1<!DOCTYPE html><html><head> 2<meta charset="utf-8"> 3<title>package.json</title> 4<style> 5body { 6 background-color: #ffffff; 7 color: #24292e; 8 9 margin: 0; 10 11 line-height: 1.5; 12 13 font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; 14} 15#rainbar { 16 height: 10px; 17 background-image: linear-gradient(139deg, #fb8817, #ff4b01, #c12127, #e02aff); 18} 19 20a { 21 text-decoration: none; 22 color: #0366d6; 23} 24a:hover { 25 text-decoration: underline; 26} 27 28pre { 29 margin: 1em 0px; 30 padding: 1em; 31 border: solid 1px #e1e4e8; 32 border-radius: 6px; 33 34 display: block; 35 overflow: auto; 36 37 white-space: pre; 38 39 background-color: #f6f8fa; 40 color: #393a34; 41} 42code { 43 font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; 44 font-size: 85%; 45 padding: 0.2em 0.4em; 46 background-color: #f6f8fa; 47 color: #393a34; 48} 49pre > code { 50 padding: 0; 51 background-color: inherit; 52 color: inherit; 53} 54h1, h2, h3 { 55 font-weight: 600; 56} 57 58#logobar { 59 background-color: #333333; 60 margin: 0 auto; 61 padding: 1em 4em; 62} 63#logobar .logo { 64 float: left; 65} 66#logobar .title { 67 font-weight: 600; 68 color: #dddddd; 69 float: left; 70 margin: 5px 0 0 1em; 71} 72#logobar:after { 73 content: ""; 74 display: block; 75 clear: both; 76} 77 78#content { 79 margin: 0 auto; 80 padding: 0 4em; 81} 82 83#table_of_contents > h2 { 84 font-size: 1.17em; 85} 86#table_of_contents ul:first-child { 87 border: solid 1px #e1e4e8; 88 border-radius: 6px; 89 padding: 1em; 90 background-color: #f6f8fa; 91 color: #393a34; 92} 93#table_of_contents ul { 94 list-style-type: none; 95 padding-left: 1.5em; 96} 97#table_of_contents li { 98 font-size: 0.9em; 99} 100#table_of_contents li a { 101 color: #000000; 102} 103 104header.title { 105 border-bottom: solid 1px #e1e4e8; 106} 107header.title > h1 { 108 margin-bottom: 0.25em; 109} 110header.title > .description { 111 display: block; 112 margin-bottom: 0.5em; 113 line-height: 1; 114} 115 116footer#edit { 117 border-top: solid 1px #e1e4e8; 118 margin: 3em 0 4em 0; 119 padding-top: 2em; 120} 121</style> 122</head> 123<body> 124<div id="banner"> 125<div id="rainbar"></div> 126<div id="logobar"> 127<svg class="logo" role="img" height="32" width="32" viewBox="0 0 700 700"> 128<polygon fill="#cb0000" points="0,700 700,700 700,0 0,0"></polygon> 129<polygon fill="#ffffff" points="150,550 350,550 350,250 450,250 450,550 550,550 550,150 150,150"></polygon> 130</svg> 131<div class="title"> 132npm command-line interface 133</div> 134</div> 135</div> 136 137<section id="content"> 138<header class="title"> 139<h1 id="packagejson">package.json</h1> 140<span class="description">Specifics of npm's package.json handling</span> 141</header> 142 143<section id="table_of_contents"> 144<h2 id="table-of-contents">Table of contents</h2> 145<div id="_table_of_contents"><ul><li><a href="#description">Description</a></li><li><a href="#name">name</a></li><li><a href="#version">version</a></li><li><a href="#description2">description</a></li><li><a href="#keywords">keywords</a></li><li><a href="#homepage">homepage</a></li><li><a href="#bugs">bugs</a></li><li><a href="#license">license</a></li><li><a href="#people-fields-author-contributors">people fields: author, contributors</a></li><li><a href="#funding">funding</a></li><li><a href="#files">files</a></li><li><a href="#main">main</a></li><li><a href="#browser">browser</a></li><li><a href="#bin">bin</a></li><li><a href="#man">man</a></li><li><a href="#directories">directories</a></li><ul><li><a href="#directoriesbin">directories.bin</a></li><li><a href="#directoriesman">directories.man</a></li></ul><li><a href="#repository">repository</a></li><li><a href="#scripts">scripts</a></li><li><a href="#config">config</a></li><li><a href="#dependencies">dependencies</a></li><ul><li><a href="#urls-as-dependencies">URLs as Dependencies</a></li><li><a href="#git-urls-as-dependencies">Git URLs as Dependencies</a></li><li><a href="#github-urls">GitHub URLs</a></li><li><a href="#local-paths">Local Paths</a></li></ul><li><a href="#devdependencies">devDependencies</a></li><li><a href="#peerdependencies">peerDependencies</a></li><li><a href="#peerdependenciesmeta">peerDependenciesMeta</a></li><li><a href="#bundledependencies">bundleDependencies</a></li><li><a href="#optionaldependencies">optionalDependencies</a></li><li><a href="#overrides">overrides</a></li><li><a href="#engines">engines</a></li><li><a href="#os">os</a></li><li><a href="#cpu">cpu</a></li><li><a href="#private">private</a></li><li><a href="#publishconfig">publishConfig</a></li><li><a href="#workspaces">workspaces</a></li><li><a href="#default-values">DEFAULT VALUES</a></li><li><a href="#see-also">SEE ALSO</a></li></ul></div> 146</section> 147 148<div id="_content"><h3 id="description">Description</h3> 149<p>This document is all you need to know about what's required in your 150package.json file. It must be actual JSON, not just a JavaScript object 151literal.</p> 152<p>A lot of the behavior described in this document is affected by the config 153settings described in <a href="../using-npm/config.html"><code>config</code></a>.</p> 154<h3 id="name">name</h3> 155<p>If you plan to publish your package, the <em>most</em> important things in your 156package.json are the name and version fields as they will be required. The 157name and version together form an identifier that is assumed to be 158completely unique. Changes to the package should come along with changes 159to the version. If you don't plan to publish your package, the name and 160version fields are optional.</p> 161<p>The name is what your thing is called.</p> 162<p>Some rules:</p> 163<ul> 164<li>The name must be less than or equal to 214 characters. This includes the 165scope for scoped packages.</li> 166<li>The names of scoped packages can begin with a dot or an underscore. This 167is not permitted without a scope.