Butterfish Shell is a command-line tool that wraps your existing shell (bash or zsh) and injects AI-powered assistance. It allows you to prompt OpenAI's GPT models directly from the terminal by simply starting a command with a capital letter. The AI sees your shell history, enabling contextual help like debugging failed commands or generating new ones. Features include autosuggest for commands, configurable prompts, transparent model interactions, and a Goal Mode where the AI acts as an agent to execute multi-step tasks. It is designed for developers and power users who want seamless, copy-paste-free AI integration without disrupting their workflow.