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NAME

       package.json - Specifics of npm's package.json handling

   Description
       This document is all you need to know about what's required in your package.json file.  It
       must be actual JSON, not just a JavaScript object literal.

       A lot of the behavior described in this  document  is  affected  by  the  config  settings
       described in npm help config.

   name
       If  you  plan  to publish your package, the most important things in your package.json are
       the name and version fields as they will be required. The name and version  together  form
       an identifier that is assumed to be completely unique.  Changes to the package should come
       along with changes to the version. If you don't plan to publish your package, the name and
       version fields are optional.

       The name is what your thing is called.

       Some rules:

       • The  name  must  be  less  than  or equal to 214 characters. This includes the scope for
         scoped packages.

       • The names of scoped packages can begin  with  a  dot  or  an  underscore.  This  is  not
         permitted without a scope.

       • New packages must not have uppercase letters in the name.

       • The  name  ends  up  being  part of a URL, an argument on the command line, and a folder
         name. Therefore, the name can't contain any non-URL-safe characters.

       Some tips:

       • Don't use the same name as a core Node module.

       • Don't put "js" or "node" in the name.  It's assumed that it's js, since you're writing a
         package.json  file,  and  you  can  specify  the engine using the "engines" field.  (See
         below.)

       • The name will probably be passed as an argument to require(), so it should be  something
         short, but also reasonably descriptive.

       • You may want to check the npm registry to see if there's something by that name already,
         before you get too attached to it. https://www.npmjs.com/

       A name can be optionally prefixed by a scope, e.g. @myorg/mypackage. See  npm  help  scope
       for more detail.

   version
       If  you  plan  to publish your package, the most important things in your package.json are
       the name and version fields as they will be required. The name and version  together  form
       an identifier that is assumed to be completely unique.  Changes to the package should come
       along with changes to the version. If you don't plan to publish your package, the name and
       version fields are optional.

       Version  must  be parseable by node-semver https://github.com/isaacs/node-semver, which is
       bundled with npm as a dependency.  (npm install semver to use it yourself.)

       More on version numbers and ranges at npm help semver.

   description
       Put a description in it.  It's a string.  This helps people discover your package, as it's
       listed in npm search.

   keywords
       Put keywords in it.  It's an array of strings.  This helps people discover your package as
       it's listed in npm search.

   homepage
       The url to the project homepage.

       Example:

         "homepage": "https://github.com/owner/project#readme"

   bugs
       The url to your project's issue tracker and / or the email address to which issues  should
       be reported. These are helpful for people who encounter issues with your package.

       It should look like this:

         { "url" : "https://github.com/owner/project/issues"
         , "email" : "project@hostname.com"
         }

       You  can  specify  either  one  or both values. If you want to provide only a url, you can
       specify the value for "bugs" as a simple string instead of an object.

       If a url is provided, it will be used by the npm bugs command.

   license
       You should specify a license for your package so that people know how they  are  permitted
       to use it, and any restrictions you're placing on it.

       If  you're  using a common license such as BSD-2-Clause or MIT, add a current SPDX license
       identifier for the license you're using, like this:

         { "license" : "BSD-3-Clause" }

       You can check the full list of SPDX license IDs https://spdx.org/licenses/.   Ideally  you
       should pick one that is OSI https://opensource.org/licenses/alphabetical approved.

       If your package is licensed under multiple common licenses, use an SPDX license expression
       syntax version 2.0 string https://www.npmjs.com/package/spdx, like this:

         { "license" : "(ISC OR GPL-3.0)" }

       If you are using a license that hasn't been assigned an SPDX identifier,  or  if  you  are
       using a custom license, use a string value like this one:

         { "license" : "SEE LICENSE IN <filename>" }

       Then include a file named <filename> at the top level of the package.