</li> 168<li>New packages must not have uppercase letters in the name.</li> 169<li>The name ends up being part of a URL, an argument on the command line, 170and a folder name. Therefore, the name can't contain any non-URL-safe 171characters.</li> 172</ul> 173<p>Some tips:</p> 174<ul> 175<li>Don't use the same name as a core Node module.</li> 176<li>Don't put "js" or "node" in the name. It's assumed that it's js, since 177you're writing a package.json file, and you can specify the engine using 178the "engines" field. (See below.)</li> 179<li>The name will probably be passed as an argument to require(), so it 180should be something short, but also reasonably descriptive.</li> 181<li>You may want to check the npm registry to see if there's something by 182that name already, before you get too attached to it. 183<a href="https://www.npmjs.com/">https://www.npmjs.com/</a></li> 184</ul> 185<p>A name can be optionally prefixed by a scope, e.g. <code>@myorg/mypackage</code>. See 186<a href="../using-npm/scope.html"><code>scope</code></a> for more detail.</p> 187<h3 id="version">version</h3> 188<p>If you plan to publish your package, the <em>most</em> important things in your 189package.json are the name and version fields as they will be required. The 190name and version together form an identifier that is assumed to be 191completely unique. Changes to the package should come along with changes 192to the version. If you don't plan to publish your package, the name and 193version fields are optional.</p> 194<p>Version must be parseable by 195<a href="https://github.com/npm/node-semver">node-semver</a>, which is bundled with 196npm as a dependency. (<code>npm install semver</code> to use it yourself.)</p> 197<h3 id="description2">description</h3> 198<p>Put a description in it. It's a string. This helps people discover your 199package, as it's listed in <code>npm search</code>.</p> 200<h3 id="keywords">keywords</h3> 201<p>Put keywords in it. It's an array of strings. This helps people discover 202your package as it's listed in <code>npm search</code>.</p> 203<h3 id="homepage">homepage</h3> 204<p>The url to the project homepage.</p> 205<p>Example:</p> 206<pre><code class="language-json">"homepage": "https://github.com/owner/project#readme" 207</code></pre> 208<h3 id="bugs">bugs</h3> 209<p>The url to your project's issue tracker and / or the email address to which 210issues should be reported. These are helpful for people who encounter 211issues with your package.</p> 212<p>It should look like this:</p> 213<pre><code class="language-json">{ 214 "bugs": { 215 "url": "https://github.com/owner/project/issues", 216 "email": "project@hostname.com" 217 } 218} 219</code></pre> 220<p>You can specify either one or both values. If you want to provide only a 221url, you can specify the value for "bugs" as a simple string instead of an 222object.</p> 223<p>If a url is provided, it will be used by the <code>npm bugs</code> command.</p> 224<h3 id="license">license</h3> 225<p>You should specify a license for your package so that people know how they 226are permitted to use it, and any restrictions you're placing on it.</p> 227<p>If you're using a common license such as BSD-2-Clause or MIT, add a current 228SPDX license identifier for the license you're using, like this:</p> 229<pre><code class="language-json">{ 230 "license" : "BSD-3-Clause" 231} 232</code></pre> 233<p>You can check <a href="https://spdx.org/licenses/">the full list of SPDX license 234IDs</a>. Ideally you should pick one that is 235<a href="https://opensource.org/licenses/">OSI</a> approved.</p> 236<p>If your package is licensed under multiple common licenses, use an <a href="https://spdx.dev/specifications/">SPDX 237license expression syntax version 2.0 238string</a>, like this:</p> 239<pre><code class="language-json">{ 240 "license" : "(ISC OR GPL-3.0)" 241} 242</code></pre> 243<p>If you are using a license that hasn't been assigned an SPDX identifier, or if 244you are using a custom license, use a string value like this one:</p> 245<pre><code class="language-json">{ 246 "license" : "SEE LICENSE IN <filename>" 247} 248</code></pre> 249<p>Then include a file named <code><filename></code> at the top level of the package.</p> 250<p>Some old packages used license objects or a "licenses" property containing 251an array of license objects:</p> 252<pre><code class="language-json">// Not valid metadata 253{ 254 "license" : { 255 "type" : "ISC", 256 "url" : "https://opensource.org/licenses/ISC" 257 } 258} 259 260// Not valid metadata 261{ 262 "licenses" : [ 263 { 264 "type": "MIT", 265 "url": "https://www.opensource.org/licenses/mit-license.php" 266 }, 267 { 268 "type": "Apache-2.0", 269 "url": "https://opensource.org/licenses/apache2.0.php" 270 } 271 ] 272} 273</code></pre> 274<p>Those styles are now deprecated. Instead, use SPDX expressions, like this:</p> 275<pre><code class="language-json">{ 276 "license": "ISC" 277} 278</code></pre> 279<pre><code class="language-json">{ 280 "license": "(MIT OR Apache-2.0)" 281} 282</code></pre> 283<p>Finally, if you do not wish to grant others the right to use a private or 284unpublished package under any terms:</p> 285<pre><code class="language-json">{ 286 "license": "UNLICENSED" 287} 288</code></pre> 289<p>Consider also setting <code>"private": true</code> to prevent accidental publication.</p> 290<h3 id="people-fields-author-contributors">people fields: author, contributors</h3> 291<p>The "author" is one person. "contributors" is an array of people. A 292"person" is an object with a "name" field and optionally "url" and "email", 293like this:</p> 294<pre><code class="language-json">{ 295 "name" : "Barney Rubble", 296 "email" : "b@rubble.com", 297 "url" : "http://barnyrubble.tumblr.com/" 298} 299</code></pre> 300<p>Or you can shorten that all into a single string, and npm will parse it for 301you:</p> 302<pre><code class="language-json">{ 303 "author": "Barney Rubble <b@rubble.com> (http://barnyrubble.tumblr.com/)" 304} 305</code></pre> 306<p>Both email and url are optional either way.