1NPM-EXEC(1) NPM-EXEC(1)
2
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 npm exec [--ws] [-w <workspace-name] [args...]
14 npx <pkg>[@<specifier>] [args...]
16 npx -p <pkg>[@<specifier>] <cmd> [args...]
17 npx -c '<cmd> [args...]'
18 npx -p <pkg>[@<specifier>] -c '<cmd> [args...]'
19 Run without --call or positional args to open interactive subshell
20 alias: npm x, npx
22 common options:
24 --package=<pkg> (may be specified multiple times)
25 -p is a shorthand for --package only when using npx executable
26 -c <cmd> --call=<cmd> (may not be mixed with positional arguments)
27 Description
29 This command allows you to run an arbitrary command from an npm package
30 (either one installed locally, or fetched remotely), in a similar con‐
31 text as running it via npm run.
32 Run without positional arguments or --call, this allows you to interac‐
34 tively run commands in the same sort of shell environment that pack‐
35 age.json scripts are run. Interactive mode is not supported in CI en‐
36 vironments when standard input is a TTY, to prevent hangs.
37 Whatever packages are specified by the --package option will be pro‐
39 vided in the PATH of the executed command, along with any locally in‐
40 stalled package executables. The --package option may be specified
41 multiple times, to execute the supplied command in an environment where
42 all specified packages are available.
43 If any requested packages are not present in the local project depen‐
45 dencies, then they are installed to a folder in the npm cache, which is
46 added to the PATH environment variable in the executed process. A
47 prompt is printed (which can be suppressed by providing either --yes or
48 --no).
49 Package names provided without a specifier will be matched with what‐
51 ever version exists in the local project. Package names with a speci‐
52 fier will only be considered a match if they have the exact same name
53 and version as the local dependency.
54 If no -c or --call option is provided, then the positional arguments
56 are used to generate the command string. If no --package options are
57 provided, then npm will attempt to determine the executable name from
58 the package specifier provided as the first positional argument accord‐
59 ing to the following heuristic:
60 • If the package has a single entry in its bin field in package.json,
62 or if all entries are aliases of the same command, then that command
63 will be used.
64 • If the package has multiple bin entries, and one of them matches the
66 unscoped portion of the name field, then that command will be used.
67 • If this does not result in exactly one option (either because there
69 are no bin entries, or none of them match the name of the package),
70 then npm exec exits with an error.
71 To run a binary other than the named binary, specify one or more
74 --package options, which will prevent npm from inferring the package
75 from the first command argument.
76 npx vs npm exec
78 When run via the npx binary, all flags and options must be set prior to
79 any positional arguments. When run via npm exec, a double-hyphen --
80 flag can be used to suppress npm's parsing of switches and options that
81 should be sent to the executed command.
82 For example:
84 $ npx foo@latest bar --package=@npmcli/foo
86 In this case, npm will resolve the foo package name, and run the fol‐
88 lowing command:
89 $ foo bar --package=@npmcli/foo
91 Since the --package option comes after the positional arguments, it is
93 treated as an argument to the executed command.
94 In contrast, due to npm's argument parsing logic, running this command
96 is different:
97 $ npm exec foo@latest bar --package=@npmcli/foo
99 In this case, npm will parse the --package option first, resolving the
101 @npmcli/foo package. Then, it will execute the following command in
102 that context:
103 $ foo@latest bar
105 The double-hyphen character is recommended to explicitly tell npm to
107 stop parsing command line options and switches. The following command
108 would thus be equivalent to the npx command above:
109 $ npm exec -- foo@latest bar --package=@npmcli/foo
111 Configuration
113 <!-- AUTOGENERATED CONFIG DESCRIPTIONS START --> <!-- automatically
114 generated, do not edit manually --> <!-- see lib/utils/config/defini‐
115 tions.js -->
116 package
118 • Default:
119 • Type: String (can be set multiple times)
121 The package to install for npm help exec <!-- automatically generated,
124 do not edit manually --> <!-- see lib/utils/config/definitions.js -->
125 call
128 • Default: ""
129 • Type: String
131 Optional companion option for npm exec, npx that allows for specifying
134 a custom command to be run along with the installed packages.
135 npm exec --package yo --package generator-node --call "yo node"
137 <!-- automatically generated, do not edit manually --> <!-- see
138 lib/utils/config/definitions.js -->
139 workspace
142 • Default:
143 • Type: String (can be set multiple times)
145 Enable running a command in the context of the configured workspaces of
148 the current project while filtering by running only the workspaces de‐
149 fined by this configuration option.
150 Valid values for the workspace config are either:
152 • Workspace names
154 • Path to a workspace directory
156 • Path to a parent workspace directory (will result to selecting all of
158 the nested workspaces)
159 When set for the npm init command, this may be set to the folder of a
162 workspace which does not yet exist, to create the folder and set it up
163 as a brand new workspace within the project.
164 This value is not exported to the environment for child processes.
166 <!-- automatically generated, do not edit manually --> <!-- see
167 lib/utils/config/definitions.js -->
168 workspaces
171 • Default: false
172 • Type: Boolean
174 Enable running a command in the context of all the configured
177 workspaces.
