adobe-after-effects-integrations

Build, package, install and debug components that run beside or inside Adobe After Effects, and choose between them. Covers CEP extension panels (CSXS/manifest.xml, CSInterface.evalScript, Node.js in a panel, .debug files, PlayerDebugMode, ZXP signing and UPIA installs, and CEP's retirement schedule), UXP plugins (After Effects beta from 27.0), C++ effect, AEGP and AEIO plugins on the After Effects SDK (PiPL, entry points, Multi-Frame Rendering, SmartFX, GPU, AEGP_ExecuteScript, idle hooks), and MCP servers or other bridges that let an AI agent, a pipeline or another application drive After Effects (command-line scripts, file mailboxes polled with app.scheduleTask, loopback servers in a CEP panel, AEGP sockets). Use when deciding how an outside program reaches After Effects, or when building, installing or fixing one of these components. For the ExtendScript or expressions such a component runs inside After Effects, use adobe-after-effects-scripting.

Build the things that run beside or inside After Effects: panels, native plugins, and the bridges an outside program uses to drive it.

Scope

This skill	adobe-after-effects-scripting
CEP and UXP panels: manifests, packaging, debugging, installing	The ExtendScript a panel sends with evalScript
C++ effect, AEGP and AEIO plugins on the After Effects SDK	Scripts run by hand, from the Scripts folders, or with AfterFX.exe -r
MCP servers and other bridges, and how they reach After Effects	The object model those bridges' scripts use
Choosing which kind of component a job needs	Expressions, ScriptUI panels, aerender

A bridge's process, protocol and security belong here. Every line of ExtendScript it runs inside After Effects belongs to the scripting skill.

Choose the component

The job	Build
Run one automation from a terminal, scheduler or CI	No integration: a script with AfterFX.exe -r, or aerender to render. See the scripting skill.
A panel of buttons and fields, ExtendScript only	A ScriptUI panel. See the scripting skill.
A panel with HTML, CSS and Node.js	A CEP extension today; a UXP plugin once After Effects' UXP support leaves beta. See CEP and UXP.
A new effect that processes pixels or audio	A C++ effect plugin. See The C++ SDK.
Menu commands, idle-time work, deep hooks, or running scripts from native code	An AEGP.
Import or export a file format After Effects lacks	An AEIO.
An AI agent, pipeline or web application driving After Effects	A bridge, often behind an MCP server. See Bridges and MCP servers.

Versions

After Effects 2025 is 25.x, 2026 is 26.x, and 2027 is 27.0. Read the version from the installed Support Files\AfterFX.exe on Windows, or app.version from a script, before choosing an API: CEP 12 arrived in 25.0, and UXP support starts at 27.0.

CEP and UXP

CEP

A CEP extension is an HTML page in a Chromium panel that calls After Effects through ExtendScript.

• Layout: a folder holding CSXS/manifest.xml, the panel's HTML and JavaScript, Adobe's CSInterface.js for the matching CEP version, and the ExtendScript file the manifest names.
• Host: After Effects' host ID is AEFT. After Effects 25.0 ships CEP 12, and 26.0 still does: its Support Files\CEPHtmlEngine\CEPHtmlEngine.exe is version 12.0.1, though no Adobe document lists 26.x. Read that file's version to check an installation.
• Calling After Effects: csInterface.evalScript(script, callback) runs ExtendScript on After Effects' main thread and hands the callback a string, or "EvalScript error." when it fails. Serialize results yourself, because ExtendScript has no JSON. Keep every call short: the main thread is the user interface.
• Node.js: --enable-nodejs and --mixed-context in the manifest's <CEFCommandLine>. CEP 12 bundles Node.js 17.7.1 and Chromium 99, so native modules must be built for that Node.js.
• Development: unsigned extensions load only with PlayerDebugMode set for the CEP version (CSXS.12 for CEP 12). A .debug file in the extension root maps the extension to a port for Chrome DevTools, and must name AEFT itself.
• Distribution: sign with ZXPSignCmd into a .zxp, with a timestamp, on the platform it will run on, and install with Adobe's Unified Plugin Installer Agent (UPIA). ExManCmd no longer works with Creative Cloud 2022 apps and later.
• Limits: After Effects does not support resizing a panel from code.
• Scaffolding: Hyper Brew's Bolt CEP builds CEP extensions with Vite, TypeScript and React, Svelte or Vue, compiles modern ExtendScript down to ES3, and packages ZXPs.

Manifest, folders, debug settings and signing commands are in references/cep.md.

CEP's retirement

Adobe's announcement, published September 2026: After Effects, Illustrator and Media Encoder stop accepting new CEP submissions and turn CEP off by default in December 2028, users can turn it back on, and CEP is removed from these apps at the end of 2029. Every flagship app gets at least two years from its UXP public beta before CEP goes. ExtendScript scripts are not affected. A new panel meant to last past 2028 needs a UXP plan.

UXP

• After Effects added UXP plugin support in the 27.0 beta, first as a private beta that used a special build of the UXP Developer Tool, with a public beta announced for November 2026. Check the current status before building on it.
• Documentation: https://developer.adobe.com/after-effects/uxp/, where every API lists 27.0 as its minimum version. The host module is require("aftereffects").
• The manifest's host.app value for After Effects is not yet in the general UXP manifest documentation; take it from the After Effects UXP pages.
• Bolt UXP lists After Effects only for private-beta participants, and its hybrid C++ plugins do not support After Effects.

