DemoVexa is a software application that generates product demonstration videos directly from an application's source code. It serves as a bridge between software development and product explanation. The tool reads an application's code, documentation, and navigation structure to understand its features, screens, workflows, and terminology. It then produces a finished demo video that includes a written script, a native voiceover, and an animated version of the real user interface. The application supports any programming language and framework. It can generate voiceovers in 85 languages. The output video can be rendered in 16:9, 9:16, and 1:1 aspect ratios. DemoVexa runs locally on macOS, Windows, and Linux operating systems. It can be installed via npm or downloaded as a standalone application. The tool integrates with AI models such as Claude, Codex, and GitHub Copilot to assist in the video generation process. Users can request changes to the video using plain language, and the tool can rebuild the video from the latest code without requiring a screen recording. The typical workflow involves connecting a product repository, writing a brief for the desired video, and allowing the AI to generate the script, voiceover, and animated scenes. The application provides a half-resolution preview mode and a full-quality export option. It can apply a specified brand kit, including fonts and colors, to the final video. DemoVexa is intended for use by SaaS founders, product marketing teams, developer relations professionals, and customer education specialists. A 14-day free trial is available and does not require a credit card.