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CEP 11.1 HTML Extension

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CEP 11 HTML Extension Cookbook


This cookbook is a guide to creating CEP 11.1 HTML/JavaScript Extensions for Creative Cloud applications. CSXS is the old name before CS6, and CEP (Common Extensibility Platform) is new name from CS6. When we talk about CEP or CSXS, they refer to the same project.

CEP Extensions

CEP (formerly CSXS) Extensions extend the functionality of the Adobe point products in which they run. Extensions are loaded into applications through the PlugPlug Library architecture. Starting from CEP 4.0, HTML/CSS and JavaScript (ECMAScript 5) can be used to develop extensions.

Extension Types

These extension types are supported by CEP. You need to specify an extension's type in its manifest.xml.

  • Panel
    • The Panel type behaves like any other application panel. It can be docked, participates in workspaces, has fly-out menus, and is re-opened at start-up if open at shutdown.
  • ModalDialog
    • A Modal Dialog type opens a new extension window and forces the user to interact only with the extenison window before returning control to the host application. User can interact with host application only after closing extension window.
  • Modeless
    • A Modeless Dialog type opens a new extension window but doesn't force the user to interact with the extension window
  • Embedded
    • An Embedded Panel is the same as a Panel, but it cannot be undocked.
  • Custom (Since CEP 5.0)
    • This type is for invisible extensions. An invisible extension remains hidden and never becomes visible during its whole life cycle. Read "Invisible HTML Extensions" for more details.

Applications Integrated with CEP

These applications support CEP HTML extensions. (For older applications, see this chart.)

Application Host ID(Product SAPCode) CC 2019 Version CC 2020 Version FY 2020 FY2021
Photoshop PHSP/PHXS 20 (CEP 9) 21 (CEP 9) 22.0 (CEP 10) 23.0 (CEP 11)
InDesign IDSN 14 (CEP 9) 15 (CEP 9) 16.0 (CEP 10 ) 16.3(CEP 11)
InCopy AICY 14 (CEP 9) 15 (CEP 9) 16.0 (CEP 10 ) 16.3(CEP 11)
Illustrator ILST 23 (CEP 9) 24 (CEP 9) 25.0 (CEP 10) 25.3(CEP 11)
Premiere Pro PPRO 13 (CEP 9) 14 (CEP 9) 14.4 (CEP 10) 15.4(CEP 11)
Prelude PRLD 8 (CEP 9) 9 (CEP 9) 10.0(CEP 10) 10.1(CEP 11)
After Effects AEFT 16 (CEP 9) 17 (CEP 9) 17.1.4 (CEP 10) 18.4(CEP 11)
Animate FLPR 19 (CEP 9) 20 (CEP 9) 21.0 (CEP 10) 22.0(CEP 11)
Audition AUDT 12 (CEP 9) 13 (CEP 9) 13.0.10 (CEP 10) 14.4(CEP 11)
Dreamweaver DRWV 19 (CEP 9) 20 (CEP 9) 21.0 (CEP 10) 22.0(CEP 11)
Bridge KBRG 9 (CEP 9) 10 (CEP 9) 11.0 (CEP 10) 12.0(CEP 11)
Rush RUSH 1 (CEP 9) 1.2.1 (CEP 9) 1.5.29 (CEP 10) 2.1(CEP 11)

Chromium Embedded Framework (CEF)

CEP HTML engine is based on Chromium Embedded Framework version 3 (CEF3). You can find more information about CEF here. Here are the versions used in CEP:

Component CEP 9.0 CEP 10.0 CEP 11.1
CEF 3 CEF 3 release branch 3163 CEF 3 release branch 3729 CEF 3 release branch - (88)
Chromium 61.0.3163.91 74.0.3729.157 88
Node.js Node.js 8.6.0 Node.js 12.3.1 Node.js 15.9.0
CEF/Node integration Node-Webkit 0.25 Node-Webkit 0.38 Node-Webkit 0.50.1
v8 7.4.288 8.7

Browser Features supported by CEP

HTTP Cookie

CEP supports two kinds of cookies:

  • Session Cookies - Temporary in-memory cookie which will expire and disappear when user closes extension
  • Persistent Cookies - No expiry date or validity interval, stored in user's file system

Persistent Cookies location:

 - Windows: `C:\Users\<USERNAME>\AppData\Local\Temp\cep_cache\`
 - macOS: `/Users/<USERNAME>/Library/Caches/CSXS/cep_cache/`

Each persistent cookie is a file. File name is HostID_HostVersion_ExtensionName, such as PHXS_15.0.0_com.adobe.extension1.

Development and Debugging

Migration from CEP 10 to CEP 11

  1. Update the Node Modules: CEP 11 works with NodeJS 15.9.0 and Node-WebKit 0.50.1 versions. If extensions were build on older version of NodeJS there can be cases where these extensions may not load in CEP 11 due to incompatible node modules. In such cases, the node modules need to be updated using NodeJS version 15.9.0 or higher.

  2. Content-Security-Policy Changes: With CEP 11.1 that integrates CEF #88, content-security-policy checks have been enforced strictly. Extensions that embed third-party sites may not be able to do so anymore if the site that is being embedded has a content-security-policy directive that doesn't allow sites to frame them. Refer Known issues for few such scenarios and possible temporary workarounds.

  3. Cookies: With #CEF v88 version, we have seen that when no SameSite attribute is set in a cookie, it defaults to SameSite=Lax. This will cause the cookie to be blocked in cross-site contexts. If your application needs cookies to be used in a cross-site context, we suggest you set SameSite=None.If component is not sending SameSite attribute in the cookie it would default to SameSite=Lax for preventing to set the cookie in cross-site context.

    Note: as per a temporary workaround provided by CEF, the following option can be added in manifest --disable-features=SameSiteByDefaultCookies. Example:

    + <Parameter>--disable-features=SameSiteByDefaultCookies,CookiesWithoutSameSiteMustBeSecure,NetworkService</Parameter>
    + <Parameter>--disable-site-isolation-trials</Parameter>

    Note: NetworkService needs to be added to provide backward compatibility with CEP 10.

  4. CORS checks: With CEP 11, with security updates, we are seeing that a lot more requests are being blocked by CORS checks. The extension may encounter this if it is trying to access an endpoint that does not have the Access-Control-Allow-Origin header. Please ensure that the endpoints that are being accessed have Access-Control-Allow-Origin headers set appropriately.

Also Refer Known issues in CEP 11

Migration from CEP 9 to CEP 10

There is no migration required for the extensions working in CEP 9. Extensions running on CEP 9 should run on CEP 10 out of the box. 

However few point to be noted with CEP 10

  1. Issues seen on NWJS version 0.38 will also be applicable in CEP 10

For example: There are errors noticed when node module "winston" is used with any other node module which uses duplex. Workaround: In case you are using the node module "winston" please add this below script to the extension.

var {Duplex} = require('stream')
var {Writable} = require('stream')
  // Allow the keys array to be GC'ed.
  const keys = Object.keys(Writable.prototype);
  for (var v = 0; v < keys.length; v++)
	const method = keys[v];     
	if (!Duplex.prototype[method])       
	Duplex.prototype[method] = Writable.prototype[method];   
  1. Update your node modules

CEP 10 works with NodeJS 12.3.1 and Node-WebKit 0.38 versions. If extensions were build on older version of NodeJS there can be cases where these extensions may not load in CEP 10 due to incompatible node modules. In such cases, the node modules need to be updated using NodeJS version 12.3.1 or higher.

3.Issues in CSS properties due to deprecation in Chromium will be applicable in CEP 10

In such cases, extension developers will need to update the CSS for the extension, in order for the extension to render correctly in CEP 10. For eg:

  1. Also refer details for the disable nodejs option here.

Migration from CEP 8 to CEP 9

There is no migration required for the extensions working in CEP 8. Extensions running on CEP 8 should run on CEP 9 out of the box. 

Note: <Size> element in manifest file is mandatory as per the documentation but it used to work by taking max or min size provided in the manifest till CEP 8, this bug has been fixed in CEP 9. Please ensure to define <Size> element in your manifest.


Below listed changes are applicable when --enable-nodejs is passed as CEFCommandline parameter.

New Symbols in the global context

CEP 8 and later versions introduces additional symbol: cep_node in the global context when nodejs is enabled. cep_node will hold following node specific symbols:

cep_node members Buffer, global, process and require

Accessing nodejs APIs in iframe

nodejs symbols will not be available in iframe's global context, only way you can access nodejs APIs within iframe's context is through cep_node. When --mixed-context is enabled, global node symbols and cep_node is available within iframe's global context as browser and node gets executed at the same context. It is also important to note that, if you have existing code to check or use nodejs symbols in iframe's global context, it used to work till last release and in the current release, it breaks in separate context mode.

