npm-install | npm Docs (2023)

Synopsis

npm install (with no args, in package dir)
npm install [<@scope>/]<name>
npm install [<@scope>/]<name>@<tag>
npm install [<@scope>/]<name>@<version>
npm install [<@scope>/]<name>@<version range>
npm install <alias>@npm:<name>
npm install <git-host>:<git-user>/<repo-name>
npm install <git repo url>
npm install <tarball file>
npm install <tarball url>
npm install <folder>
aliases: npm i, npm add
common options: [-P|--save-prod|-D|--save-dev|-O|--save-optional] [-E|--save-exact] [-B|--save-bundle] [--no-save] [--dry-run]

Description

This command installs a package, and any packages that it depends on. If thepackage has a package-lock or shrinkwrap file, the installation of dependencieswill be driven by that, with an npm-shrinkwrap.json taking precedence if bothfiles exist. See package-lock.json and npm shrinkwrap.

A package is:

a) a folder containing a program described by a package.json file
b) a gzipped tarball containing (a)
c) a url that resolves to (b)
d) a <name>@<version> that is published on the registry (see registry) with (c)
e) a <name>@<tag> (see npm dist-tag) that points to (d)
f) a <name> that has a "latest" tag satisfying (e)
g) a <git remote url> that resolves to (a)

Even if you never publish your package, you can still get a lot ofbenefits of using npm if you just want to write a node program (a), andperhaps if you also want to be able to easily install it elsewhereafter packing it up into a tarball (b).

npm install (in package directory, no arguments):
Install the dependencies in the local node_modules folder.
In global mode (ie, with -g or --global appended to the command),it installs the current package context (ie, the current workingdirectory) as a global package.
By default, npm install will install all modules listed as dependenciesin package.json.
With the --production flag (or when the NODE_ENV environment variableis set to production), npm will not install modules listed indevDependencies. To install all modules listed in both dependenciesand devDependencies when NODE_ENV environment variable is set to production,you can use --production=false.
NOTE: The --production flag has no particular meaning when adding adependency to a project.
npm install <folder>:
Install the package in the directory as a symlink in the current project.Its dependencies will be installed before it's linked. If <folder> sitsinside the root of your project, its dependencies may be hoisted to thetoplevel node_modules as they would for other types of dependencies.
npm install <tarball file>:
Install a package that is sitting on the filesystem. Note: if you just wantto link a dev directory into your npm root, you can do this more easily byusing npm link.
Tarball requirements:
- The filename must use .tar, .tar.gz, or .tgz asthe extension.
- The package contents should reside in a subfolder inside the tarball (usually it is called package/). npm strips one directory layer when installing the package (an equivalent of tar x --strip-components=1 is run).
- The package must contain a package.json file with name and version properties.
  Example:
```
npm install ./package.tgz
```
npm install <tarball url>:
Fetch the tarball url, and then install it. In order to distinguish betweenthis and other options, the argument must start with "http://" or "https://"
Example:
```
npm install https://github.com/indexzero/forever/tarball/v0.5.6
```
npm install [<@scope>/]<name>:
Do a <name>@<tag> install, where <tag> is the "tag" config. (Seeconfig. The config's default value is latest.)
In most cases, this will install the version of the modules tagged aslatest on the npm registry.
Example:
```
npm install sax
```
npm install <alias>@npm:<name>:
Install a package under a custom alias. Allows multiple versions ofa same-name package side-by-side, more convenient import names forpackages with otherwise long ones and using git forks replacementsor forked npm packages as replacements. Aliasing works only on yourproject and does not rename packages in transitive dependencies.Aliases should follow the naming conventions stated invalidate-npm-package-name.
Examples:
```
npm install my-react@npm:react
 npm install jquery2@npm:jquery@2
 npm install jquery3@npm:jquery@3
 npm install npa@npm:npm-package-arg
```

`npm install` saves any specified packages into `dependencies` by default.
Additionally, you can control where and how they get saved with some
additional flags:
* `-P, --save-prod`: Package will appear in your `dependencies`. This is the
 default unless `-D` or `-O` are present.
* `-D, --save-dev`: Package will appear in your `devDependencies`.
* `-O, --save-optional`: Package will appear in your `optionalDependencies`.
* `--no-save`: Prevents saving to `dependencies`.
When using any of the above options to save dependencies to your
package.json, there are two additional, optional flags:
* `-E, --save-exact`: Saved dependencies will be configured with an
 exact version rather than using npm's default semver range
 operator.
* `-B, --save-bundle`: Saved dependencies will also be added to your `bundleDependencies` list.
Further, if you have an `npm-shrinkwrap.json` or `package-lock.json` then it
will be updated as well.
`<scope>` is optional. The package will be downloaded from the registry
associated with the specified scope. If no registry is associated with
the given scope the default registry is assumed. See [`scope`](/cli/v6/using-npm/scope).
Note: if you do not include the @-symbol on your scope name, npm will
interpret this as a GitHub repository instead, see below. Scopes names
must also be followed by a slash.
Examples:
```bash
npm install sax
npm install githubname/reponame
npm install @myorg/privatepackage
npm install node-tap --save-dev
npm install dtrace-provider --save-optional
npm install readable-stream --save-exact
npm install ansi-regex --save-bundle
```
**Note**: If there is a file or folder named `<name>` in the current
working directory, then it will try to install that, and only try to
fetch the package by name if it is not valid.

