Reasonix is a local AI coding agent engine written in Go, providing a terminal UI, desktop application (Electron + React), and HTTP server for interacting with large language models (OpenAI, Anthropic, DeepSeek, etc.) to automate software engineering tasks. The kernel manages sessions, context windows, planning, sub-agent delegation, tool execution (file operations, shell, browser, MCP servers), and a sophisticated safety sandbox. It persists conversation history with checkpoints for undo/rewind, tracks token usage, and maintains an evidence ledger for auditing tool effects. The architecture is a monolithic Go binary with multiple frontends: a CLI/TUI, a desktop host that communicates via SSE/JSON, and a REST API server. A plugin system using the Model Context Protocol (MCP) allows extension. Separate Cloudflare Workers handle account management, forum, and crash reporting. The codebase is well-structured with a clean layered architecture (base utilities, domain contracts, state persistence, runtime agent, assembly wiring, frontends), extensive test coverage, and internal linters enforcing quality. It is actively maintained with frequent commits and professional CI/CD pipelines.