Anthropic released Opus 5.5, which is 40% cheaper and three times faster than Opus 5, posting the best overall score in a hard CAD task evaluation. OpenAI's GPT-6 Sol offers improved value with better performance at similar cost, while Gemini 3.8 Flash remains the default for partforge due to superior reliability and lower cost per correctly solved task despite Opus 5.5's stronger benchmark performance.
AI-CAD is an open-source multi-agent system that autonomously designs manufacturable mechanical parts and assemblies from text briefs or sketches. LLM agents collaborate to plan designs, write parametric CadQuery code, render engineering views, and iteratively critique and repair geometry against design-for-manufacturing rules until the design meets specifications.