1NPM-EXEC(1) NPM-EXEC(1)
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6 npm-exec - Run a command from a local or remote npm package
7 Synopsis
9 npm exec -- <pkg>[@<version>] [args...]
10 npm exec --package=<pkg>[@<version>] -- <cmd> [args...]
11 npm exec -c '<cmd> [args...]'
12 npm exec --package=foo -c '<cmd> [args...]'
13 alias: x
15 Description
17 This command allows you to run an arbitrary command from an npm package
18 (either one installed locally, or fetched remotely), in a similar con‐
19 text as running it via npm run.
20 Run without positional arguments or --call, this allows you to interac‐
22 tively run commands in the same sort of shell environment that pack‐
23 age.json scripts are run. Interactive mode is not supported in CI en‐
24 vironments when standard input is a TTY, to prevent hangs.
25 Whatever packages are specified by the --package option will be pro‐
27 vided in the PATH of the executed command, along with any locally in‐
28 stalled package executables. The --package option may be specified
29 multiple times, to execute the supplied command in an environment where
30 all specified packages are available.
31 If any requested packages are not present in the local project depen‐
33 dencies, then they are installed to a folder in the npm cache, which is
34 added to the PATH environment variable in the executed process. A
35 prompt is printed (which can be suppressed by providing either --yes or
36 --no).
37 Package names provided without a specifier will be matched with what‐
39 ever version exists in the local project. Package names with a speci‐
40 fier will only be considered a match if they have the exact same name
41 and version as the local dependency.
42 If no -c or --call option is provided, then the positional arguments
44 are used to generate the command string. If no --package options are
45 provided, then npm will attempt to determine the executable name from
46 the package specifier provided as the first positional argument accord‐
47 ing to the following heuristic:
48 • If the package has a single entry in its bin field in package.json,
50 or if all entries are aliases of the same command, then that command
51 will be used.
52 • If the package has multiple bin entries, and one of them matches the
54 unscoped portion of the name field, then that command will be used.
55 • If this does not result in exactly one option (either because there
57 are no bin entries, or none of them match the name of the package),
58 then npm exec exits with an error.
59 To run a binary other than the named binary, specify one or more
62 --package options, which will prevent npm from inferring the package
63 from the first command argument.
64 npx vs npm exec
66 When run via the npx binary, all flags and options must be set prior to
67 any positional arguments. When run via npm exec, a double-hyphen --
68 flag can be used to suppress npm's parsing of switches and options that
69 should be sent to the executed command.
70 For example:
72 $ npx foo@latest bar --package=@npmcli/foo
74 In this case, npm will resolve the foo package name, and run the fol‐
76 lowing command:
77 $ foo bar --package=@npmcli/foo
79 Since the --package option comes after the positional arguments, it is
81 treated as an argument to the executed command.
82 In contrast, due to npm's argument parsing logic, running this command
84 is different:
85 $ npm exec foo@latest bar --package=@npmcli/foo
87 In this case, npm will parse the --package option first, resolving the
89 @npmcli/foo package. Then, it will execute the following command in
90 that context:
91 $ foo@latest bar
93 The double-hyphen character is recommended to explicitly tell npm to
95 stop parsing command line options and switches. The following command
96 would thus be equivalent to the npx command above:
97 $ npm exec -- foo@latest bar --package=@npmcli/foo
99 Configuration
101 package
102 • Default:
103 • Type: String (can be set multiple times)
105 The package or packages to install for npm help exec
108 call
110 • Default: ""
111 • Type: String
113 Optional companion option for npm exec, npx that allows for specifying
116 a custom command to be run along with the installed packages.
117 npm exec --package yo --package generator-node --call "yo node"
119 workspace
121 • Default:
122 • Type: String (can be set multiple times)
124 Enable running a command in the context of the configured workspaces of
127 the current project while filtering by running only the workspaces de‐
128 fined by this configuration option.
129 Valid values for the workspace config are either:
131 • Workspace names
133 • Path to a workspace directory
135 • Path to a parent workspace directory (will result in selecting all
137 workspaces within that folder)
138 When set for the npm init command, this may be set to the folder of a
141 workspace which does not yet exist, to create the folder and set it up
142 as a brand new workspace within the project.
143 This value is not exported to the environment for child processes.
145 workspaces
147 • Default: null
148 • Type: null or Boolean
150 Set to true to run the command in the context of all configured
153 workspaces.
154 Explicitly setting this to false will cause commands like install to
156 ignore workspaces altogether. When not set explicitly:
157 • Commands that operate on the node_modules tree (install, update,
159 etc.) will link workspaces into the node_modules folder. - Commands
160 that do other things (test, exec, publish, etc.) will operate on the
161 root project, unless one or more workspaces are specified in the
162 workspace config.
163 This value is not exported to the environment for child processes.
166 include-workspace-root
168 • Default: false
169 • Type: Boolean
171 Include the workspace root when workspaces are enabled for a command.
174 When false, specifying individual workspaces via the workspace config,
176 or all workspaces via the workspaces flag, will cause npm to operate
177 only on the specified workspaces, and not on the root project.
