# Supported software within custom test environments
<a name="custom-test-environments-hosts-software"></a>

 Device Farm uses host machines that are pre-installed with many of the necessary software libraries to run test frameworks supported on our service, providing a ready testing environment on launch. Device Farm supports multiple languages through the use of our software selection mechanism, and will periodically update the versions of the languages included in the environment. 

For any other required software, you can modify the test spec file to install from your test package, download from the internet, or access private sources within your VPC (see [VPC ENI](https://docs.aws.amazon.com//devicefarm/latest/developerguide/vpc-eni.html) for more information). For more information, see [Test spec examples](custom-test-environment-test-spec.md#custom-test-environment-test-spec-example).

## Pre-configured software
<a name="custom-test-environments-hosts-software-configured"></a>

 In order to facilitate device testing on each platform, the following tooling is provided on the test host: 


| Tools | Device Platform(s) | 
| --- | --- | 
|   Android SDK Build-Tools   |   Android   | 
|   Android SDK Platform-Tools (includes `adb`)   |   Android   | 
|   Xcode   |   iOS   | 

## Selectable software
<a name="custom-test-environments-hosts-software-selection"></a>

 In addition to the pre-configured software on the host, Device Farm offers a way to select certain versions of supported software via the `devicefarm-cli` tooling. 

 The following table contains the selectable software and the test hosts that contain them. 


| Software / Tool | Hosts that support this software | Command to use in your test spec | 
| --- | --- | --- | 
|   Java 17   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use java 17`   | 
|   Java 11   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use java 11`   | 
|   Java 8   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use java 8`   | 
|   Node.js 22   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use node 22`   | 
|   Node.js 20   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use node 20`   | 
|   Node.js 18   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use node 18`   | 
|   Node.js 16   |   amazon\$1linux\$12   |   `devicefarm-cli use node 16`   | 
|   Python 3.12   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use python 3.12`   | 
|   Python 3.11   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use python 3.11`   | 
|   Python 3.10   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use python 3.10`   | 
|   Python 3.9   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use python 3.9`   | 
|   Python 3.8   |   amazon\$1linux\$12   |   `devicefarm-cli use python 3.8`   | 
|   Ruby 3.2   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use ruby 3.2`   | 
|   Ruby 2.7   |   amazon\$1linux\$12   |   `devicefarm-cli use ruby 2.7`   | 
|   Appium 3   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use appium 3`   | 
|   Appium 2   |   amazon\$1linux\$12   macos\$1sequoia   |   `devicefarm-cli use appium 2`   | 
|   Appium 1   |   amazon\$1linux\$12   |   `devicefarm-cli use appium 1`   | 
|   Xcode 26   |   macos\$1sequoia   |   `devicefarm-cli use xcode 26`   | 
|   Xcode 16   |   macos\$1sequoia   |   `devicefarm-cli use xcode 16`   | 

The test host also includes commonly used supporting tools for each software version, such as the `pip` and `npm` package managers (included with Python and Node.js respectively) and dependencies (such as the Appium UIAutomator2 Driver) for tools like Appium. This ensures you have the tools needed to work with the supported test frameworks.

# Using the devicefarm-cli tool in custom test environments
<a name="custom-test-environments-hosts-software-cli"></a>

The test host uses a standardized version management tool called ` devicefarm-cli` to select software versions. This tool is separate from the AWS CLI and only available on the Device Farm test host. With `devicefarm-cli`, you can switch to any pre-installed software version on the test host. This provides a straightforward way to maintain your Device Farm test spec file over time and gives you a predictable mechanism to upgrade software versions in the future.

**Important**  
 This command line tool is not available on legacy iOS hosts. For more information, see the topic on the [Legacy iOS test host](custom-test-environments-hosts-ios.md#legacy-ios-host). 

The snippet below shows the `help` page of `devicefarm-cli`:

```
$ devicefarm-cli help
 Usage: devicefarm-cli COMMAND [ARGS]
     
     Commands:
         help                         Prints this usage message.
         list                         Lists all versions of software configurable
                                      via this CLI.
         use <software> <version>     Configures the software for usage within the
                                      current shell's environment.
```

Let's review a couple of examples using `devicefarm-cli`. To use the tool to change the Python version from *3.10* to *3.9* in your test spec file, run the following commands:

```
$ python --version
Python 3.10.12
$ devicefarm-cli use python 3.9
$ python --version
Python 3.9.17
```

To change the Appium version from *1* to *2* :

```
$ appium --version
1.22.3
$ devicefarm-cli use appium 2
$ appium --version
2.1.2
```

**Tip**  
Note that when you select a software version, `devicefarm-cli` also switches the supporting tools for those languages, such as `pip` for Python and `npm` for NodeJS. 

For more information about the preinstalled software on the test host, see [Supported software within custom test environments](custom-test-environments-hosts-software.md).