Scripting Changes in Adobe’s Video Applications

Upcoming changes will affect all ExtendScript integration and CEP panels within Adobe Premiere Pro, After Effects, Audition, Media Encoder and Prelude.

We’re sharing this information as early as we can, to provide maximum response time for our partners. Here’s what we’re doing, and how partners can respond.


A vision from the future: Your Adobe (UXP-hosted) integrations are, simply, JavaScript, executed in an engine over 25 years newer than the ExtendScript engine. You’re no longer required to pass control flow and information back and forth between JavaScript and ExtendScript layers, via string. Your integration has access to the UI components used by the application, and scripting access to the UI components provided by the application.

Sounds nice, eh? Here’s how we get there.


Two modernization efforts underway within Adobe impact all ExtendScript and CEP integrations.

Effort 1: Replace ExtendScript with JavaScript

We’re replacing our ExtendScript interpreter with a modern JavaScript engine. The new engine is already shipping in our recent releases of Premiere Pro, Audition, Media Encoder and Prelude (After Effects will offer updates later this year).

The new engine is off by default; unless you specifically request it, your integration’s behavior is unchanged.

The new engine does an uncanny impersonation of the old ExtendScript interpreter; we call this “New World scripting”.

Due Date: As of our MAX 2019 releases, use of the New World scripting engine will become “opt-out”: The new engine will be used by default, with the old one available via configuration, for emergency use only.

What you can do, today:

Test your current, shipping integration in New World scripting, as soon as possible.

Also, please join our Integration Engineering pre-release program, where we’ll be discussing such issues and posting any builds containing fixes for New World issues. You can also report issues to me directly.

Effort 2: Replace CEP extensions with UXP plugins

All Adobe applications are replacing CEP extension support with UXP plugin support; schedules vary by application. No CEP removal is currently scheduled.

The video applications are already integrating UXP, and plan to deliver initial UXP plugin hosting in the first half of 2020. This initial support will likely not include a full 1:1 replacement for ExtendScript API calls, but will allow you to get started with the UXP version of your integration.

What you can do today:

Learn about UXP!

Thank You

We know these Adobe-imposed architectural changes require time and resources from our partners. We’re grateful for your efforts!