cavalry-mcp

MCP server that connects Claude to Cavalry animation software. Create layers, set attributes, animate with keyframes, render frames, and more — all through natural language.

How it works

Claude <--MCP (stdio)--> cavalry-mcp <--HTTP POST--> Stallion <---> Cavalry

The MCP server sends JavaScript to Cavalry via the Stallion bridge (an HTTP server running inside Cavalry on 127.0.0.1:8080).

Prerequisites

• Cavalry (with Stallion script enabled: Scripts > Stallion)
• Node.js >= 18

Setup

npm install
npm run build

Configure in Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "cavalry": {
      "command": "node",
      "args": ["/absolute/path/to/cavalry-mcp/dist/index.js"]
    }
  }
}

Available tools

Tool	Description
cavalry_ping	Check if Cavalry + Stallion are reachable
cavalry_run_script	Execute arbitrary JavaScript in Cavalry
cavalry_create_layer	Create a layer (textShape, basicShape, null, etc.)
cavalry_set_attribute	Set attributes on a layer
cavalry_get_attribute	Read an attribute value
cavalry_connect	Connect attributes between layers
cavalry_keyframe	Set a keyframe at a specific frame
cavalry_magic_easing	Apply easing to keyframed attributes
cavalry_get_scene_layers	List all layers in the scene
cavalry_get_selected_layers	Get currently selected layers
cavalry_select_layers	Select layers by ID
cavalry_delete_layers	Delete layers by ID
cavalry_get_composition_info	Get resolution, frame range, FPS
cavalry_set_current_frame	Move the playhead
cavalry_render_png	Render current frame as PNG
cavalry_set_generator	Set a generator on a layer (ellipse, rectangle, etc.)
cavalry_duplicate_layer	Duplicate a layer
cavalry_get_bounding_box	Get a layer's bounding box
cavalry_save_scene	Save the scene
cavalry_open_scene	Open a .cv scene file
cavalry_add_dynamic_attribute	Add a dynamic attribute to a layer

Example conversation

You: Create a bouncing text that says "Hello World"

Claude will:

1. Create a textShape layer
2. Set the text content, font size, and color
3. Add position keyframes for the bounce
4. Apply BounceOut easing

Common layer types

basicShape, textShape, null, colorPlane, group, subMesh, linearGradient, duplicator, connectShape, noiseDeformer, stagger, trail, javaScriptUtility, javaScriptShape, imageAsset, videoAsset, soundAsset

Common attribute paths

• position.x, position.y — Layer position
• rotation — Rotation in degrees
• scale.x, scale.y — Scale
• opacity — Layer opacity (0–100)
• fontSize — Text layer font size
• fill.color — Fill color (hex string)
• stroke.color, stroke.width — Stroke properties

License

MIT