1147 lines
30 KiB
Markdown
1147 lines
30 KiB
Markdown
---
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title: package.json
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section: 5
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description: Specifics of npm's package.json handling
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---
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### Description
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This document is all you need to know about what's required in your
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package.json file. It must be actual JSON, not just a JavaScript object
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literal.
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A lot of the behavior described in this document is affected by the config
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settings described in [`config`](/using-npm/config).
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### name
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If you plan to publish your package, the *most* important things in your
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package.json are the name and version fields as they will be required. The
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name and version together form an identifier that is assumed to be
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completely unique. Changes to the package should come along with changes
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to the version. If you don't plan to publish your package, the name and
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version fields are optional.
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The name is what your thing is called.
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Some rules:
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* The name must be less than or equal to 214 characters. This includes the
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scope for scoped packages.
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* The names of scoped packages can begin with a dot or an underscore. This
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is not permitted without a scope.
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* New packages must not have uppercase letters in the name.
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* The name ends up being part of a URL, an argument on the command line,
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and a folder name. Therefore, the name can't contain any non-URL-safe
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characters.
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Some tips:
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* Don't use the same name as a core Node module.
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* Don't put "js" or "node" in the name. It's assumed that it's js, since
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you're writing a package.json file, and you can specify the engine using
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the "engines" field. (See below.)
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* The name will probably be passed as an argument to require(), so it
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should be something short, but also reasonably descriptive.
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* You may want to check the npm registry to see if there's something by
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that name already, before you get too attached to it.
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<https://www.npmjs.com/>
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A name can be optionally prefixed by a scope, e.g. `@myorg/mypackage`. See
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[`scope`](/using-npm/scope) for more detail.
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### version
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If you plan to publish your package, the *most* important things in your
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package.json are the name and version fields as they will be required. The
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name and version together form an identifier that is assumed to be
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completely unique. Changes to the package should come along with changes
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to the version. If you don't plan to publish your package, the name and
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version fields are optional.
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Version must be parseable by
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[node-semver](https://github.com/npm/node-semver), which is bundled with
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npm as a dependency. (`npm install semver` to use it yourself.)
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### description
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Put a description in it. It's a string. This helps people discover your
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package, as it's listed in `npm search`.
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### keywords
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Put keywords in it. It's an array of strings. This helps people discover
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your package as it's listed in `npm search`.
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### homepage
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The url to the project homepage.
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Example:
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```json
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"homepage": "https://github.com/owner/project#readme"
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```
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### bugs
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The url to your project's issue tracker and / or the email address to which
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issues should be reported. These are helpful for people who encounter
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issues with your package.
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It should look like this:
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```json
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{
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"url" : "https://github.com/owner/project/issues",
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"email" : "project@hostname.com"
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}
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```
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You can specify either one or both values. If you want to provide only a
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url, you can specify the value for "bugs" as a simple string instead of an
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object.
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If a url is provided, it will be used by the `npm bugs` command.
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### license
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You should specify a license for your package so that people know how they
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are permitted to use it, and any restrictions you're placing on it.
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If you're using a common license such as BSD-2-Clause or MIT, add a current
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SPDX license identifier for the license you're using, like this:
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```json
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{
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"license" : "BSD-3-Clause"
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}
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```
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You can check [the full list of SPDX license
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IDs](https://spdx.org/licenses/). Ideally you should pick one that is
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[OSI](https://opensource.org/licenses/alphabetical) approved.
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If your package is licensed under multiple common licenses, use an [SPDX
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license expression syntax version 2.0
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string](https://www.npmjs.com/package/spdx), like this:
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```json
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{
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"license" : "(ISC OR GPL-3.0)"
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}
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```
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If you are using a license that hasn't been assigned an SPDX identifier, or if
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you are using a custom license, use a string value like this one:
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```json
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{
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"license" : "SEE LICENSE IN <filename>"
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}
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```
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Then include a file named `<filename>` at the top level of the package.
