Cat's Neovim config

_{The demo is a C program shaped like an egg that prints an egg. Claude laid it, I reviewed it, Claude wrote the commit message. No chickens were involved. 🥚}

I made this Neovim config with Claude because I needed one tool where I could write, review and commit code with Claude. Before, it was random terminal windows with random Claude sessions, next to a pretty much vanilla Neovim. Now it's all in one place:

• Claude, built in. Claude Code runs in a split next to your code (,ac). It sees the file you're in and what you've selected, and its edits arrive as diffs to accept or reject. Ctrl-h / Ctrl-l hop between it and your code.
• A review screen for everything that's changed. ,gv lists every changed file with its diff side by side, for your uncommitted work or for past commits and branches. Stage each file as you read it, and whatever's still unstaged is what's left to review. Handy when an agent has just changed twenty files.
• Commit messages written by Claude. Commit straight from the review (cc, or ,gc anywhere) and Claude drafts the message from the staged diff in a couple of seconds; tweak it and :wq. It only does this in your own repos, so work code is never sent anywhere.

Underneath, it's an everyday editor for Rust and Python (plus C++/CUDA, GLSL and Lua), built on my old vimrc's habits: , as leader, CtrlP on <C-p>, EasyMotion on ,,, Enter clears the search highlight, gl/gs for cargo run/cargo test, Esc leaves the terminal. Every key is in the cheat sheet, and pressing , and waiting shows what comes next.

It uses Neovim's built-in plugin manager (vim.pack) and built-in LSP client, so there's no plugin-manager bootstrap. Startup is about 50 ms.

Set up on a new machine

git clone https://github.com/catchouli/nvim.git ~/projects/cat/nvim   # any folder works
~/projects/cat/nvim/install.sh

install.sh does all of this (safe to re-run; anything it replaces goes to a dated .bak-…):

What	How	Used for
Neovim 0.12+, ripgrep, fd	brew install neovim ripgrep fd	the editor; text and file search
Ghostty	brew install --cask ghostty	full colour + icons (Terminal.app can't do either)
rust-analyzer	rustup component add rust-analyzer	Rust language server
basedpyright	npm install -g basedpyright	Python types, go-to-definition
ruff	pip, in ~/.local/share/ruff-venv, linked into ~/.local/bin	Python lint + format
tree-sitter CLI	GitHub release binary → ~/.local/bin	builds the syntax parsers
lua-language-server	GitHub release → ~/.local/share/lua-language-server	editing this config
Config	~/.config/nvim → this folder, ~/.config/ghostty/config → ghostty/config
Plugins + parsers	installed on first run, pinned by nvim-pack-lock.json

ruff, tree-sitter and lua-language-server come as prebuilt binaries rather than from Homebrew because Homebrew compiles them from source on macOS 14 (an hour-plus LLVM build). On a newer macOS, brew install ruff tree-sitter-cli lua-language-server basedpyright works too. Needs gh logged in (for the downloads), ~/.local/bin on the PATH, and Node/npm for basedpyright. Already have the tools? ./install.sh --no-tools.

Files

File	What's in it
init.lua	leader, picks fancy vs plain look, loads the rest
lua/cat/options.lua	settings: numbers, 4-space tabs, persistent undo, diagnostics look
lua/cat/keymaps.lua	general keys
lua/cat/plugins.lua	the plugin list (vim.pack.add)
lua/cat/ui.lua	colour scheme, icons, statusline, minimap
lua/cat/editing.lua	text objects, surround, jumps, key hints, syntax trees
lua/cat/languages.lua	languages to install syntax parsers for
lua/cat/lsp.lua	language servers, completion, formatting
lua/cat/commitmsg.lua	Claude drafts commit messages (only in your own repos; see the top of the file)
lua/cat/tools.lua	finder, start screen, folders, git, GitHub, tests, Claude Code
after/ftplugin/rust.lua	Rust-only keys
ghostty/config	the terminal's settings
CHEATSHEET.md	every key, shown in Neovim with ,?

Keys

Leader is ,. Press , and wait for the key popup, or see CHEATSHEET.md (also ? on the start screen, ,? anywhere).

Plugins

Plugin	For
catppuccin (mocha)	colour scheme; molokai in Terminal.app
mini.nvim	statusline, icons, text objects, surround, jumps, key hints, git signs, TODO highlights
diffview.nvim	reviewing changes: changed files in a tree, side-by-side diffs, file history
oil.nvim	folders as editable buffers (nvim ., -)
neominimap.nvim	minimap down the right-hand side
snacks.nvim	finder, start screen, notifications, indent guides, GitHub
nvim-treesitter	syntax parsers: highlighting and folds
nvim-lspconfig	language server settings
blink.cmp	completion menu
rustaceanvim, crates.nvim	Rust extras, Cargo.toml
neotest (+ neotest-python, nvim-nio, plenary)	running tests
claudecode.nvim	Claude Code integration

Update plugins: :lua vim.pack.update(), read what changed, :write to apply (or :quit to skip), then :restart. Add one: add it to plugins.lua and :restart. Remove one: delete it from plugins.lua, :restart, then :lua vim.pack.del({ 'name' }).

Ideas for later

• A debugger (nvim-dap with codelldb for Rust, debugpy for Python): rustaceanvim and neotest already support it.
• lazygit (brew install lazygit): snacks has a built-in Snacks.lazygit().
• A CatApp plugin: notes, to-dos and the next step from inside Neovim (CatApp task #159).