JS Lib Break due to node symbols (possible for many other libraries)

Newly integrated nodejs adds "module" and "exports" symbols to the global context. Many libraries such as JQuery relies on its booting based on the availability of "module" symbol in the global scope. For ex, JQuery has following code while booting:

JQuery startup code

if ( typeof module === "object" && typeof module.exports === "object" ) {
    // set jQuery in `module`
} else {
   // set jQuery in `window`

When this code is executed in CEP's browser with nodejs enabled, it will make JQuery to load in module context instead of Browser context. This would cause issues to extension's startup. Please use below code to handle such scenarios:

global symbols handling

<!-- Insert this line above script imports -->
<script>if (typeof module === 'object') {window.module = module; module = undefined;}</script>
<script>if (typeof exports === 'object') {window.exports = exports; exports = undefined;}</script>
<!-- extension's imports -->
<script src="scripts/jquery.min.js"></script>
<script src="scripts/csinterface.js"></script>
<!-- Insert this line after script imports -->
<script>if (window.module) module = window.module;</script>
<script>if (window.exports) exports = window.exports;</script>

If you are not using "module" and "exports" in the extension, you could skip last 2 lines of above code. This logic is similar to how users handled nodejs's require while importing. If you are handling require already, you should continue to handle same way.

require path is absolute instead of relative

Nodejs 7.7.4 or higher versions requires path to be included as absolute path. So, if you have nodejs require for the js file,replace the path to absolute instead of relative. For eg. replace:



Win require absolute path for nodejs

var loc = window.location.pathname;
var dir = decodeURI(loc.substring(1, loc.lastIndexOf('/')));
require(dir + "/js/lib/jquery.js");

On macOS (there is a change in index passed on to substring)

macOS require absolute path for nodejs

var loc = window.location.pathname;
var dir = decodeURI(loc.substring(0, loc.lastIndexOf('/')));
require(dir + "/js/lib/jquery.js");
require(__dirname + "/js/lib/jquery.js");

Contexts in CEP

CEP will have multiple contexts defined at the start. Following are the default contexts:

  1. Browser Context

    This is the default JS context associated with CEP's browser engine. Apart from Browser objects, CEP's file system APIs are accessed in this context.

  2. Native Context

    This is extended context through "cep" object to provide file system access via CSInterface.js.

  3. Node Context (When nodejs is enabled through --enable-nodejs command line switch)

    1. Separate Context
    2. Mixed Context
  4. Host app context

    This is the context which would be accessed through evalscript API.

Separate Context Mode

This context will be created with following command line switch: --enable-nodejs (and --mixed-context is not passed). When CEP is starting with this context, it would have following symbols:

  1. cep_node: This is treated as global symbol available across frames and helps to access node symbols. Any modification to this symbol will be reflected at all the frame context. This symbols is introduced from CEP 8.

  2. node globals: could be accessed only in main frame (which is current document). If there is a new frame created in the current document, these symbols will not be available in frame's context. Please note that, this behavior is different CEP 7 for frames. In CEP 7, node globals are available for access in all frames.

Following representation provides visual context:

Separate Context

      <!-- cep_node and node globals are available in this context -->
      <!-- cep_node and node globals are available in this context -->
      <iframe name="iframe_1">
         <!-- only cep_node is available and node globals are not available within this iframe -->
      <iframe name="iframe_2">
         <!-- only cep_node is available and node globals are not available within this iframe -->
         <!-- In the following line cep_node is modified and this change will be available for any frame's which is loading later than iframe_2 -->
         cep_node.process.myVar = "Hello";
      <iframe name="iframe_3">
         <!-- cep_node is available with change: cep_node.process.myVar(iframe's loading order is important as change should be accessed after the modifications) and node globals are not available  -->

Mixed Context Mode

This context will be created with following command line switch: --enable-nodejs and --mixed-context. When CEP is starting with this context, it would have following symbols:

  1. cep_node: This is treated as local symbol available within each frames and helps to access node symbols. Any modification to this symbol will not be reflected to other frames. This symbols is introduced from CEP 8.

  2. node globals: could be accessed in all the frames which is unique to each frame.

Following representation provides visual context

Mixed Context

      <!-- cep_node and node globals are available in this context -->
      <!-- cep_node and node globals are available in this context -->
      <iframe name="iframe_1">
         <!-- only cep_node is available and node globals are available within this iframe -->
      <iframe name="iframe_2">
         <!-- only cep_node is available and node globals are available within this iframe -->
         <!-- In the following line cep_node is modified and this change will not be available for any other frames -->
         cep_node.process.myVar = "Hello";
      <iframe name="iframe_3">
         <!-- cep_node is available which is unique to this context and it's built from start up time. So, it will not have the changes from previous iframe. node globals are available  -->

Development Machine Setup

CEP HTML Extensions can be developed on both Windows and macOS platforms. The development machine needs to have the following applications in order to successfully develop CSXS extensions:

  • Adobe Creative Cloud applications supporting CEP HTML extensions.
  • VS Code and extensions for building CEP HTML extensions for Adobe Creative Cloud.
  • Adobe ExtendScript Tool Kit (This is available as an optional install, note that this 32-bit app is not supported by macOS High Sierra 10.13.4 and later).
  • Chrome browser for debug workflow.

VS Code

VS Code supports development and debugging of CEP HTML extensions as well as debugging ExtendScript. Learn more about the ExtendScript tools here.

Signing extensions

Debugging Unsigned Extensions

If you are in the midst of development and want to bypass the need to sign your extensions, you can bypass the check for extension signatures by editing the CSXS preference properties file, located at:

  • Win: regedit > HKEY_CURRENT_USER/Software/Adobe/CSXS.11, then add a new entry PlayerDebugMode of type "string" with the value of "1".
  • macOS: In the terminal, type: defaults write com.adobe.CSXS.11 PlayerDebugMode 1 (The plist is also located at /Users/<username>/Library/Preferences/com.adobe.CSXS.11.plist)

These entries will enable debug extensions to be displayed in the host applications. Please note that, CSXS.11 is given with the assumption that, you are developing the extension for CEP 11. If you are developing extension for previous version of CEP, replace 11 with corresponding version number.

Special notes for macOS 10.9 and higher

Staring with macOS 10.9, Apple introduced a caching mechanism for plist files. Your modifications to plist files does not take effect until the cache gets updated (on a periodic basis, you cannot know exactly when the update will happen). To make sure your modifications take effect, there are two methods.

  • Kill cfprefsd process. It will restart automatically. Then the update takes effect.
  • Restart your macOS, or log out the current user and re-log in.
  • More Information

Remote Debugging

CEP supports remote debugging for HTML extensions from 5.0.

  • Create a “.debug” file to the extension root directory such as Test_Extension\.debug. The .debug file contains remote debug ports. Developers must create this file and use valid debug ports because both remote debugging and dev tools are based on it.
  • ".debug" file name is special for both Windows and macOS platforms, it has to be created via command line.
    • On Windows, use "copy con .debug" and "Ctrl+Z" to create an empty file.
    • On macOS, use "touch .debug" to create an empty file.
  • The value of Port should be between 1024 and 65535 (not include 65535), otherwise remote debugging and dev tools will not work.
  • One extension bundle may have multiple extensions. The .debug file can specify debug ports for each extension. Here is an example file:
<?xml version="1.0" encoding="UTF-8"?>
    <Extension Id="com.adobe.CEPHTMLTEST.Panel1">
            <Host Name="PHXS" Port="8000"/>
            <Host Name="IDSN" Port="8001"/>
            <Host Name="AICY" Port="8002"/>
            <Host Name="ILST" Port="8003"/>
            <Host Name="PPRO" Port="8004"/>
            <Host Name="PRLD" Port="8005"/>
            <Host Name="FLPR" Port="8006"/>
			<Host Name="AUDT" Port="8007"/>
    <Extension Id="com.adobe.CEPHTMLTEST.Panel2">
            <Host Name="PHXS" Port="8100"/>
            <Host Name="IDSN" Port="8101"/>
            <Host Name="AICY" Port="8102"/>
            <Host Name="ILST" Port="8103"/>
            <Host Name="PPRO" Port="8104"/>
            <Host Name="PRLD" Port="8105"/>
            <Host Name="FLPR" Port="8106"/>
			<Host Name="AUDT" Port="8107"/>
    <Extension Id="com.adobe.CEPHTMLTEST.ModalDialog">
            <Host Name="PHXS" Port="8200"/>
            <Host Name="IDSN" Port="8201"/>
            <Host Name="AICY" Port="8202"/>
            <Host Name="ILST" Port="8203"/>
            <Host Name="PPRO" Port="8204"/>
            <Host Name="PRLD" Port="8205"/>
            <Host Name="FLPR" Port="8206"/>
			<Host Name="AUDT" Port="8207"/>
    <Extension Id="com.adobe.CEPHTMLTEST.Modeless">
            <Host Name="PHXS" Port="8300"/>
            <Host Name="IDSN" Port="8301"/>
            <Host Name="AICY" Port="8302"/>
            <Host Name="ILST" Port="8303"/>
            <Host Name="PPRO" Port="8304"/>
            <Host Name="PRLD" Port="8305"/>
            <Host Name="FLPR" Port="8306"/>
			<Host Name="AUDT" Port="8307"/>

If you load an extension whose debug port is 8088, you can load the debugger through http://localhost:8088/ on Chrome.

Where are the Log Files

PlugPlug Logs

Log files with useful debugging information are created for each of the applications supporting CEP extensions. The platform-specific locations for the log files are as follows:

  • Win: C:\Users\<USERNAME>\AppData\Local\Temp
  • macOS: /Users/<USERNAME>/Library/Logs/CSXS

These files are generated with the following naming conventions:

  • CEP 4.0 - 6.0 releases: csxs<versionNumber>-<HostID>.log. For example, PlugPlug in Illustrator generates log file csxs8-ILST.log.
  • CEP 6.1 and later releases: CEP<versionNumber>-<HostID>.log. For example, PlugPlug in Illustrator generates log file CEP8-ILST.log.

