Tutorial

Here you will learn enough to configure Neovim from scratch with LSP support. We will create a configuration file called init.lua, install a plugin manager, a colorscheme and finally install some plugins.

If you already have a Neovim configuration with a plugin manager, go to the getting started page for a quick start.

Requirements

Basic knowledge about Neovim: what is normal mode, insert mode, command mode and how to navigate between them.
Neovim v0.10 or greater
git

The Entry Point

To start we will create the file known as init.lua. The location of this file depends on your operating system. If you want to know where that is execute this command on your terminal.

nvim --headless -c 'echo stdpath("config")' -c 'echo ""' -c 'quit'

Create that folder and then navigate to it. Use whatever method you know best, use a terminal or a graphical file explorer.

Now create an empty file called init.lua.

Once the configuration exists in your system you can access it from the terminal using this command.

nvim -c 'edit $MYVIMRC'

Now let's make sure Neovim is actually loading our file. We will change the colorscheme. So, open your init.lua and add this block.

lua

if vim.fn.has('nvim-0.10') == 1 then
  vim.cmd('colorscheme morning')
else
  vim.cmd('colorscheme blue')
end

Save the file and restart Neovim, you should notice the light theme. If you get the blue theme then your Neovim version does not meet the requirements. Visit Neovim's github repository, in the release section you'll find prebuilt executables for the latest versions.

Assuming everything went well, you can now delete the if block and change to a dark theme.

lua

vim.cmd('colorscheme habamax')

Install the Plugin Manager

Note:

We don't need a plugin manager but they make our lives easier.

We are going to use lazy.nvim, only because that's what the cool kids are doing these days. You can do a lot with lazy.nvim but I'm just going to show the most basic usage.

First step is to install it from github. It just so happens we can do this using lua. In lazy.nvim's documentation they show us how to do it.

Add this to your init.lua.

lua

local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'

-- Auto-install lazy.nvim if not present
if not vim.uv.fs_stat(lazypath) then
  print('Installing lazy.nvim....')
  vim.fn.system({
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    '--branch=stable', -- latest stable release
    lazypath,
  })
  print('Done.')
end

vim.opt.rtp:prepend(lazypath)

Notice in lazypath we use stdpath('data'), this will return the path to Neovim's data folder. So now we don't need to worry about changing our paths depending on the operating system, Neovim will do that for us. If you want to inspect the path, use this command inside Neovim.

vim

:echo stdpath('data') . '/lazy/lazy.nvim'

To actually use lazy.nvim we need to call the .setup() function of the lua module called lazy. Like this.

lua

require('lazy').setup({
  ---
  -- List of plugins...
  ---
})

Adding a new plugin

Now let's use lazy.nvim for real this time. We are going to test it with a plugin called tokyonight.nvim, this is a colorscheme that will make Neovim look pretty.

Ready? We are going to follow these steps.

Add the plugin in lazy's setup.

lua

require('lazy').setup({
  {'folke/tokyonight.nvim'},
})

We need to delete the old colorscheme line if it's still there.
Call the new colorscheme at the end of the init.lua file.

lua

vim.opt.termguicolors = true
vim.cmd.colorscheme('tokyonight')

Save the file.
Restart Neovim.

When Neovim starts it should show a message telling us is cloning the plugin manager. After it's done another window will show up, it'll tell us the progress of the plugins download. After the plugins are installed they will be loaded.

Learning more about lazy.nvim

If you want to know more details about lazy.nvim, here are a few resources (that you can read later).

Lazy.nvim: plugin configuration. This will teach you the basics of the "plugin spec" and how to split your plugin setup into multiple files.
Lazy.nvim: how to revert a plugin back to a previous version. Learn how to recover from a bad plugin update.

LSP support

Now we need to add all the lua plugins in lazy's setup function.

lua

require('lazy').setup({
  {'folke/tokyonight.nvim'},
  {'neovim/nvim-lspconfig'},
  {'hrsh7th/cmp-nvim-lsp'},
  {'hrsh7th/nvim-cmp'},
})

Next, we prepare our custom keymaps and add extra settings from cmp_nvim_lsp to nvim-lspconfig defaults.

