What is 99?

99 is a plugin for Neovim, a text editor popular among programmers, that adds AI assistance to the coding workflow. Unlike tools that try to take over and write code on your behalf, 99 is designed to work alongside a programmer rather than replace them. The author explicitly states a belief that hand coding remains important and that the goal is to augment what a programmer already does, not automate it away. The plugin connects to AI backends, specifically OpenCode and Claude Code, which it uses to process your requests. The two main features are search and visual. The search function lets you ask a question about your codebase, and the plugin returns a list of relevant locations that get loaded into Neovim's quickfix list, a standard way to jump through a collection of file locations. The visual function takes whatever you have highlighted in the editor and sends it to the AI along with a prompt, then replaces your selection with the result. Setup involves adding the plugin to your Neovim configuration using a standard plugin manager, then calling a setup function with options. You can point it at a folder of custom rule files written in Markdown, configure how file completion works in the prompt buffer, and set a log path for debugging. Keybindings for triggering search, visual, and cancel are set manually by the user. There is also a Worker extension for tracking longer-running tasks, though the README describes it as an area of active development with significant changes expected. The project is openly described as beta software with an API that may still change. It was created by ThePrimeagen, a developer known for Neovim content, and originated from a YouTube video that introduced an earlier version of the concept.