What is nimbus-lite?

Nimbus Lite is a free user interface kit for building AI chat applications. It is built with plain HTML, CSS, and JavaScript, meaning it does not rely on any external libraries or frameworks like React or Vue. The main selling point is its simplicity: you can clone the repository and open the main file in your web browser to see a working chat interface immediately. There is no installation process, no build step, and no package manager required. The interface includes several features you would expect from a modern chat application. It supports live text streaming, so text appears progressively as the AI generates it. It formats messages with basic styling, displays code blocks with syntax highlighting, and includes a button to copy code with one click. The layout comes with a sidebar for managing multiple conversations, a header, a text input area at the bottom, and a menu for selecting different AI models. It also includes light and dark themes plus five accent color options, all adjustable through a single CSS variable. The project is designed to be a front-end component only. You need to connect it to your own backend, which could be a service from a company like OpenAI or Anthropic, or a model running locally. The README provides a short code example showing how to send a request to your backend and append the response text to the screen as it arrives. This setup gives developers control over their own data and model choices while providing a finished interface. A paid version called the full Nimbus kit is also available for purchase. The full version adds features aimed at production use, such as inline citations, reasoning blocks for the AI, tool-call display chips, file and image attachments, and error handling with retry options. The free version covered here does not include these additions. The license for the free version allows use and modification in personal or commercial projects, with a request not to resell the kit itself. The project is maintained by a single developer.