NPX¶

What is NPX¶

npx is a tool for running npm packages that:

live inside of a local node_modules folder, or
are not installed globally.

Example:

# Before
$ node ./node_modules/.bin/mocha
# Now with npx:
$ npx mocha

npx looks into the local node_modules folder for the package and if it can’t find it, it will download and run it without having that package globally installed.

npx is a replacement for installing global packages. It encourages you to install packages locally, but still be able run them as if they were global, just with npx.

Usage¶

Run Local Packages¶

Suppose we want run gulp from the command prompt. We have two options. Either install gulp globally or not install gulp globally and just use npx:

$ cd /path/to/project/folder
# option 1: install globally
$ npm i -D gulp gulp-cli
# option 2: don't install globally but use npx
$ npx gulp

Run One-off Packages via URL¶

npx will download and execute any package you give it. This is useful for one-off commands, e.g., to check the accessibility score of a website:

1 2	$ npx pa11y https://scottlogic.com > Running Pa11y on URL https://scottlogic.com/

Create a Boilerplate App¶

Creating a boilerplate React app.

1	$ npx create-react-app harrys-site

Run a Static Web Server¶

Running a static web server.

$ cd my-website
$ npx http-server
> Starting up http-server, serving ./
> Available on:
>  http://192.168.36.65:8080
>  http://127.0.0.1:8080
> Hit CTRL-C to stop the server

Deploy to a Live Server¶

Deploying to a live server.

1
2
3

$ cd my-website
$ npx now --public
> Ready! https://test-hffvgcpvvq.now.sh [2s]

Execute a Package from a URL¶

npx can also execute a package from a URL, e.g. this GitHub gist:

1 2	$ npx https://gist.github.com/zkat/4bc19503fe9e9309e2bfaa2c58074d32 > yay gist

Credits¶

This information is taken this article: Harry Mumford-Turner, “How to use npx: the npm package runner”.

Goodbye¶

$ npx cowsay goodbye!
npx: installed 10 in 5.303s
 __________
< goodbye! >
 ----------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

Egghead.io Course¶

There is a free Egghead.io course on NPX: Learn about the npx Package Runner. Here is the list of lessons:

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