NeoCodeium is a Neovim plugin that provides AI-powered code completion using the Windsurf (formerly Codeium) service. It features a modular architecture with separate modules for state management, completion logic, rendering, server communication, and utility functions. The plugin integrates with Neovim's autocommands to provide real-time suggestions as virtual text, supports cycling through completions, accepting partial suggestions, and includes a chat interface via the Windsurf service. It is designed to be highly configurable and works alongside other completion plugins like nvim-cmp and blink.cmp.