       Some  old  packages  used  license objects or a "licenses" property containing an array of
       license objects:

         // Not valid metadata
         { "license" :
           { "type" : "ISC"
           , "url" : "https://opensource.org/licenses/ISC"
           }
         }

         // Not valid metadata
         { "licenses" :
           [
             { "type": "MIT"
             , "url": "https://www.opensource.org/licenses/mit-license.php"
             }
           , { "type": "Apache-2.0"
             , "url": "https://opensource.org/licenses/apache2.0.php"
             }
           ]
         }

       Those styles are now deprecated. Instead, use SPDX expressions, like this:

         { "license": "ISC" }

         { "license": "(MIT OR Apache-2.0)" }

       Finally, if you do not wish to grant others the right to  use  a  private  or  unpublished
       package under any terms:

         { "license": "UNLICENSED" }

       Consider also setting "private": true to prevent accidental publication.

   people fields: author, contributors
       The  "author"  is  one  person.   "contributors"  is an array of people.  A "person" is an
       object with a "name" field and optionally "url" and "email", like this:

         { "name" : "Barney Rubble"
         , "email" : "b@rubble.com"
         , "url" : "http://barnyrubble.tumblr.com/"
         }

       Or you can shorten that all into a single string, and npm will parse it for you:

         "Barney Rubble <b@rubble.com> (http://barnyrubble.tumblr.com/)"

       Both email and url are optional either way.

       npm also sets a top-level "maintainers" field with your npm user info.

   funding
       You can specify an object containing an URL that  provides  up-to-date  information  about
       ways to help fund development of your package, or a string URL, or an array of these:

         "funding": {
           "type" : "individual",
           "url" : "http://example.com/donate"
         }

         "funding": {
           "type" : "patreon",
           "url" : "https://www.patreon.com/my-account"
         }

         "funding": "http://example.com/donate"

         "funding": [
           {
             "type" : "individual",
             "url" : "http://example.com/donate"
           },
           "http://example.com/donateAlso",
           {
             "type" : "patreon",
             "url" : "https://www.patreon.com/my-account"
           }
         ]

       Users  can  use  the  npm  fund subcommand to list the funding URLs of all dependencies of
       their project, direct and indirect. A shortcut to visit each funding url is also available
       when  providing  the project name such as: npm fund <projectname> (when there are multiple
       URLs, the first one will be visited)

   files
       The optional files field is an array of file patterns that describes  the  entries  to  be
       included  when  your  package is installed as a dependency. File patterns follow a similar
       syntax to .gitignore, but reversed: including a file, directory, or glob pattern (*, **/*,
       and  such) will make it so that file is included in the tarball when it's packed. Omitting
       the field will make it default to ["*"], which means it will include all files.

       Some special files and directories are also included or  excluded  regardless  of  whether
       they exist in the files array (see below).

       You  can  also provide a .npmignore file in the root of your package or in subdirectories,
       which will keep files from being included. At  the  root  of  your  package  it  will  not
       override  the "files" field, but in subdirectories it will. The .npmignore file works just
       like a .gitignore. If there is a .gitignore file, and .npmignore is missing,  .gitignore's
       contents will be used instead.

       Files  included  with the "package.json#files" field cannot be excluded through .npmignore
       or .gitignore.

       Certain files are always included, regardless of settings:

       • package.jsonREADMECHANGES / CHANGELOG / HISTORYLICENSE / LICENCENOTICE

       • The file in the "main" field

       README, CHANGES, LICENSE & NOTICE can have any case and extension.

       Conversely, some files are always ignored:

       • .gitCVS.svn.hg.lock-wscript.wafpickle-N.*.swp.DS_Store._*npm-debug.log.npmrcnode_modulesconfig.gypi*.origpackage-lock.json (use shrinkwrap instead)

   main
       The main field is a module ID that is the primary entry point to your program.   That  is,
       if  your  package is named foo, and a user installs it, and then does require("foo"), then
       your main module's exports object will be returned.

       This should be a module ID relative to the root of your package folder.

       For most modules, it makes the most sense to have a main script and often not much else.

   browser
       If your module is meant to be used client-side the browser field should be used instead of
       the main field. This is helpful to hint users that it might rely on primitives that aren't
       available in Node.js modules. (e.g. window)

   bin
       A lot of packages have one or more executable files that they'd like to install  into  the
       PATH.  npm  makes  this  pretty  easy  (in fact, it uses this feature to install the "npm"
       executable.)

       To use this, supply a bin field in your package.json which is a map  of  command  name  to
       local  file  name.  On  install,  npm  will  symlink  that file into prefix/bin for global
       installs, or ./node_modules/.bin/ for local installs.

