On Adding items in cart for guest user using Postman getting error

Question

I have successfully run two REST API's but on running the third one

http://127.0.0.1/mag/rest/V1/guest-carts/81/items
{
"cart_item": {
    "quoteId": 81,
    "sku": "test",
    "qty": 1,
    "quote_id": "HWgMbh8XAVWzsakhskakjsassaas"
}
}

with this param

it will still give me this error

{
        "message": "\"%fieldName\" is required. Enter and try again.",
        "parameters": {
            "fieldName": "quoteId"
        },
        "trace": "#0 /var/www/html/reg-dealers/vendor/magento/module-quote/Model/GuestCart/GuestCartItemRepository.php(66): Magento\\Quote\\Model\\Quote\\Item\\Repository->save(Object(Magento\\Quote\\Model\\Quote\\Item))\n#1 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(58): Magento\\Quote\\Model\\GuestCart\\GuestCartItemRepository->save(Object(Magento\\Quote\\Model\\Quote\\Item))\n#2 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(138): Magento\\Quote\\Model\\GuestCart\\GuestCartItemRepository\\Interceptor->___callParent('save', Array)\n#3 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(153): Magento\\Quote\\Model\\GuestCart\\GuestCartItemRepository\\Interceptor->Magento\\Framework\\Interception\\{closure}(Object(Magento\\Quote\\Model\\Quote\\Item))\n#4 /var/www/html/reg-dealers/generated/code/Magento/Quote/Model/GuestCart/GuestCartItemRepository/Interceptor.php(26): Magento\\Quote\\Model\\GuestCart\\GuestCartItemRepository\\Interceptor->___callPlugins('save', Array, Array)\n#5 [internal function]: Magento\\Quote\\Model\\GuestCart\\GuestCartItemRepository\\Interceptor->save(Object(Magento\\Quote\\Model\\Quote\\Item))\n#6 /var/www/html/reg-dealers/vendor/magento/module-webapi/Controller/Rest/SynchronousRequestProcessor.php(95): call_user_func_array(Array, Array)\n#7 /var/www/html/reg-dealers/vendor/magento/module-webapi/Controller/Rest.php(188): Magento\\Webapi\\Controller\\Rest\\SynchronousRequestProcessor->process(Object(Magento\\Framework\\Webapi\\Rest\\Request\\Proxy))\n#8 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(58): Magento\\Webapi\\Controller\\Rest->dispatch(Object(Magento\\Framework\\App\\Request\\Http))\n#9 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(138): Magento\\Webapi\\Controller\\Rest\\Interceptor->___callParent('dispatch', Array)\n#10 /var/www/html/reg-dealers/vendor/magento/framework/Interception/Interceptor.php(153): Magento\\Webapi\\Controller\\Rest\\Interceptor->Magento\\Framework\\Interception\\{closure}(Object(Magento\\Framework\\App\\Request\\Http))\n#11 /var/www/html/reg-dealers/generated/code/Magento/Webapi/Controller/Rest/Interceptor.php(26): Magento\\Webapi\\Controller\\Rest\\Interceptor->___callPlugins('dispatch', Array, Array)\n#12 /var/www/html/reg-dealers/vendor/magento/framework/App/Http.php(116): Magento\\Webapi\\Controller\\Rest\\Interceptor->dispatch(Object(Magento\\Framework\\App\\Request\\Http))\n#13 /var/www/html/reg-dealers/vendor/magento/framework/App/Bootstrap.php(263): Magento\\Framework\\App\\Http->launch()\n#14 /var/www/html/reg-dealers/index.php(42): Magento\\Framework\\App\\Bootstrap->run(Object(Magento\\Framework\\App\\Http\\Interceptor))\n#15 {main}"
    }

Any idea i have added that key but still give me this error.

Any help is appriciated.

Answer 1

1. Create a request to create the empty cart POST {{magento_api_url}}/rest/default/V1/guest-carts/ - this will return a token which is the cart ID (e.g 'KZepbhhPiGORreBKqIRlMCywGDTyQtR4')
2. Use that cart ID in the request which adds item to the cart POST {{magento_api_url}}/rest/default/V1/guest-carts/KZepbhhPiGORreBKqIRlMCywGDTyQtR4/items with the payload similar to what you see below (where quote_id is the key you previously used and the sku is the SKU of the product you want to add):

{
    "cartItem": {
        "qty": 5,
        "sku": "24-UG06"
    }
}