docs/development/prebuilt_packages/prebuilt_cipd_packages_in_fuchsia.md

# Prebuilt CIPD packages in Fuchsia

The Fuchsia project uses Chrome Infrastructure Package Deployment
([CIPD](https://github.com/luci/luci-go/tree/HEAD/cipd){: .external}) to store
and distribute prebuilt files.

Note: A CIPD store is not a package server for Fuchsia devices. In other words,
a Fuchsia device doesn't run components from prebuilt CIPD packages.

A CIPD package is an arbitrary collection of files, stored in
[a remote content-addressed store](https://chrome-infra-packages.appspot.com/p/fuchsia){: .external},
and is distributed to a Fuchsia checkout through the
<code>[jiri](https://fuchsia.googlesource.com/jiri/+/HEAD/){:.external}</code>
tool. Also, using the `cipd` command-line tool, you can download a CIPD package
directly, for example, to examine its content.

CIPD packages are typically used to distribute the following files:

*   Host prebuilt binaries required by the build (for example, clang toolchain).
*   Fuchsia prebuilt
    [ELF](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format){: .external}
    binaries generated out-of-tree (for example, Goldfish Vulkan ICD).
*   Prebuilt Fuchsia archive
    ([FAR](/docs/development/source_code/archive_format.md)) files that contain
    binaries and metadata for software that is built for Fuchsia by other teams
    (for example,
    [chromium/fuchsia/webrunner-arm64](https://chrome-infra-packages.appspot.com/p/chromium/fuchsia/webrunner-arm64/+/){: .external}).

Once you set up continuous integration (CI) with Fuchsia, Fuchsia’s CI system
fetches those new packages and rolls them into the Fuchsia project through the
[global integration](https://fuchsia.googlesource.com/integration/+/refs/heads/master)
process.

<a name="figure-1"></a> <figure>
<img src="/docs/images/prebuilt_packages/publish-prebuilt-packages-to-fuchsia-00.png" alt="The latest ref and other refs shown in the CIPD UI">
<figcaption><b>Figure 1</b>. The CIPD UI shows the latest ref and other refs
used for this CIPD package instances.</figcaption> </figure>

When you publish a new revision of your prebuilt package to CIPD, the `latest`
[ref](https://github.com/luci/luci-go/tree/HEAD/cipd#refs){: .external} in the
CIPD store automatically points to the new revision. Fuchsia’s CI system
monitors your package’s `latest` ref. When it detects that the `latest` ref is
updated, the system fetches the new package and rolls it into the Fuchsia
project.