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  1. <html><head>
  2. <title>npx</title>
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  116. </svg>
  117. <div class="title">
  118. npm command-line interface
  119. </div>
  120. </div>
  121. </div>
  122. <section id="content">
  123. <header class="title">
  124. <h1 id="npx">npx</h1>
  125. <span class="description">Run a command from a local or remote npm package</span>
  126. </header>
  127. <section id="table_of_contents">
  128. <h2 id="table-of-contents">Table of contents</h2>
  129. <div id="_table_of_contents"><ul><li><a href="#synopsis">Synopsis</a></li><li><a href="#description">Description</a></li><li><a href="#npx-vs-npm-exec"><code>npx</code> vs <code>npm exec</code></a></li><li><a href="#examples">Examples</a></li><li><a href="#compatibility-with-older-npx-versions">Compatibility with Older npx Versions</a></li><li><a href="#see-also">See Also</a></li></ul></div>
  130. </section>
  131. <div id="_content"><h3 id="synopsis">Synopsis</h3>
  132. <pre lang="bash"><code>npm exec -- &lt;pkg&gt;[@&lt;version&gt;] [args...]
  133. npm exec --package=&lt;pkg&gt;[@&lt;version&gt;] -- &lt;cmd&gt; [args...]
  134. npm exec -c '&lt;cmd&gt; [args...]'
  135. npm exec --package=foo -c '&lt;cmd&gt; [args...]'
  136. npx &lt;pkg&gt;[@&lt;specifier&gt;] [args...]
  137. npx -p &lt;pkg&gt;[@&lt;specifier&gt;] &lt;cmd&gt; [args...]
  138. npx -c '&lt;cmd&gt; [args...]'
  139. npx -p &lt;pkg&gt;[@&lt;specifier&gt;] -c '&lt;cmd&gt; [args...]'
  140. alias: npm x, npx
  141. --package=&lt;pkg&gt; (may be specified multiple times)
  142. -p is a shorthand for --package only when using npx executable
  143. -c &lt;cmd&gt; --call=&lt;cmd&gt; (may not be mixed with positional arguments)
  144. </code></pre>
  145. <h3 id="description">Description</h3>
  146. <p>This command allows you to run an arbitrary command from an npm package
  147. (either one installed locally, or fetched remotely), in a similar context
  148. as running it via <code>npm run</code>.</p>
  149. <p>Whatever packages are specified by the <code>--package</code> option will be
  150. provided in the <code>PATH</code> of the executed command, along with any locally
  151. installed package executables. The <code>--package</code> option may be
  152. specified multiple times, to execute the supplied command in an environment
  153. where all specified packages are available.</p>
  154. <p>If any requested packages are not present in the local project
  155. dependencies, then they are installed to a folder in the npm cache, which
  156. is added to the <code>PATH</code> environment variable in the executed process. A
  157. prompt is printed (which can be suppressed by providing either <code>--yes</code> or
  158. <code>--no</code>).</p>
  159. <p>Package names provided without a specifier will be matched with whatever
  160. version exists in the local project. Package names with a specifier will
  161. only be considered a match if they have the exact same name and version as
  162. the local dependency.</p>
  163. <p>If no <code>-c</code> or <code>--call</code> option is provided, then the positional arguments
  164. are used to generate the command string. If no <code>--package</code> options
  165. are provided, then npm will attempt to determine the executable name from
  166. the package specifier provided as the first positional argument according
  167. to the following heuristic:</p>
  168. <ul>
  169. <li>If the package has a single entry in its <code>bin</code> field in <code>package.json</code>,
  170. or if all entries are aliases of the same command, then that command
  171. will be used.</li>
  172. <li>If the package has multiple <code>bin</code> entries, and one of them matches the
  173. unscoped portion of the <code>name</code> field, then that command will be used.</li>
  174. <li>If this does not result in exactly one option (either because there are
  175. no bin entries, or none of them match the <code>name</code> of the package), then
  176. <code>npm exec</code> exits with an error.</li>
  177. </ul>
  178. <p>To run a binary <em>other than</em> the named binary, specify one or more
  179. <code>--package</code> options, which will prevent npm from inferring the package from
  180. the first command argument.</p>
  181. <h3 id="npx-vs-npm-exec"><code>npx</code> vs <code>npm exec</code></h3>
  182. <p>When run via the <code>npx</code> binary, all flags and options <em>must</em> be set prior to
  183. any positional arguments. When run via <code>npm exec</code>, a double-hyphen <code>--</code>
  184. flag can be used to suppress npm’s parsing of switches and options that