</p> 307<p>npm also sets a top-level "maintainers" field with your npm user info.</p> 308<h3 id="funding">funding</h3> 309<p>You can specify an object containing a URL that provides up-to-date 310information about ways to help fund development of your package, or a 311string URL, or an array of these:</p> 312<pre><code class="language-json">{ 313 "funding": { 314 "type" : "individual", 315 "url" : "http://example.com/donate" 316 }, 317 318 "funding": { 319 "type" : "patreon", 320 "url" : "https://www.patreon.com/my-account" 321 }, 322 323 "funding": "http://example.com/donate", 324 325 "funding": [ 326 { 327 "type" : "individual", 328 "url" : "http://example.com/donate" 329 }, 330 "http://example.com/donateAlso", 331 { 332 "type" : "patreon", 333 "url" : "https://www.patreon.com/my-account" 334 } 335 ] 336} 337</code></pre> 338<p>Users can use the <code>npm fund</code> subcommand to list the <code>funding</code> URLs of all 339dependencies of their project, direct and indirect. A shortcut to visit 340each funding url is also available when providing the project name such as: 341<code>npm fund <projectname></code> (when there are multiple URLs, the first one will 342be visited)</p> 343<h3 id="files">files</h3> 344<p>The optional <code>files</code> field is an array of file patterns that describes the 345entries to be included when your package is installed as a dependency. File 346patterns follow a similar syntax to <code>.gitignore</code>, but reversed: including a 347file, directory, or glob pattern (<code>*</code>, <code>**/*</code>, and such) will make it so 348that file is included in the tarball when it's packed. Omitting the field 349will make it default to <code>["*"]</code>, which means it will include all files.</p> 350<p>Some special files and directories are also included or excluded regardless 351of whether they exist in the <code>files</code> array (see below).</p> 352<p>You can also provide a <code>.npmignore</code> file in the root of your package or in 353subdirectories, which will keep files from being included. At the root of 354your package it will not override the "files" field, but in subdirectories 355it will. The <code>.npmignore</code> file works just like a <code>.gitignore</code>. If there is 356a <code>.gitignore</code> file, and <code>.npmignore</code> is missing, <code>.gitignore</code>'s contents 357will be used instead.</p> 358<p>Certain files are always included, regardless of settings:</p> 359<ul> 360<li><code>package.json</code></li> 361<li><code>README</code></li> 362<li><code>LICENSE</code> / <code>LICENCE</code></li> 363<li>The file in the "main" field</li> 364<li>The file(s) in the "bin" field</li> 365</ul> 366<p><code>README</code> & <code>LICENSE</code> can have any case and extension.</p> 367<p>Some files are always ignored by default:</p> 368<ul> 369<li><code>*.orig</code></li> 370<li><code>.*.swp</code></li> 371<li><code>.DS_Store</code></li> 372<li><code>._*</code></li> 373<li><code>.git</code></li> 374<li><code>.hg</code></li> 375<li><code>.lock-wscript</code></li> 376<li><code>.npmrc</code></li> 377<li><code>.svn</code></li> 378<li><code>.wafpickle-N</code></li> 379<li><code>CVS</code></li> 380<li><code>config.gypi</code></li> 381<li><code>node_modules</code></li> 382<li><code>npm-debug.log</code></li> 383<li><code>package-lock.json</code> (use 384<a href="../configuring-npm/npm-shrinkwrap-json.html"><code>npm-shrinkwrap.json</code></a> 385if you wish it to be published)</li> 386<li><code>pnpm-lock.yaml</code></li> 387<li><code>yarn.lock</code></li> 388</ul> 389<p>Most of these ignored files can be included specifically if included in 390the <code>files</code> globs. Exceptions to this are:</p> 391<ul> 392<li><code>.git</code></li> 393<li><code>.npmrc</code></li> 394<li><code>node_modules</code></li> 395<li><code>package-lock.json</code></li> 396<li><code>pnpm-lock.yaml</code></li> 397<li><code>yarn.lock</code></li> 398</ul> 399<p>These can not be included.</p> 400<h3 id="main">main</h3> 401<p>The main field is a module ID that is the primary entry point to your 402program. That is, if your package is named <code>foo</code>, and a user installs it, 403and then does <code>require("foo")</code>, then your main module's exports object will 404be returned.</p> 405<p>This should be a module relative to the root of your package folder.</p> 406<p>For most modules, it makes the most sense to have a main script and often 407not much else.</p> 408<p>If <code>main</code> is not set, it defaults to <code>index.js</code> in the package's root folder.</p> 409<h3 id="browser">browser</h3> 410<p>If your module is meant to be used client-side the browser field should be 411used instead of the main field. This is helpful to hint users that it might 412rely on primitives that aren't available in Node.js modules. (e.g. 413<code>window</code>)</p> 414<h3 id="bin">bin</h3> 415<p>A lot of packages have one or more executable files that they'd like to 416install into the PATH. npm makes this pretty easy (in fact, it uses this 417feature to install the "npm" executable.)</p> 418<p>To use this, supply a <code>bin</code> field in your package.json which is a map of 419command name to local file name. When this package is installed globally, 420that file will be either linked inside the global bins directory or 421a cmd (Windows Command File) will be created which executes the specified 422file in the <code>bin</code> field, so it is available to run by <code>name</code> or <code>name.cmd</code> (on 423Windows PowerShell). When this package is installed as a dependency in another 424package, the file will be linked where it will be available to that package 425either directly by <code>npm exec</code> or by name in other scripts when invoking them 426via <code>npm run-script</code>.