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Some old packages used license objects or a "licenses" property containing
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an array of license objects:
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```json
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// Not valid metadata
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{
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"license" : {
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"type" : "ISC",
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"url" : "https://opensource.org/licenses/ISC"
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}
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}
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// Not valid metadata
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{
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"licenses" : [
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{
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"type": "MIT",
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"url": "https://www.opensource.org/licenses/mit-license.php"
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},
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{
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"type": "Apache-2.0",
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"url": "https://opensource.org/licenses/apache2.0.php"
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}
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]
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}
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```
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Those styles are now deprecated. Instead, use SPDX expressions, like this:
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```json
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{
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"license": "ISC"
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}
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```
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```json
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{
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"license": "(MIT OR Apache-2.0)"
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}
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```
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Finally, if you do not wish to grant others the right to use a private or
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unpublished package under any terms:
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```json
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{
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"license": "UNLICENSED"
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}
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```
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Consider also setting `"private": true` to prevent accidental publication.
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### people fields: author, contributors
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The "author" is one person. "contributors" is an array of people. A
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"person" is an object with a "name" field and optionally "url" and "email",
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like this:
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```json
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{
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"name" : "Barney Rubble",
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"email" : "b@rubble.com",
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"url" : "http://barnyrubble.tumblr.com/"
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}
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```
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Or you can shorten that all into a single string, and npm will parse it for
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you:
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```json
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{
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"author": "Barney Rubble <b@rubble.com> (http://barnyrubble.tumblr.com/)"
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}
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```
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Both email and url are optional either way.
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npm also sets a top-level "maintainers" field with your npm user info.
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### funding
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You can specify an object containing an URL that provides up-to-date
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information about ways to help fund development of your package, or a
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string URL, or an array of these:
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```json
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{
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"funding": {
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"type" : "individual",
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"url" : "http://example.com/donate"
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},
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"funding": {
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"type" : "patreon",
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"url" : "https://www.patreon.com/my-account"
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},
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"funding": "http://example.com/donate",
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"funding": [
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{
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"type" : "individual",
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"url" : "http://example.com/donate"
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},
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"http://example.com/donateAlso",
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{
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"type" : "patreon",
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"url" : "https://www.patreon.com/my-account"
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}
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]
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}
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```
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Users can use the `npm fund` subcommand to list the `funding` URLs of all
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dependencies of their project, direct and indirect. A shortcut to visit
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each funding url is also available when providing the project name such as:
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`npm fund <projectname>` (when there are multiple URLs, the first one will
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be visited)
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### files
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The optional `files` field is an array of file patterns that describes the
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entries to be included when your package is installed as a dependency. File
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patterns follow a similar syntax to `.gitignore`, but reversed: including a
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file, directory, or glob pattern (`*`, `**/*`, and such) will make it so
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that file is included in the tarball when it's packed. Omitting the field
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will make it default to `["*"]`, which means it will include all files.
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Some special files and directories are also included or excluded regardless
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of whether they exist in the `files` array (see below).
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You can also provide a `.npmignore` file in the root of your package or in
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subdirectories, which will keep files from being included. At the root of
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your package it will not override the "files" field, but in subdirectories
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it will. The `.npmignore` file works just like a `.gitignore`. If there is
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a `.gitignore` file, and `.npmignore` is missing, `.gitignore`'s contents
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will be used instead.
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Files included with the "package.json#files" field _cannot_ be excluded
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through `.npmignore` or `.gitignore`.
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Certain files are always included, regardless of settings:
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* `package.json`
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* `README`
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* `LICENSE` / `LICENCE`
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* The file in the "main" field
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`README` & `LICENSE` can have any case and extension.
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Conversely, some files are always ignored:
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* `.git`
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* `CVS`
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* `.svn`
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* `.hg`
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* `.lock-wscript`
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* `.wafpickle-N`
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* `.*.swp`
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* `.DS_Store`
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* `._*`
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* `npm-debug.log`
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* `.npmrc`
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* `node_modules`
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* `config.gypi`
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* `*.orig`
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* `package-lock.json` (use
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[`npm-shrinkwrap.json`](/configuring-npm/npm-shrinkwrap-json) if you wish
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it to be published)
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### main
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The main field is a module ID that is the primary entry point to your
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program. That is, if your package is named `foo`, and a user installs it,
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and then does `require("foo")`, then your main module's exports object will
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be returned.
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This should be a module relative to the root of your package folder.
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For most modules, it makes the most sense to have a main script and often
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not much else.
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If `main` is not set it defaults to `index.js` in the packages root folder.