Logging levels can be modified as per the following levels:

  • 0 - Off (No logs are generated)
  • 1 - Error (the default logging value)
  • 2 - Warn
  • 3 - Info
  • 4 - Debug
  • 5 - Trace
  • 6 - All

The LogLevel key can be updated at the following location (The application should be restarted for the log level changes to take effect):

  • Win: regedit > HKEY_CURRENT_USER/Software/Adobe/CSXS.11
  • macOS: /Users/<USERNAME>/Library/Preferences/com.adobe.CSXS.11.plist

For example of macOS, in the terminal do:

defaults write com.adobe.CSXS.11 LogLevel 6

Please note that, higher the log level will make the extension loading time slower.

CEPHtmlEngine Logs

In CEP 6.1 and later releases, CEPHtmlEngine generates logs. Each CEPHtmlEngine instance usually generate two log files, one for browser process, the other for renderer process. These files are generated with the following naming conventions:

  • Browser process: CEPHtmlEngine<versionNumber>-<HostID>-<HostVersion>-<ExtensionID>.log
  • Renderer process: CEPHtmlEngine<versionNumber>-<HostID>-<HostVersion>-<ExtensionID>-renderer.log

For example:

  • CEPHtmlEngine8-PHXS-18.1.1-com.adobe.DesignLibraries.angular.log
  • CEPHtmlEngine8-PHXS-18.1.1-com.adobe.DesignLibraries.angular-renderer.log

They are also controlled by the PlugPlug log level.


In CEP 4.0 - 6.0, the Chromium Embedded Framework (CEF) in CEPHtmlEngine also generates a log:

  • Win: C:\Users\<USERNAME>\AppData\Local\Temp\cef_debug.log
  • macOS: /Users/<USERNAME>/Library/Logs/CSXS/cef_debug.log

In CEP 6.1 and later releases, this log is merged into CEPHtmlEngine log.

Extension Folders

CEP supports 3 types of extension folders.

  • Product extension folder. Here is a suggestion, but each point product can decide where this folder should be. Third party extension can't be installed at this location.

    • ${PP}/CEP/extensions (PPs may use different folder.)
  • System extension folder

    • Win(x64): C:\Program Files (x86)\Common Files\Adobe\CEP\extensions, and C:\Program Files\Common Files\Adobe\CEP\extensions (since CEP 6.1)
    • macOS: /Library/Application Support/Adobe/CEP/extensions
  • Per-user extension folder

    • Win: C:\Users\<USERNAME>\AppData\Roaming\Adobe\CEP/extensions
    • macOS: ~/Library/Application Support/Adobe/CEP/extensions

How does CEP decide which extension to load?

  • CEP first searches the product extension folder, then the system extension folder, and finally per-user extension folder.
  • Extensions without an appropriate host application ID and version are filtered out.
  • If two extensions have same extension bundle ID, the one with higher version is loaded.
  • If two extensions have same extension bundle ID and same version, the one whose manifest file has latest modification date is loaded.
  • If two extensions have same extension bundle ID, same version and same manifest modification date, CEP loads the first one that is found.

Extension Installation:

  • Host application installers should install extensions to product extension folder.
  • Extensions installed through should get install at system extension folder or per-user extension folder.


  • Character '#' is not allowed in extension folder path on both Windows and Mac OSX, since CEF treats '#' as a delimiter.

CEP HTML Test Extensions

CEP provides some sample extensions for extension developers. Get its source code from:

Extension Manifest

The manifest.xml file is required for every extension and provides the necessary information to configure a CEP extension. ExtensionManifest is the root element of the manifest.xml file. Extensions, ExtensionList, and DispatchList are the three child elements of the ExtensionManifest root element.

Extension Manifest XSD

All HTML extensions must use 5.0 or above version. Get XSD from the GitHub repo: (No elements change from CEP 7)

To check if the extension's manifest is in sync with the latest schema, perform the following steps:

  1. Download the latest schema (ExtensionManifest_<version>.xsd). Please note that, schema is not changed in CEP 8, so refer to for CEP 8 and 9 as well.
  2. Navigate here
  3. Upload the schema and your latest ExtensionManifest (from a real build to check the validity of the versions).
  4. Hit validate

Important Manifest Change for CEP 5.0 Extensions

Make sure correct point product versions are used. Here is an example.

    <Host Name="PHXS" Version="[15.0,15.9]"/>
    <Host Name="PHSP" Version="[15.0,15.9]"/>

This will support Photoshop version 15.0 up to, and including, 15.9. If you use the following syntax then you are supporting releases up to 15.9 but not including 15.9

    <Host Name="PHXS" Version="[15.0,15.9)"/>
    <Host Name="PHSP" Version="[15.0,15.9)"/>

Make sure correct CEP version is used.

    <RequiredRuntime Name="CSXS" Version="5.0"/>

Important Manifest Change for CEP 7.0 Extensions

CEP 7.0 manifest files now support the use of a HostList specific to an extension in the bundle. For example, the following qualifies as the "default" HostList:

    <Host Name="DRWV" Version="15.0" />
    <Host Name="FLPR" Version="15.0" />
    <Host Name="IDSN" Version="11.0 "/>
    <Host Name="AICY" Version="11.0" />
    <Host Name="ILST" Version="19.0" />
    <Host Name="PHSP" Version="16.0" />
    <Host Name="PHXS" Version="16.0" />
    <Host Name="PPRO" Version="9.0" />
    <Host Name="PRLD" Version="4.0" />
    <Host Name="AEFT" Version="13.0" />
    <Host Name="DEMO" Version="1.0" />
    <Host Name="AUDT" Version="8.0" />
    <Host Name="LTRM" Version="7.0" />
    <Host Name="MUSE" Version="2015" />
</Execution Environment>

However, you can also specify a custom HostList on a per extension basis as in the following example:

  <Extension Id="com.adobe.CEPHTMLTEST.Panel1">
      <Host Name="PHXS" />

HostLists specified under extension tags will override the default HostList specified under the execution environment tag. It is important to note that adding HostList nodes with no child nodes is akin to turning that particular extension off for all host applications; this behavior is intentional. Please refrain from specifying both HostList tags and Host attributes in DispatchInfo tags for each extension; choose one or the other. Specifying both will more than likely result in unexpected behavior. The Host attribute is only maintained for backward compatibility. New extensions should use HostList tags, not the Host attribute.

Extension Size

You can specify extension size, max size and min size in extension manifest. Size is mandatory; max size and min size are optional.

A modal or modeless dialog is resizable if there are different max and min size, otherwise it is un-resizable. When you move mouse pointer over dialog border, CEP shows different cursor for resizable and un-resizable dialogs.


Customize Extension Menu

This is only supported in InDesign and InCopy.

You can customize the extension menu by editing <menu/> item in manifest. Here is an example. In this example, the Adobe Add-ons extension is displayed under Windows main menu, rather than extensions menu under Windows. You can customize the location of extension to somewhere else by changing the value of attribute Placement in <menu/> item.

<?xml version="1.0" encoding="UTF-8"?>
    <Extension Id="Adobe Add-ons" Version="1.0"/>
        <Host Name="IDSN" Version="8.0"/>
    <Extension Id="com.adobe.CEPHTMLTEST.Panel1">
               <Menu Placement="'Main:&amp;Window',600.0,'KBSCE Window menu'">Adobe Add-ons</Menu> 

High DPI Panel Icons

In high DPI display mode, panel extensions may want to use high DPI icons. You set these icons in extension's manifest.


 <Icon Type="Normal">./images/IconLight.png</Icon>

 <Icon Type="RollOver">./images/IconLight.png</Icon>

 <Icon Type="DarkNormal">./images/IconDark.png</Icon>

 <Icon Type="DarkRollOver">./images/IconDark.png</Icon>


You pack both normal icon files (IconLight.png and IconDark.png) and high DPI icon files (IconLight@2X.png and IconDark@2X.png) in your extension.

Host applications will be able to find and use

@2X.ext is the industry standard. Please see more details on

Note: Photoshop supports _x2.ext format.

Dialog Size based on Screen Size

You can specify CEP dialog size as a percentage of screen size. Here is an example.


Shortcut Keys for HTML Extensions

(Since 5.2)

CEP 5.2 supports shortcut keys for HTML extensions. When focus is on HTML extensions, these shortcut keys are handled by extension.

Windows Keys macOS Keys Function
Ctrl + A Command + A Select All
Ctrl + C Command + C Copy
Ctrl + V Command + V Paste
Ctrl + X Command + X Cut

Other shortcut keys are handled by point products, such as pressing Ctrl + N to create a new document.

CEP JavaScript Programming

CEP JavaScript Libraries

CEP JavaScript Libraries are counterparts of the Flex CSXS Library. They provide JavaScript APIs to access application and CEP information.

  • CSInterface.js
  • Vulcan.js

Get them from:

To use them, please include these JavaScript files in your HTML extension.

API version

The CEP JavaScript APIs keep changing in each new CEP release. The changes are guaranteed to be backward compatible. For newly added APIs, a version tag like "Since x.x.x" is added to its API comments indicating since which CEP version the APIs is available.

You will need to check the version tag against the version of CEP integrated by the Adobe Product you are using to make sure the API you want to use is available. To do so, use CSInterface.getCurrentApiVersion() to retrieve the version of CEP integrated by the Adobe Product. Please note this API itself is available only since 4.2.0. If you get an error saying getCurrentApiVersion is undefined, then you are running in CEP 4.0 or 4.1. Otherwise, the value returned will tell you the version of CEP integrated by the Adobe product.

