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VSNeo — Neovim for Visual Studio

Visual Studio keeps its editor. Neovim is the brain behind it.

VSNeo embeds a real, headless Neovim inside Visual Studio and lets it drive the standard editor: modes, motions, operators, registers, marks, macros and the command line are executed by Neovim itself, while Visual Studio keeps rendering, IntelliSense, refactorings and undo. Not a C# reimplementation of Vim, and not a terminal in a tool window — the same nvim.exe you already have, speaking msgpack-rpc over a named pipe.

Why not VsVim / a Vim emulation?

Because emulation drifts. Every Vim-behaving layer eventually has to re-implement operators, text objects, '/ register quirks and the command line, and every one of them gets it almost right. VSNeo runs the real thing: if Neovim does it, VSNeo does it — including :%s/a/b/g end to end, with the preview and the undo transaction you expect. And because Visual Studio remains the editor, gd is Roslyn's Go To Definition across projects, not a same-file text search.

What you get

• Real Vim semantics — modes, motions, operators, counts, registers, marks, macros, visual mode — executed by Neovim against a mirrored buffer and applied back into Visual Studio's undo history as proper transactions.
• A real : and / command line, drawn as a floating popup at the top of the window (the Ctrl+Q shape), with wildmenu completion.
• Search that is Neovim's regex engine, with matches highlighted in the editor and the current match in CurSearch; yank flash on TextYankPost.
• Window management that understands tab groups — Ctrl-W h/j/k/l moves between splits by frame geometry, :split/:vsplit/:q map to the Visual Studio commands that produce the same layout, Ctrl-6 walks most-recently-used documents, gb jumps to any tab by letter label.
• A flash-style s jump with letter labels over visible matches, and labels on f/F/t/T when a line holds several matches.
• Visual Studio commands from mappings: :Vsc Some.Command runs anything from Tools > Options > Keyboard, so .vsvimrc mappings port nearly verbatim. gd, gD, gi, gr, [d, ]d, K, <leader>rn, <leader>ca, <leader>f are pre-wired to Roslyn navigation and refactorings.
• Register peek — " lists Neovim's registers with previews beside the caret.
• Insert mode stays Visual Studio's — IntelliSense, snippets, Copilot and brace completion work untouched. Only Esc and Ctrl-W are claimed there.
• Your config and (some of) your plugins — ~/.vsneorc is sourced at startup, and buffer/motion-layer plugins (surround, commentary, text objects) load from ~/.vsneo/pack/<group>/{start,opt}.

Requirements

• Windows, Visual Studio 2022 17.14+ or Visual Studio 2026.
• Neovim — any recent build (developed against 0.12), nvim.exe on PATH or pointed at with VSNEO_NVIM_PATH.

Install

From the Visual Studio Marketplace, or grab the VSIX from a GitHub Release / the CI build on the Open VSIX Gallery.

Then open a code file and look for VSNeo: connected in the status bar.

Quickstart

1. Open any source file. You start in normal mode — the caret is a block.
2. gg, %, ci", vap, . — everything behaves as in Vim.
3. : and / open the floating command line; Tab completes.
4. :Vsc Edit.GoToBrace, or map it: nnoremap [{ :Vsc Edit.GotoBrace<CR> in ~/.vsneorc.

Configuration

VSNeo sources %USERPROFILE%\.vsneorc (vimscript) at startup if it exists. examples/vsneorc.vim is a full .vsvimrc ported to VSNeo — copy it and restart Visual Studio. Two porting notes:

• inoremap can never fire — insert-mode keys go to Visual Studio, not Neovim.
• Ctrl+Alt(+Shift) chords are never claimed — that is AltGr on many layouts and Visual Studio's own binding namespace.

Plugins live under %USERPROFILE%\.vsneo\pack\<group>\start\<plugin> (loaded at startup) or ...\opt\<plugin> (:packadd-able). Your regular Neovim plugins are deliberately not loaded; UI plugins draw to a grid nothing displays and cannot work here.

Troubleshooting

• Lifecycle diagnostics go to %TEMP%\vsneo.log — check there first.
• set VSNEO_TRACE_KEYS=1 before launching Visual Studio logs every key decision (Debug builds only). It answers the only question the outside cannot: did the key reach the extension at all.
• If Neovim isn't found, set VSNEO_NVIM_PATH=C:\path\to\nvim.exe.

Development

You need Windows, Visual Studio 2022 17.14+ or 2026 with the Visual Studio extension development workload, and Neovim on PATH.

git clone https://github.com/knilecrack/VSNeo.git
cd VSNeo
start VSNeo.slnx

Press F5 to launch an experimental instance (/rootsuffix Exp) with the extension deployed. Deploy with F5, not from the command line: msbuild builds the VSIX but doesn't install it, and VSIXInstaller doesn't trigger the extension rescan — both fail silently and you test an old build.

Command-line build (from a Developer Command Prompt, where msbuild is on PATH):

msbuild VSNeo.slnx -restore -p:Configuration=Debug

dotnet build is not sufficient — the project references the Visual Studio SDK and WPF assemblies that require MSBuild.

Design rationale, the key-path invariant and the known landmines live in CLAUDE.md; AGENTS.md is the contributor/agent guide with the project layout and conventions.

How it works, in one paragraph

A KeyProcessor and an IOleCommandTarget filter intercept keystrokes and decide swallow-vs-passthrough from a locally cached mode — zero I/O on the key path. The effect travels over msgpack-rpc to a headless Neovim (--headless --listen \\.\pipe\vsneo-<guid>), which edits a mirrored buffer; buffer, cursor, viewport, mode, command line and search state stream back as RPC notifications and are applied to the Visual Studio editor. A companion Lua script (Lua/vsneo.lua) inside Neovim pushes the state the redraw protocol doesn't carry.

License

MIT