Codeium

Codeium is an AI coding assistant built by Exafunction, a startup founded in 2021 in Mountain View, California. You install it as a plugin in the editor you already use, and the Codeium plugin suggests code as you type, answers questions in a chat panel, and helps you clean up or explain existing code. Its main pitch is simple: most of this was paid elsewhere, and Codeium gave the core assistant away for free.

The team later rebuilt the whole experience around a standalone editor called Windsurf, and in 2025 the company rebranded from Codeium to Windsurf. So the name Codeium points to two things depending on when you look: the original autocomplete plugin that still runs in VS Code, JetBrains, Neovim, and dozens of other editors, and the company that now ships the Windsurf editor. Both share the same context engine, which reads your files and project structure to make suggestions that fit what you're already writing.

Where it holds up best is fast, low-friction completion. Where it struggles is the long tail: very large repositories can stall the context engine, and the free tier leans on lighter models, so heavy agent-style work across many files will feel the ceiling. Knowing which one you're reaching for matters, because the plugin and the editor split the same brand.

Getting Started

1. Open your editor's extension marketplace and install the Codeium plugin, or download the Windsurf editor from windsurf.com.
2. Sign in with a Google account or an email address, no API key or credit card needed.
3. Start typing in any file and accept the grey suggestion with the Tab key when it matches what you meant.
4. Open the chat panel to ask questions about a file, generate boilerplate, or refactor a block.
5. Move to a paid plan only when you need stronger models, more usage, or team controls.