178 This value is not exported to the environment for child processes.
180 <!-- automatically generated, do not edit manually --> <!-- see
181 lib/utils/config/definitions.js -->
182 <!-- AUTOGENERATED CONFIG DESCRIPTIONS END -->
184 Examples
187 Run the version of tap in the local dependencies, with the provided ar‐
188 guments:
189 $ npm exec -- tap --bail test/foo.js
191 $ npx tap --bail test/foo.js
192 Run a command other than the command whose name matches the package
194 name by specifying a --package option:
195 $ npm exec --package=foo -- bar --bar-argument
197 # ~ or ~
198 $ npx --package=foo bar --bar-argument
199 Run an arbitrary shell script, in the context of the current project:
201 $ npm x -c 'eslint && say "hooray, lint passed"'
203 $ npx -c 'eslint && say "hooray, lint passed"'
204 Workspaces support
206 You may use the workspace or workspaces configs in order to run an ar‐
207 bitrary command from an npm package (either one installed locally, or
208 fetched remotely) in the context of the specified workspaces. If no
209 positional argument or --call option is provided, it will open an in‐
210 teractive subshell in the context of each of these configured
211 workspaces one at a time.
212 Given a project with configured workspaces, e.g:
214 .
216 +-- package.json
217 `-- packages
218 +-- a
219 | `-- package.json
220 +-- b
221 | `-- package.json
222 `-- c
223 `-- package.json
224 Assuming the workspace configuration is properly set up at the root
226 level package.json file. e.g:
227 {
229 "workspaces": [ "./packages/*" ]
230 }
231 You can execute an arbitrary command from a package in the context of
233 each of the configured workspaces when using the workspaces configura‐
234 tion options, in this example we're using eslint to lint any js file
235 found within each workspace folder:
236 npm exec --ws -- eslint ./*.js
238 Filtering workspaces
240 It's also possible to execute a command in a single workspace using the
241 workspace config along with a name or directory path:
242 npm exec --workspace=a -- eslint ./*.js
244 The workspace config can also be specified multiple times in order to
246 run a specific script in the context of multiple workspaces. When
247 defining values for the workspace config in the command line, it also
248 possible to use -w as a shorthand, e.g:
249 npm exec -w a -w b -- eslint ./*.js
251 This last command will run the eslint command in both ./packages/a and
253 ./packages/b folders.
254 Compatibility with Older npx Versions
256 The npx binary was rewritten in npm v7.0.0, and the standalone npx
257 package deprecated at that time. npx uses the npm exec command instead
258 of a separate argument parser and install process, with some affor‐
259 dances to maintain backwards compatibility with the arguments it ac‐
260 cepted in previous versions.
261 This resulted in some shifts in its functionality:
263 • Any npm config value may be provided.
265 • To prevent security and user-experience problems from mistyping pack‐
267 age names, npx prompts before installing anything. Suppress this
268 prompt with the -y or --yes option.
269 • The --no-install option is deprecated, and will be converted to --no.
271 • Shell fallback functionality is removed, as it is not advisable.
273 • The -p argument is a shorthand for --parseable in npm, but shorthand
275 for --package in npx. This is maintained, but only for the npx exe‐
276 cutable.
277 • The --ignore-existing option is removed. Locally installed bins are
279 always present in the executed process PATH.
280 • The --npm option is removed. npx will always use the npm it ships
282 with.
283 • The --node-arg and -n options are removed.
285 • The --always-spawn option is redundant, and thus removed.
287 • The --shell option is replaced with --script-shell, but maintained in
289 the npx executable for backwards compatibility.
290 A note on caching
293 The npm cli utilizes its internal package cache when using the package
294 name specified. You can use the following to change how and when the
295 cli uses this cache. See npm help cache for more on how the cache
296 works.
297 prefer-online
299 Forces staleness checks for packages, making the cli look for updates
300 immediately even if the package is already in the cache.
301 prefer-offline
303 Bypasses staleness checks for packages. Missing data will still be re‐
304 quested from the server. To force full offline mode, use offline.
305 offline
307 Forces full offline mode. Any packages not locally cached will result
308 in an error.
309 workspace
311 • Default:
312 • Type: String (can be set multiple times)
314 Enable running a command in the context of the configured workspaces of
317 the current project while filtering by running only the workspaces de‐
318 fined by this configuration option.
319 Valid values for the workspace config are either:
321 • Workspace names
323 • Path to a workspace directory
325 • Path to a parent workspace directory (will result to selecting all of
327 the nested workspaces)
328 This value is not exported to the environment for child processes.
331 workspaces
333 • Alias: --ws
334 • Type: Boolean
336 • Default: false
338 Run scripts in the context of all configured workspaces for the current
341 project.
342 See Also
344 • npm help run-script
345 • npm help scripts
347 • npm help test
349 • npm help start
351 • npm help restart
353 • npm help stop
355 • npm help config
357 • npm help workspaces
359 October 2021 NPM-EXEC(1)