After Effects MCP for Antigravity

A production-grade Model Context Protocol (MCP) integration and Adobe CEP Bridge that connects Google Antigravity (and compatible MCP clients) directly to Adobe After Effects (CC 2018 through CC 2025+) on Windows 10/11.

It enables AI assistants to programmatically control After Effects: inspect projects, build compositions, create solid and text layers, manipulate transforms, apply visual effects, animate properties with keyframes, and automate render queue jobs using natural language.

📖 Table of Contents

• What is it & Why Use It?

• How It Works (Architecture)

• Security & Reliability Features

• Supported Tools (32 Operations)

• Prerequisites

• Step-by-Step Setup Guide

  • Step 1: Clone the Repository

  • Step 2: Install Node Dependencies

  • Step 3: Enable CEP Developer Mode (PlayerDebugMode)

  • Step 4: Install the CEP Extension

  • Step 5: Launch the Extension in After Effects

  • Step 6: Configure Google Antigravity

• Verification & Diagnostics

• Prompt Examples for Antigravity

• Project Structure

• Troubleshooting & FAQ

• License

Related MCP server: ae-mcp

💡 What is it & Why Use It?

Motion graphics, title animation, and VFX setups in After Effects can require hundreds of manual clicks.

After Effects MCP for Antigravity exposes a safe, bidirectional bridge:

• Ask Antigravity to construct complex motion graphics, kinetic typography, lower-thirds, or logo stingers.

• Antigravity queries composition dimensions, creates layers, sets layer transforms and blend modes, applies effects, adds ease keyframes, and triggers exports.

• Antigravity acts as a pair-programmer and motion designer inside Adobe After Effects.

🏗️ How It Works (Architecture)

After Effects hosts its automation runtime inside an ES3 ExtendScript engine. Modern MCP clients, however, communicate via JSON-RPC 2.0 over stdio. This repository bridges the two environments safely:

┌───────────────────────────────────────┐
│     Google Antigravity / MCP Client   │
└───────────────────┬───────────────────┘
                    │  (stdio JSON-RPC 2.0)
                    ▼
┌───────────────────────────────────────┐
│       Node.js MCP Server Process      │
│         (mcp-server/index.js)         │
│  - Parameter validation & sanitation  │
│  - Security token generation          │
└───────────────────┬───────────────────┘
                    │  (Loopback HTTP: 127.0.0.1:17892, Token Auth)
                    ▼
┌───────────────────────────────────────┐
│       After Effects CEP Panel         │
│ (com.antigravity.aftereffects.mcp)    │
│  - Dispatches to ExtendScript host    │
└───────────────────┬───────────────────┘
                    │  (window.__adobe_cep__.evalScript)
                    ▼
┌───────────────────────────────────────┐
│       ExtendScript Host Engine        │
│          (aftereffects.jsx)           │
└───────────────────┬───────────────────┘
                    │  (Direct app.project DOM API)
                    ▼
┌───────────────────────────────────────┐
│      Adobe After Effects Engine       │
│     Compositions, Layers, Renders     │
└───────────────────────────────────────┘

1. Node.js MCP Server: Started automatically by Antigravity. It starts a local loopback HTTP server on 127.0.0.1:17892.

2. Local Token Authentication: A cryptographically random 256-bit token is generated and persisted locally in .bridge-state.json. Every request between the CEP panel and the server is authenticated.

3. CEP 9+ Panel: Runs inside After Effects (Window > Extensions > After Effects MCP Bridge). It maintains a heartbeat connection with the local HTTP server and executes actions via evalScript.

4. ExtendScript Host: Manipulates compositions, properties, effects, and the Render Queue in native After Effects memory.

🛡️ Security & Reliability Features

• Strict Loopback Binding: The bridge binds exclusively to 127.0.0.1 and immediately drops any external network or non-localhost traffic.

• Constant-Time Token Comparison: Protects against timing attacks using crypto.timingSafeEqual.

• Whitelisted Actions: Only pre-defined, rigorously sanitized actions are permitted. Arbitrary shell commands or unsanitized code evaluation are strictly blocked.

• Destructive Operation Guards: Critical actions (such as removing a layer or rendering queue items) require explicit confirmation flags (confirm_removal: true, confirm_render: true).