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### browser
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If your module is meant to be used client-side the browser field should be
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used instead of the main field. This is helpful to hint users that it might
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rely on primitives that aren't available in Node.js modules. (e.g.
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`window`)
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### bin
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A lot of packages have one or more executable files that they'd like to
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install into the PATH. npm makes this pretty easy (in fact, it uses this
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feature to install the "npm" executable.)
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To use this, supply a `bin` field in your package.json which is a map of
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command name to local file name. When this package is installed
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globally, that file will be linked where global bins go so it is
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available to run by name. When this package is installed as a
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dependency in another package, the file will be linked where it will be
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available to that package either directly by `npm exec` or by name in other
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scripts when invoking them via `npm run-script`.
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For example, myapp could have this:
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```json
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{
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"bin": {
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"myapp": "./cli.js"
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}
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}
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```
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So, when you install myapp, it'll create a symlink from the `cli.js` script
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to `/usr/local/bin/myapp`.
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If you have a single executable, and its name should be the name of the
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package, then you can just supply it as a string. For example:
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```json
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{
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"name": "my-program",
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"version": "1.2.5",
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"bin": "./path/to/program"
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}
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```
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would be the same as this:
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```json
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{
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"name": "my-program",
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"version": "1.2.5",
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"bin": {
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"my-program": "./path/to/program"
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}
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}
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```
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Please make sure that your file(s) referenced in `bin` starts with
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`#!/usr/bin/env node`, otherwise the scripts are started without the node
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executable!
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Note that you can also set the executable files using [directories.bin](#directoriesbin).
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See [folders](/configuring-npm/folders#executables) for more info on
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executables.
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### man
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Specify either a single file or an array of filenames to put in place for
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the `man` program to find.
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If only a single file is provided, then it's installed such that it is the
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result from `man <pkgname>`, regardless of its actual filename. For
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example:
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```json
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{
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"name": "foo",
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"version": "1.2.3",
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"description": "A packaged foo fooer for fooing foos",
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"main": "foo.js",
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"man": "./man/doc.1"
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}
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```
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would link the `./man/doc.1` file in such that it is the target for `man
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foo`
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If the filename doesn't start with the package name, then it's prefixed.
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So, this:
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```json
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{
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"name": "foo",
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"version": "1.2.3",
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"description": "A packaged foo fooer for fooing foos",
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"main": "foo.js",
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"man": [
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"./man/foo.1",
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"./man/bar.1"
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]
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}
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```
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will create files to do `man foo` and `man foo-bar`.
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Man files must end with a number, and optionally a `.gz` suffix if they are
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compressed. The number dictates which man section the file is installed
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into.
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```json
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{
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"name": "foo",
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"version": "1.2.3",
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"description": "A packaged foo fooer for fooing foos",
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"main": "foo.js",
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"man": [
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"./man/foo.1",
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"./man/foo.2"
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]
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}
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```
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will create entries for `man foo` and `man 2 foo`
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### directories
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The CommonJS [Packages](http://wiki.commonjs.org/wiki/Packages/1.0) spec
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details a few ways that you can indicate the structure of your package
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using a `directories` object. If you look at [npm's
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package.json](https://registry.npmjs.org/npm/latest), you'll see that it
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has directories for doc, lib, and man.
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In the future, this information may be used in other creative ways.
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#### directories.bin
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If you specify a `bin` directory in `directories.bin`, all the files in
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that folder will be added.
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Because of the way the `bin` directive works, specifying both a `bin` path
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and setting `directories.bin` is an error. If you want to specify
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individual files, use `bin`, and for all the files in an existing `bin`
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directory, use `directories.bin`.
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#### directories.man
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A folder that is full of man pages. Sugar to generate a "man" array by
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walking the folder.
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### repository
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Specify the place where your code lives. This is helpful for people who
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want to contribute. If the git repo is on GitHub, then the `npm docs`
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command will be able to find you.
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Do it like this:
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```json
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{
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"repository": {
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"type": "git",
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"url": "https://github.com/npm/cli.git"
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}
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}
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```
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The URL should be a publicly available (perhaps read-only) url that can be
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handed directly to a VCS program without any modification. It should not
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be a url to an html project page that you put in your browser. It's for
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computers.