  185. should be sent to the executed command.</p>
  186. <p>For example:</p>
  187. <pre><code>$ npx foo@latest bar --package=@npmcli/foo
  188. </code></pre>
  189. <p>In this case, npm will resolve the <code>foo</code> package name, and run the
  190. following command:</p>
  191. <pre><code>$ foo bar --package=@npmcli/foo
  192. </code></pre>
  193. <p>Since the <code>--package</code> option comes <em>after</em> the positional arguments, it is
  194. treated as an argument to the executed command.</p>
  195. <p>In contrast, due to npm’s argument parsing logic, running this command is
  196. different:</p>
  197. <pre><code>$ npm exec foo@latest bar --package=@npmcli/foo
  198. </code></pre>
  199. <p>In this case, npm will parse the <code>--package</code> option first, resolving the
  200. <code>@npmcli/foo</code> package. Then, it will execute the following command in that
  201. context:</p>
  202. <pre><code>$ foo@latest bar
  203. </code></pre>
  204. <p>The double-hyphen character is recommended to explicitly tell npm to stop
  205. parsing command line options and switches. The following command would
  206. thus be equivalent to the <code>npx</code> command above:</p>
  207. <pre><code>$ npm exec -- foo@latest bar --package=@npmcli/foo
  208. </code></pre>
  209. <h3 id="examples">Examples</h3>
  210. <p>Run the version of <code>tap</code> in the local dependencies, with the provided
  211. arguments:</p>
  212. <pre><code>$ npm exec -- tap --bail test/foo.js
  213. $ npx tap --bail test/foo.js
  214. </code></pre>
  215. <p>Run a command <em>other than</em> the command whose name matches the package name
  216. by specifying a <code>--package</code> option:</p>
  217. <pre><code>$ npm exec --package=foo -- bar --bar-argument
  218. # ~ or ~
  219. $ npx --package=foo bar --bar-argument
  220. </code></pre>
  221. <p>Run an arbitrary shell script, in the context of the current project:</p>
  222. <pre><code>$ npm x -c 'eslint &amp;&amp; say "hooray, lint passed"'
  223. $ npx -c 'eslint &amp;&amp; say "hooray, lint passed"'
  224. </code></pre>
  225. <h3 id="compatibility-with-older-npx-versions">Compatibility with Older npx Versions</h3>
  226. <p>The <code>npx</code> binary was rewritten in npm v7.0.0, and the standalone <code>npx</code>
  227. package deprecated at that time. <code>npx</code> uses the <code>npm exec</code>
  228. command instead of a separate argument parser and install process, with
  229. some affordances to maintain backwards compatibility with the arguments it
  230. accepted in previous versions.</p>
  231. <p>This resulted in some shifts in its functionality:</p>
  232. <ul>
  233. <li>Any <code>npm</code> config value may be provided.</li>
  234. <li>To prevent security and user-experience problems from mistyping package
  235. names, <code>npx</code> prompts before installing anything. Suppress this
  236. prompt with the <code>-y</code> or <code>--yes</code> option.</li>
  237. <li>The <code>--no-install</code> option is deprecated, and will be converted to <code>--no</code>.</li>
  238. <li>Shell fallback functionality is removed, as it is not advisable.</li>
  239. <li>The <code>-p</code> argument is a shorthand for <code>--parseable</code> in npm, but shorthand
  240. for <code>--package</code> in npx. This is maintained, but only for the <code>npx</code>
  241. executable.</li>
  242. <li>The <code>--ignore-existing</code> option is removed. Locally installed bins are
  243. always present in the executed process <code>PATH</code>.</li>
  244. <li>The <code>--npm</code> option is removed. <code>npx</code> will always use the <code>npm</code> it ships
  245. with.</li>
  246. <li>The <code>--node-arg</code> and <code>-n</code> options are removed.</li>
  247. <li>The <code>--always-spawn</code> option is redundant, and thus removed.</li>
  248. <li>The <code>--shell</code> option is replaced with <code>--script-shell</code>, but maintained
  249. in the <code>npx</code> executable for backwards compatibility.</li>
  250. </ul>
  251. <h3 id="see-also">See Also</h3>
  252. <ul>
  253. <li><a href="../commands/npm-run-script.html">npm run-script</a></li>
  254. <li><a href="../using-npm/scripts.html">npm scripts</a></li>
  255. <li><a href="../commands/npm-test.html">npm test</a></li>
  256. <li><a href="../commands/npm-start.html">npm start</a></li>
  257. <li><a href="../commands/npm-restart.html">npm restart</a></li>
  258. <li><a href="../commands/npm-stop.html">npm stop</a></li>
  259. <li><a href="../commands/npm-config.html">npm config</a></li>
  260. </ul>
  261. </div>
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