Update Cart

curl --request POST \
  --url https://your-store.launchmystore.io/cart/update.js \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "updates": {},
  "note": "<string>",
  "attributes": {},
  "discount": "<string>"
}
'

import requests

url = "https://your-store.launchmystore.io/cart/update.js"

payload = {
    "updates": {},
    "note": "<string>",
    "attributes": {},
    "discount": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({updates: {}, note: '<string>', attributes: {}, discount: '<string>'})
};

fetch('https://your-store.launchmystore.io/cart/update.js', 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://your-store.launchmystore.io/cart/update.js",
  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([
    'updates' => [
        
    ],
    'note' => '<string>',
    'attributes' => [
        
    ],
    'discount' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($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://your-store.launchmystore.io/cart/update.js"

	payload := strings.NewReader("{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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://your-store.launchmystore.io/cart/update.js")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://your-store.launchmystore.io/cart/update.js")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}"

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

POST

cart

update.js

Update Cart

curl --request POST \
  --url https://your-store.launchmystore.io/cart/update.js \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "updates": {},
  "note": "<string>",
  "attributes": {},
  "discount": "<string>"
}
'

import requests

url = "https://your-store.launchmystore.io/cart/update.js"

payload = {
    "updates": {},
    "note": "<string>",
    "attributes": {},
    "discount": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({updates: {}, note: '<string>', attributes: {}, discount: '<string>'})
};

fetch('https://your-store.launchmystore.io/cart/update.js', 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://your-store.launchmystore.io/cart/update.js",
  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([
    'updates' => [
        
    ],
    'note' => '<string>',
    'attributes' => [
        
    ],
    'discount' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($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://your-store.launchmystore.io/cart/update.js"

	payload := strings.NewReader("{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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://your-store.launchmystore.io/cart/update.js")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://your-store.launchmystore.io/cart/update.js")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"updates\": {},\n  \"note\": \"<string>\",\n  \"attributes\": {},\n  \"discount\": \"<string>\"\n}"

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

Update Cart

Updates quantities of items in the cart, or updates the cart note, attributes, and discount codes.

Cart update is a storefront surface, not part of the OAuth /api/v1 app API. It follows the Shopify-AJAX cart contract: requests are made against the storefront origin (your store domain), identity is the cart cookie token (not a Bearer access token), and the response is the flat Shopify cart object — not wrapped in a { status, type, data } envelope.

Request

curl -X POST "https://your-store.launchmystore.io/cart/update.js" \
  -H "Content-Type: application/json" \
  -H "Cookie: cart=c1-xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx" \
  -d '{
    "updates": {
      "639664": 3,
      "640001": 0
    }
  }'

const response = await fetch('/cart/update.js', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    updates: {
      "639664": 3,
      "640001": 0  // Remove item
    }
  })
});
const cart = await response.json();

Body Parameters

updates

object

Object mapping variant IDs to new quantities. Set a quantity to 0 to remove that item.

note

string

Update the cart note

attributes

object

Update cart attributes (replaces existing attributes)

discount

string

Discount code(s) to apply. Accepts a single code or comma-separated codes. Pass an empty string to clear all applied discount codes.

Response

The response is the flat Shopify cart object (the same shape returned by Get Cart), reflecting the updated cart. For quantity updates the response also includes an items_changelog object ({ added, removed }).

Example Response

{
  "token": "c1-9a3f0c2e-7b1d-4e8a-9f2c-1a2b3c4d5e6f",
  "items": [
    {
      "key": "639664:default",
      "id": 639664,
      "product_id": 12001,
      "variant_id": 639664,
      "title": "Classic T-Shirt",
      "variant_title": "Medium / Black",
      "quantity": 3,
      "price": 2500,
      "line_price": 7500,
      "sku": "TSHIRT-M-BLK"
    }
  ],
  "item_count": 3,
  "total_price": 7500,
  "currency": "USD",
  "note": "",
  "attributes": {},
  "items_changelog": {
    "added": [{ "id": 639664, "quantity": 3 }],
    "removed": [{ "id": 640001 }]
  }
}

Updating Cart Note, Attributes, and Discounts

{
  "note": "Please gift wrap this order",
  "attributes": {
    "gift_message": "Happy Birthday!",
    "preferred_delivery_date": "2024-03-25"
  },
  "discount": "SUMMER10"
}

Errors

On failure the endpoint returns a Shopify-style error body with the real HTTP status:

{
  "status": 422,
  "message": "Requested quantity exceeds available stock",
  "description": "Requested quantity exceeds available stock"
}

Add to Cart Remove from Cart

​Update Cart

​Request

​Body Parameters

​Response

​Example Response

​Updating Cart Note, Attributes, and Discounts

​Errors

Update Cart

Request

Body Parameters

Response

Example Response

Updating Cart Note, Attributes, and Discounts

Errors