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For GitHub, GitHub gist, Bitbucket, or GitLab repositories you can use the
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same shortcut syntax you use for `npm install`:
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```json
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{
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"repository": "npm/npm",
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"repository": "github:user/repo",
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"repository": "gist:11081aaa281",
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"repository": "bitbucket:user/repo",
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"repository": "gitlab:user/repo"
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}
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```
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If the `package.json` for your package is not in the root directory (for
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example if it is part of a monorepo), you can specify the directory in
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which it lives:
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```json
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{
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"repository": {
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"type": "git",
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"url": "https://github.com/facebook/react.git",
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"directory": "packages/react-dom"
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}
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}
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```
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### scripts
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The "scripts" property is a dictionary containing script commands that are
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run at various times in the lifecycle of your package. The key is the
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lifecycle event, and the value is the command to run at that point.
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See [`scripts`](/using-npm/scripts) to find out more about writing package
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scripts.
|
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|
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### config
|
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|
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A "config" object can be used to set configuration parameters used in
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package scripts that persist across upgrades. For instance, if a package
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had the following:
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|
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```json
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{
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"name": "foo",
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"config": {
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"port": "8080"
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}
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}
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```
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It could also have a "start" command that referenced the
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`npm_package_config_port` environment variable.
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|
|
### dependencies
|
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|
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Dependencies are specified in a simple object that maps a package name to a
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version range. The version range is a string which has one or more
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space-separated descriptors. Dependencies can also be identified with a
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tarball or git URL.
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|
|
**Please do not put test harnesses or transpilers or other "development"
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time tools in your `dependencies` object.** See `devDependencies`, below.
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|
|
See [semver](https://github.com/npm/node-semver#versions) for more details about specifying version ranges.
|
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|
|
* `version` Must match `version` exactly
|
|
* `>version` Must be greater than `version`
|
|
* `>=version` etc
|
|
* `<version`
|
|
* `<=version`
|
|
* `~version` "Approximately equivalent to version" See
|
|
[semver](https://github.com/npm/node-semver#versions)
|
|
* `^version` "Compatible with version" See [semver](https://github.com/npm/node-semver#versions)
|
|
* `1.2.x` 1.2.0, 1.2.1, etc., but not 1.3.0
|
|
* `http://...` See 'URLs as Dependencies' below
|
|
* `*` Matches any version
|
|
* `""` (just an empty string) Same as `*`
|
|
* `version1 - version2` Same as `>=version1 <=version2`.
|
|
* `range1 || range2` Passes if either range1 or range2 are satisfied.
|
|
* `git...` See 'Git URLs as Dependencies' below
|
|
* `user/repo` See 'GitHub URLs' below
|
|
* `tag` A specific version tagged and published as `tag` See [`npm
|
|
dist-tag`](/commands/npm-dist-tag)
|
|
* `path/path/path` See [Local Paths](#local-paths) below
|
|
|
|
For example, these are all valid:
|
|
|
|
```json
|
|
{
|
|
"dependencies": {
|
|
"foo": "1.0.0 - 2.9999.9999",
|
|
"bar": ">=1.0.2 <2.1.2",
|
|
"baz": ">1.0.2 <=2.3.4",
|
|
"boo": "2.0.1",
|
|
"qux": "<1.0.0 || >=2.3.1 <2.4.5 || >=2.5.2 <3.0.0",
|
|
"asd": "http://asdf.com/asdf.tar.gz",
|
|
"til": "~1.2",
|
|
"elf": "~1.2.3",
|
|
"two": "2.x",
|
|
"thr": "3.3.x",
|
|
"lat": "latest",
|
|
"dyl": "file:../dyl"
|
|
}
|
|
}
|
|
```
|
|
|
|
#### URLs as Dependencies
|
|
|
|
You may specify a tarball URL in place of a version range.
|
|
|
|
This tarball will be downloaded and installed locally to your package at
|
|
install time.
|
|
|
|
#### Git URLs as Dependencies
|
|
|
|
Git urls are of the form:
|
|
|
|
```bash
|
|
<protocol>://[<user>[:<password>]@]<hostname>[:<port>][:][/]<path>[#<commit-ish> | #semver:<semver>]
|
|
```
|
|
|
|
`<protocol>` is one of `git`, `git+ssh`, `git+http`, `git+https`, or
|
|
`git+file`.
