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]
This command installs a package, and any packages that it depends on. If the package has a package-lock or shrinkwrap file, the installation of dependencies will be driven by that, with an npm-shrinkwrap.json taking precedence if both files exist. See npm help package-lock.json and npm help shrinkwrap.
A package is:
Even if you never publish your package, you can still get a lot of benefits of using npm if you just want to write a node program (a), and perhaps if you also want to be able to easily install it elsewhere after packing it up into a tarball (b).
npm install ./package.tgz
npm install sax
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 npm help `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 sax@latest npm install @myorg/mypackage@latest
npm install sax@0.1.1 npm install @myorg/privatepackage@1.5.0
npm install sax@">=0.1.0 <0.2.0" npm install @myorg/privatepackage@">=0.1.0 <0.2.0"
<protocol>://[<user>[:<password>]@]<hostname>[:<port>][:][/]<path>[#<commit-ish> | #semver:<semver>]
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 mygithubuser/myproject npm install github:mygithubuser/myproject
npm install gist:101a11beef
npm install bitbucket:mybitbucketuser/myproject
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 a tag with the given name exists, the tagged version is preferred over newer versions.
The --dry-run argument will report in the usual way what the install would have 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 a local copy exists on disk.
npm install sax --force
The --no-fund argument will hide the message displayed at the end of each install 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 globally rather than locally. See npm help folders.
The --global-style argument will cause npm to install the package into your local node_modules folder with the same layout it uses with the global node_modules folder. Only your direct dependencies will show in node_modules and everything they depend on will be flattened in their node_modules folders. This obviously will eliminate some deduping.
The --ignore-scripts argument will cause npm to not execute any scripts defined in the package.json. See npm help scripts.
The --legacy-bundling argument will cause npm to install the package such that 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 the local space in some cases.
The --no-bin-links argument will prevent npm from creating symlinks for any binaries the package might contain.
The --no-optional argument will prevent optional dependencies from being installed.
The --no-shrinkwrap argument, which will ignore an available package lock or shrinkwrap file and use the package.json instead.
The --no-package-lock argument will prevent npm from creating a package-lock.json file. When running with package-lock's disabled npm will not automatically prune your node modules when installing.
The --nodedir=/path/to/node/source argument will allow npm to find the node source code so that npm can compile native modules.
The --only={prod[uction]|dev[elopment]} argument will cause either only devDependencies 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 to the configured registries. See npm-audit npm-audit for details on what is sent.
See npm help config. Many of the configuration params have some effect on installation, since that's most of what npm does.
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:
A +-- B +-- C +-- D
That is, the dependency from B to C is satisfied by the fact that A already caused C to be installed at a higher level. D is still installed at the top level because nothing conflicts with it.
For A{B,C}, B{C,D@1}, C{D@2}, this algorithm produces:
A +-- B +-- C `-- D@2 +-- D@1
Because B's D@1 will be installed in the top level, C now has to install D@2 privately for itself. This algorithm is deterministic, but different trees may be produced if two dependencies are requested for installation in a different order.
See npm help folders for a more detailed description of the specific folder structures that npm creates.
npm will refuse to install any package with an identical name to the current package. This can be overridden with the --force flag, but in most cases can simply be addressed by changing the local package name.
There are some very rare and pathological edge-cases where a cycle can cause npm to try to install a never-ending tree of packages. Here is the simplest case:
A -> B -> A' -> B' -> A -> B -> A' -> B' -> A -> ...
where A is some version of a package, and A' is a different version of the same package. Because B depends on a different version of A than the one that is already in the tree, it must install a separate copy. The same is true of A', which must install B'. Because B' depends on the original version of A, which has been overridden, the cycle falls into infinite regress.
To avoid this situation, npm flat-out refuses to install any name@version that is already present anywhere in the tree of package folder ancestors. A more correct, but more complex, solution would be to symlink the existing version into the new location. If this ever affects a real use-case, it will be investigated.