Add this code at the end of the file.

lua

-- Reserve a space in the gutter
-- This will avoid an annoying layout shift in the screen
vim.opt.signcolumn = 'yes'

-- Add cmp_nvim_lsp capabilities settings to lspconfig
-- This should be executed before you configure any language server
local lspconfig_defaults = require('lspconfig').util.default_config
lspconfig_defaults.capabilities = vim.tbl_deep_extend(
  'force',
  lspconfig_defaults.capabilities,
  require('cmp_nvim_lsp').default_capabilities()
)

-- This is where you enable features that only work
-- if there is a language server active in the file
vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    local opts = {buffer = event.buf}

    vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
    vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
    vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
    vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
    vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
    vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
    vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
    vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
    vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
    vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
  end,
})

Save the file, restart Neovim and wait for everything to be downloaded.

Right now this setup won't do much. We don't have any language server installed (and the code to use them is not there yet).

Language servers and how to use them

First thing you should do is install a language server. There are two ways you can do this:

Manual global install

In nvim-lspconfig's documentation you will find the list of language servers currently supported. Some of them have install instructions you can follow, others will have a link to the repository of the language server.

Let's pretend that we installed gopls and rust_analyzer, this is how we would use them.

lua

require('lspconfig').gopls.setup({})
require('lspconfig').rust_analyzer.setup({})

We use the module lspconfig and call the setup function of each language server we installed.

If you need to customize a language server, add your config inside the curly braces of the setup function. Here is an example.

lua

require('lspconfig').gopls.setup({
  single_file_support = false,
  on_attach = function(client, bufnr)
    print('hello world')
  end,
})

At this point the configuration code should look like this.

lua

-- Reserve a space in the gutter
-- This will avoid an annoying layout shift in the screen
vim.opt.signcolumn = 'yes'

-- Add cmp_nvim_lsp capabilities settings to lspconfig
-- This should be executed before you configure any language server
local lspconfig_defaults = require('lspconfig').util.default_config
lspconfig_defaults.capabilities = vim.tbl_deep_extend(
  'force',
  lspconfig_defaults.capabilities,
  require('cmp_nvim_lsp').default_capabilities()
)

-- This is where you enable features that only work
-- if there is a language server active in the file
vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    local opts = {buffer = event.buf}

    vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
    vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
    vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
    vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
    vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
    vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
    vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
    vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
    vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
    vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
  end,
})

-- These are just examples. Replace them with the language
-- servers you have installed in your system
require('lspconfig').gopls.setup({})
require('lspconfig').rust_analyzer.setup({})

Local installation with mason.nvim

There is a plugin called mason.nvim, is often described as a portable package manager. This plugin will allow Neovim to download language servers (and other type of tools) into a particular folder, meaning that the servers you install using this method will not be available system-wide.

If you decide to use this plugin you'll need some extra tools in your system. So, take a look at mason.nvim's requirements.

Note:

mason.nvim doesn't provide any "special integration" to the tools it downloads. It's only good for installing and updating tools.

Anyway, if you choose this method you will need to add these two plugins:

williamboman/mason.nvim
williamboman/mason-lspconfig.nvim

lua

require('lazy').setup({
  {'folke/tokyonight.nvim'},
  {'williamboman/mason.nvim'},
  {'williamboman/mason-lspconfig.nvim'},
  {'neovim/nvim-lspconfig'},
  {'hrsh7th/cmp-nvim-lsp'},
  {'hrsh7th/nvim-cmp'},
})

mason.nvim will make sure we have access to the language servers. And we will use mason-lspconfig to configure the automatic setup of every language server we install.

lua

vim.opt.signcolumn = 'yes'

local lspconfig_defaults = require('lspconfig').util.default_config
lspconfig_defaults.capabilities = vim.tbl_deep_extend(
  'force',
  lspconfig_defaults.capabilities,
  require('cmp_nvim_lsp').default_capabilities()
)

vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    ---
    -- code omitted for brevity...
    ---
  end,
})

require('mason').setup({})
require('mason-lspconfig').setup({
  handlers = {
    function(server_name)
      require('lspconfig')[server_name].setup({})
    end,
  },
})

Now you will have access to a command called :LspInstall. If you execute that command while you have a file opened mason-lspconfig.nvim will suggest a language server compatible with that type of file.

