Parameter Missing or Invalid: Required parameter missing or invalid: channel

[DerBasler]

We have a homepage where we integrate shopify using @shopify/buy-button-js this worked well until lately.

Out of the blue (no code or config change) we got the following error if a user tried to checkout:
Parameter Missing or Invalid: Required parameter missing or invalid: channel

The URL where the checkout redirected the user and where the error appeared was:
https://shop.myDomain.xx/cart/c/hWN3GVUNI6d0pgq3QFiiAnyA?key=someKey&channel=buy_button

I saw that the cause was in @shopify/buy-button-js/dist/buybutton.js:15038

  /**
   * get params for online store URL.
   * @return {Object}
   */

}, {
  key: "onlineStoreParams",
  get: function get() {
    return {
      channel: '**buy_button**',
      referrer: encodeURIComponent(windowUtils.location()),
      variant: this.selectedVariant.id.split('/')[4]
    };
  }

I noticed that the checkout worked in case I completely removed the channel. (https://shop.myDomain.xx/cart/c/hWN3GVUNI6d0pgq3QFiiAnyA?key=someKey)

I go this to work with the

.createComponent('cart', {
 options: {
      "cart":  events: {
      beforeInit: (chart) => {
 cart.checkout.open = function(url: string): void {
    // open it in a new tab
    windowReference = window.open();
    windowReference!.location = url.replace('&channel=buy_button', '');
  }
},
    },

This workaround works but I would like to know how it come to that issue and my fix seams to be really dirty so what do I need to do to fix this properly?

Any input is appreciated.

[AlexTzone]

I had this issue too and used a similar fix to yours. However, after encountering another problem I went back and checked our custom app in Shopify, and noticed it used API version 2024-07 (Unsupported) in the Admin API. After setting it to the latest version (2025-07) it worked again. What API version are you using?

[DerBasler]

Hey @AlexTzone thanks for the replay :) I am using 2025-01 according to the network traffic.
"@shopify/buy-button-js": "3.0.0",
Which contains this code:

dist\buybutton.js

      if (attrs.hasOwnProperty('apiVersion')) {
        this.apiVersion = attrs.apiVersion;
      } else {
        this.apiVersion = '2024-04';
      }

and

    function Client(config) {
      var GraphQLClientClass = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : Client$2;
      var fetchFunction = arguments[2];
      classCallCheck$1(this, Client);

      var url = 'https://' + config.domain + '/api/2025-01/graphql';

So I guess they internally use multiple versions 🤔

But there have been a couple of minor changes

I see that they updated mainly some dependency with some hopefully minor changes if they follow semver 🤞

I checked there latest verion 3.0.6 but they still use 2025-01.