CEP Events

CEP supports sending and receiving events within an extension, among extensions in an application, and among extensions in different applications. Since all extensions are based on the common communication layer with the same event data format, they can communicate with each other through CEP events, and even they can communicate with native side as long as point products invoke PlugPlugAddEventListener/PlugPlugDispatchEvent accordingly.

There are dispatchEvent/addEventListener/removeEventListener APIs available in JavaScript to dispatch and listen for events. Let's go through CEP event data format/structure, APIs to dispatch and listen event, and sample code snippet accordingly in JavaScript.


In terms of CSEvent, it just means CEP Event here. The data structure of CSEvent (CEP Event) is as below.

 * Class CSEvent.
 * You can use it to dispatch a standard CEP event.
 * @param type	          Event type.
 * @param scope 	  The scope of event, can be "GLOBAL" or "APPLICATION".
 * @param appId 	  The unique identifier of the application that generated the event. Optional.
 * @param extensionId The unique identifier of the extension that generated the event. Optional.
 * @return CSEvent object
function CSEvent(type, scope, appId, extensionId)
    this.type = type;
    this.scope = scope;
    this.appId = appId;
    this.extensionId = extensionId;

You could create a CSEvent object and dispatch it by using CSInterface.dispatchEvent. Also you could access its property in your callback of CSInterface.addEventListener. Refer to the section addEventListener/dispatchEvent below for more details.

Listen for and Dispatch CSEvent

dispatchEvent/addEventListener/removeEventListener APIs are available in JavaScript world to dispatch and listen for CSEvent.


Here is the definition for addEventListener. Refer to CSInterface.js for more information:

 * Registers an interest in a CEP event of a particular type, and
 * assigns an event handler.
 * The event infrastructure notifies your extension when events of this type occur,
 * passing the event object to the registered handler function.
 *  * @param type     The name of the event type of interest.
 * @param listener The JavaScript handler function or method.
 * @param obj      Optional, the object containing the handler method, if any.
 *         Default is null.
CSInterface.prototype.addEventListener = function(type, listener, obj)

One thing needs to be mentioned here is both named and anonymous callback functions are supported in CSInterface.addEventListener.

  • An example of how to use named callback function in CSInterface.addEventListener.
function callback(event)
    console.log(“type=” + event.type + “, data=” +;
var csInterface = new CSInterface();
csInterface.addEventListener(“com.adobe.cep.test”, callback); //invoke the function
  • An example of how to use anonymous callback function in CSInterface.addEventListener.
var csInterface = new CSInterface();
csInterface.addEventListener(“com.adobe.cep.test”, function (event)
     console.log(“type=” + event.type + “, data=” +;
); // Anonymous function is the second parameter

The can be an object (i.e. you could use an object as

Before CEP 6.1, we regarded every attribute in object as a regular string, but from CEP 6.1, we revised the behavior that keep the type of each attribute in as it was. If the value is a valid JSON string, CEP will parse it natively and convert it to an object. Here is an example on how to use it.

var csInterface = new CSInterface();
csInterface.addEventListener(“com.adobe.cep.test”, function (event)
     var obj =;
     console.log(“type=” + event.type + “, data.property1=” + obj.property1 + “, data.property2=” + obj.property2);
); // Anonymous function is the second parameter

Here is the definition for CSInterface.dispatchEvent. Refer to CSInterface.js for more details.

 * Triggers a CEP event programmatically. Yoy can use it to dispatch
 * an event of a predefined type, or of a type you have defined.
 * @param event A \c CSEvent object.
CSInterface.prototype.dispatchEvent = function(event)

Here are three samples to demonstrate how to dispatch an event in JavaScript.

  • An example of how to dispatch event in JavaScript.
var csInterface = new CSInterface();
var event = new CSEvent("com.adobe.cep.test", "APPLICATION"); = "This is a test!";
  • Another example of creating event object and setting property, then dispatch it.
var csInterface = new CSInterface();
var event = new CSEvent();
event.type = "com.adobe.cep.test";
event.scope = "APPLICATION"; = "This is a test!";
  • An example of dispatching an event whose data is an object.
var event = new CSEvent("com.adobe.cep.test", "APPLICATION");
var obj = new Object();
obj.a = "a";
obj.b = "b"; = obj;
Communication between Native Point Product and CEP extensions

CEP event based communication between native point product and CEP extensions is simple. You can use PlugPlugAddEventListener/PlugPlugDispatchEvent to communicate with CEP extensions.

Please refer the following steps:

First, define a callback function in CEP extension:

function callback(event)
    // do something here

Then call CSInterface.addEventListener with event type you want to listen and the callback function:

var csInterface = new CSInterface();
csInterface.addEventListener(“com.adobe.cep.test”, callback);
Standard Events in Point Products

Following table lists the standard events supported by point products.

Event Type Event Scope Description Event Parameter PS ID AI AN PR PL AU
documentAfterActivate APPLICATION Event fired when a document has been activated(after new/open document; after document has retrieved focus). URL to the active document. If the doc was not save, the NAME will be set instead of the URL. No Yes Yes No No No Yes
documentAfterDeactivate APPLICATION Event fired when the active document has been de-activated.(after document loses focus) URL to the active document. If the doc was not save, the name will be set instead of the URL. Yes Yes Yes No No No Yes
applicationBeforeQuit APPLICATION Event fired when the application got the signal to start to terminate. none No Issue Issue No No No No
applicationActivate APPLICATION Event fired when the Application got an "activation" event from the OS. none Yes Yes Yes No Yes on macOS;
No on Windows
Yes on macOS;
No on Windows
documentAfterSave APPLICATION Event fired after the document has been saved URL to the saved document. Yes Yes Yes No No No Yes

(Yes = supported, No = not supported)

Note: CEP is unloaded from the point products ID and AI right after the event applicationBeforeQuit is emitted from the point products, therefore CEP may have no chance to get this event handled in HTML extensions.

Specific Events in Products

In Photoshop, the following specific events are defined:

  • com.adobe.PhotoshopPersistent
  • com.adobe.PhotoshopUnPersistent
  • com.adobe.PhotoshopWorkspaceSet
  • com.adobe.PhotoshopWorkspaceGet
  • com.adobe.PhotoshopWorkspaceAware
  • com.adobe.PhotoshopWorkspaceData
  • com.adobe.PhotoshopWorkspaceRequest
  • com.adobe.PhotoshopRegisterEvent
  • com.adobe.PhotoshopUnRegisterEvent
  • com.adobe.PhotoshopLoseFocus
  • com.adobe.PhotoshopQueryDockingState

For example, a CEP extension yields the mouse focus back to Photoshop by sending the com.adobe.PhotoshopLoseFocus event:

var csInterface = new CSInterface();
var event = new CSEvent("com.adobe.PhotoshopLoseFocus", "APPLICATION");
event.extensionId = csInterface.getExtensionID();

com.adobe.PhotoshopCallback will be removed in Photoshop 17.0 as adding a listener results in all CS Extensions receiving the event. As of Photoshop CC 2015 June release, developers can now use this alternative, which fixes the broadcast issue:

csInterface.addEventListener("com.adobe.PhotoshopJSONCallback" + gExtensionID, PhotoshopCallbackUnique);
Invoke point product's scripts from html extension

First, define a callback function in CEP extension:

function evalScriptCallback(result)
   // process the result string here.

Then call CSInterface.evalScript with the script you want to call and the callback function:

var script = "app.documents.add";  //Demo script
CSInterface.evalScript(script, evalScriptCallback);

Please be aware that the script in evalScript and the jsx file which is configured in <ScriptPath> in the extension's manifest are executed in host application's ExtendScript engine, which runs in host application's main thread. On the other hand, CEP event is also dispatched from host application's main thread. If the interaction between the script and CEP event is needed, please split the script into small parts and call them separately so that CEP event has a chance to be scheduled.

Vulcan messages

Starting with CEP 5.0, global CEP Events whose scope attribute is set to "GLOBAL" are no longer supported. Please use the APIs in Vulcan.js instead.

Vulcan message

The data structure of Vulcan message in JavaScript is as below.

 * @class VulcanMessage
 * Message type for sending messages between host applications.
 * A message of this type can be sent to the designated destination
 * when appId and appVersion are provided and valid. Otherwise,
 * the message is broadcast to all running Vulcan-enabled applications.
 * To send a message between extensions running within one
 * application, use the <code>CSEvent</code> type in CSInterface.js.
 * @param type            The message type.
 * @param appId           The peer appId.
 * @param appVersion      The peer appVersion.
function VulcanMessage(type, appId, appVersion)
    this.type = type;
    this.scope = VulcanMessage.SCOPE_SUITE;
    this.appId = requiredParamsValid(appId) ? appId : VulcanMessage.DEFAULT_APP_ID;
	this.appVersion = requiredParamsValid(appVersion) ? appVersion : VulcanMessage.DEFAULT_APP_VERSION; = VulcanMessage.DEFAULT_DATA;

VulcanMessage.TYPE_PREFIX    = "vulcan.SuiteMessage.";
VulcanMessage.SCOPE_SUITE    = "GLOBAL";
VulcanMessage.DEFAULT_DATA = "<data><payload></payload></data>";
VulcanMessage.dataTemplate = "<data>{0}</data>";
VulcanMessage.payloadTemplate = "<payload>{0}</payload>";
Listen for and Dispatch Vulcan message

addMessageListener, removeMessageListener, dispatchMessage and getPayload APIs are available to dispatch and listen for Vulcan messages. The API definitions are as below. Refer to Vulcan.js for more information.

