mvim

Small Python-focused Neovim config, installed as mvim.

mvim is short for “myvim”: my Vim, my rules.

Key Bindings

Leader key is Space.

Files and Basics

Key	Mode	Action
Space w	normal	Write current file
Space q	normal	Quit current window
Space h	normal	Clear search highlight
Space t	normal	Toggle project tree
Space T	normal	Reveal current file in project tree
Ctrl-w h	normal	Move focus to the left window, usually the project tree
Ctrl-w l	normal	Move focus to the right window, usually the file
Space c	normal	Open live colorscheme navigator (↑/↓ preview; Enter save; Esc restore)
Ctrl-/	normal	Toggle the language-specific comment on the current line
Ctrl-/	visual	Toggle language-specific comments on the selected lines
Tab	visual/select	Indent the selected lines and keep them selected
Shift-Tab	visual/select	Outdent the selected lines and keep them selected
Ctrl-Shift-Up / Ctrl-Shift-Down	normal	Move the current line up / down
Ctrl-Shift-Up / Ctrl-Shift-Down	insert	Move the current line up / down and remain in insert mode
Ctrl-Shift-Up / Ctrl-Shift-Down	visual	Move all selected lines up / down and keep them selected

Commenting uses each filetype's syntax. In Python, # is inserted after the line's indentation, and uncommenting restores the original indentation.

Multiple Cursors

Multiple-cursor editing is provided by vim-visual-multi with its default mappings. Its occurrence matching is case-sensitive by default.

Key	Mode	Action
Ctrl-n	normal	Select the word under the cursor; press again to add its next occurrence
Ctrl-n	visual	Select the next occurrence of the current selection
\\A	normal/visual	Select all occurrences of the word under the cursor or the visual selection
n / N	multi-cursor	Add the next/previous occurrence
\\c	multi-cursor	Cycle matching from case-sensitive to case-insensitive to smart-case
q	multi-cursor	Skip the current occurrence
Q	multi-cursor	Remove the current cursor
Esc	multi-cursor	Leave multi-cursor mode

After selecting the occurrences, use normal Vim editing commands such as c, d, or I; the edit is applied to every cursor.

To include matches with different capitalization, start a multi-cursor selection and press \\c once. Press it again for smart-case matching, or leave and restart multi-cursor mode to return to the case-sensitive default.

Python Send To IPython/tmux

Key	Mode	Action
Ctrl-Space	normal	Send current line; send whole block when on a Python block opener
F5	normal	Same as Ctrl-Space; reliable terminal fallback
Space s	normal	Same as Ctrl-Space; mnemonic fallback
Ctrl-Enter	normal	Same as Ctrl-Space when terminal emits a distinct key code
Ctrl-Space	visual	Send selected text
F5	visual	Send selected text
Space s	visual	Send selected text
Space Enter	normal	Send current # %% cell
Space r p	normal	Start IPython in tmux

Multiline statements expand through matching (), [], and {} before indentation-based block expansion.

Ctrl-Enter support depends on the terminal. If it does nothing, use Ctrl-Space, F5, or Space s.

Python LSP

Key	Mode	Action
gd	normal	Go to definition
gr	normal	Show references
K	normal	Hover documentation
Space rn	normal	Rename symbol
Space ca	normal/visual	Code action
Ctrl-o	normal	Jump back
Ctrl-i	normal	Jump forward

Python Formatting

Python files are formatted with Black on write when the project has .venv/bin/black. Disable this with:

vim.g.mvim_black_on_save = false

Diagnostics

Key	Mode	Action
Space e	normal	Show diagnostic under cursor
[d	normal	Previous diagnostic
]d	normal	Next diagnostic

Completion

Key	Mode	Action
Ctrl-Space	insert	Open completion menu
Tab	insert/select	Next completion item or snippet jump
Shift-Tab	insert/select	Previous completion item or snippet jump back
Enter	insert	Confirm selected completion item
Ctrl-e	insert	Abort completion menu

Brackets and Quotes

Bracket and quote pairs are inserted automatically in insert mode by nvim-autopairs.

