1NPX(1)                           User Commands                          NPX(1)
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NAME

6       npx - execute npm package binaries
7

SYNOPSIS

9       npx [options] <command>[@version] [command-arg]...
10
11       npx [options] [-p|--package <pkg>]... <command> [command-arg]...
12
13       npx [options] -c '<command-string>'
14
15       npx --shell-auto-fallback [shell]
16

INSTALL

18       npm install -g npx
19

DESCRIPTION

21       Executes  <command>  either  from  a local node_modules/.bin, or from a
22       central cache, installing any packages needed in order for <command> to
23       run.
24
25       By default, npx will check whether <command> exists in $PATH, or in the
26       local project binaries, and execute that. If <command> is not found, it
27       will be installed prior to execution.
28
29       Unless  a --package option is specified, npx will try to guess the name
30       of the binary to invoke depending on the specifier provided. All  pack‐
31       age  specifiers  understood  by npm may be used with npx, including git
32       specifiers, remote tarballs, local directories, or scoped packages.
33
34       If a full specifier is included, or if  --package  is  used,  npx  will
35       always  use a freshly-installed, temporary version of the package. This
36       can also be forced with the --ignore-existing flag.
37
38       · -p, --package <package> - define the package to  be  installed.  This
39         defaults  to the value of <command>. This is only needed for packages
40         with multiple binaries if you want to call one of the other  executa‐
41         bles,  or  where  the binary name does not match the package name. If
42         this option is provided <command> will  be  executed  as-is,  without
43         interpreting  @version  if it's there. Multiple --package options may
44         be provided, and all the packages specified will be installed.
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46       · --no-install - If passed to npx, it will only try to run <command> if
47         it  already  exists  in  the  current  path  or  in $prefix/node_mod‐
48         ules/.bin. It won't try to install missing commands.
49
50       · --cache <path> - set the location of the npm cache. Defaults to npm's
51         own cache settings.
52
53       · --userconfig  <path> - path to the user configuration file to pass to
54         npm. Defaults to whatever npm's current default is.
55
56       · -c <string> - Execute <string> inside an  npm  run-script-like  shell
57         environment, with all the usual environment variables available. Only
58         the first item in <string> will be automatically used  as  <command>.
59         Any others must use -p.
60
61       · --shell <string> - The shell to invoke the command with, if any.
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63       · --shell-auto-fallback  [<shell>]  -  Generates shell code to override
64         your shell's "command not found" handler with  one  that  calls  npx.
65         Tries  to  figure  out  your  shell, or you can pass its name (either
66         bash, fish, or zsh) as an option. See below for how to install.
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68       · --ignore-existing - If this flag is set, npx will not look in  $PATH,
69         or in the current package's node_modules/.bin for an existing version
70         before deciding whether to install.  Binaries  in  those  paths  will
71         still  be  available for execution, but will be shadowed by any pack‐
72         ages requested by this install.
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74       · -q, --quiet - Suppressed any output from npx itself  (progress  bars,
75         error  messages,  install reports). Subcommand output itself will not
76         be silenced.
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78       · -n, --node-arg - Extra node argument to supply to node when binary is
79         a  node script. You can supply this option multiple times to add more
80         arguments.
81
82       · -v, --version - Show the current npx version.
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84

EXAMPLES

86   Running a project-local bin
87         $ npm i -D webpack
88         $ npx webpack ...
89
90   One-off invocation without local installation
91         $ npm rm webpack
92         $ npx webpack -- ...
93         $ cat package.json
94         ...webpack not in "devDependencies"...
95
96   Invoking a command from a github repository
97         $ npx github:piuccio/cowsay
98         ...or...
99         $ npx git+ssh://my.hosted.git:cowsay.git#semver:^1
100         ...etc...
101
102   Execute a full shell command using one npx call w/ multiple packages
103         $ npx -p lolcatjs -p cowsay -c \
104           'echo "$npm_package_name@$npm_package_version" | cowsay | lolcatjs'
105         ...
106          _____
107         < your-cool-package@1.2.3 >
108          -----
109                 \   ^__^
110                  \  (oo)\_______
111                     (__)\       )\/\
112                         ||----w |
113                         ||     ||
114
115   Run node binary with --inspect
116         $ npx --node-arg=--inspect cowsay
117         Debugger listening on ws://127.0.0.1:9229/....
118
119   Specify a node version to run npm scripts (or anything else!)
120         npx -p node@8 npm run build
121

SHELL AUTO FALLBACK

123       You can configure npx to run as your default fallback command when  you
124       type  something  in  the  command line with an @ but the command is not
125       found. This includes installing packages that were  not  found  in  the
126       local prefix either.
127
128       For example:
129
130         $ npm@4 --version
131         (stderr) npm@4 not found. Trying with npx...
132         4.6.1
133         $ asdfasdfasf
134         zsh: command not found: asfdasdfasdf
135
136       Currently,  zsh,  bash  (>=  4), and fish are supported. You can access
137       these completion scripts using npx --shell-auto-fallback <shell>.
138
139       To install permanently, add the relevant line below to your  ~/.bashrc,
140       ~/.zshrc, ~/.config/fish/config.fish, or as needed. To install just for
141       the shell session, simply run the line.
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143       You can optionally pass through --no-install when generating the  fall‐
144       back to prevent it from installing packages if the command is missing.
145
146   For bash@>=4:
147         $ source <(npx --shell-auto-fallback bash)
148
149   For zsh:
150         $ source <(npx --shell-auto-fallback zsh)
151
152   For fish:
153         $ source (npx --shell-auto-fallback fish | psub)
154

ACKNOWLEDGEMENTS

156       Huge  thanks to Kwyn Meagher https://blog.kwyn.io for generously donat‐
157       ing the package name in the main npm registry. Previously npx was  used
158       for  a  Tessel  board  Neopixels  library, which can now be found under
159       npx-tessel https://npm.im/npx-tessel.
160

AUTHOR

162       Written by Kat Marchan https://github.com/zkat.
163

REPORTING BUGS

165       Please file any relevant issues on Github. https://github.com/zkat/npx
166

LICENSE

168       This work is released by its  authors  into  the  public  domain  under
169       CC0-1.0. See LICENSE.md for details.
170

SEE ALSO

172       · npm(1)
173
174       · npm-run-script(1)
175
176       · npm-config(7)
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180
181npx@10.1.1                        April 2018                            NPX(1)
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