error name.</ResponseField>
    <ResponseField name="type" type="string">One of `payment_authorization_error` or `payment_requires_more_error`.</ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST 'http://localhost:9000/store/carts/cart_01JB2KB1CD/complete' \
    -H 'x-publishable-api-key: pk_01JB2K3XYZ'
  ```

  ```ts JS Client theme={null}
  const result = await client.store.carts.$id.complete.mutate({ $id: "cart_01JB2KB1CD" })
  if (result.type === "order_group") {
    console.log(result.order_group.id)
  }
  ```
</RequestExample>

<ResponseExample>
  ```json 200 (success) theme={null}
  {
    "type": "order_group",
    "order_group": {
      "id": "og_01JB2KE7NP",
      "customer_id": "cus_01JB2KE8QR",
      "cart_id": "cart_01JB2KB1CD",
      "seller_count": 2,
      "total": 9900,
      "created_at": "2026-05-01T10:05:00.000Z",
      "updated_at": "2026-05-01T10:05:00.000Z"
    }
  }
  ```

  ```json 200 (payment error) theme={null}
  {
    "type": "cart",
    "cart": { "id": "cart_01JB2KB1CD", "total": 9900 },
    "error": {
      "message": "Payment authorization failed",
      "name": "Error",
      "type": "payment_authorization_error"
    }
  }
  ```
</ResponseExample>