 * Registers a message listener callback function for a Vulcan message.
 * @param type            The message type.
 * @param callback        The callback function that handles the message.
 *                        Takes one argument, the message object.
 * @param obj             Optional, the object containing the callback method, if any.
 *                        Default is null.
Vulcan.prototype.addMessageListener = function(type, callback, obj)
 * Removes a registered message listener callback function for a Vulcan message.
 * @param type            The message type.
 * @param callback        The callback function that was registered.
 *                        Takes one argument, the message object.
 * @param obj             Optional, the object containing the callback method, if any.
 *                        Default is null.
Vulcan.prototype.removeMessageListener = function(type, callback, obj)
 * Dispatches a Vulcan message.
 * @param vulcanMessage   The message object.
Vulcan.prototype.dispatchMessage = function(vulcanMessage)
 * Retrieves the message payload of a Vulcan message for the registered message listener callback function.
 * @param vulcanMessage   The message object.
 * @return                A string containing the message payload.
Vulcan.prototype.getPayload = function(vulcanMessage)

Here is the example to demonstrate how to use the APIs in JavaScript.

var testVulcanMessage = new VulcanMessage(VulcanMessage.TYPE_PREFIX + "test");
testVulcanMessage.setPayload("To be or not to be that is a question!");
var callback = function (message) {
VulcanInterface.addMessageListener(testVulcanMessage.type, callback);
VulcanInterface.removeMessageListener(testVulcanMessage.type, callback);

getEndPoints and getSelfEndPoint APIs are available to support point-to-point Vulcan message. The API definitions are as below. Refer to Vulcan.js for more information.

 * Gets all available endpoints of the running Vulcan-enabled applications.
 * Since 7.0.0
 * @return                The array of all available endpoints.
 * An example endpoint string:
 * <endPoint>
 *   <appId>PHXS</appId>
 *   <appVersion>16.1.0</appVersion>
 * </endPoint>
Vulcan.prototype.getEndPoints = function()

 * Gets the endpoint for itself.
 * Since 7.0.0
 * @return                The endpoint string for itself.
Vulcan.prototype.getSelfEndPoint = function()

The steps to send point-to-point Vulcan message are as follows:

  • Get all available endpoints.
  • Select the destination endpoint and get appId and appVersion from it.
  • Create Vulcan message with the destination appId and appVersion.
  • Dispatch Vulcan message.
var endPointList = VulcanInterface.getEndPoints();
var destIndex = 0;
var appId = GetValueByKey(endPointList[destIndex], "appId");
var appVersion = GetValueByKey(endPointList[destIndex], "appVersion");
var message = new VulcanMessage(VulcanMessage.TYPE_PREFIX + "test", appId, appVersion);

Access Application DOM from Html Extension

There are two separate JavaScript engines here.

  • JavaScript engine of host application - Application DOM/Extend script DOM
  • JavaScript engine of CEP HTML runtime - HTML DOM

Application DOM is not available in CEP extension's engine and CEP DOM is not available in host application's engine.

To access Application DOM from CEP extensions, CEP JavaScript library provides an API, CSInterface.evalScript, to execute extend script to access the host application's DOM. Here is a brief diagram to indicate how to access Application DOM through this API.

enter image description here

Here is the sample JavaScript code snippet in HTML extension.

var csInterface = new CSInterface();
csInterface.evalScript('app.documents.add();', function(result){

Access HTML DOM from extend script

There is no way to access HTML extension's JavaScript DOM directly from Application's ExtendScript. If you need to access it, CEP event based communication can be used as a substitution.

CEP creates a library which uses External Object mechanism of ExtendScript to send CSXS events. The external object provides an ExtendScript class CSXSEvent for creating and dispatching application-level CSXS events. On HTML extension side, event listeners can be registered via the addEventListener API in CSInterface.js to listen to the events.

Some CC applications (Photoshop, Illustrator, Premiere Pro) integrated PlugPlugExternalObject library and started to support this functionality in CC 2014 release. Audition supports this functionality since CC 2015.1 release.

Sample Code

ExtendScript developers need to create external object instance first.

var externalObjectName = "PlugPlugExternalObject"; 
var mylib = new ExternalObject( "lib:" + externalObjectName );

And then create the CSXSEvent instance.

var eventObj = new CSXSEvent(); 

At last use this instance to dispatch event:


Below is the sample code of ExtendScript.

var cs = new CSInterface();

cs.addEventListener("documentCreated", function(event){
  alert('Cool!' +;

var extendScript = 'var externalObjectName = "PlugPlugExternalObject"; var mylib = new ExternalObject( "lib:" + externalObjectName ); app.document.add(); var eventObj = new CSXSEvent(); eventObj.type="documentCreated";"blahblah"; eventObj.dispatch();'

Fly-out menu

For fly-out menu on the native panel of HTML extension, it has been supported.

Two new interfaces are added to CSInterface.

CSInterface.prototype.setPanelFlyoutMenu = function(menu){
  window.__adobe_cep__.invokeSync("setPanelFlyoutMenu", menu);
CSInterface.prototype.updatePanelMenuItem = function(menuItemLabel, enabled, checked){
  var ret = false;
  if (this.getHostCapabilities().EXTENDED_PANEL_MENU){
	var itemStatus = new MenuItemStatus(menuItemLabel, enabled, checked);
	ret = window.__adobe_cep__.invokeSync("updatePanelMenuItem", JSON.stringify(itemStatus));

  return ret;

The "menu" parameter for setPanelFlyoutMenu is a XML string. Below is an example:

  <MenuItem Id="menuItemId1" Label="TestExample1" Enabled="true" Checked="false"/>
  <MenuItem Label="TestExample2">
     <MenuItem Label="TestExample2-1" >
        <MenuItem Label="TestExample2-1-1" Enabled="false" Checked="true"/>
     <MenuItem Label="TestExample2-2" Enabled="true" Checked="true"/>
  <MenuItem Label="---" />
  <MenuItem Label="TestExample3" Enabled="false" Checked="false"/>

If user wants to be notified when clicking a menu item, user needs to register event by calling AddEventListener. When a menu item is clicked, the event callback function will be called. The data attribute of event is an object which contains menuId and menuName attributes.

To get notified when fly-out menu is opened and closed, register event listener for below event types respectively:


Customize Context Menu

Set and Update Context Menu

There are three APIs in CSInterface for developers to set and update the customized context menu.

CSInterface.prototype.setContextMenu = function(menu, callback){
  window.__adobe_cep__.invokeAsync("setContextMenu", menu, callback);
CSInterface.prototype.setContextMenuByJSON = function(menu, callback){
  window.__adobe_cep__.invokeAsync("setContextMenuByJSON", menu, callback);
CSInterface.prototype.updateContextMenuItem = function(menuItemID, enabled, checked){
  var itemStatus = new ContextMenuItemStatus(menuItemID, enabled, checked);
  ret = window.__adobe_cep__.invokeSync("updateContextMenuItem", JSON.stringify(itemStatus));

The "menu" parameter for "setContextMenu" is a XML string.

  • Id - Menu item ID. It should be plain text.
  • Icon - Menu item icon path. It is a path relative to the extension root path. For optimal display results please supply a 16 x 16px PNG icon as larger dimensions will increase the size of the menu item.
  • Label - Menu item label. It supports localized languages.
  • Enabled - Whether the item is enabled or disabled. Default value is true.
  • Checkable - Whether the item can be checked/unchecked. Default value is false.
  • Checked - Whether the item is checked or unchecked. Default value is false.
  • The items with icons and checkable items cannot coexist on the same menu level. The former take precedences over the latter.

Here is an example.

   <MenuItem Id="menuItemId1" Label="TestExample1" Enabled="true" Checked="false" Icon="./img/small_16X16.png"/>
   <MenuItem Id="menuItemId2" Label="TestExample2">
     <MenuItem Id="menuItemId2-1" Label="TestExample2-1" >
       <MenuItem Id="menuItemId2-1-1" Label="TestExample2-1-1" Enabled="false" Checkable="true" Checked="true"/>
     <MenuItem Id="menuItemId2-2" Label="TestExample2-2" Enabled="true" Checkable="true" Checked="true"/>
   <MenuItem Label="---" />
   <MenuItem Id="menuItemId3" Label="TestExample3" Enabled="false" Checked="false"/>

The "callback" parameter is the callback function which is called when user clicks a menu item. The only parameter is the ID of clicked menu item.

If you prefer to using a JSON string to set context menu, you can achieve it by calling setContextMenuByJSON.

The "menu" parameter for setContextMenuByJSON is a JSON string.

  • id - Menu item ID. It should be plain text.
  • icon - Menu item icon path. It is a path relative to the extension root path. For optimal display results please supply a 16 x 16px PNG icon as larger dimensions will increase the size of the menu item.
  • label - Menu item label. It supports localized languages.
  • enabled - Whether the item is enabled or disabled. Default value is true.
  • checkable - Whether the item can be checked/unchecked. Default value is false.
  • checked - Whether the item is checked or unchecked. Default value is false.
  • The items with icons and checkable items cannot coexist on the same menu level. The former take precedences over the latter.