178 This value is not exported to the environment for child processes.
180 Examples
182 Run the version of tap in the local dependencies, with the provided ar‐
183 guments:
184 $ npm exec -- tap --bail test/foo.js
186 $ npx tap --bail test/foo.js
187 Run a command other than the command whose name matches the package
189 name by specifying a --package option:
190 $ npm exec --package=foo -- bar --bar-argument
192 # ~ or ~
193 $ npx --package=foo bar --bar-argument
194 Run an arbitrary shell script, in the context of the current project:
196 $ npm x -c 'eslint && say "hooray, lint passed"'
198 $ npx -c 'eslint && say "hooray, lint passed"'
199 Workspaces support
201 You may use the workspace or workspaces configs in order to run an ar‐
202 bitrary command from an npm package (either one installed locally, or
203 fetched remotely) in the context of the specified workspaces. If no
204 positional argument or --call option is provided, it will open an in‐
205 teractive subshell in the context of each of these configured
206 workspaces one at a time.
207 Given a project with configured workspaces, e.g:
209 .
211 +-- package.json
212 `-- packages
213 +-- a
214 | `-- package.json
215 +-- b
216 | `-- package.json
217 `-- c
218 `-- package.json
219 Assuming the workspace configuration is properly set up at the root
221 level package.json file. e.g:
222 {
224 "workspaces": [ "./packages/*" ]
225 }
226 You can execute an arbitrary command from a package in the context of
228 each of the configured workspaces when using the workspaces configura‐
229 tion options, in this example we're using eslint to lint any js file
230 found within each workspace folder:
231 npm exec --ws -- eslint ./*.js
233 Filtering workspaces
235 It's also possible to execute a command in a single workspace using the
236 workspace config along with a name or directory path:
237 npm exec --workspace=a -- eslint ./*.js
239 The workspace config can also be specified multiple times in order to
241 run a specific script in the context of multiple workspaces. When
242 defining values for the workspace config in the command line, it also
243 possible to use -w as a shorthand, e.g:
244 npm exec -w a -w b -- eslint ./*.js
246 This last command will run the eslint command in both ./packages/a and
248 ./packages/b folders.
249 Compatibility with Older npx Versions
251 The npx binary was rewritten in npm v7.0.0, and the standalone npx
252 package deprecated at that time. npx uses the npm exec command instead
253 of a separate argument parser and install process, with some affor‐
254 dances to maintain backwards compatibility with the arguments it ac‐
255 cepted in previous versions.
256 This resulted in some shifts in its functionality:
258 • Any npm config value may be provided.
260 • To prevent security and user-experience problems from mistyping pack‐
262 age names, npx prompts before installing anything. Suppress this
263 prompt with the -y or --yes option.
264 • The --no-install option is deprecated, and will be converted to --no.
266 • Shell fallback functionality is removed, as it is not advisable.
268 • The -p argument is a shorthand for --parseable in npm, but shorthand
270 for --package in npx. This is maintained, but only for the npx exe‐
271 cutable.
272 • The --ignore-existing option is removed. Locally installed bins are
274 always present in the executed process PATH.
275 • The --npm option is removed. npx will always use the npm it ships
277 with.
278 • The --node-arg and -n options are removed.
280 • The --always-spawn option is redundant, and thus removed.
282 • The --shell option is replaced with --script-shell, but maintained in
284 the npx executable for backwards compatibility.
285 A note on caching
288 The npm cli utilizes its internal package cache when using the package
289 name specified. You can use the following to change how and when the
290 cli uses this cache. See npm help cache for more on how the cache
291 works.
292 prefer-online
294 Forces staleness checks for packages, making the cli look for updates
295 immediately even if the package is already in the cache.
296 prefer-offline
298 Bypasses staleness checks for packages. Missing data will still be re‐
299 quested from the server. To force full offline mode, use offline.
300 offline
302 Forces full offline mode. Any packages not locally cached will result
303 in an error.
304 workspace
306 • Default:
307 • Type: String (can be set multiple times)
309 Enable running a command in the context of the configured workspaces of
312 the current project while filtering by running only the workspaces de‐
313 fined by this configuration option.
314 Valid values for the workspace config are either:
316 • Workspace names
318 • Path to a workspace directory
320 • Path to a parent workspace directory (will result to selecting all of
322 the nested workspaces)
323 This value is not exported to the environment for child processes.
326 workspaces
328 • Alias: --ws
329 • Type: Boolean
331 • Default: false
333 Run scripts in the context of all configured workspaces for the current
336 project.
337 See Also
339 • npm help run-script
340 • npm help scripts
342 • npm help test
344 • npm help start
346 • npm help restart
348 • npm help stop
350 • npm help config
352 • npm help workspaces
354 • npm help npx
356 September 2022 NPM-EXEC(1)