</p> 427<p>For example, myapp could have this:</p> 428<pre><code class="language-json">{ 429 "bin": { 430 "myapp": "./cli.js" 431 } 432} 433</code></pre> 434<p>So, when you install myapp, in case of unix-like OS it'll create a symlink 435from the <code>cli.js</code> script to <code>/usr/local/bin/myapp</code> and in case of windows it 436will create a cmd file usually at <code>C:\Users\{Username}\AppData\Roaming\npm\myapp.cmd</code> 437which runs the <code>cli.js</code> script.</p> 438<p>If you have a single executable, and its name should be the name of the 439package, then you can just supply it as a string. For example:</p> 440<pre><code class="language-json">{ 441 "name": "my-program", 442 "version": "1.2.5", 443 "bin": "./path/to/program" 444} 445</code></pre> 446<p>would be the same as this:</p> 447<pre><code class="language-json">{ 448 "name": "my-program", 449 "version": "1.2.5", 450 "bin": { 451 "my-program": "./path/to/program" 452 } 453} 454</code></pre> 455<p>Please make sure that your file(s) referenced in <code>bin</code> starts with 456<code>#!/usr/bin/env node</code>, otherwise the scripts are started without the node 457executable!</p> 458<p>Note that you can also set the executable files using <a href="#directoriesbin">directories.bin</a>.</p> 459<p>See <a href="../configuring-npm/folders#executables.html">folders</a> for more info on 460executables.</p> 461<h3 id="man">man</h3> 462<p>Specify either a single file or an array of filenames to put in place for 463the <code>man</code> program to find.</p> 464<p>If only a single file is provided, then it's installed such that it is the 465result from <code>man <pkgname></code>, regardless of its actual filename. For 466example:</p> 467<pre><code class="language-json">{ 468 "name": "foo", 469 "version": "1.2.3", 470 "description": "A packaged foo fooer for fooing foos", 471 "main": "foo.js", 472 "man": "./man/doc.1" 473} 474</code></pre> 475<p>would link the <code>./man/doc.1</code> file in such that it is the target for <code>man foo</code></p> 476<p>If the filename doesn't start with the package name, then it's prefixed. 477So, this:</p> 478<pre><code class="language-json">{ 479 "name": "foo", 480 "version": "1.2.3", 481 "description": "A packaged foo fooer for fooing foos", 482 "main": "foo.js", 483 "man": [ 484 "./man/foo.1", 485 "./man/bar.1" 486 ] 487} 488</code></pre> 489<p>will create files to do <code>man foo</code> and <code>man foo-bar</code>.</p> 490<p>Man files must end with a number, and optionally a <code>.gz</code> suffix if they are 491compressed. The number dictates which man section the file is installed 492into.</p> 493<pre><code class="language-json">{ 494 "name": "foo", 495 "version": "1.2.3", 496 "description": "A packaged foo fooer for fooing foos", 497 "main": "foo.js", 498 "man": [ 499 "./man/foo.1", 500 "./man/foo.2" 501 ] 502} 503</code></pre> 504<p>will create entries for <code>man foo</code> and <code>man 2 foo</code></p> 505<h3 id="directories">directories</h3> 506<p>The CommonJS <a href="http://wiki.commonjs.org/wiki/Packages/1.0">Packages</a> spec 507details a few ways that you can indicate the structure of your package 508using a <code>directories</code> object. If you look at <a href="https://registry.npmjs.org/npm/latest">npm's 509package.json</a>, you'll see that it 510has directories for doc, lib, and man.</p> 511<p>In the future, this information may be used in other creative ways.</p> 512<h4 id="directoriesbin">directories.bin</h4> 513<p>If you specify a <code>bin</code> directory in <code>directories.bin</code>, all the files in 514that folder will be added.</p> 515<p>Because of the way the <code>bin</code> directive works, specifying both a <code>bin</code> path 516and setting <code>directories.bin</code> is an error. If you want to specify 517individual files, use <code>bin</code>, and for all the files in an existing <code>bin</code> 518directory, use <code>directories.bin</code>.</p> 519<h4 id="directoriesman">directories.man</h4> 520<p>A folder that is full of man pages. Sugar to generate a "man" array by 521walking the folder.</p> 522<h3 id="repository">repository</h3> 523<p>Specify the place where your code lives. This is helpful for people who 524want to contribute. If the git repo is on GitHub, then the <code>npm docs</code> 525command will be able to find you.</p> 526<p>Do it like this:</p> 527<pre><code class="language-json">{ 528 "repository": { 529 "type": "git", 530 "url": "https://github.com/npm/cli.git" 531 } 532} 533</code></pre> 534<p>The URL should be a publicly available (perhaps read-only) url that can be 535handed directly to a VCS program without any modification. It should not 536be a url to an html project page that you put in your browser. It's for 537computers.</p> 538<p>For GitHub, GitHub gist, Bitbucket, or GitLab repositories you can use the 539same shortcut syntax you use for <code>npm install</code>:</p> 540<pre><code class="language-json">{ 541 "repository": "npm/npm", 542 543 "repository": "github:user/repo", 544 545 "repository": "gist:11081aaa281", 546 547 "repository": "bitbucket:user/repo", 548 549 "repository": "gitlab:user/repo" 550} 551</code></pre> 552<p>If the <code>package.json</code> for your package is not in the root directory (for 553example if it is part of a monorepo), you can specify the directory in 554which it lives:</p> 555<pre><code class="language-json">{ 556 "repository": { 557 "type": "git", 558 "url": "https://github.com/facebook/react.git", 559 "directory": "packages/react-dom" 560 } 561} 562</code></pre> 563<h3 id="scripts">scripts</h3> 564<p>The "scripts" property is a dictionary containing script commands that are 565run at various times in the lifecycle of your package. The key is the 566lifecycle event, and the value is the command to run at that point.