Here is an JSON example

       "menu": [
		   	   "id": "menuItemId1",
			   "label": "testExample1",
			   "enabled": true,
			   "checkable": true,
			   "checked": false,
               "icon": "./img/small_16X16.png"
			   "id": "menuItemId2",
               "label": "testExample2",
               "menu": [
                       "id": "menuItemId2-1",
                       "label": "testExample2-1",
                       "menu": [
                               "id": "menuItemId2-1-1",
                               "label": "testExample2-1-1",
                               "enabled": false,
                               "checkable": true,
                               "checked": true
                       "id": "menuItemId2-2",
                       "label": "testExample2-2",
                       "enabled": true,
                       "checkable": true,
                       "checked": true
               "label": "---"
               "id": "menuItemId3",
               "label": "testExample3",
               "enabled": false,
               "checkable": true,
               "checked": false

If developers do not set context menu, CEP shows default items (Back, Forward, View Source, etc.). This is compatible with previous releases. If developers set context menu which has no any default id, CEP removes all default items and show customized items only. If one of the following default ids is set, the default menu item against that id will be shown.

"view source"


  1. They are case-insensitive.
  2. The quotation marks is not a part of an id.
  3. The default callback associated to each id will be used and cannot be customised.
Disable Context Menu

To disable the context menu, you can call setContextMenu by null.

Another way is to add oncontextmenu="return false;" to the HTML tag. For example,

<body oncontextmenu="return false;">

Get Display Status of HTML Extension Window

Two ways to get HTML extension window
  • Register "" CSXS event
  • Call isWindowVisible JavaScript API.
Resister "" CSXS event
  • Observe CSXS event, this is for PANEL extensions only. If user hides the panel window by clicking "X" or collapsing window, this event is going to be sent to observer with the "true" or "false" string in data attribute, while the event is not going to be sent if the extension is closed. That is to say, currently, only panel extensions which are running on Ai and persistent can receive this event, when the extension is hiding, event with "false" data is sent while the extension is shown, event with "true" is sent.
Call isWindowVisible API
  • Call isWindowVisible JS interface. Both dialog and panel extension enable to access this API, but it always returns true for modal and modeless dialog extensions while it always returns false for invisible extensions.

Getting and Changing Extension Content Size

Getting Extension Content Size

Getting extension content size can be done using window.innerWidth and window.innerHeight. However, if you are accessing these properties from inside an IFrame, you are actually accessing the properties of the IFrame's window object, not the ones for the HTML document. To access the top-most one, you will need to do parent.window.innerWidth and parent.window.innerWidth.

Changing Extension Content Size

Changing modal and modeless extension content size is supported in all Adobe applications that supports CEP. However, changing panel HTML extension size is not supported in Premiere Pro, Prelude, After Effects and Audition.

CSInterface.prototype.resizeContent = function(width, height)

The width and height parameters are expected to be unsigned integers. The function does nothing when parameters of other types are passed.

Please note that extension min/max size constraints as specified in the manifest file apply and take precedence. If the specified size is out of the min/max size range, the min or max bounds will be used. When a panel is docked with other panels, there are chances that it won't resize as expected even when the specified size satisfies the min and max constraints. The restriction is imposed by host applications, not by CEP.

Register invalid certificate error callback

(Since 6.1) Register the invalid certificate error callback for an extension. This callback will be triggered when the extension try to access the web site that contains the invalid certificate on main frame. But if the extension does not call this function and try to access the web site containing the invalid certificate, a default error page will be shown:

CSInterface.prototype.registerInvalidCertificateCallback = function(callback)

Register an interest in specific key events

(Since 6.1) Register an interest in some key events to prevent them from being sent to the host application:

CSInterface.prototype.registerKeyEventsInterest = function(keyEventsInterest)

This function works with modeless extensions and panel extensions. Generally all the key events will be sent to the host application for these two extensions if the current focused element is not text input or dropdown.

If you want to intercept some key events and you want them to be handled in the extension, please call this function in advance to prevent them being sent to the host application.

  • keyEventsInterest: A JSON string describing those key events you are interested in. A null object or an empty string will lead to removing the interest

This JSON string should be an array, each object has following keys:

  • keyCode: [Required] represents an OS system dependent virtual key code identifying the unmodified value of the pressed key.
  • ctrlKey: [optional] a Boolean that indicates if the control key was pressed (true) or not (false) when the event occurred.
  • altKey: [optional] a Boolean that indicates if the alt key was pressed (true) or not (false) when the event occurred.
  • shiftKey: [optional] a Boolean that indicates if the shift key was pressed (true) or not (false) when the event occurred.
  • metaKey: [optional] (macOS Only) a Boolean that indicates if the Meta key was pressed (true) or not (false) when the event occurred. On Macintosh keyboards, this is the command key. To detect Windows key on Windows, please use keyCode instead.

To learn all key codes:

  • Windows
  • macOS
    • /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/Headers/Events.h
    • Install Key Codes from the Mac App Store.

An example JSON string:

    "keyCode": 48
    "keyCode": 123,
    "ctrlKey": true

Set and Get the title of the extension windows

(Since 6.1) CEP 6.1 introduces two APIs to set and get the title of extension windows. Those functions work with modal and modeless extensions in all Adobe products, and panel extensions in Photoshop, InDesign, InCopy, Illustrator, Animate (Flash Pro) and Audition:

CSInterface.prototype.setWindowTitle = function(title){
  window.__adobe_cep__.invokeSync("setWindowTitle", title);
CSInterface.prototype.getWindowTitle = function(){
  return window.__adobe_cep__.invokeSync("getWindowTitle", "");

HI-DPI display

CEP JavaScript library provides APIs for detecting the availability of HI-DPI display on the macOS platform.

  • CSInterface.getScaleFactor() Use this function to retrieve the scale factor of the display on which the calling extension window is located.
  • var scaleFactor = CSLibrary.getScaleFactor();
  • CSInterface.setScaleFactorChangedHandler() Use this function to add a event handler that will be called when calling extension window is moved between HI-DPI and non-HI-DPI displays.
window.scaleFactorHandler = function(){
var scaleFactor = CSLibrary.getScaleFactor();
if (scaleFactor === 2){
imgSrc = "../img/PS_AppIcon_r.png"
} else {
imgSrc = "../img/PS_AppIcon.png"
document.getElementById("image").src = imgSrc;


CEP 5.2 has already supported HiDPI on Windows.

Other JavaScript APIs

The JavaScript engine in CEP HTML engine had been extended to provide some APIs, including:

  • local file access
  • native process
  • others

These APIs are in JavaScript DOM and can be used as other built-in JavaScript APIs. You do NOT need to include any JavaScript files.

API reference is as below.

CEPEngine_extensions.js is actually a CEF extension that is built in CEPHtmlEngine to expand the DOM of CEPHtmlEngine, like create/delete folder, read/write file, create/quit process, and so on. You can invoke these built-in APIs directly in your HTML extension without any JavaScript file reference.

For example, you want to

  • create a folder.
var path = "/tmp/test";
var result = window.cep.fs.makedir(path);
if (0 == result.err){
  ...// success
} else {
  ...// fail
  • write a file.
var data = "This is a test.";
var path = "/tmp/test";
var result = window.cep.fs.writeFile(path, data);
if (0 == result.err){
  ...// success
} else {
  ...// fail
  • Write file with base64 encoding mode. To use this mode, you need to convert the input string to a base64-encoded string before calling writeFile(). The following is an example.
var data = "This is a test.";
var path = "/tmp/test";
data = cep.encoding.convertion.utf8_to_b64(data);
var result = window.cep.fs.writeFile(fileName, data, cep.encoding.Base64);
if (0 == result.err) {
  ...// success
} else {
  ...// fail
  • read a file.
var path = "/tmp/test";
var result = window.cep.fs.readFile(path);
if(result.err === 0){
  alert(; // is file content
} else {
  ...// fail
  • Read file with base64 encoding mode in which the read data after readFile called is converted to a base-encoded string. You need to decode this string to any format you want. The following is an example
var path = "/tmp/test";
result = window.cep.fs.readFile(path, cep.encoding.Base64);
if(result.err === 0){
  var base64Data =;
  var data = cep.encoding.convertion.b64_to_utf8(base64Data);
} else {
  ...// fail
  • Create a process and check if it's running.
var result = window.cep.process.createProcess("usr/X11/bin/xterm");

if(result.err === 0){
  var pid =;
  result = window.cep.process.isRunning(pid);
  if( === true){
    // running                  

You could use other APIs like delete folder, rename folder, set file permission, delete file, show file open dialog, quit process, etc.

We have the following samples that demonstrate use of some of these APIs:


In order to support localization, both the extension and the host application must provide locale information. There are two distinct types of locale information.

  • The License Locale (returned as the applicationLocale by the AMT library)
  • The Effective/Language/UI Locale (which is controlled by the user in the OS settings).

The extension must provide the list of supported locales for both the License Locale and the Language Locale via the HostEnvironment. This is particularly important in cases where the extension has features for a specific locale. PlugPlug library expects the host application to provide the locale information as part of the environmental data.

JavaScript API HostEnvironment has the appLocale property in place.

License Locale and locales supported by extension

CEP checks the License Locale of host application against supported locales declared in extensions locale list to determine if the extension is loadable for the host application.

Locale folder structure

Each property file should be placed in its corresponding locale folder. For example, the en_US property file should be <YourExtension>/locale/en_US/ Users can define a default property file (<YourExtension>/locale/, which will be used when the corresponding locale file is not defined.

     |-locale/                      <-- Directory for localized resources
         |--    <-- The one to fallback to if no localized resources is provided for a locale
         |-- en_US/
         |        |-
         |-- zh_CN/

A locale file contains multiple lines of <key>=<value>. There should be a new line below the last property key/value.