|
|
|
|
If `#<commit-ish>` is provided, it will be used to clone exactly that
|
|
commit. If the commit-ish has the format `#semver:<semver>`, `<semver>` can
|
|
be any valid semver range or exact version, and npm will look for any tags
|
|
or refs matching that range in the remote repository, much as it would for
|
|
a registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
|
|
specified, then `master` is used.
|
|
|
|
Examples:
|
|
|
|
```bash
|
|
git+ssh://git@github.com:npm/cli.git#v1.0.27
|
|
git+ssh://git@github.com:npm/cli#semver:^5.0
|
|
git+https://isaacs@github.com/npm/cli.git
|
|
git://github.com/npm/cli.git#v1.0.27
|
|
```
|
|
|
|
#### GitHub URLs
|
|
|
|
As of version 1.1.65, you can refer to GitHub urls as just "foo":
|
|
"user/foo-project". Just as with git URLs, a `commit-ish` suffix can be
|
|
included. For example:
|
|
|
|
```json
|
|
{
|
|
"name": "foo",
|
|
"version": "0.0.0",
|
|
"dependencies": {
|
|
"express": "expressjs/express",
|
|
"mocha": "mochajs/mocha#4727d357ea",
|
|
"module": "user/repo#feature\/branch"
|
|
}
|
|
}
|
|
```
|
|
|
|
#### Local Paths
|
|
|
|
As of version 2.0.0 you can provide a path to a local directory that
|
|
contains a package. Local paths can be saved using `npm install -S` or `npm
|
|
install --save`, using any of these forms:
|
|
|
|
```bash
|
|
../foo/bar
|
|
~/foo/bar
|
|
./foo/bar
|
|
/foo/bar
|
|
```
|
|
|
|
in which case they will be normalized to a relative path and added to your
|
|
`package.json`. For example:
|
|
|
|
```json
|
|
{
|
|
"name": "baz",
|
|
"dependencies": {
|
|
"bar": "file:../foo/bar"
|
|
}
|
|
}
|
|
```
|
|
|
|
This feature is helpful for local offline development and creating tests
|
|
that require npm installing where you don't want to hit an external server,
|
|
but should not be used when publishing packages to the public registry.
|
|
|
|
### devDependencies
|
|
|
|
If someone is planning on downloading and using your module in their
|
|
program, then they probably don't want or need to download and build the
|
|
external test or documentation framework that you use.
|
|
|
|
In this case, it's best to map these additional items in a
|
|
`devDependencies` object.
|
|
|
|
These things will be installed when doing `npm link` or `npm install` from
|
|
the root of a package, and can be managed like any other npm configuration
|
|
param. See [`config`](/using-npm/config) for more on the topic.
|
|
|
|
For build steps that are not platform-specific, such as compiling
|
|
CoffeeScript or other languages to JavaScript, use the `prepare` script to
|
|
do this, and make the required package a devDependency.
|
|
|
|
For example:
|
|
|
|
```json
|
|
{
|
|
"name": "ethopia-waza",
|
|
"description": "a delightfully fruity coffee varietal",
|
|
"version": "1.2.3",
|
|
"devDependencies": {
|
|
"coffee-script": "~1.6.3"
|
|
},
|
|
"scripts": {
|
|
"prepare": "coffee -o lib/ -c src/waza.coffee"
|
|
},
|
|
"main": "lib/waza.js"
|
|
}
|
|
```
|
|
|
|
The `prepare` script will be run before publishing, so that users can
|
|
consume the functionality without requiring them to compile it themselves.
|
|
In dev mode (ie, locally running `npm install`), it'll run this script as
|
|
well, so that you can test it easily.
|
|
|
|
### peerDependencies
|
|
|
|
In some cases, you want to express the compatibility of your package with a
|
|
host tool or library, while not necessarily doing a `require` of this host.
|
|
This is usually referred to as a *plugin*. Notably, your module may be
|
|
exposing a specific interface, expected and specified by the host
|
|
documentation.
