Bigcommerce cart 422: Missing required fields error

I’m using Laravel to consume the Bigcommerce V3 API.

I have ben able to succesfully create a new cart. But when trying to add an item to it, I keep getting a 422: Missing required fields error.

I’m making my request trough Guzzle like this:

return json_decode($this->client->getRestClient()
            ->post('carts/'.$cartId.'/items?include=line_items.physical_items.options', [
                'Accept' => 'application/json',
                'json' => [
                    'line_items' => [
                        'product_id' => 86,
                        'quantity' => 1

The product I’m trying to add has no options or modifiers, so I don’t understand what could wrong with my request. According to the docs, this should be all that’s needed.

Does anyone have any idea what could be wrong? I tried contacting support, but to no avail. Thanks in advance!


line_items is an array of objects. Try wrapping your product data in an object.

Like this:

'line_items' => [
    'quantity' => 1,
    'product_id' => 86