AI Agents & Coding · Free

OpenCode

OpenCode is an open-source AI coding agent that runs in the terminal, as a desktop app and as an IDE extension. It is MIT-licensed, developed in public on GitHub (the repository moved from sst/opencode to anomalyco/opencode), and is model-agnostic: it connects to more than 75 LLM providers through the AI SDK and the Models.dev catalog, including local models. It suits developers who want one agent interface across vendors, teams that need to route coding work to a specific provider or a self-hosted model, and anyone who wants to read or modify the agent's source. Because it is not tied to one model company, it is often used to compare models on the same task in the same harness. Key features include a terminal user interface, multiple parallel sessions on the same project, a Plan mode (toggled with Tab) that suggests an implementation without editing files, and a Build mode that makes the changes. Running /init analyzes the project and writes an AGENTS.md file with project instructions, /undo and /redo step through changes, and you can reference files with @ and drop images into the prompt. Providers are added with the /connect command. It can log in with an existing GitHub Copilot account or a ChatGPT Plus or Pro account, so people who already pay for those plans can use their allowance through OpenCode. A set of free models is included. OpenCode Models is an optional paid provider run by the OpenCode team, offering a curated list of models it has tested and verified for coding agents. OpenCode 2 is the current major version; OpenCode 1 is still documented, and both use the opencode command, so they cannot be installed side by side under the default name. OpenCode 2 installs with a script (curl -fsSL https://opencode.ai/v2/install | bash) or npm (npm i -g @opencode/cli@latest), and Homebrew's opencode formula also installs version 2. Docker, Chocolatey, Scoop and mise options are documented too, and on Windows the project recommends WSL. Pricing: the software is free. You pay whichever model provider you connect, or use the included free models, an existing Copilot or ChatGPT subscription, or OpenCode Models credits. Model quality and cost therefore depend entirely on the provider you choose, and the agent's results can vary from model to model. Alternatives include Claude Code, OpenAI's Codex CLI, GitHub Copilot CLI and Google's Antigravity CLI, which are each built around their own vendor's models and plans. Official site: https://opencode.ai.