gear-ui
An open-source tool that generates a screen UI specification and an HTML mockup from a plain-language requirements description, using a two-stage LLM pipeline with an intermediate JSON specification to keep screens consistent.
gear-ui takes a free-form requirements description and generates a screen UI specification document as an intermediate JSON representation before generating any HTML, so that field names, transitions, and components stay consistent across multiple related screens instead of jumping directly from natural language to a mockup. It can use Claude, OpenAI, or any OpenAI-compatible provider such as OpenRouter, Together, Groq, or Ollama, selected through an environment variable or a bring-your-own-key setting in the browser.
Generated mockups are shown in an isolated, sandboxed iframe preview and follow a design-token rule baked into the generation prompt: raw color codes are disallowed in favor of semantic CSS variables, so swapping a token stylesheet re-themes every generated screen without regenerating them. A design-rules panel lets a user set information density, corner rounding, navigation layout, and overall tone as presets or free-form instructions, saved per project and applied to future mockup generation.