npm install [<@scope>/]<name>@<tag>:
Install the version of the package that is referenced by the specified tag.If the tag does not exist in the registry data for that package, then thiswill fail.
Example:
```
npm install sax@latest
npm install @myorg/mypackage@latest
```
npm install [<@scope>/]<name>@<version>:
Install the specified version of the package. This will fail if theversion has not been published to the registry.
Example:
```
npm install sax@0.1.1
npm install @myorg/privatepackage@1.5.0
```
npm install [<@scope>/]<name>@<version range>:
Install a version of the package matching the specified version range. Thiswill follow the same rules for resolving dependencies described in package.json.
Note that most version ranges must be put in quotes so that your shell willtreat it as a single argument.
Example:
```
npm install sax@">=0.1.0 <0.2.0"
npm install @myorg/privatepackage@">=0.1.0 <0.2.0"
```
npm install <git remote url>:
Installs the package from the hosted git provider, cloning it with git.For a full git remote url, only that URL will be attempted.
```
<protocol>://[<user>[:<password>]@]<hostname>[:<port>][:][/]<path>[#<commit-ish> | #semver:<semver>]
```
<protocol> is one of git, git+ssh, git+http, git+https, orgit+file.
If #<commit-ish> is provided, it will be used to clone exactly thatcommit. If the commit-ish has the format #semver:<semver>, <semver> canbe any valid semver range or exact version, and npm will look for any tagsor refs matching that range in the remote repository, much as it would for aregistry dependency. If neither #<commit-ish> or #semver:<semver> isspecified, then the default branch of the repository is used.
If the repository makes use of submodules, those submodules will be clonedas well.
If the package being installed contains a prepare script, itsdependencies and devDependencies will be installed, and the preparescript will be run, before the package is packaged and installed.
The following git environment variables are recognized by npm and will beadded to the environment when running git:
- GIT_ASKPASS
- GIT_EXEC_PATH
- GIT_PROXY_COMMAND
- GIT_SSH
- GIT_SSH_COMMAND
- GIT_SSL_CAINFO
- GIT_SSL_NO_VERIFY
  See the git man page for details.
  Examples:
```
npm install git+ssh://git@github.com:npm/cli.git#v1.0.27
npm install git+ssh://git@github.com:npm/cli#semver:^5.0
npm install git+https://isaacs@github.com/npm/cli.git
npm install git://github.com/npm/cli.git#v1.0.27
GIT_SSH_COMMAND='ssh -i ~/.ssh/custom_ident' npm install git+ssh://git@github.com:npm/cli.git
```
npm install <githubname>/<githubrepo>[#<commit-ish>]:
npm install github:<githubname>/<githubrepo>[#<commit-ish>]:
Install the package at https://github.com/githubname/githubrepo byattempting to clone it using git.
If #<commit-ish> is provided, it will be used to clone exactly thatcommit. If the commit-ish has the format #semver:<semver>, <semver> canbe any valid semver range or exact version, and npm will look for any tagsor refs matching that range in the remote repository, much as it would for aregistry dependency. If neither #<commit-ish> or #semver:<semver> isspecified, then master is used.
As with regular git dependencies, dependencies and devDependencies willbe installed if the package has a prepare script, before the package isdone installing.
Examples:
```
npm install mygithubuser/myproject
npm install github:mygithubuser/myproject
```
npm install gist:[<githubname>/]<gistID>[#<commit-ish>|#semver:<semver>]:
Install the package at https://gist.github.com/gistID by attempting toclone it using git. The GitHub username associated with the gist isoptional and will not be saved in package.json.
As with regular git dependencies, dependencies and devDependencies willbe installed if the package has a prepare script, before the package isdone installing.
Example:
```
npm install gist:101a11beef
```
npm install bitbucket:<bitbucketname>/<bitbucketrepo>[#<commit-ish>]:
Install the package at https://bitbucket.org/bitbucketname/bitbucketrepoby attempting to clone it using git.
If #<commit-ish> is provided, it will be used to clone exactly thatcommit. If the commit-ish has the format #semver:<semver>, <semver> canbe any valid semver range or exact version, and npm will look for any tagsor refs matching that range in the remote repository, much as it would for aregistry dependency. If neither #<commit-ish> or #semver:<semver> isspecified, then master is used.
As with regular git dependencies, dependencies and devDependencies willbe installed if the package has a prepare script, before the package isdone installing.
Example:
```
npm install bitbucket:mybitbucketuser/myproject
```
npm install gitlab:<gitlabname>/<gitlabrepo>[#<commit-ish>]:
Install the package at https://gitlab.com/gitlabname/gitlabrepoby attempting to clone it using git.
If #<commit-ish> is provided, it will be used to clone exactly thatcommit. If the commit-ish has the format #semver:<semver>, <semver> canbe any valid semver range or exact version, and npm will look for any tagsor refs matching that range in the remote repository, much as it would for aregistry dependency. If neither #<commit-ish> or #semver:<semver> isspecified, then master is used.
As with regular git dependencies, dependencies and devDependencies willbe installed if the package has a prepare script, before the package isdone installing.
Example:
```
npm install gitlab:mygitlabuser/myproject
npm install gitlab:myusr/myproj#semver:^5.0
```