|
|
|
|
For example:
|
|
|
|
```json
|
|
{
|
|
"name": "tea-latte",
|
|
"version": "1.3.5",
|
|
"peerDependencies": {
|
|
"tea": "2.x"
|
|
}
|
|
}
|
|
```
|
|
|
|
This ensures your package `tea-latte` can be installed *along* with the
|
|
second major version of the host package `tea` only. `npm install
|
|
tea-latte` could possibly yield the following dependency graph:
|
|
|
|
```bash
|
|
├── tea-latte@1.3.5
|
|
└── tea@2.2.0
|
|
```
|
|
|
|
In npm versions 3 through 6, `peerDependencies` were not automatically
|
|
installed, and would raise a warning if an invalid version of the peer
|
|
dependency was found in the tree. As of npm v7, peerDependencies _are_
|
|
installed by default.
|
|
|
|
Trying to install another plugin with a conflicting requirement may cause
|
|
an error if the tree cannot be resolved correctly. For this reason, make
|
|
sure your plugin requirement is as broad as possible, and not to lock it
|
|
down to specific patch versions.
|
|
|
|
Assuming the host complies with [semver](https://semver.org/), only changes
|
|
in the host package's major version will break your plugin. Thus, if you've
|
|
worked with every 1.x version of the host package, use `"^1.0"` or `"1.x"`
|
|
to express this. If you depend on features introduced in 1.5.2, use
|
|
`"^1.5.2"`.
|
|
|
|
### peerDependenciesMeta
|
|
|
|
When a user installs your package, npm will emit warnings if packages
|
|
specified in `peerDependencies` are not already installed. The
|
|
`peerDependenciesMeta` field serves to provide npm more information on how
|
|
your peer dependencies are to be used. Specifically, it allows peer
|
|
dependencies to be marked as optional.
|
|
|
|
For example:
|
|
|
|
```json
|
|
{
|
|
"name": "tea-latte",
|
|
"version": "1.3.5",
|
|
"peerDependencies": {
|
|
"tea": "2.x",
|
|
"soy-milk": "1.2"
|
|
},
|
|
"peerDependenciesMeta": {
|
|
"soy-milk": {
|
|
"optional": true
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
Marking a peer dependency as optional ensures npm will not emit a warning
|
|
if the `soy-milk` package is not installed on the host. This allows you to
|
|
integrate and interact with a variety of host packages without requiring
|
|
all of them to be installed.
|
|
|
|
### bundledDependencies
|
|
|
|
This defines an array of package names that will be bundled when publishing
|
|
the package.
|
|
|
|
In cases where you need to preserve npm packages locally or have them
|
|
available through a single file download, you can bundle the packages in a
|
|
tarball file by specifying the package names in the `bundledDependencies`
|
|
array and executing `npm pack`.
|
|
|
|
For example:
|
|
|
|
If we define a package.json like this:
|
|
|
|
```json
|
|
{
|
|
"name": "awesome-web-framework",
|
|
"version": "1.0.0",
|
|
"bundledDependencies": [
|
|
"renderized",
|
|
"super-streams"
|
|
]
|
|
}
|
|
```
|
|
|
|
we can obtain `awesome-web-framework-1.0.0.tgz` file by running `npm pack`.
|
|
This file contains the dependencies `renderized` and `super-streams` which
|
|
can be installed in a new project by executing `npm install
|
|
awesome-web-framework-1.0.0.tgz`. Note that the package names do not
|
|
include any versions, as that information is specified in `dependencies`.
|
|
|
|
If this is spelled `"bundleDependencies"`, then that is also honored.
|
|
|
|
Alternatively, `"bundledDependencies"` can be defined as a boolean value. A
|
|
value of `true` will bundle all dependencies, a value of `false` will bundle
|
|
none.
|
|
|
|
### optionalDependencies
|
|
|
|
If a dependency can be used, but you would like npm to proceed if it cannot
|
|
be found or fails to install, then you may put it in the
|
|
`optionalDependencies` object. This is a map of package name to version or
|
|
url, just like the `dependencies` object. The difference is that build
|
|
failures do not cause installation to fail. Running `npm install
|
|
--no-optional` will prevent these dependencies from being installed.
|
|
|
|
It is still your program's responsibility to handle the lack of the
|
|
dependency. For example, something like this:
|
|
|
|
```js
|
|
try {
|
|
var foo = require('foo')
|
|
var fooVersion = require('foo/package.json').version
|
|
} catch (er) {
|
|
foo = null
|
|
}
|
|
if ( notGoodFooVersion(fooVersion) ) {
|
|
foo = null
|
|
}
|
|
|
|
// .. then later in your program ..