After you install a language server you need to restart Neovim so it can start properly.

Root directory

This is a very important concept you need to keep in mind. The "root directory" is the path where your code is. Think of it as your project folder. When you open a file compatible with a language server lspconfig will search for a set of files in the current folder (your working directory) or any of the parent folders. If it finds them, the language server will start analyzing that folder.

Some language servers have "single file support" enabled, this means if lspconfig can't determine the root directory then the current working directory becomes your root directory.

Let's say you have lua_ls installed, if you want it to detect the root directory of your Neovim config you can create a file called .luarc.json in the same folder your init.lua is located.

Configure lua language server

If you installed the language server for lua you are probably getting lots of warnings, most of them should be about the global variable vim. That is a Neovim specific variable, the lua language server doesn't know anything about it. Here is a quick way to fix it:

We can create a file called .luarc.json file in our Neovim config folder, and then add this.

json

{
  "runtime.version": "LuaJIT",
  "runtime.path": [
    "lua/?.lua",
    "lua/?/init.lua"
  ],
  "diagnostics.globals": ["vim"],
  "workspace.checkThirdParty": false,
  "workspace.library": [
    "$VIMRUNTIME"
  ]
}

Setup autocompletion

Last thing we are going to do is setup the autocompletion plugin: nvim-cmp.

To configure nvim-cmp use the lua module called cmp. And to make it work with Neovim's LSP client this is the minimal configuration needed.

lua

local cmp = require('cmp')

cmp.setup({
  sources = {
    {name = 'nvim_lsp'},
  },
  mapping = cmp.mapping.preset.insert({}),
  snippet = {
    expand = function(args)
      vim.snippet.expand(args.body)
    end,
  },
})

This will work but is worth mention the keybindings you get emulate Neovim's defaults, which might not be enough for some.

Here are some keybindings I suggest.

lua

local cmp = require('cmp')

cmp.setup({
  sources = {
    {name = 'nvim_lsp'},
  },
  mapping = cmp.mapping.preset.insert({
    -- Navigate between completion items
    ['<C-p>'] = cmp.mapping.select_prev_item({behavior = 'select'}),
    ['<C-n>'] = cmp.mapping.select_next_item({behavior = 'select'}),

    -- `Enter` key to confirm completion
    ['<CR>'] = cmp.mapping.confirm({select = false}),

    -- Ctrl+Space to trigger completion menu
    ['<C-Space>'] = cmp.mapping.complete(),

    -- Scroll up and down in the completion documentation
    ['<C-u>'] = cmp.mapping.scroll_docs(-4),
    ['<C-d>'] = cmp.mapping.scroll_docs(4),
  }),
  snippet = {
    expand = function(args)
      vim.snippet.expand(args.body)
    end,
  },
})

Complete code

Expand: Manual setup of language servers

lua

local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'

-- Auto-install lazy.nvim if not present
if not vim.uv.fs_stat(lazypath) then
  print('Installing lazy.nvim....')
  vim.fn.system({
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    '--branch=stable', -- latest stable release
    lazypath,
  })
  print('Done.')
end

vim.opt.rtp:prepend(lazypath)

require('lazy').setup({
  {'folke/tokyonight.nvim'},
  {'neovim/nvim-lspconfig'},
  {'hrsh7th/cmp-nvim-lsp'},
  {'hrsh7th/nvim-cmp'},
})

-- Set colorscheme
vim.opt.termguicolors = true
vim.cmd.colorscheme('tokyonight')

---
-- LSP setup
---

-- Reserve a space in the gutter
-- This will avoid an annoying layout shift in the screen
vim.opt.signcolumn = 'yes'

-- Add cmp_nvim_lsp capabilities settings to lspconfig
-- This should be executed before you configure any language server
local lspconfig_defaults = require('lspconfig').util.default_config
lspconfig_defaults.capabilities = vim.tbl_deep_extend(
  'force',
  lspconfig_defaults.capabilities,
  require('cmp_nvim_lsp').default_capabilities()
)

