NodeJS client API for vim8 and neovim

Usage no npm install needed!

<script type="module">
  import chemzqmNeovim from 'https://cdn.skypack.dev/@chemzqm/neovim';



Fork of neovim/node-client which works on both vim8 and neovim.

Currently works on node >= 8.

This module is used by coc.nvim, you can this module to create extension for vim8 and neovim, but it's recommended to build extension for coc.nvim.


Install the neovim package globally using npm.

npm install -g @chemzqm/neovim

Build from source code

Git clone then run yarn install.


import {attach, NeovimClient} from '@chemzqm/neovim'
// attach option could be ReadableStream & WritableStream or ChildProcess or socket string
const nvim: NeovimClient = attach({
  reader: process.stdin,
  writer: process.stdout
// current buffer object
let buf = await nvim.buffer
// current window object
let win = await nvim.window
// current tabpage object
let tabpage = await nvim.tabpage

Debug on vim8

Build this module from source code, in root of project folder, start the server by command: vim -u mini.vim.

Checkout the vim8's log file by :Openlog command.

Checkout log of node-client by open the file $XDG_RUNTIME_DIR/node-client.log.

To change the behavior, change the file mini.vim and ./bin/server.js which are used for test purpose.

Debugging / troubleshooting

Default location for log file would be $XDG_RUNTIME_DIR/node-client.log.

Use $NODE_CLIENT_LOG_FILE to specify full path of the log.

Use $NODE_CLIENT_LOG_LEVEL to specify the log level, which default to info, could also be debug or trace.

Use let g:node_client_debug = 1 in vim8 to enable logfile of vim8, use :call nvim#rpc#open_log() to open vim8 logfile.

Usage through node REPL

Note, it only works with neovim, you also need build this module from source code.


First, start Nvim with a known address (or use the $NVIM_LISTEN_ADDRESS of a running instance):

NVIM_LISTEN_ADDRESS=/tmp/nvim nvim

In another terminal, cd to root of this module then start node REPL by:

NVIM_LISTEN_ADDRESS=/tmp/nvim node

connect to Nvim:

let nvim
// `scripts/nvim` will detect if `NVIM_LISTEN_ADDRESS` is set and use that unix socket
require('./scripts/nvim').then(n => (nvim = n))