|
|
|
|
if (foo) {
|
|
foo.doFooThings()
|
|
}
|
|
```
|
|
|
|
Entries in `optionalDependencies` will override entries of the same name in
|
|
`dependencies`, so it's usually best to only put in one place.
|
|
|
|
### overrides
|
|
|
|
If you need to make specific changes to dependencies of your dependencies, for
|
|
example replacing the version of a dependency with a known security issue,
|
|
replacing an existing dependency with a fork, or making sure that the same
|
|
version of a package is used everywhere, then you may add an override.
|
|
|
|
Overrides provide a way to replace a package in your dependency tree with
|
|
another version, or another package entirely. These changes can be scoped as
|
|
specific or as vague as desired.
|
|
|
|
To make sure the package `foo` is always installed as version `1.0.0` no matter
|
|
what version your dependencies rely on:
|
|
|
|
```json
|
|
{
|
|
"overrides": {
|
|
"foo": "1.0.0"
|
|
}
|
|
}
|
|
```
|
|
|
|
The above is a short hand notation, the full object form can be used to allow
|
|
overriding a package itself as well as a child of the package. This will cause
|
|
`foo` to always be `1.0.0` while also making `bar` at any depth beyond `foo`
|
|
also `1.0.0`:
|
|
|
|
```json
|
|
{
|
|
"overrides": {
|
|
"foo": {
|
|
".": "1.0.0",
|
|
"bar": "1.0.0"
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
To only override `foo` to be `1.0.0` when it's a child (or grandchild, or great
|
|
grandchild, etc) of the package `bar`:
|
|
|
|
```json
|
|
{
|
|
"overrides": {
|
|
"bar": {
|
|
"foo": "1.0.0"
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
Keys can be nested to any arbitrary length. To override `foo` only when it's a
|
|
child of `bar` and only when `bar` is a child of `baz`:
|
|
|
|
```json
|
|
{
|
|
"overrides": {
|
|
"baz": {
|
|
"bar": {
|
|
"foo": "1.0.0"
|
|
}
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
The key of an override can also include a version, or range of versions.
|
|
To override `foo` to `1.0.0`, but only when it's a child of `bar@2.0.0`:
|
|
|
|
```json
|
|
{
|
|
"overrides": {
|
|
"bar@2.0.0": {
|
|
"foo": "1.0.0"
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
You may not set an override for a package that you directly depend on unless
|
|
both the dependency and the override itself share the exact same spec. To make
|
|
this limitation easier to deal with, overrides may also be defined as a
|
|
reference to a spec for a direct dependency by prefixing the name of the
|
|
package you wish the version to match with a `$`.
|
|
|
|
```json
|
|
{
|
|
"dependencies": {
|
|
"foo": "^1.0.0"
|
|
},
|
|
"overrides": {
|
|
// BAD, will throw an EOVERRIDE error
|
|
// "foo": "^2.0.0"
|
|
// GOOD, specs match so override is allowed
|
|
// "foo": "^1.0.0"
|
|
// BEST, the override is defined as a reference to the dependency
|
|
"foo": "$foo",
|
|
// the referenced package does not need to match the overridden one
|
|
"bar": "$foo"
|
|
}
|
|
}
|
|
```
|
|
|
|
### engines
|
|
|
|
You can specify the version of node that your stuff works on:
|
|
|
|
```json
|
|
{
|
|
"engines": {
|
|
"node": ">=0.10.3 <15"
|
|
}
|
|
}
|
|
```
|
|
|
|
And, like with dependencies, if you don't specify the version (or if you
|
|
specify "\*" as the version), then any version of node will do.
|
|
|
|
You can also use the "engines" field to specify which versions of npm are
|
|
capable of properly installing your program. For example:
|
|
|
|
```json
|
|
{
|
|
"engines": {
|
|
"npm": "~1.0.20"
|
|
}
|
|
}
|
|
```
|
|
|
|
Unless the user has set the `engine-strict` config flag, this field is
|
|
advisory only and will only produce warnings when your package is installed
|
|
as a dependency.