CEP provides a JS interface named initResourceBundle to initialize the locale resources. This should be called during the loading of the extension. CEP initializes the resource bundle for the extension with property values for the current application and UI locale. Then users can access the resource bundle (object) to get the localized strings.

var csInterface = new CSInterface();

Sharing localization resources across multiple locales

CEP 6.0 provided a mechanism to allow multiple locales to share the same localization resources (

For example, you want es_MX to use the for es_ES. To do so, supply a file named in the es_MX folder as illustrated below.

         |-- es_ES/
         |        |-
         |-- es_MX/

In the file, you specify which locale's localized resources you want es_MX to use, in below format


Side Notes:

  • The file takes precedence when both and exist at the same time.
  • If is malformed, or it specifies a non-existent fallback locale, the file in the same directory will be used.

Localized menu

In manifest, it supports to use locale string as menu. For example, in ShareOnBehance's manifest, it is using %UI_share_on_Behance. UI_share_on_Behance is defined as UI_share_on_Behance=xxx in



Example 1
var cs = new CSInterface();
// Get properties according to current locale of host application.
var resourceBundle = cs.initResourceBundle();
// Use the localized strings.
<script type="text/javascript">document.write(resourceBundle.key1);</script>
Example 2

data-locale is the custom HTML element attribute and you can add to each HTML element that you want to localize.

In this example, there is key3.value=value3 in the property file. In the HTML file, the input widget has attribute data-locale with key3, then its value is set to value3.

In this example, there is key4.innerHTML=value4 in the property file. In the HTML file, the text area widget has attribute data-locale with key4, then its innerHTML is set to value4.

<script type="text/javascript">
  var cs = new CSInterface();
  // Get properties according to current locale of host application.
  var resourceBundle = cs.initResourceBundle();
  // Use the localized strings.

<input type="submit" value="" data-locale="key3"/>
<textarea rows="10" cols="80" data-locale="key4"></textarea>
Example 3

Use parameters ($1, $2, ...) in localized strings.

var localize = function(key){
  var cs = new CSInterface();
  var resourceBundle = cs.initResourceBundle();
  var localizedStr = resourceBundle[key];
  if (localizedStr){
    var index = 1;
    while (localizedStr.indexOf("$" + index) !== -1){
      localizedStr = localizedStr.replace("$" + index, arguments[index]);
    return localizedStr;
  } else {
    return '';

Supporting MENA locales

MENA stands for "Middle East and North Africa". Support needs to be provided for Arabic, Hebrew, and NA French languages.

Language ISO Code
Arabic (Middle East Enabled English Arabic) en_AE
Hebrew (Middle East Enabled English Hebrew) en_IL
NA French fr_MA

If an extension needs to be loaded in host applications in MENA locales, MENA locales must be added to the supported locale list of the extension manifest file. For example:

    <Locale Code="en_AE"/>
    <Locale Code="en_IL"/>
    <Locale Code="fr_MA"/>
Extension localization for MENA locales

Suppose your extension has this directory layout

         |-locale/                                <-- Directory for localized resources
                 |--          <-- The one to fallback to if no localized resources is provided for a locale
                 |-- fr_FR/
                 |        |-
                 |-- en_GB/

When CSInterface.initResourceBundle() is called, CEP uses the app UI locale (not app locale) reported by PP to load localized resources. If there is no localized resources for an app UI locale, for example fr_MA, then CEP will fall back to use located under the locale folder.

With MENA feature, point products map en_AE/en_IL to en_US and fr_MA to fr_FR for app UI locale. In this case, for en_AE and en_IL build of point product, en_US resources will be used if provided and for fr_MA build of point product, fr_FR resources will be used if provided. What extension team needs to do in this case is to provide en_US version of resources for en_AE/en_IL and fr_FR version of resources for fr_MA.

Video/Audio Playback

CEP 5.0 and higher versions supports playing video and audio encoded in below formats.

Format MIME-Type Misc.
MP4 video/mp4 MPEG 4 files with H.264 video codec and AAC audio codec
Ogg video/ogg Ogg files with Theora video codec and Vorbis audio codec
mp3 audio/mpeg

Here is an example of playing video in your extension:

<video poster="" controls>
    <source src="" type='video/mp4; codecs="avc1.42E01E, mp4a.40.2"'/>

One thing to note is that because HTML extensions are hosted in integrating application's windows, video cannot be played in full-screen mode.


WebRTC is targeting to serve stream audio, video capture, like online video conference. WebRTC is not enabled by default. To enable it, the schema below need to be added in manifest file. For details, refer to Customize CEF command parameters.

<CEFCommandLine> <Parameter>--enable-media-stream</Parameter> </CEFCommandLine>

For WebRTC related development, CEP runtime just keeps the same experiences as the usage in Chrome. Please refer to samples for the implementation.

Scroll bar tips

On macOS, scroll bars of panel are hidden by OS (since Lion by design). It can be always shown by settings as below.

  1. Click the Apple menu at the top-left of the screen, then select System Preferences.

  2. Next, select the General preferences pane; it’s the very first one, up at the top.

  3. Under the “Show scroll bars” heading, you’ll find three options: “Automatically based on input device,” “When scrolling,” and “Always.” Chose "Always."

Invisible HTML Extensions

An HTML extension can be invisible during its whole life cycle. This means

  • It always runs in the background
  • It is never visible

To make an HTML extension invisible

  • Set extension manifest version to "5.0" or higher.
  • Specify its window type as 'Custom' in the manifest file.
  • Set <AutoVisible> to false in the manifest file.
  • If you do not want the extension to appear in the Window->Extensions menu, do not add the <Menu> tag.
  • If you want the extension to start on specific types of events, specify those events using <StartOn> tag.

Here is an example:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<ExtensionManifest xmlns:xsi="" ExtensionBundleId="IamInvisible" ExtensionBundleVersion="1.0" Version="5.0">
        <Extension Id="IamInvisible" Version="1.0"/>
            <Host Name="PHXS" Version="13.0"/>
            <Locale Code="All"/>
            <RequiredRuntime Name="CSXS" Version="5.0"/>
        <Extension Id="IamInvisible">
                        <!-- Photoshop dispatches this event on startup -->
                        <!-- Premiere Pro dispatches this event on startup -->
                        <!-- You can add more events -->

One important thing to note is that not all host applications support Invisible HTML Extension. See table below for more information:

Point Product Supports Invisible Extension Misc.
Photoshop Yes
Premiere Pro Yes
Prelude Yes
Animate (Flash Pro) Yes
Audition Yes
InDesign Yes However, as of 2019 you must include a width and height.
InCopy Yes However, as of 2019 you must include a width and height.
Illustrator Yes

Customize CEF Command Line Parameters

Chromium/CEF command line parameters can be passed to CEPHtmlEngine, like --enable-media-stream. Available Chromium command line parameters.

CEP filters out some parameters due to various reasons:

Parameters What is it filtered out?
--remote-debugging-port This could overwrite the one in .debug file. Filter out to avoid conflict.
--ignore-certificate-errors This ignores SSL certificate errors. It is a security concern to ignore invalid server certificate, which allows extensions to load files from malicious sites.

All other parameters are passed to underlying CEF. It is up to CEF to decide whether a parameter is supported and what is the behavior.

How to use CEF command line parameters

  • Add <CEFCommandLine><Parameter>--param1<Parameter/> ... </CEFCommandLine> in manifest.
  • For key=value parameter, add <CEFCommandLine><Parameter>--param1=value1<Parameter/> ... </CEFCommandLine> in manifest.

Here is an example:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<ExtensionManifest xmlns:xsi="" ExtensionBundleId="xx.yy.zz" ExtensionBundleVersion="1.0" Version="5.0">
        <Extension Id="xx.yy.zz" Version="1.0"/>
            <Host Name="PHXS" Version="13.0"/>
            <Host Name="PPRO" Version="6.0"/>
            <Locale Code="All"/>
            <RequiredRuntime Name="CSXS" Version="5.0"/>
        <Extension Id="xx.yy.zz">

Commonly used CEF command parameters

Parameters Notes
--enable-media-stream Enable media (WebRTC audio/video) streaming.
--enable-speech-input Enable speech input (x-webkit-speech).
--persist-session-cookies Persist session cookies.
--disable-image-loading Disable loading of images from the network. A cached image will still be rendered if requested.
--disable-javascript-open-windows Disable opening of windows via JavaScript.
--disable-javascript-close-windows Disable closing of windows via JavaScript.
--disable-javascript-access-clipboard Disable clipboard access via JavaScript.
--enable-caret-browsing Enable caret browsing.
--proxy-auto-detect This tells Chrome to try and automatically detect your proxy configuration.
See more info at
--user-agent A string used to override the default user agent with a custom one.
--disable-application-cache Disable the ApplicationCache.
--enable-nodejs Enable Node.js APIs in extensions. Supported since CEP 6.1.
--disable-pinch Disable compositor-accelerated touch-screen pinch gestures.
--mixed-context Enable the "mixed context" mode. Supported since CEP 7.0.

HTML Extension Persistent

The purpose of persistent is to force not reload HTML extension when it is closed or hidden. Photoshop has provided persistent since the version 14.2. Please note that, this feature is product specific and may not be available in few host applications.

