Turn your browser into a Neovim client.

Just click on any textarea and it will be immediately replaced by an instance of Firenvim. When you want to set the content of the now hidden textarea to the content of the Neovim instance, just :w. If you want to close the Firenvim overlay and return to the textarea run :q. If you selected an element where you expected the Firenvim frame to appear and it didn't, try pressing <C-e> (you can configure this binding in about://addons or chome://extensions), this should manually trigger firenvim. Please also open an issue in order to let us know the website and element this happened on.

Before installing anything please read SECURITY.md and make sure you're okay with everything mentioned. In the event you think of a way to compromise Firenvim, please send me an email (you can find my address in my commits).

1. Make sure you are using Neovim 0.4.0 or later. This plugin will not work with vanilla VIM or Vimr.

2. Check if the luabitop package is available by running :lua bit.band(1,1) in Neovim. If this throws an error, you will need to install it.

3. Install Firenvim as a VIM plugin as you would any other, then run the built in post-install hook script.

   • vim-plug

     Plug 'glacambre/firenvim', { 'do': function('firenvim#install') }

   • dein

     call dein#add('glacambre/firenvim', { 'hook_post_update': function('firenvim#install') })

   • minpac

     call minpac#add('glacambre/firenvim', { 'do': function('firenvim#install') })

   • pathogen, vundle, others

     Install the plugin as you usually would, then run this shell command:

     $ nvim --headless "+call firenvim#install(0) | q"

4. Finally install Firenvim in your browser from Mozilla's store or Google's.

Installing from source requires NodeJS, npm, and Neovim >= 0.4.

First, install Firenvim like a regular vim plugin (either by changing your runtime path manually or by using your favourite plugin manager).

Then, run the following commands:

git clone https://git.sr.ht/~glacambre/firenvim
cd firenvim
npm install
npm run build
npm run install_manifests

These commands should create three directories: target/chrome, target/firefox and target/xpi.

Go to about:addons, click on the cog icon and select install addon from file (note: this might require setting xpinstall.signatures.required to false in about:config).

Go to chrome://extensions, enable "Developer mode", click on Load unpacked and select the target/chrome directory.

Other browsers aren't supported for now. Opera, Vivaldi and other Chromium-based browsers should however work just like in Chromium and have similar install steps. Brave and Edge might work, Safari doesn't (it doesn't support Webextensions).

Firenvim currently requires the following permissions for the following reasons:

• Access your data for all websites: this is necessary in order to be able to append elements (= the neovim iframe) to the DOM.
• Exchange messages with programs other than Firefox: this is necessary in order to be able to start neovim instances.
• Access browser tabs: This is required in order to find out what the currently active tab is.

Firenvim is configured by creating a variable named g:firenvim_config in your init.vim. This variable is a dictionary containing the key "localSettings". g:firenvim_config["localSettings"] is a dictionary the keys of which have to be a Javascript pattern matching a URL and the values of which are dictionaries containing settings that apply for all URLs matched by the Javascript pattern. When multiple patterns match a same URL, the pattern with the highest "priority" value is used.

Here's an example g:firenvim_config that matches the default configuration:

let g:firenvim_config = {
    \ 'localSettings': {
        \ '.*': {
            \ 'selector': 'textarea',
            \ 'priority': 0,
        \ }
    \ }
\ }

This means that for all URLs (".*"), textareas will be turned into Firenvim instances. Here's an example that disables Firenvim everywhere but enables it on GitHub:

let g:firenvim_config = {
    \ 'localSettings': {
        \ '.*': {
            \ 'selector': '',
            \ 'priority': 0,
        \ },
        \ 'github\.com': {
            \ 'selector': 'textarea',
            \ 'priority': 1,
        \ },
    \ }
\ }

Note that it is not necessary to specify the priority key because it defaults to 1, except for the .* pattern, which has a priority of 0.

Since Firenvim just uses the BufWrite event in order to detect when it needs to write neovim's buffers to the page, Firenvim can be made to automatically synchronize all changes like this:

au TextChanged * ++nested write
au TextChangedI * ++nested write

Depending on how large the edited buffer is, this could be a little slow. A better approach would then be to delay writes, like this:

let g:dont_write = v:false
function! My_Write(timer) abort
	let g:dont_write = v:false
	write
endfunction

function! Delay_My_Write() abort
	if g:dont_write
		return
	end
	let g:dont_write = v:true
	call timer_start(10000, 'My_Write')
endfunction

au TextChanged * ++nested call Delay_My_Write()
au TextChangedI * ++nested call Delay_My_Write()

You can detect when Firenvim connects to Neovim with the following code:

function! OnUIEnter(event)
    let l:ui = nvim_get_chan_info(a:event.chan)
    if has_key(l:ui, 'client') && has_key(l:ui.client, "name")
        if l:ui.client.name == "Firenvim"
            set laststatus=0
        endif
    endif
endfunction
autocmd UIEnter * call OnUIEnter(deepcopy(v:event))

Similarly, you can detect when Firenvim disconnects from a Neovim instance with the UILeave autocommand.

If you want to use different settings depending on the textarea you're currently editing, you can use autocommands to do that too. All buffers are named like this: domainname_page_selector.txt (see the toFileName function). This means that you can for example set the file type to markdown for all GitHub buffers:

au BufEnter github.com_*.txt set filetype=markdown

The main issue with Firenvim is that some keybindings (e.g. <C-w>) are not overridable. I circumvent this issue by running a patched version of Firefox.

• Tridactyl, provides vim-like keybindings to use Firefox. Also lets you edit input fields and text areas in your favourite editor with its :editor command.
• GhostText, lets you edit text areas in your editor with a single click. Requires installing a plugin in your editor too. Features live updates!
• Textern, a Firefox addon that lets you edit text areas in your editor without requiring you to install a plugin in your editor.
• withExEditor, same thing as Textern, except you can also edit/view a page's source with your editor.