Download the Android source

The Android source is located in a collection of Git repositories hosted by Google. The Git repository includes the entire history of the Android source, including changes to the source and when the changes were made. This page describes how to download the source.

Initialize the Repo client

Set up your client to access the Android source repository:

Create and navigate to a working directory:
```
mkdir WORKING_DIRECTORY
cd WORKING_DIRECTORY
```
Note: You can have more than one version of Android on your development machine as long as they exist in separate directories. Each checkout and build uses 300 GB, or more, of space.
Initialize your working directory for source control:
```
repo init --partial-clone -b main -u https://android.googlesource.com/platform/manifest
```
The -b option is used to identify the branch you are initializing. If -b isn't provided, repo init defaults to the main branch. For a list of branches and tag names, see Source code tags and builds.

The -u option is required and is used to specify a manifest file, which is an XML file specifying where the various Git projects in the Android source are placed within your working directory. In this example, the name of the manifest file isn't specified, so the command uses the default manifest file (default.xml).

The output should contain the message:
```
repo has been initialized in path_to_working_directory
```

For information on manifest file format, see repo Manifest Format.

For a list of all Repo commands, see the Repo command reference.

Download the Android source

Run the following command to download the Android source tree to your working directory:

$ repo sync -c -j8

The -c argument instructs Repo to fetch the current manifest branch from the server. The -j8 command splits the sync across threads for faster completion.

This operation should take a little over an hour.

If you run into any problems during download, refer to Troubleshoot and fix sync issues.

Download proprietary binaries

AOSP can run on Cuttlefish emulators directly, but AOSP can't be used on hardware without additional device-specific proprietary libraries. Here's how to obtain those device binaries:

If you're downloading the main branch and building for a Nexus or Pixel device, download the latest binaries from the Binaries preview site.
If you're downloading and building the main branch and building for your own device, you must provide your device-specific binaries.
If you're downloading and building a tagged, non-main, branch and building for a Nexus or Pixel device, download the device-specific binary from Binaries for Nexus and Pixel devices.

Extract proprietary binaries

Each set of binaries comes as a self-extracting script in a compressed archive. To extract and place these binaries in the correct location of your source tree:

Extract the archive.
Run the included self-extracting shell script from the root of your AOSP source tree.
Agree to the terms of the enclosed license agreement. The binaries and their matching makefiles are installed in the vendor/ hierarchy of the source tree.

(optional) Verify code legitimacy

If you're concerned about the legitimacy of the source code, such as whether it came from Google, you can verify the git tags for the branch. To verify Git tags:

Copy and paste the following key block into a text file, such as keyfile.asc.

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.2.2 (GNU/Linux)

mQGiBEnnWD4RBACt9/h4v9xnnGDou13y3dvOx6/t43LPPIxeJ8eX9WB+8LLuROSV
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/HMdOY7LJlHaqtXmZxXjjtw5Uc2QG8UY8aziU3IE9nTjSwCXeJnuyvoizl9/I1S5
jU5SA/9WwIps4SC84ielIXiGWEqq6i6/sk4I9q1YemZF2XVVKnmI1F4iCMtNKsR4
MGSa1gA8s4iQbsKNWPgp7M3a51JCVCu6l/8zTpA+uUGapw4tWCp4o0dpIvDPBEa9
b/aF/ygcR8mh5hgUfpF9IpXdknOsbKCvM9lSSfRciETykZc4wrRCVGhlIEFuZHJv
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cm9pZC5jb20+iGAEExECACAFAknnWD4CGwMGCwkIBwMCBBUCCAMEFgIDAQIeAQIX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=Wi5D
-----END PGP PUBLIC KEY BLOCK-----

Run the following command to input a public key into your GnuPG key database. The key is used to sign annotated tags that represent releases.
```
$ gpg --import keyfile.asc
```
After importing the keys, you can verify any tag by running this command:
```
$ git tag -v TAG_NAME
```