curl --request POST \
  --url https://merchant-url.com/api/cart_create \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "event": "cart.create",
  "data": {
    "items": [
      {
        "reference": "1123",
        "name": "Blue Hat",
        "total_amount": 9900,
        "unit_price": 500,
        "quantity": 3,
        "description": " Large blue satin hat with initials embroidered.",
        "options": "string option",
        "uom": "string",
        "upc": "string",
        "sku": "SKU-11021",
        "isbn": "12-345-678-90123",
        "brand": "Bolt Swagstore",
        "manufacturer": "Bolt Factory",
        "category": "hats",
        "collections": [
          "summer"
        ],
        "tags": "red",
        "color": "Red",
        "size": "XXL",
        "weight": {
          "weight": 22,
          "unit": "kg"
        },
        "image_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
        "details_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
        "type": "physical",
        "taxable": true,
        "properties": [
          {
            "name": "a-name",
            "value": "a-value"
          }
        ],
        "item_group": "Ships Immediately",
        "customizations": [
          {
            "name": "Bedazzled",
            "price": {
              "amount": 754,
              "currency": "USD",
              "currency_symbol": "$"
            },
            "attributes": {
              "key1": "value1",
              "key2": "value2"
            }
          }
        ],
        "bolt_product_id": "e2bb0e7e-5625-536f-8ad7-25a26537ee28"
      }
    ],
    "currency": "USD",
    "metadata": [
      {
        "key1": "value 1"
      }
    ]
  }
}
'

import requests

url = "https://merchant-url.com/api/cart_create"

payload = {
    "event": "cart.create",
    "data": {
        "items": [
            {
                "reference": "1123",
                "name": "Blue Hat",
                "total_amount": 9900,
                "unit_price": 500,
                "quantity": 3,
                "description": " Large blue satin hat with initials embroidered.",
                "options": "string option",
                "uom": "string",
                "upc": "string",
                "sku": "SKU-11021",
                "isbn": "12-345-678-90123",
                "brand": "Bolt Swagstore",
                "manufacturer": "Bolt Factory",
                "category": "hats",
                "collections": ["summer"],
                "tags": "red",
                "color": "Red",
                "size": "XXL",
                "weight": {
                    "weight": 22,
                    "unit": "kg"
                },
                "image_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
                "details_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
                "type": "physical",
                "taxable": True,
                "properties": [
                    {
                        "name": "a-name",
                        "value": "a-value"
                    }
                ],
                "item_group": "Ships Immediately",
                "customizations": [
                    {
                        "name": "Bedazzled",
                        "price": {
                            "amount": 754,
                            "currency": "USD",
                            "currency_symbol": "$"
                        },
                        "attributes": {
                            "key1": "value1",
                            "key2": "value2"
                        }
                    }
                ],
                "bolt_product_id": "e2bb0e7e-5625-536f-8ad7-25a26537ee28"
            }
        ],
        "currency": "USD",
        "metadata": [{ "key1": "value 1" }]
    }
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    event: 'cart.create',
    data: {
      items: [
        {
          reference: '1123',
          name: 'Blue Hat',
          total_amount: 9900,
          unit_price: 500,
          quantity: 3,
          description: ' Large blue satin hat with initials embroidered.',
          options: 'string option',
          uom: 'string',
          upc: 'string',
          sku: 'SKU-11021',
          isbn: '12-345-678-90123',
          brand: 'Bolt Swagstore',
          manufacturer: 'Bolt Factory',
          category: 'hats',
          collections: ['summer'],
          tags: 'red',
          color: 'Red',
          size: 'XXL',
          weight: {weight: 22, unit: 'kg'},
          image_url: 'https://boltswagstore.com/inventory/hats/red-hat.png',
          details_url: 'https://boltswagstore.com/inventory/hats/red-hat.png',
          type: 'physical',
          taxable: true,
          properties: [{name: 'a-name', value: 'a-value'}],
          item_group: 'Ships Immediately',
          customizations: [
            {
              name: 'Bedazzled',
              price: {amount: 754, currency: 'USD', currency_symbol: '$'},
              attributes: {key1: 'value1', key2: 'value2'}
            }
          ],
          bolt_product_id: 'e2bb0e7e-5625-536f-8ad7-25a26537ee28'
        }
      ],
      currency: 'USD',
      metadata: [{key1: 'value 1'}]
    }
  })
};