You may combine multiple arguments, and even multiple types of arguments.For example:

npm install sax@">=0.1.0 <0.2.0" bench supervisor

The --tag argument will apply to all of the specified install targets. If atag with the given name exists, the tagged version is preferred over newerversions.

The --dry-run argument will report in the usual way what the install wouldhave done without actually installing anything.

The --package-lock-only argument will only update the package-lock.json,instead of checking node_modules and downloading dependencies.

The -f or --force argument will force npm to fetch remote resources even if alocal copy exists on disk.

npm install sax --force

The --no-fund argument will hide the message displayed at the end of eachinstall that acknowledges the number of dependencies looking for funding.See npm-fund(1)

The -g or --global argument will cause npm to install the package globallyrather than locally. See folders.

The --global-style argument will cause npm to install the package intoyour local node_modules folder with the same layout it uses with theglobal node_modules folder. Only your direct dependencies will show innode_modules and everything they depend on will be flattened in theirnode_modules folders. This obviously will eliminate some deduping.

The --ignore-scripts argument will cause npm to not execute anyscripts defined in the package.json. See scripts.

The --legacy-bundling argument will cause npm to install the package suchthat versions of npm prior to 1.4, such as the one included with node 0.8,can install the package. This eliminates all automatic deduping.

The --link argument will cause npm to link global installs into thelocal space in some cases.

The --no-bin-links argument will prevent npm from creating symlinks forany binaries the package might contain.

The --no-optional argument will prevent optional dependencies frombeing installed.

The --no-shrinkwrap argument, which will ignore an availablepackage lock or shrinkwrap file and use the package.json instead.

The --no-package-lock argument will prevent npm from creating apackage-lock.json file. When running with package-lock's disabled npmwill not automatically prune your node modules when installing.

The --nodedir=/path/to/node/source argument will allow npm to find thenode source code so that npm can compile native modules.

The --only={prod[uction]|dev[elopment]} argument will cause either onlydevDependencies or only non-devDependencies to be installed regardless of the NODE_ENV.

The --no-audit argument can be used to disable sending of audit reports tothe configured registries. See npm-audit for details on what is sent.

See config. Many of the configuration params have someeffect on installation, since that's most of what npm does.

Algorithm

To install a package, npm uses the following algorithm:

load the existing node_modules tree from disk

clone the tree

fetch the package.json and assorted metadata and add it to the clone

walk the clone and add any missing dependencies

dependencies will be added as close to the top as is possible

without breaking any other modules

compare the original tree with the cloned tree and make a list of

actions to take to convert one to the other

execute all of the actions, deepest first

kinds of actions are install, update, remove and move

For this package{dep} structure: A{B,C}, B{C}, C{D},this algorithm produces:

+-- B

+-- C

+-- D

That is, the dependency from B to C is satisfied by the fact that Aalready caused C to be installed at a higher level. D is still installedat the top level because nothing conflicts with it.

For A{B,C}, B{C,D@1}, C{D@2}, this algorithm produces:

+-- B

+-- C

`-- D@2

+-- D@1

Because B's D@1 will be installed in the top level, C now has to install D@2privately for itself. This algorithm is deterministic, but different trees maybe produced if two dependencies are requested for installation in a differentorder.

See folders for a more detailed description of the specific folder structures that npm creates.

Limitations of npm's Install Algorithm

npm will refuse to install any package with an identical name to thecurrent package. This can be overridden with the --force flag, but inmost cases can simply be addressed by changing the local package name.

There are some very rare and pathological edge-cases where a cycle cancause npm to try to install a never-ending tree of packages. Here isthe simplest case:

A -> B -> A' -> B' -> A -> B -> A' -> B' -> A -> ...

where A is some version of a package, and A' is a different versionof the same package. Because B depends on a different version of Athan the one that is already in the tree, it must install a separatecopy. The same is true of A', which must install B'. Because B'depends on the original version of A, which has been overridden, thecycle falls into infinite regress.

To avoid this situation, npm flat-out refuses to install anyname@version that is already present anywhere in the tree of packagefolder ancestors. A more correct, but more complex, solution would beto symlink the existing version into the new location. If this everaffects a real use-case, it will be investigated.

npm-install | npm Docs (2023)

Synopsis

Description

Algorithm

Limitations of npm's Install Algorithm

See Also