All packages downloaded from the registry are stored in a global cache at ~/.bun/install/cache
. They are stored in subdirectories named like ${name}@${version}
, so multiple versions of a package can be cached.
[install.cache]
# the directory to use for the cache
dir = "~/.bun/install/cache"
# when true, don't load from the global cache.
# Bun may still write to node_modules/.cache
disable = false
# when true, always resolve the latest versions from the registry
disableManifest = false
See details
Minimizing re-downloads
Bun strives to avoid re-downloading packages multiple times. When installing a package, if the cache already contains a version in the range specified by package.json
, Bun will use the cached package instead of downloading it again.
Installation details
Fast copying
Once a package is downloaded into the cache, Bun still needs to copy those files into node_modules
. Bun uses the fastest syscalls available to perform this task. On Linux, it uses hardlinks; on macOS, it uses clonefile
.
Saving disk space
Since Bun uses hardlinks to "copy" a module into a project's node_modules
directory on Linux, the contents of the package only exist in a single location on disk, greatly reducing the amount of disk space dedicated to node_modules
.
This benefit also applies to macOS, but there are exceptions. It uses clonefile
which is copy-on-write, meaning it will not occupy disk space, but it will count towards drive's limit. This behavior is useful if something attempts to patch node_modules/*
, so it's impossible to affect other installations.
Installation strategies