npm-ci (1) - Linux Manuals

npm-ci: Install a project with a clean slate


npm-ci - Install a project with a clean slate


npm ci


Make sure you have a package-lock and an up-to-date install:

$ cd ./my/npm/project
$ npm install
added 154 packages in 10s
$ ls | grep package-lock

Run npm ci in that project

$ npm ci
added 154 packages in 5s

Configure Travis to build using npm ci instead of npm install:

# .travis.yml
- npm ci
# keep the npm cache around to speed up installs
  - "$HOME/.npm"


This command is similar to npm help install, except it's meant to be used in automated environments such as test platforms, continuous integration, and deployment -- or any situation where you want to make sure you're doing a clean install of your dependencies. It can be significantly faster than a regular npm install by skipping certain user-oriented features. It is also more strict than a regular install, which can help catch errors or inconsistencies caused by the incrementally-installed local environments of most npm users.

In short, the main differences between using npm install and npm ci are:

The project must have an existing package-lock.json or npm-shrinkwrap.json.
If dependencies in the package lock do not match those in package.json, npm ci will exit with an error, instead of updating the package lock.
npm ci can only install entire projects at a time: individual dependencies cannot be added with this command.
If a node_modules is already present, it will be automatically removed before npm ci begins its install.
It will never write to package.json or any of the package-locks: installs are essentially frozen.

See Also

npm help install
npm help package-locks