What is opencode?

OpenCode is an open source AI coding agent, a tool that lives on your computer and helps you write, edit, and understand code. You can think of it as a smart assistant that can read your project files, suggest changes, run commands, and do the actual editing for you. It's similar to tools like Claude Code or Cursor's agent features, but fully open source and not tied to any single AI provider. The tool runs as a terminal application (with a beta desktop app available too) and ships with two built-in modes you can switch between. The "build" agent has full access, it can edit files and run commands to do real development work. The "plan" agent is read-only, designed for exploring an unfamiliar codebase or thinking through a change before making it. There's also a background subagent called "general" that handles complex searches and multi-step tasks, which you can invoke by mentioning @general in your messages. The people who'd get the most out of this are developers who are comfortable in the terminal and want an AI pair programmer that can actually modify their code, not just suggest snippets. If you've ever jumped into a codebase you didn't write and wanted something to help you map it out before touching anything, the plan agent is built for exactly that scenario. It's also appealing if you want flexibility: you can use it with Claude, OpenAI, Google, or even local models rather than being locked into one vendor. A few things stand out about how the project is built. It uses a client/server architecture, which means the AI engine and the interface are separate, so in theory you could run the engine on your laptop and drive it from another device, like a phone. It also has built-in opt-in support for LSP (Language Server Protocol), which is the same technology that gives code editors their autocomplete and error-checking abilities. The team behind it comes from the neovim and terminal.shop world, so the terminal interface is a priority for them.