websocket-text-relay.nvim

websocket-text-relay.nvim is a Neovim plugin designed to enhance your live coding experience by leveraging the power of WebSockets and the Language Server Protocol (LSP). This tool watches for changes to your files and seamlessly relays these updates to the frontend client. With websocket-text-relay.nvim, you can see your code changes reflected live, without the need to save or refresh your browser.

This repo contains just the neovim client. The server implementation can be found in the websocket-text-relay repo

First Install the Language Server

Requirements: Nodejs

First install the websocket-text-relay language server

npm install --global websocket-text-relay@latest

Updating the Language Server

If the language server is already installed, you can run the same command again to update to the latest version.

Install Neovim Plugin

websocket-text-relay.nvim can be installed using lazy.nvim.

With Lazy

Add the following lines to your Neovim configuration to install websocket-text-relay.nvim and configure <M-w> to toggle the language server on and off:

require('lazy').setup {

  { 'niels4/websocket-text-relay.nvim', 
    keys = {
      { mode = 'n', '<M-w>', '<cmd>WtrToggle<cr>', desc = '[w]tr toggle' },
    },
  }

}

Without Lazy

Use any package manager you like to install the plugin in the github repo niels4/websocket-text-relay.nvim

Once installed 3 commands become available: WtrToggle, WtrEnable, and WtrDisable

Map with standard keymap.set

vim.keymap.set('n', '<M-w>', '<cmd>WtrToggle<cr>', { 
  desc = '[w]tr toggle',
  silent = true 
})

Usage

Once the plugin is installed, enable it with your hotkey or enter the command :WtrEnable to start the language server and websocket interface.

Verify the plugin is working by viewing the status UI hosted at http://localhost:38378

After installation, continue with step 2 in the websocket-text-relay README to connect your editor to a front end client and see your updates rendered as you type.

configuration

---@class WtrOptions
---@field enabled? boolean Enabled on startup?
---@field allow_network_access? boolean Allow other computers on local network to access websocket interface.
---@field allowed_hosts? string[] Similar to CORS. Choose which urls are allowed to connect to the websocket interface.
---@field cmd? string|string[] The command to start the LSP. Can be a string or a list of strings.
---@field updates_per_second? number How many times per second to sync text.


---@param user_opts WtrOptions
M.setup = function(user_opts)

enabled

By default, the language server is not enabled. Set the enabled option to true to start the language server and websocket interface when neovim starts.

  { 'niels4/websocket-text-relay.nvim', opts = {
      enabled = true
  }},

allow_network_access

By default, the http and websocket server will only accept incoming connections from your local machine. If you wish to allow network access you must set the allow_network_access option to true.

  { 'niels4/websocket-text-relay.nvim', opts = {
      allow_network_access = true
  }},

allowed_hosts

This is similar to (CORS)[https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/CORS]. But enforced server side.

By default, the http and websocket server will only accept connections from a web browser where the hostname is localhost. If you wish visit another website and allow your browser to connect to the websocket interface, you must explicitly allow them using the allowed_hosts option. Only add hosts that you trust, as they will be able to the contents of any source files opened in your editor.

  { 'niels4/websocket-text-relay.nvim', opts = {
      allowed_hosts = { "niels4.github.io", "some-other-host.test" },
  }},

cmd

You can override the command used to start the language server using the cmd option. This is useful for local development and debugging the application using the chrome debugger. See the developer's guide for more information.

local home_dir = vim.fn.resolve(os.getenv("HOME"))

require('lazy').setup {

  { 'niels4/websocket-text-relay.nvim', opts = {
    cmd = { "node", "--inspect",  home_dir .. "/dev/src/websocket-text-relay/start.js" }
  }}

}

updates_per_second

You can use the updates_per_second option to override the default update rate of the LSP client. As of September 2025, it seems that the max updates per second that neovim will send to the LSP server is 30. That is the default setting for websocket-text-relay, if you wish to send updates at a lower rate you can reduce the value in the config.

  { 'niels4/websocket-text-relay.nvim', opts = {
      updates_per_second = 30
  }},

License

websocket-text-relay.nvim is released under the MIT License.