The legacy monkeyrunner tool provides an API for writing programs that control an Android device or emulator from outside of Android code.

The monkeyrunner tool is primarily designed to test apps and devices at the functional/framework level and for running unit test suites, but you can use it for other purposes. With monkeyrunner, you can write a Python program that installs an Android app or test package, runs it, sends keystrokes to it, takes screenshots of its user interface, and stores screenshots on the workstation.

Caution: The monkeyrunner API is unmaintained. We recommend using the App Crawler tool or UI Automator testing framework instead.

The monkeyrunner tool isn't related to the UI/Application Exerciser Monkey, also known as the monkey tool. The monkey tool runs in an adb shell directly on the device or emulator and generates pseudo-random streams of user and system events. In comparison, the monkeyrunner tool controls devices and emulators from a workstation by sending specific commands and events from an API.

The monkeyrunner tool provides these features for Android testing:

  • Multiple device control: The monkeyrunner API can apply one or more test suites across multiple devices or emulators. You can physically attach all the devices or start up all the emulators (or both) at once, connect to each one in turn programmatically, and then run one or more tests. You can also start up an emulator configuration programmatically, run one or more tests, and then shut down the emulator.
  • Functional testing: monkeyrunner can run an automated start-to-finish test of an Android app. You provide input values with keystrokes or touch events and view the results as screenshots.
  • Regression testing: monkeyrunner can test app stability by running an app and comparing its output screenshots to a set of screenshots that are known to be correct.
  • Extensible automation: Since monkeyrunner is an API toolkit, you can develop a system of Python-based modules and programs for controlling Android devices. Besides using the monkeyrunner API itself, you can use the standard Python os and subprocess modules to call Android tools, such as Android Debug Bridge.

    You can also add your own classes to the monkeyrunner API. This is described in more detail in the Extend monkeyrunner with plugins section.

The monkeyrunner tool uses Jython, an implementation of Python that uses the Java programming language. Jython lets the monkeyrunner API interact easily with the Android framework. With Jython, you can use Python syntax to access the constants, classes, and methods of the API.

A simple monkeyrunner program

Here is a simple monkeyrunner program that connects to a device, creating a MonkeyDevice object. Using the MonkeyDevice object, the program installs an Android application package, runs one of its activities, and sends key events to the activity. The program then takes a screenshot of the result, creating a MonkeyImage object. From this object, the program writes out a PNG file containing the screenshot.

# Imports the monkeyrunner modules used by this program.
from import MonkeyRunner, MonkeyDevice

# Connects to the current device, returning a MonkeyDevice object.
device = MonkeyRunner.waitForConnection()

# Installs the Android package. Notice that this method returns a boolean, so you can test
# whether the installation worked.

# Sets a variable with the package's internal name.
package = ''

# Sets a variable with the name of an Activity in the package.
activity = ''

# Sets the name of the component to start.
runComponent = package + '/' + activity

# Runs the component.

# Presses the Menu button.'KEYCODE_MENU', MonkeyDevice.DOWN_AND_UP)

# Takes a screenshot.
result = device.takeSnapshot()

# Writes the screenshot to a file.

The monkeyrunner API

The monkeyrunner API is contained in three modules in the package:

  • MonkeyRunner: A class of utility methods for monkeyrunner programs. This class provides a method for connecting monkeyrunner to a device or emulator. It also provides methods for creating UIs for a monkeyrunner program and for displaying the built-in help.
  • MonkeyDevice: Represents a device or emulator. This class provides methods for installing and uninstalling packages, starting an Activity, and sending keyboard or touch events to an app. You also use this class to run test packages.
  • MonkeyImage: Represents a screen capture image. This class provides methods for capturing screens, converting bitmap images to various formats, comparing two MonkeyImage objects, and writing an image to a file.

In a Python program, you access each class as a Python module. The monkeyrunner tool does not import these modules automatically. To import a module, use the Python from statement:

from import <module>

Where <module> is the class name you want to import. You can import more than one module in the same from statement by separating the module names with commas.

Run monkeyrunner

You can run monkeyrunner programs either from a file or by entering monkeyrunner statements in an interactive session. You do both by invoking the monkeyrunner command, which is found in the tools/ subdirectory of your SDK directory. If you provide a filename as an argument, the monkeyrunner command runs the file's contents as a Python program; otherwise, it starts an interactive session.

The following is the syntax of the monkeyrunner command:

monkeyrunner -plugin <plugin_jar> <program_filename> <program_options>

Table 1 explains the monkeyrunner flags and arguments.

Table 1. monkeyrunner flags and arguments

Argument Description
-plugin <plugin_jar> (Optional) Specifies a JAR file containing a plugin for monkeyrunner. To learn more about monkeyrunner plugins, see the Extend monkeyrunner with plugins section. To specify more than one file, include the argument multiple times.
<program_filename> If you provide this argument, the monkeyrunner command runs the contents of the file as a Python program. Otherwise, the command starts an interactive session.
<program_options> (Optional) Flags and arguments for the program in <program_file>.

monkeyrunner built-in help

You can generate an API reference for monkeyrunner by running:

monkeyrunner <format> <outfile>

The arguments are:

  • <format> is either text for plain text output or html for HTML output.
  • <outfile> is a path-qualified name for the output file.

Extend monkeyrunner with plugins

You can extend the monkeyrunner API with classes you write in Java and build into one or more JAR files. You can use this feature to extend the monkeyrunner API with your own classes or to extend the existing classes. You can also use this feature to initialize the monkeyrunner environment.

To provide a plugin to monkeyrunner, invoke the monkeyrunner command with the -plugin <plugin_jar> argument described in table 1.

In your plugin code, you can import and extend the main monkeyrunner classes MonkeyDevice, MonkeyImage, and MonkeyRunner in (see the section about the monkeyrunner API).

Note that plugins don't give you access to the Android SDK. You can't import packages such as This is because monkeyrunner interacts with the device or emulator below the level of the framework APIs.

The plugin startup class

The JAR file for a plugin can specify a class that is instantiated before script processing starts. To specify this class, add the key MonkeyRunnerStartupRunner to the JAR file's manifest. For the value, use the name of the class to run at startup. The following snippet shows how to do this within an ant build script:

<jar jarfile="myplugin" basedir="${build.dir}">
<attribute name="MonkeyRunnerStartupRunner" value="com.myapp.myplugin"/>

To get access to the monkeyrunner tool's runtime environment, the startup class can implement<PythonInterpreter>. For example, this class sets up some variables in the default namespace:



import org.python.util.PythonInterpreter

class Main: Predicate<PythonInterpreter> {

    override fun apply(anInterpreter: PythonInterpreter): Boolean {
         * Examples of creating and initializing variables in the monkeyrunner environment's
         * namespace. During execution, the monkeyrunner program can refer to the variables
         * "newtest" and "use_emulator"
        anInterpreter.set("newtest", "enabled")
        anInterpreter.set("use_emulator", 1)
        return true



import org.python.util.PythonInterpreter;

public class Main implements Predicate<PythonInterpreter> {
    public boolean apply(PythonInterpreter anInterpreter) {

        * Examples of creating and initializing variables in the monkeyrunner environment's
        * namespace. During execution, the monkeyrunner program can refer to the variables "newtest"
        * and "use_emulator"
        anInterpreter.set("newtest", "enabled");
        anInterpreter.set("use_emulator", 1);

        return true;