Harth is an AI-powered, browser-based workspace built for architecture teams. It brings multiple frontier AI models (including Gemini, ChatGPT, Claude, and Grok) together with 3D building data and rendering tools in a single interface, so architects don't have to switch between separate applications. Harth imports models from existing CAD tools like Revit, ArchiCAD, SketchUp, and IFC files, and works alongside them rather than replacing them. Purpose-built AI agents handle complex architectural tasks and can be sequenced into multi-agent workflows, while built-in rendering tools visualize 3D spaces in a range of styles. The platform also supports collaboration through live comments on 3D models, a multiplayer design mode, and shareable boards, plus site-context tools like terrain import and 3D satellite data for accurate site placement.