AI Block Fill

Key	Mode	Action
Space a f	normal	Replace the current Python block from a #claude: or #codex: instruction

Write an instruction comment inside a Python block, then run <leader>af:

def parse_row(row):
    #claude: finish this function; return a dict with id, name, and score

or:

def parse_row(row):
    #codex: finish this function; return a dict with id, name, and score

mvim sends the current block and buffer context to the selected CLI, then replaces only that block with the returned code. The edit stays in the buffer, so normal undo works.

Install from GitHub

git clone <your-github-url> mvim
cd mvim
make install

make install detects Linux/macOS and CPU architecture, downloads Neovim v0.12.3, installs it as ~/.local/bin/mvim, links this repo to ~/.config/nvim, installs plugins, and installs Pyright through Mason.

Main dependencies:

• Neovim v0.12.3, downloaded by make install as mvim
• lazy.nvim, plugin manager bootstrapped by the config
• Pyright, installed by Mason for Python LSP
• nvim-tree.lua for a toggleable project work-tree
• nvim-cmp/LuaSnip for completion and snippets
• nvim-autopairs for bracket/quote completion
• vim-slime plus tmux for send-to-REPL workflow
• Optional minuet-ai.nvim for OpenAI API-backed AI completion
• Optional claude or codex CLI for marker-driven block fill

Prerequisites:

• bash, make, curl, git, tar
• python3
• Node/npm, for Mason installing Pyright
• tmux, for Python send-to-REPL workflow
• IPython for the Python REPL workflow, installable with python3 -m pip install ipython if missing

Supported Neovim downloads:

• Linux x86_64 / arm64: official tarball
• macOS x86_64 / arm64: official tarball

Make sure ~/.local/bin is on PATH:

export PATH="$HOME/.local/bin:$PATH"

Then start the editor with:

mvim file.py

To browse a project tree, start mvim from the project directory and press <leader>t. Use <leader>T to reveal the current file in the tree. After opening a file from the tree, use Ctrl-w h to move focus back to the tree and Ctrl-w l to return to the file window.

Useful make targets:

make install   # install mvim and sync plugins/tools
make sync      # resync plugins and Pyright
make check     # syntax/startup check
make doctor    # show executable/config/tool status
make uninstall # remove ~/.local/bin/mvim, installed tarball dir, and this repo's ~/.config/nvim link

Python REPL sending

You do not need to run mvim inside tmux. There only needs to be a tmux pane to receive code.

One simple setup:

tmux
python3 -m IPython

Detach with Ctrl-b d, then open a Python file elsewhere:

mvim file.py

Or ask mvim to start IPython in tmux with:

<leader>rp

Send code to the active pane in an attached tmux session, falling back to the last listed tmux pane:

• <F5>, <leader>s, <C-Space>, or <C-Enter> when your terminal emits a distinct key code: send current line, or the whole block when on a Python block opener; then move to the next line at its indentation
• visual <F5> or <C-Space>: selected text
• <leader><Enter>: current # %% cell

<F5> is the reliable fallback because many terminals do not send a distinct Ctrl+Enter key code. Sending targets an explicit tmux pane id, so mvim can run outside tmux.

LSP

Pyright is installed by Mason. For Python package completions, start mvim from the project root and either activate a virtualenv first or keep it at .venv/ or venv/ in the project root:

python3 -m venv .venv
. .venv/bin/activate
python -m pip install numpy pandas ipython
mvim file.py

Pyright uses that interpreter, so imports and completions come from packages installed in the venv. Useful keys:

• gd: definition
• gr: references
• K: hover
• <leader>rn: rename
• <leader>ca: code action

Optional AI completion

AI completion uses minuet-ai.nvim only when OPENAI_API_KEY is present in the environment. It is API-billed and separate from Codex subscription credits.

Optional AI block fill

Install and authenticate either the claude or codex CLI, then add a marker comment such as #claude: implement this function or #codex: implement this function inside a Python block. Press <leader>af or run :AIFill.

You can force a provider with :AIFill claude or :AIFill codex. Codex is run with read-only sandboxing; Claude is run in print mode with tools disabled.