AI Assistant and MCP

AI Assistant and MCP

Cindr3D exposes a localhost-only Model Context Protocol server during development. The server relays AI tool calls into the open Cindr3D browser tab.

Visual Cues

Connection

Item	Value
Default app URL	http://localhost:5173
Default MCP URL	http://localhost:5174/mcp?token=...
Port override	CINDR3D_MCP_PORT
Pairing command	Copy the command from the AI MCP status badge

The browser tab must remain open because CAD and printer actions execute through the in-page bridge.

Safety Model

The MCP server:

• Accepts localhost clients only
• Requires a pairing token
• Rate-limits tool calls
• Records activity in the AI MCP status badge
• Supports token rotation from the badge
• Can gate destructive operations behind confirmation

Tool Areas

Common read-only tools:

• cindr3d_status
• list_objects
• get_object_properties
• snapshot_view

Common creation and editing tools:

• Primitive creation: boxes, cylinders, spheres, cones
• Sketch creation: rectangles, circles, polygons, dimensions
• Features: extrude, revolve, fillet, chamfer, hole
• Booleans: union, subtract, intersect
• Transforms: translate, scale, mirror, linear pattern, circular pattern

Export tools:

• save_session
• export_stl
• export_step
• export_gcode

Client Guidance

Prefer read-only calls before editing a design. Use object ids from list_objects instead of visible names when changing existing geometry. After meaningful geometry changes, call snapshot_view so the assistant can inspect placement, scale, and selection state.

For example workflows, see the repository docs:

• https://github.com/exzile/Cindr3D/blob/master/docs/ai-mcp-tools.md
• https://github.com/exzile/Cindr3D/blob/master/docs/ai-examples.md