curl --request PATCH \
  --url https://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId} \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "quantity": 123
}
'

import requests

url = "https://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}"

payload = { "quantity": 123 }
headers = {
    "x-api-key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({quantity: 123})
};

fetch('https://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}', 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://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'quantity' => 123
  ]),
  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://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}"

	payload := strings.NewReader("{\n  \"quantity\": 123\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}")
  .header("x-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"quantity\": 123\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.vaultgraph.com/api/commerce/checkouts/{id}/line-items/{lineId}")

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

request = Net::HTTP::Patch.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"quantity\": 123\n}"

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

{
  "data": {
    "id": "<string>",
    "currency": "<string>",
    "line_items": [
      {
        "item": {
          "id": "<string>",
          "title": "<string>",
          "price": 123,
          "image_url": "<string>"
        },
        "quantity": 2,
        "id": "<string>",
        "parent_id": "<string>",
        "properties": [
          {
            "name": "<string>",
            "value": "<string>"
          }
        ],
        "totals": [
          {
            "amount": 123,
            "display_text": "<string>"
          }
        ]
      }
    ],
    "totals": [
      {
        "amount": 123,
        "display_text": "<string>"
      }
    ],
    "links": [
      {
        "type": "<string>",
        "url": "<string>",
        "title": "<string>"
      }
    ],
    "payment": {
      "handlers": [
        {
          "config": {},
          "config_schema": "<string>",
          "id": "<string>",
          "instrument_schemas": [
            "<string>"
          ],
          "name": "<string>",
          "spec": "<string>",
          "version": "<string>"
        }
      ],
      "instruments": [
        {
          "handler_id": "<string>",
          "id": "<string>",
          "type": "card",
          "brand": "<string>",
          "last_digits": "<string>",
          "billing_address": {
            "address_country": "<string>",
            "address_locality": "<string>",
            "address_region": "<string>",
            "extended_address": "<string>",
            "first_name": "<string>",
            "full_name": "<string>",
            "last_name": "<string>",
            "phone_number": "<string>",
            "postal_code": "<string>",
            "street_address": "<string>"
          },
          "credential": {
            "type": "<string>",
            "cryptogram": "<string>",
            "cvc": "<string>",
            "eci_value": "<string>",
            "expiry_month": 123,
            "expiry_year": 123,
            "name": "<string>",
            "number": "<string>"
          },
          "expiry_month": 123,
          "expiry_year": 123,
          "rich_card_art": "<string>",
          "rich_text_description": "<string>"
        }
      ],
      "selected_instrument_id": "<string>"
    },
    "ucp": {
      "capabilities": [
        {
          "name": "<string>",
          "version": "<string>",
          "config": {},
          "extends": "<string>",
          "schema": "<string>",
          "spec": "<string>"
        }
      ],
      "version": "<string>"
    },
    "buyer": {
      "email": "<string>",
      "first_name": "<string>",
      "full_name": "<string>",
      "last_name": "<string>",
      "phone_number": "<string>"
    }
  }
}