⚡ Supported Tools (32 Operations)

📋 Prerequisites

• Operating System: Windows 10 or 11 (64-bit)

• Adobe After Effects: CC 2018, CC 2019, CC 2020, CC 2021, CC 2022, CC 2023, CC 2024, or CC 2025+

• Node.js: Node.js 18.x or later installed

• MCP Client: Google Antigravity, Claude Desktop, or Cursor

🚀 Step-by-Step Setup Guide

Step 1: Clone the Repository

Open PowerShell or Command Prompt:

git clone https://github.com/okaybhargav/After-Effects-MCP-for-Antigravity.git "C:\MCP\After Effect MCP"
cd "C:\MCP\After Effect MCP"

Step 2: Install Node Dependencies

npm install

Step 3: Enable CEP Developer Mode (PlayerDebugMode)

Adobe CEP requires PlayerDebugMode to load local, unsigned developer panels. Run the following command in PowerShell:

# Enables debug mode for CSXS 8 through 16 (covers CC 2018 through 2025+)
8..16 | ForEach-Object { reg add "HKCU\Software\Adobe\CSXS.$_" /v PlayerDebugMode /t REG_SZ /d 1 /f }

Step 4: Install the CEP Extension

Run the bundled PowerShell install script:

powershell -ExecutionPolicy Bypass -File scripts\install.ps1

This automatically deploys the extension folder to: %APPDATA%\Adobe\CEP\extensions\com.antigravity.aftereffects.mcp

Step 5: Launch the Extension in After Effects

1. Start Adobe After Effects.

2. Open any project or create a new one.

3. In the top menu, navigate to: Window > Extensions > After Effects MCP Bridge.

4. A panel will appear. When the MCP server runs, the status indicator will turn Green (Connected).

Step 6: Configure Google Antigravity

Open your Antigravity configuration file:

• File path: C:\Users\<YourUsername>\.gemini\config\mcp_config.json

Add the after-effects server to your mcpServers block:

{
  "mcpServers": {
    "after-effects": {
      "command": "node",
      "args": [
        "C:\\MCP\\After Effect MCP\\mcp-server\\index.js"
      ]
    }
  }
}

(Make sure to adjust the path to match where you cloned the repository).

Restart Antigravity or refresh MCP tools.

🔍 Verification & Diagnostics

To verify your installation and test communication before making requests:

# 1. Run diagnostic check (checks paths, registry, and process availability)
powershell -ExecutionPolicy Bypass -File scripts\diagnose.ps1

# 2. Run automated test suite
npm test

💬 Prompt Examples for Antigravity

• "Check if After Effects is open and tell me which composition is currently active."

• "Create a 1920x1080 60fps composition named 'TitleStinger' with a duration of 5 seconds."

• "Add a black solid layer, then add a text layer with 'ANTIGRAVITY' in the center."

• "Apply 'ADBE Gaussian Blur 2' to the text layer and animate the blurriness from 40 to 0 between seconds 0 and 1.5."

• "Add the active comp to the Render Queue with output path 'C:\Exports\title.mov' and verify its status."

📁 Project Structure

After-Effects-MCP-for-Antigravity/
├── cep-extension/
│   ├── CSXS/manifest.xml         # CEP 9+ manifest (CSXS version definitions)
│   ├── host/aftereffects.jsx     # ExtendScript host automation functions
│   ├── index.html                # Panel UI
│   ├── panel.js                  # CEP bridge client and HTTP polling
│   └── styles.css                # Dark theme styling
├── mcp-server/
│   ├── index.js                  # MCP stdio server entry point
│   ├── bridge.js                 # Local 127.0.0.1:17892 HTTP bridge with auth
│   ├── tools.js                  # 32 MCP tool definitions, JSON schemas, handlers
│   └── validation.js             # Strict input validation and sanitization
├── scripts/
│   ├── install.ps1               # Installs CEP extension to %APPDATA%
│   ├── diagnose.ps1              # Full environment & bridge diagnostics
│   └── uninstall.ps1             # Clean uninstaller
├── tests/
│   ├── bridge.test.js            # Loopback HTTP and token auth unit tests
│   └── validation.test.js        # Input schema and bounds test suite
├── package.json                  # Node dependencies & test scripts
├── .gitignore                    # Excludes node_modules and bridge runtime state
├── LICENSE                       # MIT Open-Source License
└── README.md                     # Documentation

❓ Troubleshooting & FAQ

1. The extension does not appear under Window > Extensions

• Fix: Confirm that you ran scripts\install.ps1 and that PlayerDebugMode=1 is set for your CSXS version. Make sure to restart After Effects completely after installing.

2. Panel shows "Disconnected" or "Searching for Bridge"

• Fix: The panel connects when Antigravity starts the MCP server. Ensure Antigravity is running and has the after-effects server configured in mcp_config.json. You can also test manually by running node mcp-server\index.js in a terminal.

3. Port 17892 conflict

• Fix: If port 17892 is occupied by another application, you can specify an alternate port via the AE_MCP_PORT environment variable.

📄 License

This project is licensed under the MIT License - free for personal and commercial open-source use.