</p> 567<p>See <a href="../using-npm/scripts.html"><code>scripts</code></a> to find out more about writing package 568scripts.</p> 569<h3 id="config">config</h3> 570<p>A "config" object can be used to set configuration parameters used in 571package scripts that persist across upgrades. For instance, if a package 572had the following:</p> 573<pre><code class="language-json">{ 574 "name": "foo", 575 "config": { 576 "port": "8080" 577 } 578} 579</code></pre> 580<p>It could also have a "start" command that referenced the 581<code>npm_package_config_port</code> environment variable.</p> 582<h3 id="dependencies">dependencies</h3> 583<p>Dependencies are specified in a simple object that maps a package name to a 584version range. The version range is a string which has one or more 585space-separated descriptors. Dependencies can also be identified with a 586tarball or git URL.</p> 587<p><strong>Please do not put test harnesses or transpilers or other "development" 588time tools in your <code>dependencies</code> object.</strong> See <code>devDependencies</code>, below.</p> 589<p>See <a href="https://github.com/npm/node-semver#versions">semver</a> for more details about specifying version ranges.</p> 590<ul> 591<li><code>version</code> Must match <code>version</code> exactly</li> 592<li><code>>version</code> Must be greater than <code>version</code></li> 593<li><code>>=version</code> etc</li> 594<li><code><version</code></li> 595<li><code><=version</code></li> 596<li><code>~version</code> "Approximately equivalent to version" See 597<a href="https://github.com/npm/node-semver#versions">semver</a></li> 598<li><code>^version</code> "Compatible with version" See <a href="https://github.com/npm/node-semver#versions">semver</a></li> 599<li><code>1.2.x</code> 1.2.0, 1.2.1, etc., but not 1.3.0</li> 600<li><code>http://...</code> See 'URLs as Dependencies' below</li> 601<li><code>*</code> Matches any version</li> 602<li><code>""</code> (just an empty string) Same as <code>*</code></li> 603<li><code>version1 - version2</code> Same as <code>>=version1 <=version2</code>.</li> 604<li><code>range1 || range2</code> Passes if either range1 or range2 are satisfied.</li> 605<li><code>git...</code> See 'Git URLs as Dependencies' below</li> 606<li><code>user/repo</code> See 'GitHub URLs' below</li> 607<li><code>tag</code> A specific version tagged and published as <code>tag</code> See <a href="../commands/npm-dist-tag.html"><code>npm dist-tag</code></a></li> 608<li><code>path/path/path</code> See <a href="#local-paths">Local Paths</a> below</li> 609</ul> 610<p>For example, these are all valid:</p> 611<pre><code class="language-json">{ 612 "dependencies": { 613 "foo": "1.0.0 - 2.9999.9999", 614 "bar": ">=1.0.2 <2.1.2", 615 "baz": ">1.0.2 <=2.3.4", 616 "boo": "2.0.1", 617 "qux": "<1.0.0 || >=2.3.1 <2.4.5 || >=2.5.2 <3.0.0", 618 "asd": "http://asdf.com/asdf.tar.gz", 619 "til": "~1.2", 620 "elf": "~1.2.3", 621 "two": "2.x", 622 "thr": "3.3.x", 623 "lat": "latest", 624 "dyl": "file:../dyl" 625 } 626} 627</code></pre> 628<h4 id="urls-as-dependencies">URLs as Dependencies</h4> 629<p>You may specify a tarball URL in place of a version range.</p> 630<p>This tarball will be downloaded and installed locally to your package at 631install time.</p> 632<h4 id="git-urls-as-dependencies">Git URLs as Dependencies</h4> 633<p>Git urls are of the form:</p> 634<pre><code class="language-bash"><protocol>://[<user>[:<password>]@]<hostname>[:<port>][:][/]<path>[#<commit-ish> | #semver:<semver>] 635</code></pre> 636<p><code><protocol></code> is one of <code>git</code>, <code>git+ssh</code>, <code>git+http</code>, <code>git+https</code>, or 637<code>git+file</code>.</p> 638<p>If <code>#<commit-ish></code> is provided, it will be used to clone exactly that 639commit. If the commit-ish has the format <code>#semver:<semver></code>, <code><semver></code> can 640be any valid semver range or exact version, and npm will look for any tags 641or refs matching that range in the remote repository, much as it would for 642a registry dependency. If neither <code>#<commit-ish></code> or <code>#semver:<semver></code> is 643specified, then the default branch is used.</p> 644<p>Examples:</p> 645<pre><code class="language-bash">git+ssh://git@github.com:npm/cli.git#v1.0.27 646git+ssh://git@github.com:npm/cli#semver:^5.0 647git+https://isaacs@github.com/npm/cli.git 648git://github.com/npm/cli.git#v1.0.27 649</code></pre> 650<p>When installing from a <code>git</code> repository, the presence of certain fields in the 651<code>package.json</code> will cause npm to believe it needs to perform a build. To do so 652your repository will be cloned into a temporary directory, all of its deps 653installed, relevant scripts run, and the resulting directory packed and 654installed.</p> 655<p>This flow will occur if your git dependency uses <code>workspaces</code>, or if any of the 656following scripts are present:</p> 657<ul> 658<li><code>build</code></li> 659<li><code>prepare</code></li> 660<li><code>prepack</code></li> 661<li><code>preinstall</code></li> 662<li><code>install</code></li> 663<li><code>postinstall</code></li> 664</ul> 665<p>If your git repository includes pre-built artifacts, you will likely want to 666make sure that none of the above scripts are defined, or your dependency 667will be rebuilt for every installation.