File: README.md Copy Chapter

Fast Node Manager (`fnm`)

🚀 Fast and simple Node.js version manager, built in Rust

Features Copy Chapter

🌎 Cross-platform support (macOS, Windows, Linux)

✨ Single file, easy installation, instant startup

🚀 Built with speed in mind

📂 Works with .node-version and .nvmrc files

Installation Copy Chapter

Using a script (macOS/Linux) Copy Section

For bash, zsh and fish shells, there's an automatic installation script.

First ensure that curl and unzip are already installed on your operating system. Then execute:

curl -fsSL https://fnm.vercel.app/install | bash

Upgrade

On macOS, it is as simple as brew upgrade fnm.

On other operating systems, upgrading fnm is almost the same as installing it. To prevent duplication in your shell config file, pass --skip-shell to the install command:

curl -fsSL https://fnm.vercel.app/install | bash -s -- --skip-shell

Parameters

--install-dir

Set a custom directory for fnm to be installed. The default is $XDG_DATA_HOME/fnm (if $XDG_DATA_HOME is not defined it falls back to $HOME/.local/share/fnm on linux and $HOME/Library/Application Support/fnm on MacOS).

Note: On macOS, this option is only meaningful when using --force-install since Homebrew is the default installation method.

--skip-shell

Skip appending shell specific loader to shell config file, based on the current user shell, defined in $SHELL. e.g. for Bash, $HOME/.bashrc. $HOME/.zshrc for Zsh. For Fish - $HOME/.config/fish/conf.d/fnm.fish

--force-install

macOS installations using the installation script are deprecated in favor of the Homebrew formula, but this forces the script to install using it anyway.

Example:

curl -fsSL https://fnm.vercel.app/install | bash -s -- --install-dir "./.fnm" --skip-shell

Manually Copy Section

Using Homebrew (macOS/Linux)

brew install fnm

Then, set up your shell for fnm

Using Winget (Windows)

winget install Schniz.fnm

Using Scoop (Windows)

scoop install fnm

Then, set up your shell for fnm

Using Chocolatey (Windows)

choco install fnm

Then, set up your shell for fnm

Using Cargo (Linux/macOS/Windows)

cargo install fnm

Then, set up your shell for fnm

Using a release binary (Linux/macOS/Windows)

• Download the latest release binary for your system
• Make it available globally on PATH environment variable
• Set up your shell for fnm

Removing Copy Section

To remove fnm (😢), just delete the .fnm folder in your home directory. You should also edit your shell configuration to remove any references to fnm (ie. read Shell Setup, and do the opposite).

Completions Copy Chapter

fnm ships its completions with the binary:

fnm completions --shell <SHELL>

Where <SHELL> can be one of the supported shells:

• bash
• zsh
• fish
• powershell

Please follow your shell instructions to install them.

Shell Setup Copy Section

Environment variables need to be setup before you can start using fnm.
This is done by evaluating the output of fnm env.

[!TIP]
Prefer passing an explicit shell (for example fnm env --shell bash) instead of relying on shell inference at runtime. It is a bit faster and avoids process tree detection.

[!NOTE]
Check out the Configuration section to enable highly
recommended features, like automatic version switching.

Adding a .node-version to your project is as simple as:

$ node --version
v14.18.3
$ node --version > .node-version

Check out the following guides for the shell you use:

Bash

Add the following to your .bashrc profile:

eval "$(fnm env --use-on-cd --shell bash)"

Zsh

Add the following to your .zshrc profile:

eval "$(fnm env --use-on-cd --shell zsh)"

Fish shell

Create ~/.config/fish/conf.d/fnm.fish and add this line to it:

fnm env --use-on-cd --shell fish | source

PowerShell

Add the following to the end of your profile file:

fnm env --use-on-cd --shell powershell | Out-String | Invoke-Expression

• For macOS/Linux, the profile is located at ~/.config/powershell/Microsoft.PowerShell_profile.ps1
• For Windows location is either:
  • %userprofile%\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1 Powershell 5
  • %userprofile%\Documents\PowerShell\Microsoft.PowerShell_profile.ps1 Powershell 6+
• To create the profile file you can run this in PowerShell:
  powershell Copy

  if (-not (Test-Path $profile)) { New-Item $profile -Force }

• To edit your profile run this in PowerShell:
  powershell Copy

  Invoke-Item $profile

Windows Command Prompt aka Batch aka WinCMD

fnm is also supported but is not entirely covered. You can set up a startup script for cmd.exe or Windows Terminal and append the following lines:

@echo off
:: for /F will launch a new instance of cmd so we create a guard to prevent an infnite loop
if not defined FNM_AUTORUN_GUARD (
    set "FNM_AUTORUN_GUARD=AutorunGuard"
    FOR /f "tokens=*" %%z IN ('fnm env --use-on-cd') DO CALL %%z
)

Usage with Cmder

Usage is very similar to the normal WinCMD install, apart for a few tweaks to allow being called from the cmder startup script. The example assumes that the CMDER_ROOT environment variable is set to the root directory of your Cmder installation.
Then you can do something like this:

• Make a .cmd file to invoke it

:: %CMDER_ROOT%\bin\fnm_init.cmd
@echo off
FOR /f "tokens=*" %%z IN ('fnm env --use-on-cd') DO CALL %%z

• Add it to the startup script

:: %CMDER_ROOT%\config\user_profile.cmd
call "%CMDER_ROOT%\bin\fnm_init.cmd"

You can replace %CMDER_ROOT% with any other convenient path too.

