- execute npm package binaries
npx [options] <command>[@version] [command-arg]...
npx [options] [-p|--package <pkg>]... <command>
npx [options] -c '<command-string>'
npx --shell-auto-fallback [shell]
npm install -g npx
either from a local node_modules/.bin
from a central cache, installing any packages needed in order for
By default, npx
will check whether <command>
, or in the local project binaries, and execute that. If
is not found, it will be installed prior to execution.
Unless a --package
option is specified, npx
will try to guess the
name of the binary to invoke depending on the specifier provided. All package
specifiers understood by npm
may be used with npx
, including git
specifiers, remote tarballs, local directories, or scoped packages.
If a full specifier is included, or if --package
is used, npx will always
use a freshly-installed, temporary version of the package. This can also be
forced with the --ignore-existing
- -p, --package <package> - define the package to be installed.
This defaults to the value of <command>. This is only needed
for packages with multiple binaries if you want to call one of the other
executables, or where the binary name does not match the package name. If
this option is provided <command> will be executed as-is,
without interpreting @version if it's there. Multiple
--package options may be provided, and all the packages specified
will be installed.
- --no-install - If passed to npx, it will only try to run
<command> if it already exists in the current path or in
$prefix/node_modules/.bin. It won't try to install missing
- --cache <path> - set the location of the npm cache. Defaults
to npm's own cache settings.
- --userconfig <path> - path to the user configuration file to
pass to npm. Defaults to whatever npm's current default is.
- -c <string> - Execute <string> inside an npm
run-script-like shell environment, with all the usual environment
variables available. Only the first item in <string> will be
automatically used as <command>. Any others must use
- --shell <string> - The shell to invoke the command with, if
- --shell-auto-fallback [<shell>] - Generates shell code to
override your shell's "command not found" handler with one that
calls npx. Tries to figure out your shell, or you can pass its name
(either bash, fish, or zsh) as an option. See below
for how to install.
- --ignore-existing - If this flag is set, npx will not look in
$PATH, or in the current package's node_modules/.bin for an
existing version before deciding whether to install. Binaries in those
paths will still be available for execution, but will be shadowed by any
packages requested by this install.
- -q, --quiet - Suppressed any output from npx itself (progress bars,
error messages, install reports). Subcommand output itself will not be
- -n, --node-arg - Extra node argument to supply to node when binary
is a node script. You can supply this option multiple times to add more
- -v, --version - Show the current npx version.
Running a project-local bin¶
$ npm i -D webpack
$ npx webpack ...
One-off invocation without local installation¶
$ npm rm webpack
$ npx webpack -- ...
$ cat package.json
...webpack not in "devDependencies"...
Invoking a command from a github repository¶
Execute a full shell command using one npx call w/ multiple packages¶
$ npx -p lolcatjs -p cowsay -c \
'echo "$npm_package_name@$npm_package_version" | cowsay | lolcatjs'
< firstname.lastname@example.org >
Run node binary with --inspect¶
Specify a node version to run npm scripts (or anything else!)¶
npx -p node@8 npm run build
SHELL AUTO FALLBACK¶
You can configure npx
to run as your default fallback command when you
type something in the command line with an @
but the command is not
found. This includes installing packages that were not found in the local
$ npm@4 --version
(stderr) npm@4 not found. Trying with npx...
zsh: command not found: asfdasdfasdf
(>= 4), and fish
are supported. You
can access these completion scripts using npx --shell-auto-fallback
To install permanently, add the relevant line below to your ~/.bashrc
, or as needed. To install
just for the shell session, simply run the line.
You can optionally pass through --no-install
when generating the fallback
to prevent it from installing packages if the command is missing.
$ source <(npx --shell-auto-fallback bash)
$ source <(npx --shell-auto-fallback zsh)
$ source (npx --shell-auto-fallback fish | psub)
Huge thanks to Kwyn Meagher https://blog.kwyn.io
for generously donating
the package name in the main npm registry. Previously npx
was used for
a Tessel board Neopixels library, which can now be found under
Written by Kat Marchan https://github.com/zkat
Please file any relevant issues on Github. https://github.com/zkat/npx
This work is released by its authors into the public domain under CC0-1.0. See