</p> 668<h4 id="github-urls">GitHub URLs</h4> 669<p>As of version 1.1.65, you can refer to GitHub urls as just "foo": 670"user/foo-project". Just as with git URLs, a <code>commit-ish</code> suffix can be 671included. For example:</p> 672<pre><code class="language-json">{ 673 "name": "foo", 674 "version": "0.0.0", 675 "dependencies": { 676 "express": "expressjs/express", 677 "mocha": "mochajs/mocha#4727d357ea", 678 "module": "user/repo#feature\/branch" 679 } 680} 681</code></pre> 682<h4 id="local-paths">Local Paths</h4> 683<p>As of version 2.0.0 you can provide a path to a local directory that 684contains a package. Local paths can be saved using <code>npm install -S</code> or <code>npm install --save</code>, using any of these forms:</p> 685<pre><code class="language-bash">../foo/bar 686~/foo/bar 687./foo/bar 688/foo/bar 689</code></pre> 690<p>in which case they will be normalized to a relative path and added to your 691<code>package.json</code>. For example:</p> 692<pre><code class="language-json">{ 693 "name": "baz", 694 "dependencies": { 695 "bar": "file:../foo/bar" 696 } 697} 698</code></pre> 699<p>This feature is helpful for local offline development and creating tests 700that require npm installing where you don't want to hit an external server, 701but should not be used when publishing your package to the public registry.</p> 702<p><em>note</em>: Packages linked by local path will not have their own 703dependencies installed when <code>npm install</code> is ran in this case. You must 704run <code>npm install</code> from inside the local path itself.</p> 705<h3 id="devdependencies">devDependencies</h3> 706<p>If someone is planning on downloading and using your module in their 707program, then they probably don't want or need to download and build the 708external test or documentation framework that you use.</p> 709<p>In this case, it's best to map these additional items in a 710<code>devDependencies</code> object.</p> 711<p>These things will be installed when doing <code>npm link</code> or <code>npm install</code> from 712the root of a package, and can be managed like any other npm configuration 713param. See <a href="../using-npm/config.html"><code>config</code></a> for more on the topic.</p> 714<p>For build steps that are not platform-specific, such as compiling 715CoffeeScript or other languages to JavaScript, use the <code>prepare</code> script to 716do this, and make the required package a devDependency.</p> 717<p>For example:</p> 718<pre><code class="language-json">{ 719 "name": "ethopia-waza", 720 "description": "a delightfully fruity coffee varietal", 721 "version": "1.2.3", 722 "devDependencies": { 723 "coffee-script": "~1.6.3" 724 }, 725 "scripts": { 726 "prepare": "coffee -o lib/ -c src/waza.coffee" 727 }, 728 "main": "lib/waza.js" 729} 730</code></pre> 731<p>The <code>prepare</code> script will be run before publishing, so that users can 732consume the functionality without requiring them to compile it themselves. 733In dev mode (ie, locally running <code>npm install</code>), it'll run this script as 734well, so that you can test it easily.</p> 735<h3 id="peerdependencies">peerDependencies</h3> 736<p>In some cases, you want to express the compatibility of your package with a 737host tool or library, while not necessarily doing a <code>require</code> of this host. 738This is usually referred to as a <em>plugin</em>. Notably, your module may be 739exposing a specific interface, expected and specified by the host 740documentation.</p> 741<p>For example:</p> 742<pre><code class="language-json">{ 743 "name": "tea-latte", 744 "version": "1.3.5", 745 "peerDependencies": { 746 "tea": "2.x" 747 } 748} 749</code></pre> 750<p>This ensures your package <code>tea-latte</code> can be installed <em>along</em> with the 751second major version of the host package <code>tea</code> only. <code>npm install tea-latte</code> could possibly yield the following dependency graph:</p> 752<pre><code class="language-bash">├── tea-latte@1.3.5 753└── tea@2.2.0 754</code></pre> 755<p>In npm versions 3 through 6, <code>peerDependencies</code> were not automatically 756installed, and would raise a warning if an invalid version of the peer 757dependency was found in the tree. As of npm v7, peerDependencies <em>are</em> 758installed by default.</p> 759<p>Trying to install another plugin with a conflicting requirement may cause 760an error if the tree cannot be resolved correctly. For this reason, make 761sure your plugin requirement is as broad as possible, and not to lock it 762down to specific patch versions.</p> 763<p>Assuming the host complies with <a href="https://semver.org/">semver</a>, only changes 764in the host package's major version will break your plugin. Thus, if you've 765worked with every 1.x version of the host package, use <code>"^1.0"</code> or <code>"1.x"</code> 766to express this. If you depend on features introduced in 1.5.2, use 767<code>"^1.5.2"</code>.</p> 768<h3 id="peerdependenciesmeta">peerDependenciesMeta</h3> 769<p>When a user installs your package, npm will emit warnings if packages 770specified in <code>peerDependencies</code> are not already installed. The 771<code>peerDependenciesMeta</code> field serves to provide npm more information on how 772your peer dependencies are to be used. Specifically, it allows peer 773dependencies to be marked as optional.</p> 774<p>For example:</p> 775<pre><code class="language-json">{ 776 "name": "tea-latte", 777 "version": "1.3.5", 778 "peerDependencies": { 779 "tea": "2.x", 780 "soy-milk": "1.2" 781 }, 782 "peerDependenciesMeta": { 783 "soy-milk": { 784 "optional": true 785 } 786 } 787} 788</code></pre> 789<p>Marking a peer dependency as optional ensures npm will not emit a warning 790if the <code>soy-milk</code> package is not installed on the host. This allows you to 791integrate and interact with a variety of host packages without requiring 792all of them to be installed.</p> 793<h3 id="bundledependencies">bundleDependencies</h3> 794<p>This defines an array of package names that will be bundled when publishing 795the package.</p> 796<p>In cases where you need to preserve npm packages locally or have them 797available through a single file download, you can bundle the packages in a 798tarball file by specifying the package names in the <code>bundleDependencies</code> 799array and executing <code>npm pack</code>.