dart pub get

Get is one of the commands of the pub tool.

$ dart pub get [options]

This command gets all the dependencies listed in the pubspec.yaml file in the current working directory, as well as their transitive dependenciesTransitive dependencyA dependency that a package indirectly uses because one of its dependencies requires it. Learn more. For example:

$ dart pub get
Resolving dependencies...
Got dependencies!

If the system cachePub system cacheA directory where pub stores downloaded remote packages. Learn more doesn't already contain the dependencies, dart pub get updates the cache, downloading dependencies if necessary. To map packages back to the system cache, this command creates a package_config.json file in the .dart_tool/ directory.

Once the dependencies are acquired, they may be referenced in Dart code. For example, if a package depends on test:

import 'package:test/test.dart';

When dart pub get gets new dependencies, it writes a lockfileLockfileA file named pubspec.lock that specifies the versions of each dependency. Learn more to ensure that future gets will use the same versions of those dependencies. Application packagesApplication packageA Dart package that contains a runnable application. Learn more should check in the lockfile to source control; this ensures the application will use the exact same versions of all dependencies for all developers and when deployed to production. Regular packages should not check in the lockfile, though, since they're expected to work with a range of dependency versions.

If a lockfile already exists, dart pub get uses the versions of dependencies locked in it if possible. If a dependency isn't locked, pub gets the latest version of that dependency that satisfies all the version constraintsVersion constraintA constraint associated with each dependency that specifies which versions a package is expected to work with. Learn more. This is the primary difference between dart pub get and dart pub upgrade, which always tries to get the latest versions of all dependencies.

By default, pub creates a package_config.json file in the .dart_tool/ directory that maps from package names to location URIs.

If a dependency is added to the pubspec and then dart pub get is run, it gets the new dependency and any of its transitive dependencies. However, pub won't change the versions of any already-acquired dependencies unless that's necessary to get the new dependency.

If a dependency is removed from the pubspec and then dart pub get is run, the dependency is no longer available for importing. Any transitive dependencies of the removed dependency are also removed, as long as no remaining immediate dependencies also depend on them. Removing a dependency never changes the versions of any already-acquired dependencies.

Dependencies downloaded over the internet, such as those from Git and the pub.dev site, are stored in a system-wide cachePub system cacheA directory where pub stores downloaded remote packages. Learn more. This means that if multiple packages use the same version of the same dependency, it only needs to be downloaded and stored locally once.

By default, the system package cache is located in the .pub-cache subdirectory of your home directory (on macOS and Linux), or in %LOCALAPPDATA%\Pub\Cache (on Windows; the location might vary depending on the Windows version). You can configure the location of the cache by setting the PUB_CACHE environment variable before running pub.

If you don't have network access, you can still run dart pub get. Because pub downloads packages to a central cache shared by all packages on your system, it can often find previously downloaded packages without needing to use the network.

However, by default, dart pub get tries to go online if you have any hosted dependencies, so that pub can detect newer versions of dependencies. If you don't want pub to do that, pass it the --offline flag. In offline mode, pub looks only in your local package cache, trying to find a set of versions that work with your package from what's already available.

Keep in mind that pub generates a lockfile. If the only version of some dependency in your cache happens to be old, offline dart pub get locks your app to that old version. The next time you are online, you will likely want to run dart pub upgrade to upgrade to a later version.

For options that apply to all pub commands, see Global options.

By default, pub connects to the network to retrieve hosted packages (--no-offline). To use cached packages instead, use --offline. For details, see Getting while offline.

Reports the dependencies that would be changed, but doesn't make the changes. This is useful if you want to analyze updates before making them.

By default, pub precompiles executables in immediate dependencies (--precompile). To prevent precompilation, use --no-precompile.

Enforce the resolution of the current pubspec.lock.

Fail the pub get with an error message if the pubspec.lock does not exactly specify a valid resolution of pubspec.yaml or if any content hash of a hosted package has changed.

Useful for CI or deploying to production.

Read Get dependencies for production for more details.