Bazelisk is a launcher for Bazel which automatically downloads and installs an appropriate version of Bazel. Use Bazelisk if you need to switch between different versions of Bazel depending on the current working directory, or to always keep Bazel updated to the latest release.
You can install Bazelisk in multiple ways, including:
npm install -g @bazel/bazelisk
go get github.com/bazelbuild/bazelisk
For more details, see the official README.