What is claude-mythos-ai-app?

Claude Mythos AI App is a desktop client for Anthropic's Claude models, built with C sharp. It gives users a graphical interface for chatting with Claude 3.5 Sonnet, Opus, and other models through the Anthropic API, as an alternative to using Claude through a web browser. The stated goals are better performance, more privacy, and more customization than the web version, and it is built for Windows 11, macOS, and Linux. According to its README, the app includes roleplay features, prompt templates for different characters, and options described as jailbreak and uncensored, meaning ways to get responses outside of Claude's normal safety behavior. The project itself states plainly that it is for educational and personal use only, that a user needs their own Anthropic API key to use it, and that the authors are not responsible for account issues or violations of Anthropic's terms of service that might result from using it this way. Installation is done by downloading a zip file from the project's GitHub releases page, extracting it, and running the application as administrator on Windows. After that, a user enters their own Anthropic API key and can adjust prompts, characters, and roleplay settings before chatting. The README includes a short troubleshooting table covering issues like the app failing to start, API connection problems, outdated models, and slow performance, mostly solved by running as administrator, checking the API key, updating the app, or restarting. Since the app is not an official Anthropic product and involves working around normal safety behavior, anyone considering it should be aware of the terms of service risk the project itself calls out, and should treat it with the same caution as any unofficial client that asks for an API key.