[Configuration](./docs/configuration.md) Copy Chapter

See the available configuration options for an extended configuration documentation

[Usage](./docs/commands.md) Copy Chapter

See the available commands for an extended usage documentation

Contributing Copy Chapter

PRs welcome :tada:

Developing: Copy Section

# Install Rust
git clone https://github.com/Schniz/fnm.git
cd fnm/
cargo build

Running Binary: Copy Section

cargo run -- --help # Will behave like `fnm --help`

Running Tests: Copy Section

cargo test

File: docs/commands.md Copy Chapter

`fnm`

/* Detailed source-code truncated for AI context efficiency. */

`fnm list-remote`

/* Detailed source-code truncated for AI context efficiency. */

`fnm list`

/* Detailed source-code truncated for AI context efficiency. */

`fnm install`

/* Detailed source-code truncated for AI context efficiency. */

`fnm use`

/* Detailed source-code truncated for AI context efficiency. */

`fnm env`

/* Detailed source-code truncated for AI context efficiency. */

`fnm completions`

/* Detailed source-code truncated for AI context efficiency. */

`fnm alias`

/* Detailed source-code truncated for AI context efficiency. */

`fnm unalias`

/* Detailed source-code truncated for AI context efficiency. */

`fnm default`

/* Detailed source-code truncated for AI context efficiency. */

`fnm current`

/* Detailed source-code truncated for AI context efficiency. */

`fnm exec`

/* Detailed source-code truncated for AI context efficiency. */

`fnm uninstall`

/* Detailed source-code truncated for AI context efficiency. */

`fnm help`

File: docs/configuration.md Copy Chapter

Configuration

fnm comes with many features out of the box. Some of them are not activated by default as they’re changing your shell default behavior, and some are just a feature flag to avoid breaking changes or just experimental until we decide it is worthwhile to introduce them.

All these features can be configured by adding flags to the fnm env call when initializing the shell. For instance, if your shell set up looks like eval "$(fnm env)" then you can add a flag to it by changing it to eval "$(fnm env --my-flag=value)"

Here’s a list of these features and capabilities:

`--use-on-cd` Copy Section

✅ Highly recommended

--use-on-cd appends output to fnm env's output that will hook into your shell upon changing directories, and will switch the Node.js version based on the requirements of the current directory, based on .node-version or .nvmrc (or packages.json#engines#node if --resolve-engines was enabled).

This allows you do avoid thinking about fnm use, and only cd <DIR> to make it work.

`--version-file-strategy=recursive` Copy Section

✅ Highly recommended

Makes fnm use and fnm install take parent directories into account when looking for a version file ("dotfile")--when no argument was given.

So, let's say we have the following directory structure:

repo/
├── package.json
├── .node-version <- with content: `20.0.0`
└── packages/
  └── my-package/ <- I am here
    └── package.json

And I'm running the following command:

repo/packages/my-package$ fnm use

Then fnm will switch to Node.js v20.0.0.

Without the explicit flag, the value is set to local, which will not traverse the directory tree and therefore will print:

repo/packages/my-package$ fnm use
error: Can't find version in dotfiles. Please provide a version manually to the command.

`--corepack-enabled` Copy Section

🧪 Experimental

Runs corepack enable when a new version of Node.js is installed. Experimental due to the fact Corepack itself is experimental.

`--resolve-engines` Copy Section

🧪 Experimental

Treats package.json#engines#node as a valid Node.js version file ("dotfile"). So, if you have a package.json with the following content:

{
  "engines": {
    "node": ">=20 <21"
  }
}

Then:

• fnm install will install the latest satisfying Node.js 20.x version available in the Node.js dist server
• fnm use will use the latest satisfying Node.js 20.x version available on your system, or prompt to install if no version matched.

File: docs/nightly.md Copy Chapter

Working with Node nightly builds

fnm doesn't give you any shorthands to install nightly builds, but you can
do that by manually passing a "dist mirror" with the --node-dist-mirror flag.

Example usage Copy Chapter

Here's an example of installing Node 23.

To get a list of available versions run this:

fnm --node-dist-mirror https://nodejs.org/download/nightly/ ls-remote

To use and install nightly version run this:

fnm --node-dist-mirror https://nodejs.org/download/nightly/ use 23
# or
fnm --node-dist-mirror https://nodejs.org/download/nightly/ use v23.0.0-nightly202407253de7a4c374

Once you installed it you would be able to see that version in you list:

fnm ls

And use it without providing --node-dist-mirror flag:

fnm use 23