InDesign and InCopy support perisitent feature from version 13.1. Following are the specific event names to be used: Indesign: com.adobe.InDesignPersistent com.adobe.InDesignUnPersistent Incopy: com.adobe.InCopyPersistent com.adobe.InCopyUnPersistent

To make an HTML extension persistent in Photoshop

  • Upgrade Photoshop version to 14.2 or later
  • Dispatch the event com.adobe.PhotoshopPersistent from HTML extension to Photoshop to request persistent

Sample code:

var Persistent = function(inOn){
    var event = new CSEvent("com.adobe.PhotoshopPersistent", "APPLICATION");  //Photoshop
    //var event = new CSEvent("com.adobe.InDesignPersistent", "APPLICATION"); //Indesign
    //var event = new CSEvent("com.adobe.InCopyPersistent", "APPLICATION"); //Incopy
  } else {
    var event = new CSEvent("com.adobe.PhotoshopUnPersistent", "APPLICATION"); //Photoshop
    //var event = new CSEvent("com.adobe.InDesignUnPersistent", "APPLICATION"); //Indesign
    //var event = new CSEvent("com.adobe.InCopyUnPersistent", "APPLICATION"); //Incopy
  event.extensionId = <extension id as per manifest definition>;
Persistent(true); //persistent to prevent extension from unloading
Persistent(false); //unpersistent

Open URL link in default browser

In HTML extension, URL link could be opened in the default browser by calling window.cep.util.openURLInDefaultBrowser(‘'):

<li><button onclick="window.cep.util.openURLInDefaultBrowser('')">Open browser</button></li>

Interaction between extension and point product during extension unload

When an extension is about to be unloaded, the communication channel between extension and point product has been torn down, so there's no easy way for point product to get the extension-related information such as the extension's status.

To fulfill this functionality, the cooperation between extension and point product is needed.

From extension's side, a JavaScript function registerExtensionUnloadCallback is provided to register its callback function. The definition can be found at There're some limitations as below:

  • If registerExtensionUnloadCallback is called more than once, the last callback function that's successfully registered will be used.
  • The callback function must be context-independent and it is executed in the mainframe's context.


window.cep.fs.writeFile("D:\\1.txt", "Hello");

From point product's side, csxs::event::EVENT_TYPE_CSXS_EXTENSION_UNLOADED ("") is dispatched. When point product receives the event, it can read the file written by extension to get the extension-related information.

Since the execution in the extension and the point product is in parallel, the point product needs to take care of the order.

The above method does not work due to the multi-process architecture in CEF 3.

Using Node.js APIs (CEP 6.0 and prior releases)

Node.js Support

One of the most prominent feature in CEP 5.0 and higher versions are allowing Node.js APIs to be used in HTML extensions. Most of the built-in APIs in Node.js version 0.8.22 are available to HTML extensions, with the below exceptions:

  • Cluster APIs are not supported.
  • Console APIs are not supported on Windows.

Other things to note:

  • CEP injects following symbols into the root HTML DOM:
    • global, GLOBAL, root - same with the window object
    • Buffer - node's Buffer class
    • process - node's process class
    • require - the magic function that bring you node API
    • module - in node the main script is a special module, this is for the compatibility
  • Conflicts with Web-Based Require Function
    • If your app uses libraries like RequireJS that inserts a require function into DOM, you should consider renaming CEP's require function to something else before migrating.
<script type="text/javascript">windows.nodeRequire=window.require && window.require=undefined</script>
<script type="text/javascript" src="your/require/js/file.js"></script>
  • Conflicts with Web-Based module Function
    • If your app uses JQuery that is trying to register itself as nodejs plugin, then you will have to add the script below inside script tag to define window.module as undefined.
<script type="text/javascript">window.module = undefined</script> 
  • Disable Node.js APIs in iframe
    • Because of security consideration, CEP provides an option to disable Node.js APIs in iframe. To do so, add a nodejs-disabled="true" attribute to iframe tag. For example:
<iframe id="xxx" class="xxxxx" nodejs-disabled="true">
  • Forcing the environment implementation. If you are using RequireJS, and the text plugin tries to detect what environment is available for loading text resources, Node, XMLHttpRequest (XHR) or Rhino, but sometimes the Node or Rhino environment may have loaded a library that introduces an XHR implementation. You can force the environment implementation to use by passing an "env" module config to the plugin:
   config: {
   text: {
      //Valid values are 'node', 'xhr', or 'rhino'
       env: 'rhino'

Node.js Modules

JavaScript Modules

All third-party node JavaScript modules are supported. The root search path of third-party modules is the directory which contains your HTML file. For example, when you do require in file:///your_extension/index.html, CEP will lookup modules under file:///your_extension/node_modules, this rule is exactly the same with upstream node.

Native Modules

Node.js native modules are not directly supported since CEP is using a different V8 version from the official node.


Use Environment Variables
process.env.ENV_VARIABLE // ENV_VARIABLE is the name of the variable you want to access.
Use Node.js to download files

Using Node.js APIs (CEP 6.1)

Node.js Support

CEP 6.1 upgraded its HTML engine to CEF 2272 (based on Chromium 41.0.2272.104) with IO.js version 1.2.0 integrated.

Other things to note:

  • Node.js APIs are disabled by default
    • Due to security consideration, node.js APIs are disabled by default (prior to CEP 6.1, they were enabled by default) both on the extension level and iFrame level.

To enable Node.js APIs:

  • Set ExtensionManifest version and RequiredRuntime version 5.0 or higher.
  • Specify --enable-nodejs in extension manifest. See section Customize CEF Command Line Parameters for details.
  • To use Node.js APIs in IFrames, add property enable-nodejs to it and to all its ancestor iFrames. If any of its ancestors don't have this property specified, Node.js APIs won't work
<iframe id="xxx" class="xxxxx" enable-nodejs>
  • The old nodejs-disabled CEF command line parameter and iFrame property are no longer supported and ignored by the new HTML engine.
  • Node context and Browser context
    • The way io.js was integrated into CEF introduced two types of JavaScript contexts, one for browser, the other for io.js. Global objects created in HTML pages are in browser context, while required js files run in io.js context. These two contexts don't have direct access to each other's data. To share data, pass reference to objects between the two contexts:
      • Accessing objects in io.js context from browser context - For example, in browser context, var backbone = require('backbone'); executes the backbone module's code and then pass the result object to browser context.
      • Accessing objects in browser context from io.js context - Browser context's window global object is injected to io.js context, providing a way to access objects in browser context from io.js context. For example, if you want to access a global object named localeStrings defined in browser context from your io.js module, use window.localStrings in your io.js module.

Using Node.js APIs (since CEP 7.0)

In addition to the existing Node.js support in CEP 6.1, CEP 7.0 provided a new mixed context Node.js mode. Unlike the separate context mode in CEP 6.1 where a required node module is in a separate JavaScript context, a required node module and the JavaScript code that requires it are in the same context in the new mixed context mode, eliminating all the inconveniences in the old separate context mode.

This mode is disabled by default. To enable it, add command line parameter --mixed-context to your extension manifest.


Using Node.js APIs (since CEP 10.0)

In addition to existing Node.js support in CEP 9, CEP 10 provide a new disable-nodejs attribute for iframe. When this attribute is used in iframe, Node.js will be disabled in separate context and mixed-context both.

    <iframe name="iframe-1">
    	\\ Node will be accesible here
    <iframe name="iframe-2" disable-nodejs>
        \\ Node will not be accesible here

Limitation of cep.process.stdout/stderr

There is a known limitation of cep.process.stdout/stderr which is targeting to capture one time of stdout/stderr output.

For applications that has not integrated CEP 5, there are two workarounds suggested as the following.

  • Embed cep.process.stdout/stderr:
var getSTDOutput = function(){ 
  window.cep.process.stdout(pid, function(output){
  // your code is here
  var result = window.cep.process.isRunning(pid);
  if ( === true){
    setTimeout(getSTDOutput, 1000);
  • Join all stdout output as one, like below
var str1 = 'abcdef';
var str2 = '12345';
var str3 = 'gghhtt';
console.log(str1 + str2 + str3);

An example on how to get curl downloading progress through stderr:

        var downloadPid = -1;
        function getStdErrOutput()
            window.cep.process.stderr(downloadPid, function(progress) {
                                      var keys = progress.split(new RegExp('[# ]', 'g'));
                                      for(i=0; i<keys.length; i++){
                                        if (keys[i] != '') {
            var result = window.cep.process.isRunning(downloadPid);
            if ( == true)
                setTimeout(getStdErrOutput, 100);
        var doDownload = function() {
            var qURL = '';
            var dest = '/tmp/test.js';
            console.log("ext download (curl) " + qURL + " " + dest);
            var result = window.cep.process.createProcess('/usr/bin/curl', qURL, '-#', '-o', dest);
            downloadPid =;
            console.log("download pid is " + downloadPid);

Since CEP 5, Node.js is integrated into CEP runtime and users could invoke the standard APIs of Node.js in extension directly. For applications that has integrated CEP 5, refer to on how to use the global process object in Node.js.

Adobe Exchange

Sample extension is at

Other JavaScript Information

Load Multiple JSX files

JSX files normally define some functions and objects which are intended to be executed in host application's ExtendScript environment.

There are two approaches for HTML extension to trigger JSX files to be loaded in host application's ExtendScript.

  • Define <ScriptPath> node in manifest.xml, and the value of the node is the relative path for the JSX file. For example: