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Set Up Your Environment

The Deno CLI contains a lot of the tools that are commonly needed for developing applications, including a full language server to help power your IDE of choice. Installing is all you need to do to make these tools available to you.

Outside using Deno with your favorite IDE, this section also documents shell completions and environment variables.

Using an editor/IDE Jump to heading

There is broad support for Deno in editors/IDEs. The following sections provide information about how to use Deno with editors. Most editors integrate directly into Deno using the Language Server Protocol and the language server that is integrated into the Deno CLI.

If you are trying to write or support a community integration to the Deno language server, there is some documentation located in the Deno CLI code repository, but also feel free to join the Discord community in the #dev-lsp channel.

Visual Studio Code Jump to heading

There is an official extension for Visual Studio Code called vscode_deno. When installed, it will connect to the language server built into the Deno CLI.

Because most people work in mixed environments, the extension does not enable a workspace as Deno enabled by default, and it requires that the "deno.enable" flag to be set. You can change the settings yourself, or you can choose Deno: Initialize Workspace Configuration from the command palette to enable your project.

More information can be found in the Using Visual Studio Code section of the manual.

JetBrains IDEs Jump to heading

You can get support for Deno in WebStorm and other JetBrains IDEs, including PhpStorm, IntelliJ IDEA Ultimate, and PyCharm Professional. For this, install the official Deno plugin from Preferences / Settings | Plugins - Marketplace.

Check out this blog post to learn more about how to get started with Deno.

Vim/Neovim via plugins Jump to heading

Deno is well-supported on both Vim and Neovim via coc.nvim, vim-easycomplete and ALE. coc.nvim offers plugins to integrate to the Deno language server while ALE supports it out of the box.

Neovim 0.6+ using the built-in language server Jump to heading

To use the Deno language server install nvim-lspconfig and follow the instructions to enable the supplied Deno configuration.

Note that if you also have tsserver as an LSP client, you may run into issues where both tsserver and denols are attached to your current buffer. To resolve this, make sure to set some unique root_dir for both tsserver and denols. You may also need to set single_file_support to false for tsserver to prevent it from running in single file mode. Here is an example of such a configuration:

local nvim_lsp = require('lspconfig')
nvim_lsp.denols.setup {
  on_attach = on_attach,
  root_dir = nvim_lsp.util.root_pattern("deno.json", "deno.jsonc"),

nvim_lsp.tsserver.setup {
  on_attach = on_attach,
  root_dir = nvim_lsp.util.root_pattern("package.json"),
  single_file_support = false

For Deno, the example above assumes a deno.json or deno.jsonc file exists at the root of the project.

coc.nvim Jump to heading

Once you have coc.nvim installed, you need to install the required coc-deno via :CocInstall coc-deno.

Once the plugin is installed, and you want to enable Deno for a workspace, run the command :CocCommand deno.initializeWorkspace and you should be able to utilize commands like gd (goto definition) and gr (go/find references).

ALE Jump to heading

ALE supports Deno via the Deno language server out of the box and in many uses cases doesn't require additional configuration. Once you have ALE installed you can perform the command :help ale-typescript-deno to get information on the configuration options available.

For more information on how to setup ALE (like key bindings) refer to the official documentation.

Vim-EasyComplete Jump to heading

Vim-EasyComplete supports Deno without any other configuration. Once you have vim-easycomplete installed, you need install deno via :InstallLspServer deno if you haven't installed deno. You can get more information from official documentation.

Emacs Jump to heading

lsp-mode Jump to heading

Emacs supports Deno via the Deno language server using lsp-mode. Once lsp-mode is installed it should support Deno, which can be configured to support various settings.

eglot Jump to heading

You can also use built-in Deno language server by using eglot.

An example configuration for Deno via eglot:

(add-to-list 'eglot-server-programs '((js-mode typescript-mode) . (eglot-deno "deno" "lsp")))

  (defclass eglot-deno (eglot-lsp-server) ()
    :documentation "A custom class for deno lsp.")

  (cl-defmethod eglot-initialization-options ((server eglot-deno))
    "Passes through required deno initialization options"
    (list :enable t
    :lint t))

Pulsar Jump to heading

The Pulsar editor, formerly known as Atom supports integrating with the Deno language server via the atom-ide-deno package. atom-ide-deno requires that the Deno CLI be installed and the atom-ide-base package to be installed as well.

Sublime Text Jump to heading

Sublime Text supports connecting to the Deno language server via the LSP package. You may also want to install the TypeScript package to get full syntax highlighting.

Once you have the LSP package installed, you will want to add configuration to your .sublime-project configuration like the below:

  "settings": {
    "LSP": {
      "deno": {
        "command": ["deno", "lsp"],
        "initializationOptions": {
          // "config": "", // Sets the path for the config file in your project
          "enable": true,
          // "importMap": "", // Sets the path for the import-map in your project
          "lint": true,
          "unstable": false
        "enabled": true,
        "languages": [
            "languageId": "javascript",
            "scopes": ["source.js"],
            "syntaxes": [
              "Packages/Babel/JavaScript (Babel).sublime-syntax",
            "languageId": "javascriptreact",
            "scopes": ["source.jsx"],
            "syntaxes": [
              "Packages/Babel/JavaScript (Babel).sublime-syntax",
            "languageId": "typescript",
            "scopes": ["source.ts"],
            "syntaxes": [
              "Packages/TypeScript Syntax/TypeScript.tmLanguage"
            "languageId": "typescriptreact",
            "scopes": ["source.tsx"],
            "syntaxes": [
              "Packages/TypeScript Syntax/TypeScriptReact.tmLanguage"

Nova Jump to heading

The Nova editor can integrate the Deno language server via the Deno extension.