</p> 800<p>For example:</p> 801<p>If we define a package.json like this:</p> 802<pre><code class="language-json">{ 803 "name": "awesome-web-framework", 804 "version": "1.0.0", 805 "bundleDependencies": [ 806 "renderized", 807 "super-streams" 808 ] 809} 810</code></pre> 811<p>we can obtain <code>awesome-web-framework-1.0.0.tgz</code> file by running <code>npm pack</code>. 812This file contains the dependencies <code>renderized</code> and <code>super-streams</code> which 813can be installed in a new project by executing <code>npm install awesome-web-framework-1.0.0.tgz</code>. Note that the package names do not 814include any versions, as that information is specified in <code>dependencies</code>.</p> 815<p>If this is spelled <code>"bundledDependencies"</code>, then that is also honored.</p> 816<p>Alternatively, <code>"bundleDependencies"</code> can be defined as a boolean value. A 817value of <code>true</code> will bundle all dependencies, a value of <code>false</code> will bundle 818none.</p> 819<h3 id="optionaldependencies">optionalDependencies</h3> 820<p>If a dependency can be used, but you would like npm to proceed if it cannot 821be found or fails to install, then you may put it in the 822<code>optionalDependencies</code> object. This is a map of package name to version or 823url, just like the <code>dependencies</code> object. The difference is that build 824failures do not cause installation to fail. Running <code>npm install --omit=optional</code> will prevent these dependencies from being installed.</p> 825<p>It is still your program's responsibility to handle the lack of the 826dependency. For example, something like this:</p> 827<pre><code class="language-js">try { 828 var foo = require('foo') 829 var fooVersion = require('foo/package.json').version 830} catch (er) { 831 foo = null 832} 833if ( notGoodFooVersion(fooVersion) ) { 834 foo = null 835} 836 837// .. then later in your program .. 838 839if (foo) { 840 foo.doFooThings() 841} 842</code></pre> 843<p>Entries in <code>optionalDependencies</code> will override entries of the same name in 844<code>dependencies</code>, so it's usually best to only put in one place.</p> 845<h3 id="overrides">overrides</h3> 846<p>If you need to make specific changes to dependencies of your dependencies, for 847example replacing the version of a dependency with a known security issue, 848replacing an existing dependency with a fork, or making sure that the same 849version of a package is used everywhere, then you may add an override.</p> 850<p>Overrides provide a way to replace a package in your dependency tree with 851another version, or another package entirely. These changes can be scoped as 852specific or as vague as desired.</p> 853<p>To make sure the package <code>foo</code> is always installed as version <code>1.0.0</code> no matter 854what version your dependencies rely on:</p> 855<pre><code class="language-json">{ 856 "overrides": { 857 "foo": "1.0.0" 858 } 859} 860</code></pre> 861<p>The above is a short hand notation, the full object form can be used to allow 862overriding a package itself as well as a child of the package. This will cause 863<code>foo</code> to always be <code>1.0.0</code> while also making <code>bar</code> at any depth beyond <code>foo</code> 864also <code>1.0.0</code>:</p> 865<pre><code class="language-json">{ 866 "overrides": { 867 "foo": { 868 ".": "1.0.0", 869 "bar": "1.0.0" 870 } 871 } 872} 873</code></pre> 874<p>To only override <code>foo</code> to be <code>1.0.0</code> when it's a child (or grandchild, or great 875grandchild, etc) of the package <code>bar</code>:</p> 876<pre><code class="language-json">{ 877 "overrides": { 878 "bar": { 879 "foo": "1.0.0" 880 } 881 } 882} 883</code></pre> 884<p>Keys can be nested to any arbitrary length. To override <code>foo</code> only when it's a 885child of <code>bar</code> and only when <code>bar</code> is a child of <code>baz</code>:</p> 886<pre><code class="language-json">{ 887 "overrides": { 888 "baz": { 889 "bar": { 890 "foo": "1.0.0" 891 } 892 } 893 } 894} 895</code></pre> 896<p>The key of an override can also include a version, or range of versions. 897To override <code>foo</code> to <code>1.0.0</code>, but only when it's a child of <code>bar@2.0.0</code>:</p> 898<pre><code class="language-json">{ 899 "overrides": { 900 "bar@2.0.0": { 901 "foo": "1.0.0" 902 } 903 } 904} 905</code></pre> 906<p>You may not set an override for a package that you directly depend on unless 907both the dependency and the override itself share the exact same spec. To make 908this limitation easier to deal with, overrides may also be defined as a 909reference to a spec for a direct dependency by prefixing the name of the 910package you wish the version to match with a <code>$</code>.</p> 911<pre><code class="language-json">{ 912 "dependencies": { 913 "foo": "^1.0.0" 914 }, 915 "overrides": { 916 // BAD, will throw an EOVERRIDE error 917 // "foo": "^2.0.0" 918 // GOOD, specs match so override is allowed 919 // "foo": "^1.0.0" 920 // BEST, the override is defined as a reference to the dependency 921 "foo": "$foo", 922 // the referenced package does not need to match the overridden one 923 "bar": "$foo" 924 } 925} 926</code></pre> 927<h3 id="engines">engines</h3> 928<p>You can specify the version of node that your stuff works on:</p> 929<pre><code class="language-json">{ 930 "engines": { 931 "node": ">=0.10.3 <15" 932 } 933} 934</code></pre> 935<p>And, like with dependencies, if you don't specify the version (or if you 936specify "*" as the version), then any version of node will do.