Zero is a terminal-based AI coding agent designed for local repository interaction, offering both a Text User Interface (TUI) and a scriptable command-line interface via the zero exec command. The tool allows users to integrate various LLM providers, including OpenAI, Anthropic, Gemini, Groq, DeepSeek, and local solutions like Ollama or LM Studio. Technically, Zero can inspect repositories, edit files, run shell commands, and utilize web-fetch capabilities with built-in security checks to prevent loopback or private address access. It implements a robust permission and sandbox policy to govern file writes, network access, and shell execution, with users able to grant specific directory access via the --add-dir flag. For automation, the zero exec command supports multiple I/O formats, including text, JSON, and stream-JSON, making it suitable for CI/CD pipelines. The agent features advanced session management, allowing users to resume, fork, or rewind local sessions stored on disk. Extensibility is achieved through Model Context Protocol (MCP) server support, custom plugins, and "skills." The project is implemented in Go (requiring version 1.26.6+) and is distributed via npm as a wrapper that fetches platform-specific binaries for Linux, macOS, and Windows.