       For example, myapp could have this:

         { "bin" : { "myapp" : "./cli.js" } }

       So,  when  you  install  myapp,  it'll  create  a  symlink  from  the  cli.js  script   to
       /usr/local/bin/myapp.

       If  you have a single executable, and its name should be the name of the package, then you
       can just supply it as a string.  For example:

         { "name": "my-program"
         , "version": "1.2.5"
         , "bin": "./path/to/program" }

       would be the same as this:

         { "name": "my-program"
         , "version": "1.2.5"
         , "bin" : { "my-program" : "./path/to/program" } }

       Please make sure that your file(s) referenced in  bin  starts  with  #!/usr/bin/env  node,
       otherwise the scripts are started without the node executable!

   man
       Specify  either a single file or an array of filenames to put in place for the man program
       to find.

       If only a single file is provided, then it's installed such that it is the result from man
       <pkgname>, regardless of its actual filename.  For example:

         { "name" : "foo"
         , "version" : "1.2.3"
         , "description" : "A packaged foo fooer for fooing foos"
         , "main" : "foo.js"
         , "man" : "./man/doc.1"
         }

       would link the ./man/doc.1 file in such that it is the target for man foo

       If the filename doesn't start with the package name, then it's prefixed.  So, this:

         { "name" : "foo"
         , "version" : "1.2.3"
         , "description" : "A packaged foo fooer for fooing foos"
         , "main" : "foo.js"
         , "man" : [ "./man/foo.1", "./man/bar.1" ]
         }

       will create files to do man foo and man foo-bar.

       Man files must end with a number, and optionally a .gz suffix if they are compressed.  The
       number dictates which man section the file is installed into.

         { "name" : "foo"
         , "version" : "1.2.3"
         , "description" : "A packaged foo fooer for fooing foos"
         , "main" : "foo.js"
         , "man" : [ "./man/foo.1", "./man/foo.2" ]
         }

       will create entries for man foo and man 2 foo

   directories
       The CommonJS Packages http://wiki.commonjs.org/wiki/Packages/1.0 spec details a  few  ways
       that  you  can  indicate  the structure of your package using a directories object. If you
       look at npm's package.json https://registry.npmjs.org/npm/latest, you'll see that  it  has
       directories for doc, lib, and man.

       In the future, this information may be used in other creative ways.

   directories.lib
       Tell  people  where  the  bulk  of  your library is.  Nothing special is done with the lib
       folder in any way, but it's useful meta info.

   directories.bin
       If you specify a bin directory in directories.bin, all the files in that  folder  will  be
       added.

       Because  of  the  way  the  bin  directive  works,  specifying both a bin path and setting
       directories.bin is an error. If you want to specify individual files, use bin, and for all
       the files in an existing bin directory, use directories.bin.

   directories.man
       A  folder  that  is  full  of  man  pages.  Sugar to generate a "man" array by walking the
       folder.

   directories.doc
       Put markdown files in here.  Eventually, these will be displayed nicely, maybe, someday.

   directories.example
       Put example scripts in here.  Someday, it might be exposed in some clever way.

   directories.test
       Put your tests in here. It is currently not exposed, but it might be in the future.

   repository
       Specify the place where  your  code  lives.  This  is  helpful  for  people  who  want  to
       contribute.   If the git repo is on GitHub, then the npm docs command will be able to find
       you.

       Do it like this:

         "repository": {
           "type" : "git",
           "url" : "https://github.com/npm/cli.git"
         }

         "repository": {
           "type" : "svn",
           "url" : "https://v8.googlecode.com/svn/trunk/"
         }

       The URL should be a publicly available (perhaps read-only) url that can be handed directly
       to a VCS program without any modification.  It should not be a url to an html project page
       that you put in your browser.  It's for computers.

       For GitHub, GitHub gist, Bitbucket, or GitLab repositories you can use the  same  shortcut
       syntax you use for npm install:

         "repository": "npm/npm"

         "repository": "github:user/repo"

         "repository": "gist:11081aaa281"

         "repository": "bitbucket:user/repo"

         "repository": "gitlab:user/repo"

       If  the  package.json  for your package is not in the root directory (for example if it is
       part of a monorepo), you can specify the directory in which it lives:

         "repository": {
           "type" : "git",
           "url" : "https://github.com/facebook/react.git",
           "directory": "packages/react-dom"
         }

   scripts
       The "scripts" property is a dictionary containing script commands that are run at  various
       times  in the lifecycle of your package.  The key is the lifecycle event, and the value is
       the command to run at that point.