The C++ SDK

• Get it from the Adobe Developer Console, linked as "Get the SDKs" from https://developer.adobe.com/after-effects/. Releases follow After Effects (25.2, 25.6, 26.5, then a 27.0 update for the beta). The guide is at https://ae-plugins.docsforadobe.dev/.
• Plugin types: effects, AEGPs (After Effects General Plugins), AEIOs (input and output), Artisans (3D renderers) and BlitHooks.
• Entry points: the samples use EffectMain() for effects, a PF_Cmd-dispatching function, and EntryPointFunc() for AEGPs. The real name is whatever the PiPL resource declares.
• PiPL: every plugin carries a PiPL resource. On Windows the sample projects' custom build steps turn the cross-platform .r file into an .rc file; on macOS, Rez compiles it. The out flags in the PiPL must match those set in GlobalSetup.
• Files: a DLL with the .aex extension on Windows, a .plugin bundle on macOS.
• Install: installers read HKLM\SOFTWARE\Adobe\After Effects\<version>\CommonPluginInstallPath on Windows; on macOS the shared folder is /Library/Application Support/Adobe/Common/Plug-ins/7.0/MediaCore/ (7.0 for every Creative Cloud version). After Effects ignores folders whose names end in a closing parenthesis or start with ~ (Windows) or ¬ (macOS).
• Multi-Frame Rendering: set PF_OutFlag2_SUPPORTS_THREADED_RENDERING only once the effect is thread-safe.
• SmartFX and GPU: PF_OutFlag2_SUPPORTS_SMART_RENDER brings PF_Cmd_SMART_PRE_RENDER and PF_Cmd_SMART_RENDER; PF_OutFlag2_SUPPORTS_GPU_RENDER_F32 (16.0 and later) with PF_Cmd_GPU_DEVICE_SETUP and PF_Cmd_SMART_RENDER_GPU for GPU rendering.
• Running ExtendScript from C++: AEGP_ExecuteScript in AEGP_UtilitySuite6 returns the value of the script's last line.
• AEGP threading: none. Every AEGP call happens on the main thread, in a callback or the idle hook (AEGP_RegisterIdleHook).
• macOS 15 and later refuse to load unsigned plugins.

Signatures, the thread-safety rules and build requirements are in references/cpp-sdk.md.

Bridges and MCP servers

After Effects has no network API. An outside program reaches it in one of four ways:

Bridge	How it works	Strengths	Costs
Command line	AfterFX.exe -r or -s on Windows, AppleScript DoScriptFile on macOS, runs a script in the running instance	Nothing to install inside After Effects	No return channel; results go through a file. macOS needs Automation permission.
File mailbox	A ScriptUI panel or Startup script polls a folder with app.scheduleTask and writes results beside the commands	Pure ExtendScript, no ports	Latency of the polling interval; needs the file-access preference
CEP panel server	Node.js in a CEP panel listens on loopback and calls evalScript per request	Immediate replies, rich panel	A listening socket to secure; tied to CEP's retirement
AEGP	A native plugin accepts connections and runs work from its idle hook with AEGP_ExecuteScript	Fast, no panel needed	C++, per-platform builds, main-thread-only rules

An MCP server sits in front of one of these. The rules that keep it safe and reliable:

• Use stdio unless something requires HTTP. A stdio server has no listener at all, and writes nothing to stdout except protocol messages; log to stderr. Over HTTP, bind to 127.0.0.1, validate the Origin header, and require a token.
• Use the official SDK and read the specification revision it targets. The 2026-07-28 revision changed sessions and transports, so examples written for older revisions may no longer apply.
• Expose specific tools (create a composition, add a layer, set a property, queue a render, describe the project) rather than one tool that runs any script. A run-anything tool is arbitrary code execution inside an application allowed to write files and reach the network. If one exists, keep it off by default and say so in its description.
• Never build ExtendScript by pasting strings together. Send arguments as data, serialized once and parsed inside After Effects, or escape every string with a single, tested function.
• Run one command at a time. All of it lands on After Effects' main thread. Queue requests, time them out, and report "After Effects is busy" when a render or a modal dialog holds it, rather than hanging.
• Wrap each tool call in an undo group, so the person at the keyboard can undo what an agent did, and return structured results with the error message and line when a script fails.

Patterns, open-source examples and the security detail are in references/bridges-and-mcp.md.

Sources

• CEP resources and cookbook: https://github.com/Adobe-CEP/CEP-Resources
• CEP retirement and UXP announcement: https://blog.developer.adobe.com/en/publish/2026/09/investing-in-the-future-of-creative-cloud-extensibility-uxp-comes-to-our-flagship-applications
• After Effects UXP: https://developer.adobe.com/after-effects/uxp/
• After Effects C++ SDK Guide: https://ae-plugins.docsforadobe.dev/
• Model Context Protocol: https://modelcontextprotocol.io/
• UPIA: https://blog.developer.adobe.com/en/publish/2021/06/new-command-line-tool-for-plugin-installation-replaces-exmancmd