-- This is where you enable features that only work
-- if there is a language server active in the file
vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    local opts = {buffer = event.buf}

    vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
    vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
    vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
    vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
    vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
    vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
    vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
    vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
    vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
    vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
  end,
})

-- These are just examples. Replace them with the language
-- servers you have installed in your system
require('lspconfig').gopls.setup({})
require('lspconfig').rust_analyzer.setup({})

---
-- Autocompletion config
---
local cmp = require('cmp')

cmp.setup({
  sources = {
    {name = 'nvim_lsp'},
  },
  mapping = cmp.mapping.preset.insert({
    -- `Enter` key to confirm completion
    ['<CR>'] = cmp.mapping.confirm({select = false}),

    -- Ctrl+Space to trigger completion menu
    ['<C-Space>'] = cmp.mapping.complete(),

    -- Scroll up and down in the completion documentation
    ['<C-u>'] = cmp.mapping.scroll_docs(-4),
    ['<C-d>'] = cmp.mapping.scroll_docs(4),
  }),
  snippet = {
    expand = function(args)
      vim.snippet.expand(args.body)
    end,
  },
})

Expand: Automatic setup of language servers

lua

local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'

-- Auto-install lazy.nvim if not present
if not vim.uv.fs_stat(lazypath) then
  print('Installing lazy.nvim....')
  vim.fn.system({
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    '--branch=stable', -- latest stable release
    lazypath,
  })
  print('Done.')
end

vim.opt.rtp:prepend(lazypath)

require('lazy').setup({
  {'folke/tokyonight.nvim'},
  {'williamboman/mason.nvim'},
  {'williamboman/mason-lspconfig.nvim'},
  {'neovim/nvim-lspconfig'},
  {'hrsh7th/cmp-nvim-lsp'},
  {'hrsh7th/nvim-cmp'},
})

-- Set colorscheme
vim.opt.termguicolors = true
vim.cmd.colorscheme('tokyonight')

---
-- LSP setup
---

-- Reserve a space in the gutter
-- This will avoid an annoying layout shift in the screen
vim.opt.signcolumn = 'yes'

-- Add cmp_nvim_lsp capabilities settings to lspconfig
-- This should be executed before you configure any language server
local lspconfig_defaults = require('lspconfig').util.default_config
lspconfig_defaults.capabilities = vim.tbl_deep_extend(
  'force',
  lspconfig_defaults.capabilities,
  require('cmp_nvim_lsp').default_capabilities()
)

-- This is where you enable features that only work
-- if there is a language server active in the file
vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    local opts = {buffer = event.buf}

    vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
    vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
    vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
    vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
    vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
    vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
    vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
    vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
    vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
    vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
  end,
})

require('mason').setup({})
require('mason-lspconfig').setup({
  handlers = {
    function(server_name)
      require('lspconfig')[server_name].setup({})
    end,
  }
})

---
-- Autocompletion config
---
local cmp = require('cmp')

cmp.setup({
  sources = {
    {name = 'nvim_lsp'},
  },
  mapping = cmp.mapping.preset.insert({
    -- `Enter` key to confirm completion
    ['<CR>'] = cmp.mapping.confirm({select = false}),

    -- Ctrl+Space to trigger completion menu
    ['<C-Space>'] = cmp.mapping.complete(),

    -- Scroll up and down in the completion documentation
    ['<C-u>'] = cmp.mapping.scroll_docs(-4),
    ['<C-d>'] = cmp.mapping.scroll_docs(4),
  }),
  snippet = {
    expand = function(args)
      vim.snippet.expand(args.body)
    end,
  },
})

Tutorial ​

Requirements ​

The Entry Point ​

Install the Plugin Manager ​

Adding a new plugin ​

Learning more about lazy.nvim ​

LSP support ​

Language servers and how to use them ​

Manual global install ​

Local installation with mason.nvim ​

Root directory ​

Configure lua language server ​

Setup autocompletion ​

Complete code ​