GitHub Codespaces Jump to heading

GitHub Codespaces allows you to develop fully online or remotely on your local machine without needing to configure or install Deno. It is currently in early access.

If a project is a Deno enabled project and contains the .devcontainer configuration as part of the repository, opening the project in GitHub Codespaces should just "work". If you are starting a new project, or you want to add Deno support to an existing code space, it can be added by selecting the Codespaces: Add Development Container Configuration Files... from the command pallet and then selecting Show All Definitions... and then searching for the Deno definition.

Once selected, you will need to rebuild your container so that the Deno CLI is added to the container. After the container is rebuilt, the code space will support Deno.

Kakoune Jump to heading

Kakoune supports connecting to the Deno language server via the kak-lsp client. Once kak-lsp is installed an example of configuring it up to connect to the Deno language server is by adding the following to your kak-lsp.toml:

filetypes = ["typescript", "javascript"]
roots = [".git"]
command = "deno"
args = ["lsp"]
enable = true
lint = true

Helix Jump to heading

Helix comes with built-in language server support. Enabling connection to the Deno language server requires changes in the languages.toml configuration file.

name = "typescript"
language-id = "typescript"
scope = "source.ts"
injection-regex = "^(ts|typescript)$"
file-types = ["ts"]
shebangs = ["deno"]
roots = ["deno.json", "deno.jsonc", "package.json"]
auto-format = true
language-servers = ["deno-lsp"]

command = "deno"
args = ["lsp"]

enable = true

Shell completions Jump to heading

Built into the Deno CLI is support to generate shell completion information for the CLI itself. By using deno completions <shell>, the Deno CLI will output to stdout the completions. Current shells that are supported:

  • bash
  • elvish
  • fish
  • powershell
  • zsh

bash example Jump to heading

Output the completions and add them to the environment:

> deno completions bash > /usr/local/etc/bash_completion.d/deno.bash
> source /usr/local/etc/bash_completion.d/deno.bash

PowerShell example Jump to heading

Output the completions:

> deno completions powershell >> $profile
> .$profile

This will create a Powershell profile at $HOME\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1, and it will be run whenever you launch the PowerShell.

zsh example Jump to heading

You should have a directory where the completions can be saved:

> mkdir ~/.zsh

Then output the completions:

> deno completions zsh > ~/.zsh/_deno

And ensure the completions get loaded in your ~/.zshrc:

fpath=(~/.zsh $fpath)
autoload -Uz compinit
compinit -u

If after reloading your shell and completions are still not loading, you may need to remove ~/.zcompdump/ to remove previously generated completions and then compinit to generate them again.

zsh example with ohmyzsh and antigen Jump to heading

ohmyzsh is a configuration framework for zsh and can make it easier to manage your shell configuration. antigen is a plugin manager for zsh.

Create the directory to store the completions and output the completions:

> mkdir ~/.oh-my-zsh/custom/plugins/deno
> deno completions zsh > ~/.oh-my-zsh/custom/plugins/deno/_deno

Then your .zshrc might look something like this:

source /path-to-antigen/antigen.zsh

# Load the oh-my-zsh's library.
antigen use oh-my-zsh

antigen bundle deno

fish example Jump to heading

Output the completions to a deno.fish file into the completions directory in the fish config folder:

> deno completions fish > ~/.config/fish/completions/deno.fish

Environment variables Jump to heading

There are several environment variables which can impact the behavior of Deno:

  • DENO_AUTH_TOKENS - a list of authorization tokens which can be used to allow Deno to access remote private code. See the Private modules and repositories section for more details.
  • DENO_TLS_CA_STORE - a list of certificate stores which will be used when establishing TLS connections. The available stores are mozilla and system. You can specify one, both or none. Certificate chains attempt to resolve in the same order in which you specify them. The default value is mozilla. The mozilla store will use the bundled Mozilla certs provided by webpki-roots. The system store will use your platform's native certificate store. The exact set of Mozilla certs will depend on the version of Deno you are using. If you specify no certificate stores, then no trust will be given to any TLS connection without also specifying DENO_CERT or --cert or specifying a specific certificate per TLS connection.
  • DENO_CERT - load a certificate authority from a PEM encoded file. This "overrides" the --cert option. See the Proxies section for more information.
  • DENO_DIR - this will set the directory where cached information from the CLI is stored. This includes items like cached remote modules, cached transpiled modules, language server cache information and persisted data from local storage. This defaults to the operating system's default cache location and then under the deno path.
  • DENO_INSTALL_ROOT - When using deno install where the installed scripts are stored. This defaults to $HOME/.deno/bin.
  • DENO_NO_PACKAGE_JSON - Set to disable auto-resolution of package.json files.
  • DENO_NO_PROMPT - Set to disable permission prompts on access (alternative to passing --no-prompt on invocation).
  • DENO_NO_UPDATE_CHECK - Set to disable checking if a newer Deno version is available.
  • DENO_WEBGPU_TRACE - The directory to use for WebGPU traces.
  • HTTP_PROXY - The proxy address to use for HTTP requests. See the Proxies section for more information.
  • HTTPS_PROXY - The proxy address to use for HTTPS requests. See the Proxies section for more information.
  • NO_COLOR - If set, this will prevent the Deno CLI from sending ANSI color codes when writing to stdout and stderr. See the website https://no-color.org for more information on this de facto standard. The value of this flag can be accessed at runtime without permission to read the environment variables by checking the value of Deno.noColor.
  • NO_PROXY - Indicates hosts which should bypass the proxy set in the other environment variables. See the Proxies section for more information.
  • NPM_CONFIG_REGISTRY - The npm registry to use when loading modules via npm specifiers