Cavalry Motion App MCP Bridge

A Model Context Protocol (MCP) server that connects AI assistants (like Claude Desktop, Antigravity, Cursor, and ChatGPT) directly to Cavalry, the procedural 2D motion graphics and animation application by Scene Group.

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Features

• Procedural Layer Creation: Create shapes, text, duplicators, grids, noise generators, color palettes, math nodes, deformers, and particle emitters via natural language.
• Dynamic Node Graph Connections: Connect outputs and inputs between nodes (e.g. wire a noise generator to a shape's scale or rotation).
• Attribute Control & Keyframing: Inspect and update any property, scrub the timeline, and add animated keyframes.
• Scene Introspection: Query active composition metadata, layer hierarchies, and selected nodes.
• Render Pipeline: Add compositions to the Render Queue and trigger batch renders.
• Raw Script Execution: Execute arbitrary JavaScript against Cavalry’s native api.* module.

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Architecture

┌─────────────────────────┐          stdio (MCP)         ┌─────────────────────────────────┐
│ AI Assistant / LLM      │ ◄──────────────────────────► │ Cavalry MCP Server              │
│ (Claude, Antigravity)   │                              │ (TypeScript / Node.js)          │
└─────────────────────────┘                              └────────────────┬────────────────┘
                                                                          │
                                                             HTTP POST    │ (http://127.0.0.1:8080)
                                                                          ▼
                                                         ┌─────────────────────────────────┐
                                                         │ In-Cavalry Script Bridge        │
                                                         │ (MCPBridge.js in Scripts menu)  │
                                                         │ ───► api.create(...)            │
                                                         │ ───► api.set(...)               │
                                                         │ ───► api.connect(...)           │
                                                         └─────────────────────────────────┘

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Quick Start

1. Install Dependencies & Build

From this project directory:

npm install
npm run build

2. Install Bridge Script into Cavalry

Run the installer to copy MCPBridge.js to your Cavalry scripts folder:

npm run install-bridge

On Windows, this copies MCPBridge.js to %APPDATA%\Cavalry\Scripts\.

3. Start the Bridge in Cavalry

1. Launch Cavalry.
2. Go to the top menu: Scripts → MCPBridge.
3. A small panel will open showing Status: Online (Port 8080). Keep this open while using the MCP server.

(Alternatively, if you already have the Stallion extension active, it also listens on port 8080 and works seamlessly with this MCP server).

4. Test the Connection

Verify that the MCP server can communicate with Cavalry:

npm run test-connection

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MCP Client Configuration

Claude Desktop

Add the following to your claude_desktop_config.json (located at %APPDATA%\Claude\claude_desktop_config.json on Windows or ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "cavalry": {
      "command": "node",
      "args": [
        "C:/Users/david/Documents/ANTIGRAVITY APP/CALVARY MCP/dist/index.js"
      ],
      "env": {
        "CAVALRY_BRIDGE_PORT": "8080"
      }
    }
  }
}

Antigravity / Cursor / Custom Client

Add to your settings or .cursor/mcp.json:

{
  "mcpServers": {
    "cavalry": {
      "command": "node",
      "args": ["C:/Users/david/Documents/ANTIGRAVITY APP/CALVARY MCP/dist/index.js"]
    }
  }
}

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Available MCP Tools

Tool	Description
cavalry_run_script	Run arbitrary JavaScript code in Cavalry using api.*.
cavalry_eval_expression	Evaluate a single expression and return its value.
cavalry_get_scene_info	Query active composition name, frame count, FPS, and layer count.
cavalry_get_comp_layers	List all layer IDs in the current composition.
cavalry_get_selected_layers	Get the IDs of currently selected layers.
cavalry_create_layer	Create a new layer/node (basicShape, textShape, duplicator, etc.).
cavalry_set_attributes	Set one or more attribute values on a layer.
cavalry_get_attributes	Query an attribute value on a layer.
cavalry_delete_layer	Delete a layer/node from the scene.
cavalry_connect_attributes	Connect source attribute to target attribute in dependency graph.
cavalry_disconnect_attributes	Disconnect an attribute connection.
cavalry_set_frame	Scrub the playhead to a specific frame.
cavalry_get_frame	Get the current frame number.
cavalry_set_keyframe	Add a keyframe with value at a specified frame.
cavalry_playback_control	Play, stop, or rewind the timeline.
cavalry_add_to_render_queue	Add the composition to the Render Manager.
cavalry_render_queue	Start rendering items in the queue.

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Example Prompts for AI Assistants

1. Animated Noise Grid

"Create a 12x12 grid of rounded squares in Cavalry, attach a noise modifier to their rotation and scale, and set the fill color to electric blue."

2. Kinetic Typography

"Create kinetic text with the headline 'ANTIGRAVITY' in Cavalry. Set the font size to 120, center it, and add a bouncy spring oscillation to the Y position."

3. Radial Burst Animation

"Build a radial burst animation with 24 lines radiating outwards from the center, driven by a step duplicator and keyed to expand from frame 0 to frame 45."

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License

MIT