</p> 937<p>You can also use the "engines" field to specify which versions of npm are 938capable of properly installing your program. For example:</p> 939<pre><code class="language-json">{ 940 "engines": { 941 "npm": "~1.0.20" 942 } 943} 944</code></pre> 945<p>Unless the user has set the 946<a href="../using-npm/config#engine-strict.html"><code>engine-strict</code> config</a> flag, this field is 947advisory only and will only produce warnings when your package is installed as a 948dependency.</p> 949<h3 id="os">os</h3> 950<p>You can specify which operating systems your 951module will run on:</p> 952<pre><code class="language-json">{ 953 "os": [ 954 "darwin", 955 "linux" 956 ] 957} 958</code></pre> 959<p>You can also block instead of allowing operating systems, just prepend the 960blocked os with a '!':</p> 961<pre><code class="language-json">{ 962 "os": [ 963 "!win32" 964 ] 965} 966</code></pre> 967<p>The host operating system is determined by <code>process.platform</code></p> 968<p>It is allowed to both block and allow an item, although there isn't any 969good reason to do this.</p> 970<h3 id="cpu">cpu</h3> 971<p>If your code only runs on certain cpu architectures, 972you can specify which ones.</p> 973<pre><code class="language-json">{ 974 "cpu": [ 975 "x64", 976 "ia32" 977 ] 978} 979</code></pre> 980<p>Like the <code>os</code> option, you can also block architectures:</p> 981<pre><code class="language-json">{ 982 "cpu": [ 983 "!arm", 984 "!mips" 985 ] 986} 987</code></pre> 988<p>The host architecture is determined by <code>process.arch</code></p> 989<h3 id="private">private</h3> 990<p>If you set <code>"private": true</code> in your package.json, then npm will refuse to 991publish it.</p> 992<p>This is a way to prevent accidental publication of private repositories. 993If you would like to ensure that a given package is only ever published to 994a specific registry (for example, an internal registry), then use the 995<code>publishConfig</code> dictionary described below to override the <code>registry</code> 996config param at publish-time.</p> 997<h3 id="publishconfig">publishConfig</h3> 998<p>This is a set of config values that will be used at publish-time. It's 999especially handy if you want to set the tag, registry or access, so that 1000you can ensure that a given package is not tagged with "latest", published 1001to the global public registry or that a scoped module is private by 1002default.</p> 1003<p>See <a href="../using-npm/config.html"><code>config</code></a> to see the list of config options that 1004can be overridden.</p> 1005<h3 id="workspaces">workspaces</h3> 1006<p>The optional <code>workspaces</code> field is an array of file patterns that describes 1007locations within the local file system that the install client should look 1008up to find each <a href="../using-npm/workspaces.html">workspace</a> that needs to be 1009symlinked to the top level <code>node_modules</code> folder.</p> 1010<p>It can describe either the direct paths of the folders to be used as 1011workspaces or it can define globs that will resolve to these same folders.</p> 1012<p>In the following example, all folders located inside the folder 1013<code>./packages</code> will be treated as workspaces as long as they have valid 1014<code>package.json</code> files inside them:</p> 1015<pre><code class="language-json">{ 1016 "name": "workspace-example", 1017 "workspaces": [ 1018 "./packages/*" 1019 ] 1020} 1021</code></pre> 1022<p>See <a href="../using-npm/workspaces.html"><code>workspaces</code></a> for more examples.</p> 1023<h3 id="default-values">DEFAULT VALUES</h3> 1024<p>npm will default some values based on package contents.</p> 1025<ul> 1026<li> 1027<p><code>"scripts": {"start": "node server.js"}</code></p> 1028<p>If there is a <code>server.js</code> file in the root of your package, then npm will 1029default the <code>start</code> command to <code>node server.js</code>.</p> 1030</li> 1031<li> 1032<p><code>"scripts":{"install": "node-gyp rebuild"}</code></p> 1033<p>If there is a <code>binding.gyp</code> file in the root of your package and you have 1034not defined an <code>install</code> or <code>preinstall</code> script, npm will default the 1035<code>install</code> command to compile using node-gyp.</p> 1036</li> 1037<li> 1038<p><code>"contributors": [...]</code></p> 1039<p>If there is an <code>AUTHORS</code> file in the root of your package, npm will treat 1040each line as a <code>Name <email> (url)</code> format, where email and url are 1041optional. Lines which start with a <code>#</code> or are blank, will be ignored.</p> 1042</li> 1043</ul> 1044<h3 id="see-also">SEE ALSO</h3> 1045<ul> 1046<li><a href="https://github.com/npm/node-semver#versions">semver</a></li> 1047<li><a href="../using-npm/workspaces.html">workspaces</a></li> 1048<li><a href="../commands/npm-init.html">npm init</a></li> 1049<li><a href="../commands/npm-version.html">npm version</a></li> 1050<li><a href="../commands/npm-config.html">npm config</a></li> 1051<li><a href="../commands/npm-help.html">npm help</a></li> 1052<li><a href="../commands/npm-install.html">npm install</a></li> 1053<li><a href="../commands/npm-publish.html">npm publish</a></li> 1054<li><a href="../commands/npm-uninstall.html">npm uninstall</a></li> 1055</ul></div> 1056 1057<footer id="edit"> 1058<a href="https://github.com/npm/cli/edit/latest/docs/content/configuring-npm/package-json.md"> 1059<svg role="img" viewBox="0 0 16 16" width="16" height="16" fill="currentcolor" style="vertical-align: text-bottom; margin-right: 0.3em;"> 1060<path fill-rule="evenodd" d="M11.013 1.427a1.75 1.75 0 012.474 0l1.086 1.086a1.75 1.75 0 010 2.474l-8.61 8.61c-.21.21-.47.364-.756.445l-3.251.93a.75.75 0 01-.927-.928l.929-3.25a1.75 1.75 0 01.445-.758l8.61-8.61zm1.414 1.06a.25.25 0 00-.354 0L10.811 3.75l1.439 1.44 1.263-1.263a.25.25 0 000-.354l-1.086-1.086zM11.189 6.25L9.75 4.81l-6.286 6.287a.25.25 0 00-.064.108l-.558 1.953 1.953-.558a.249.249 0 00.108-.064l6.286-6.286z"></path> 1061</svg> 1062Edit this page on GitHub 1063</a> 1064</footer> 1065</section> 1066 1067 1068 1069</body></html>