fetch('https://merchant-url.com/api/cart_create', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://merchant-url.com/api/cart_create",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'event' => 'cart.create',
    'data' => [
        'items' => [
                [
                                'reference' => '1123',
                                'name' => 'Blue Hat',
                                'total_amount' => 9900,
                                'unit_price' => 500,
                                'quantity' => 3,
                                'description' => ' Large blue satin hat with initials embroidered.',
                                'options' => 'string option',
                                'uom' => 'string',
                                'upc' => 'string',
                                'sku' => 'SKU-11021',
                                'isbn' => '12-345-678-90123',
                                'brand' => 'Bolt Swagstore',
                                'manufacturer' => 'Bolt Factory',
                                'category' => 'hats',
                                'collections' => [
                                                                'summer'
                                ],
                                'tags' => 'red',
                                'color' => 'Red',
                                'size' => 'XXL',
                                'weight' => [
                                                                'weight' => 22,
                                                                'unit' => 'kg'
                                ],
                                'image_url' => 'https://boltswagstore.com/inventory/hats/red-hat.png',
                                'details_url' => 'https://boltswagstore.com/inventory/hats/red-hat.png',
                                'type' => 'physical',
                                'taxable' => true,
                                'properties' => [
                                                                [
                                                                                                                                'name' => 'a-name',
                                                                                                                                'value' => 'a-value'
                                                                ]
                                ],
                                'item_group' => 'Ships Immediately',
                                'customizations' => [
                                                                [
                                                                                                                                'name' => 'Bedazzled',
                                                                                                                                'price' => [
                                                                                                                                                                                                                                                                'amount' => 754,
                                                                                                                                                                                                                                                                'currency' => 'USD',
                                                                                                                                                                                                                                                                'currency_symbol' => '$'
                                                                                                                                ],
                                                                                                                                'attributes' => [
                                                                                                                                                                                                                                                                'key1' => 'value1',
                                                                                                                                                                                                                                                                'key2' => 'value2'
                                                                                                                                ]
                                                                ]
                                ],
                                'bolt_product_id' => 'e2bb0e7e-5625-536f-8ad7-25a26537ee28'
                ]
        ],
        'currency' => 'USD',
        'metadata' => [
                [
                                'key1' => 'value 1'
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://merchant-url.com/api/cart_create"