|
|
|
|
### os
|
|
|
|
You can specify which operating systems your
|
|
module will run on:
|
|
|
|
```json
|
|
{
|
|
"os": [
|
|
"darwin",
|
|
"linux"
|
|
]
|
|
}
|
|
```
|
|
|
|
You can also block instead of allowing operating systems, just prepend the
|
|
blocked os with a '!':
|
|
|
|
```json
|
|
{
|
|
"os": [
|
|
"!win32"
|
|
]
|
|
}
|
|
```
|
|
|
|
The host operating system is determined by `process.platform`
|
|
|
|
It is allowed to both block and allow an item, although there isn't any
|
|
good reason to do this.
|
|
|
|
### cpu
|
|
|
|
If your code only runs on certain cpu architectures,
|
|
you can specify which ones.
|
|
|
|
```json
|
|
{
|
|
"cpu": [
|
|
"x64",
|
|
"ia32"
|
|
]
|
|
}
|
|
```
|
|
|
|
Like the `os` option, you can also block architectures:
|
|
|
|
```json
|
|
{
|
|
"cpu": [
|
|
"!arm",
|
|
"!mips"
|
|
]
|
|
}
|
|
```
|
|
|
|
The host architecture is determined by `process.arch`
|
|
|
|
### private
|
|
|
|
If you set `"private": true` in your package.json, then npm will refuse to
|
|
publish it.
|
|
|
|
This is a way to prevent accidental publication of private repositories.
|
|
If you would like to ensure that a given package is only ever published to
|
|
a specific registry (for example, an internal registry), then use the
|
|
`publishConfig` dictionary described below to override the `registry`
|
|
config param at publish-time.
|
|
|
|
### publishConfig
|
|
|
|
This is a set of config values that will be used at publish-time. It's
|
|
especially handy if you want to set the tag, registry or access, so that
|
|
you can ensure that a given package is not tagged with "latest", published
|
|
to the global public registry or that a scoped module is private by
|
|
default.
|
|
|
|
See [`config`](/using-npm/config) to see the list of config options that
|
|
can be overridden.
|
|
|
|
### workspaces
|
|
|
|
The optional `workspaces` field is an array of file patterns that describes
|
|
locations within the local file system that the install client should look
|
|
up to find each [workspace](/using-npm/workspaces) that needs to be
|
|
symlinked to the top level `node_modules` folder.
|
|
|
|
It can describe either the direct paths of the folders to be used as
|
|
workspaces or it can define globs that will resolve to these same folders.
|
|
|
|
In the following example, all folders located inside the folder
|
|
`./packages` will be treated as workspaces as long as they have valid
|
|
`package.json` files inside them:
|
|
|
|
```json
|
|
{
|
|
"name": "workspace-example",
|
|
"workspaces": [
|
|
"./packages/*"
|
|
]
|
|
}
|
|
```
|
|
|
|
See [`workspaces`](/using-npm/workspaces) for more examples.
|
|
|
|
### DEFAULT VALUES
|
|
|
|
npm will default some values based on package contents.
|
|
|
|
* `"scripts": {"start": "node server.js"}`
|
|
|
|
If there is a `server.js` file in the root of your package, then npm will
|
|
default the `start` command to `node server.js`.
|
|
|
|
* `"scripts":{"install": "node-gyp rebuild"}`
|
|
|
|
If there is a `binding.gyp` file in the root of your package and you have
|
|
not defined an `install` or `preinstall` script, npm will default the
|
|
`install` command to compile using node-gyp.
|
|
|
|
* `"contributors": [...]`
|
|
|
|
If there is an `AUTHORS` file in the root of your package, npm will treat
|
|
each line as a `Name <email> (url)` format, where email and url are
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optional. Lines which start with a `#` or are blank, will be ignored.
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### SEE ALSO
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* [semver](https://github.com/npm/node-semver#versions)
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* [workspaces](/using-npm/workspaces)
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* [npm init](/commands/npm-init)
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* [npm version](/commands/npm-version)
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* [npm config](/commands/npm-config)
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* [npm help](/commands/npm-help)
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* [npm install](/commands/npm-install)
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* [npm publish](/commands/npm-publish)
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* [npm uninstall](/commands/npm-uninstall)
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