Provided by: npm_3.5.2-0ubuntu4_all bug

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 7 npm-config.

name

       The  most important things in your package.json are the name and version fields. Those are
       actually required, and your package won´t install  without  them.  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.

       The name is what your thing is called.

       Some rules:

       •   The name must be shorter than 214 characters.  This  includes  the  scope  for  scoped
           packages.

       •   The name can´t start with a dot or an underscore.

       •   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  7
       npm-scope for more detail.

version

       The  most important things in your package.json are the name and version fields. Those are
       actually required, and your package won´t install  without  them.  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.

       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 7 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.

       NOTE:  This  is  not  the  same as "url". If you put a "url" field, then the registry will
       think it´s a redirection to your package that has been published somewhere else, and  spit
       at you.

       Literally. Spit. I´m so not kidding.

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 http://opensource.org/licenses/alphabetical approved.

       If your package is licensed under multiple common licenses, use an SPDX license expression
       syntax version 2.0 string http://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 the following valid SPDX expression:

           { "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" : "http://opensource.org/licenses/ISC"
             }
           }

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

files

       The "files" field is an array of files to include in your project. If you name a folder in
       the array, then it will also include the files inside that folder. (Unless they  would  be
       ignored by another rule.)

       You can also provide a ".npmignore" file in the root of your package or in subdirectories,
       which will keep files from being included, even if they would be picked up  by  the  files
       array. The .npmignore file works just like a .gitignore.

       Certain files are always included, regardless of settings:

       •   package.jsonREADME (and its variants)

       •   CHANGELOG (and its variants)

       •   LICENSE / LICENCE

       Conversely, some files are always ignored:

       •   .gitCVS.svn.hg.lock-wscript.wafpickle-N*.swp.DS_Store._*npm-debug.log

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.

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" } }

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.

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/npm.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": "gist:11081aaa281"

           "repository": "bitbucket:example/repo"

           "repository": "gitlab:another/repo"

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 7 npm-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 7 npm-config and npm help 7 npm-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 7 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 7 semver

       •   ^version "Compatible with version" See npm help 7 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 npm-tagpath/path/path See 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 can be of the form:

           git://github.com/user/project.git#commit-ish
           git+ssh://user@hostname:project.git#commit-ish
           git+ssh://user@hostname/project.git#commit-ish
           git+http://user@hostname/project/blah.git#commit-ish
           git+https://user@hostname/project/blah.git#commit-ish

       The commit-ish can be any tag, sha, or branch which can be supplied as an argument to  git
       checkout. The default is master.

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": "visionmedia/express",
               "mocha": "visionmedia/mocha#4727d357ea"
             }
           }

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

       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  7
       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 prepublish 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": {
               "prepublish": "coffee -o lib/ -c src/waza.coffee"
             },
             "main": "lib/waza.js"
           }

       The  prepublish  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  http://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

       Array of package names that will be bundled when publishing the package.

       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.

       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" } }

       Note that, unless the user has set the engine-strict config flag, this field  is  advisory
       only.

engineStrict

       This feature was deprecated with 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.

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

       If your package is primarily a command-line application that should be installed globally,
       then set this value to true to provide a warning if it is installed locally.

       It  doesn´t  actually  prevent  users from installing it locally, but it does help prevent
       some confusion if it doesn´t work as expected.

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 of course only  "tag",  "registry"  and  "access"
       probably matter for the purposes of publishing.

       See npm help 7 npm-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":{"preinstall": "node-gyp rebuild"}

           If there is a binding.gyp file in the root of  your  package,  npm  will  default  the
           preinstall 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 7 semver

       •   npm help init

       •   npm help version

       •   npm help config

       •   npm help 7 config

       •   npm help help

       •   npm help 7 faq

       •   npm help install

       •   npm help publish

       •   npm help uninstall

                                          December 2015                           PACKAGE.JSON(5)