android__skills/device-ai/appfunctions/references/adb-interaction-testing.md

Provides commands to interact with AppFunctions on a connected device or emulator using ADB for AppFunction testing and debugging.

Instructions

Scenario 1: List app functions

Use this scenario when you want to see which app functions are registered on the device.

1. List all functions : To view all registered app functions in JSON format, run adb shell cmd app_function list-app-functions.
2. Filter by package : To view functions for a specific package, pipe the output to grep or a JSON tool: adb shell cmd app_function list-app-functions | grep <package_name>.

Scenario 2: Invoke app functions

If you want to test the execution of an app function, use this scenario.

1. Analyze description : Before invoking, you must read the description field for the function in the list-app-functions output. This often contains critical usage constraints, required workflows, or disambiguation rules.
2. Follow constraints: Follow all instructions in the description, such as asking the user to disambiguate or calling another tool first.
3. Format parameters : Format the --parameters argument as a valid JSON string that represents the function's input arguments.
4. Execute function : Use adb shell cmd app_function execute-app-function --package <PACKAGE_NAME> --function <SERVICE_CLASS_NAME#FUNCTION_NAME> --parameters '<PARAMETERS_JSON>'.
5. Handle response : The command returns the result as a JSON string. To get brief YAML output, use --brief-yaml.

Scenario 3: Manage function state

If you need to enable or disable an app function for testing, use this scenario.

1. Set enabled state : Use adb shell cmd app_function set-enabled --package <PACKAGE_NAME> --function <SERVICE_CLASS_NAME#FUNCTION_NAME> --state <enable|disable|default>.

Critical constraints

Follow metadata descriptions

Mandatory : The description field in the app function metadata is a set of instructions for the LLM. If a description says to "disambiguate with the user" or "call another function first," you must perform those steps before execution.

JSON escaping

Critical : When passing JSON using adb shell, always wrap the JSON string in single quotes to prevent the shell from interpreting special characters or spaces. Example: --parameters '{"key": "value"}'.

Device availability

The app_function service must be available on the device. If cmd: Can't find service: app_function is returned, the device doesn't support this feature.

Examples

Example 1: Verify app function service availability on connected device

adb shell cmd app_function help

If executing the preceding command returns a help page, use the commands and parameters provided to guide the ADB interaction testing tool interactions.

Example 2: List all registered app functions

 adb shell cmd app_function list-app-functions

Example 3: Execute a "send message" function

 adb shell cmd app_function execute-app-function \
 --package com.example.messaging \
 --function
'com.example.messaging.appfunctions.MessagingAppFunctionService#sendMessage' \
 --parameters '{"recipient": "Alice", "message": "Hello!"}'

Example 4: Disable a specific function

 adb shell cmd app_function set-enabled --package com.example.app \
 --function 'com.example.app.appfunctions.SomeAppFunctionService#someFunction'
--state disable

Troubleshooting

Error: "Unknown command"

Cause: You are likely using an older version of the instructions.

Solution: Look up supported commands using "Example 1".

Error: "Function not found"

Cause: The function ID or package name is incorrect.

Solution : Run list-app-functions and search for the relevant identifiers in the JSON output.