       See npm help scripts to find out more about writing package scripts.

   config
       A "config" object can be used to set configuration parameters used in package scripts that
       persist across upgrades.  For instance, if a package had the following:

         { "name" : "foo"
         , "config" : { "port" : "8080" } }

       and   then  had  a  "start"  command  that  then  referenced  the  npm_package_config_port
       environment variable, then the user could override that by doing npm config  set  foo:port
       8001.

       See npm help config and npm help scripts for more on package configs.

   dependencies
       Dependencies are specified in a simple object that maps a package name to a version range.
       The version range  is  a  string  which  has  one  or  more  space-separated  descriptors.
       Dependencies can also be identified with a tarball or git URL.

       Please  do  not  put  test  harnesses  or  transpilers  in  your dependencies object.  See
       devDependencies, below.

       See npm help semver for more details about specifying version ranges.

       • version Must match version exactly

       • >version Must be greater than version>=version etc

       • <version<=version~version "Approximately equivalent to version"  See npm help semver

       • ^version "Compatible with version"  See npm help semver

       • 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 help dist-tagpath/path/path See Local Paths #local-paths below

       For example, these are all valid:

         { "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:

         <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:

         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:

         {
           "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:

         ../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:

         {
           "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 npm help 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:

         { "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:

         {
           "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:

         ├── tea-latte@1.3.5
         └── tea@2.2.0

       NOTE:  npm  versions  1  and 2 will automatically install peerDependencies if they are not
       explicitly depended upon higher in the dependency tree. In the next major version  of  npm
       (npm@3),  this  will  no  longer  be  the  case.  You  will  receive  a  warning  that the
       peerDependency is not installed instead. The  behavior  in  npms  1  &  2  was  frequently
       confusing  and could easily put you into dependency hell, a situation that npm is designed
       to avoid as much as possible.

       Trying to install another plugin with a conflicting requirement will cause an  error.  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 < 2".

   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:

         {
           "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.

   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:

         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.

   engines
       You can specify the version of node that your stuff works on:

         { "engines" : { "node" : ">=0.10.3 <0.12" } }

       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.

       If  you specify an "engines" field, then npm will require that "node" be somewhere on that
       list. If "engines" is omitted, then npm will just assume that it works on node.

       You can also use the "engines" field to specify which  versions  of  npm  are  capable  of
       properly installing your program.  For example:

         { "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.

   engineStrict
       This feature was removed in npm 3.0.0

       Prior to npm 3.0.0, this feature was used to treat this package as if  the  user  had  set
       engine-strict. It is no longer used.

   os
       You can specify which operating systems your module will run on:

         "os" : [ "darwin", "linux" ]

       You  can  also  blacklist  instead  of  whitelist  operating  systems,  just  prepend  the
       blacklisted os with a '!':

         "os" : [ "!win32" ]

       The host operating system is determined by process.platform

       It is allowed to both blacklist, and whitelist, 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.

         "cpu" : [ "x64", "ia32" ]

       Like the os option, you can also blacklist architectures:

         "cpu" : [ "!arm", "!mips" ]

       The host architecture is determined by process.arch

   preferGlobal
       DEPRECATED

       This option used to trigger an npm warning, but it will no longer warn. It is purely there
       for informational purposes. It is now recommended that you install any binaries  as  local
       devDependencies wherever possible.

   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.

       Any  config  values  can  be  overridden, but only "tag", "registry" and "access" probably
       matter for the purposes of publishing.

       See npm help config to see the list of config options that can be overridden.

   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 optional.  Lines
         which start with a # or are blank, will be ignored.

   SEE ALSO
       • npm help semver

       • npm help init

       • npm help version

       • npm help config

       • npm help help

       • npm help install

       • npm help publish

       • npm help uninstall

                                            April 2020                            PACKAGE.JSON(5)