MCP server for build123d to improve AI cognition when creating 3D CAD models

UEFN Toolbelt: 362 Python automation tools across 55 categories, with a PySide6 dashboard and an experimental, authenticated same-user loopback bridge for local AI control. Complements Epic's official UEFN MCP; Toolbelt is not exposed through Epic's MCP server.

A universal scaffold for AI-assisted game development. 42 agents, 51 commands, 86 skills. Multi-engine (Unity, Unreal, Godot, HTML). Multi-harness (Claude Code, Codex, Cursor, OpenCode, Kiro).