The new Flutter application is based on 2022 technology. While rebuilding all of our blocks we realised that the current Custom Javascript block is based on design patterns which  do not suit the modern way of writing javascript. 

That's why we decided to make a new and improved Javascript block, using a new bridge for the communication between your Javascript code and the app itself.

This also means that your existing "Custom JS" block will not function in the new flutter application and the new publish flow. 

If you have a Javascript block in your app

  1. Status June 20th: 
    Request access the Javascript beta via an email to
    in a few weeks this functionality will become available for all of our customers
  2. Receive additional information from AppMachine
  3. Add the New Javascript block to your app and configure it
  4. Make some changes to adapt your current Javascript code from your zip.file to the new Javascript block
  5. Disable the old Javascript block
  6. Publish your app with the new publishing flow. 

We have written technical documentation to explain to you how build new Javascript blocks using the new MyJSBlock SDK . Read more....

It is very important that the new JavaScript block will provide you with all the functionality that you're used to and more, and we need your help and feedback to achieve this! Do you want an exclusive preview of the new AppMachine build environment, and help us help you by beta testing the new JavaScript block? 

Contact  for more information.