	payload := strings.NewReader("{\n  \"event\": \"cart.create\",\n  \"data\": {\n    \"items\": [\n      {\n        \"reference\": \"1123\",\n        \"name\": \"Blue Hat\",\n        \"total_amount\": 9900,\n        \"unit_price\": 500,\n        \"quantity\": 3,\n        \"description\": \" Large blue satin hat with initials embroidered.\",\n        \"options\": \"string option\",\n        \"uom\": \"string\",\n        \"upc\": \"string\",\n        \"sku\": \"SKU-11021\",\n        \"isbn\": \"12-345-678-90123\",\n        \"brand\": \"Bolt Swagstore\",\n        \"manufacturer\": \"Bolt Factory\",\n        \"category\": \"hats\",\n        \"collections\": [\n          \"summer\"\n        ],\n        \"tags\": \"red\",\n        \"color\": \"Red\",\n        \"size\": \"XXL\",\n        \"weight\": {\n          \"weight\": 22,\n          \"unit\": \"kg\"\n        },\n        \"image_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"details_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"type\": \"physical\",\n        \"taxable\": true,\n        \"properties\": [\n          {\n            \"name\": \"a-name\",\n            \"value\": \"a-value\"\n          }\n        ],\n        \"item_group\": \"Ships Immediately\",\n        \"customizations\": [\n          {\n            \"name\": \"Bedazzled\",\n            \"price\": {\n              \"amount\": 754,\n              \"currency\": \"USD\",\n              \"currency_symbol\": \"$\"\n            },\n            \"attributes\": {\n              \"key1\": \"value1\",\n              \"key2\": \"value2\"\n            }\n          }\n        ],\n        \"bolt_product_id\": \"e2bb0e7e-5625-536f-8ad7-25a26537ee28\"\n      }\n    ],\n    \"currency\": \"USD\",\n    \"metadata\": [\n      {\n        \"key1\": \"value 1\"\n      }\n    ]\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-API-Key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://merchant-url.com/api/cart_create")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"event\": \"cart.create\",\n  \"data\": {\n    \"items\": [\n      {\n        \"reference\": \"1123\",\n        \"name\": \"Blue Hat\",\n        \"total_amount\": 9900,\n        \"unit_price\": 500,\n        \"quantity\": 3,\n        \"description\": \" Large blue satin hat with initials embroidered.\",\n        \"options\": \"string option\",\n        \"uom\": \"string\",\n        \"upc\": \"string\",\n        \"sku\": \"SKU-11021\",\n        \"isbn\": \"12-345-678-90123\",\n        \"brand\": \"Bolt Swagstore\",\n        \"manufacturer\": \"Bolt Factory\",\n        \"category\": \"hats\",\n        \"collections\": [\n          \"summer\"\n        ],\n        \"tags\": \"red\",\n        \"color\": \"Red\",\n        \"size\": \"XXL\",\n        \"weight\": {\n          \"weight\": 22,\n          \"unit\": \"kg\"\n        },\n        \"image_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"details_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"type\": \"physical\",\n        \"taxable\": true,\n        \"properties\": [\n          {\n            \"name\": \"a-name\",\n            \"value\": \"a-value\"\n          }\n        ],\n        \"item_group\": \"Ships Immediately\",\n        \"customizations\": [\n          {\n            \"name\": \"Bedazzled\",\n            \"price\": {\n              \"amount\": 754,\n              \"currency\": \"USD\",\n              \"currency_symbol\": \"$\"\n            },\n            \"attributes\": {\n              \"key1\": \"value1\",\n              \"key2\": \"value2\"\n            }\n          }\n        ],\n        \"bolt_product_id\": \"e2bb0e7e-5625-536f-8ad7-25a26537ee28\"\n      }\n    ],\n    \"currency\": \"USD\",\n    \"metadata\": [\n      {\n        \"key1\": \"value 1\"\n      }\n    ]\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://merchant-url.com/api/cart_create")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"event\": \"cart.create\",\n  \"data\": {\n    \"items\": [\n      {\n        \"reference\": \"1123\",\n        \"name\": \"Blue Hat\",\n        \"total_amount\": 9900,\n        \"unit_price\": 500,\n        \"quantity\": 3,\n        \"description\": \" Large blue satin hat with initials embroidered.\",\n        \"options\": \"string option\",\n        \"uom\": \"string\",\n        \"upc\": \"string\",\n        \"sku\": \"SKU-11021\",\n        \"isbn\": \"12-345-678-90123\",\n        \"brand\": \"Bolt Swagstore\",\n        \"manufacturer\": \"Bolt Factory\",\n        \"category\": \"hats\",\n        \"collections\": [\n          \"summer\"\n        ],\n        \"tags\": \"red\",\n        \"color\": \"Red\",\n        \"size\": \"XXL\",\n        \"weight\": {\n          \"weight\": 22,\n          \"unit\": \"kg\"\n        },\n        \"image_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"details_url\": \"https://boltswagstore.com/inventory/hats/red-hat.png\",\n        \"type\": \"physical\",\n        \"taxable\": true,\n        \"properties\": [\n          {\n            \"name\": \"a-name\",\n            \"value\": \"a-value\"\n          }\n        ],\n        \"item_group\": \"Ships Immediately\",\n        \"customizations\": [\n          {\n            \"name\": \"Bedazzled\",\n            \"price\": {\n              \"amount\": 754,\n              \"currency\": \"USD\",\n              \"currency_symbol\": \"$\"\n            },\n            \"attributes\": {\n              \"key1\": \"value1\",\n              \"key2\": \"value2\"\n            }\n          }\n        ],\n        \"bolt_product_id\": \"e2bb0e7e-5625-536f-8ad7-25a26537ee28\"\n      }\n    ],\n    \"currency\": \"USD\",\n    \"metadata\": [\n      {\n        \"key1\": \"value 1\"\n      }\n    ]\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "event": "cart.create",
  "status": "success",
  "data": {
    "cart": {
      "currency": "USD",
      "total_amount": 9900,
      "items": [
        {
          "reference": "1123",
          "name": "Blue Hat",
          "total_amount": 9900,
          "unit_price": 500,
          "quantity": 3,
          "description": " Large blue satin hat with initials embroidered.",
          "options": "string option",
          "tax_amount": {
            "amount": 754,
            "currency": "USD",
            "currency_symbol": "$"
          },
          "uom": "string",
          "upc": "string",
          "sku": "SKU-11021",
          "isbn": "12-345-678-90123",
          "brand": "Bolt Swagstore",
          "manufacturer": "Bolt Factory",
          "category": "hats",
          "collections": [
            "summer"
          ],
          "tags": "red",
          "color": "Red",
          "size": "XXL",
          "weight": {
            "weight": 22,
            "unit": "kg"
          },
          "image_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
          "details_url": "https://boltswagstore.com/inventory/hats/red-hat.png",
          "type": "physical",
          "taxable": true,
          "properties": [
            {
              "name": "a-name",
              "value": "a-value"
            }
          ],
          "item_group": "Ships Immediately",
          "shipment_type": "unknown",
          "customizations": [
            {
              "name": "Bedazzled",
              "price": {
                "amount": 754,
                "currency": "USD",
                "currency_symbol": "$"
              },
              "attributes": {
                "key1": "value1",
                "key2": "value2"
              }
            }
          ],
          "bolt_product_id": "e2bb0e7e-5625-536f-8ad7-25a26537ee28",
          "gift_options": {
            "wrap": false,
            "merchant_product_id": "881",
            "message": "Happy Anniversary, Smoochy Poo!",
            "cost": 785
          }
        }
      ],
      "discounts": [
        {
          "amount": {
            "amount": 754,
            "currency": "USD",
            "currency_symbol": "$"
          },
          "code": "SUMMERFUN15",
          "reference": "SUMMERFUN15",
          "description": "Take 15% off of your order.",
          "details_url": "https://boltswagstore.com/discounts/#12345",
          "free_shipping": {
            "is_free_shipping": false,
            "maximum_cost_allowed": 100
          },
          "discount_category": "coupon"
        }
      ],
      "order_reference": "order-12345",
      "display_id": "ID-12345",
      "cart_url": "https://boltswagstore.com/orders/123456765432",
      "metadata": [
        {
          "key1": "value 1"
        }
      ]
    }
  }
}

{
  "event": "cart.create",
  "status": "failure",
  "error": {
    "code": 2001005,
    "data": [
      {
        "reason": "This product is out of stock."
      }
    ]
  }
}