developer-device-platform-basics

SKILL.md

Developer Device Platform

Developer Device Platform (DDP) is a Google fully managed, global infrastructure
providing access to a wide variety of physical and virtual devices.

[!WARNING] Developer Device Platform (DDP) is currently at Preview.

[!IMPORTANT] For all devicerun and devicestreaming API operations (reserving,
status checking, stopping/canceling, updating, or listing a session), always
verify and use the exact instructions and curl commands provided in the linked
reference .md files.

Authentication & Setup

CRITICAL: Before running any requests, you MUST ensure the environment is
correctly initialized by following these steps:
Before running any requests, verify if the gcloud executable is present. If
missing, refer to the official
Google Cloud CLI Installation Guide
to install it on the current platform (Linux, macOS, Windows, etc.).

Google Cloud Authentication: Authenticate with your Google Cloud
credentials and configure active Application Default Credentials (ADC) for
the Developer Device Platform:

gcloud auth login --no-browser
gcloud auth application-default login --no-browser

Enable APIs (if not already enabled):

gcloud services enable devicerun.googleapis.com devicestreaming.googleapis.com testing.googleapis.com --quiet

[!NOTE] Cloud Testing API is needed for Device Streaming API during Preview.

Enable gcloud beta component:

gcloud components install beta

Setup Environment Variables: Set up the required project variable and
access token:

export PROJECT_ID=$(gcloud config get project)
export ACCESS_TOKEN=$(gcloud auth application-default print-access-token 2>/dev/null)

Python Environment: For instructions on setting up the python virtual
environment, see start_adb_forwarder.md.

Listing Available Devices

To find the correct modelCode and osVersion to use when starting a session,
you can list the available devices:

List Models: Run the following command to list available Android device
models:

gcloud beta device-run devices list

Use the ID column to find the value for the CATALOG_ID parameter to
describe a specific device (e.g., shiba-36).

Describe a Model: Run the API request to get more details about a
specific model (e.g., supportedProducts, resolution). Always rely on the
exact curl command and instructions provided in describe_device.md.

Starting a Device Session

When the user asks to reserve or connect to a device:

Check Device Availability:

Look up CATALOG_ID of the device using Listing Available Devices
instructions. Check the device availability of the CATALOG_ID by using the
exact curl command and instructions provided in describe_device.md. The
device MUST contain "deviceStreaming" in "supportedProducts" to be reserved.

If no specific device is specified, use CATALOG_ID=shiba-34 (Pixel 8 on
SDK 34).

If OS_VERSION was not specified by the user, ask the user to select a
version from the device list (preferring the version with the highest
availability {"available": "AVAILABILITY_HIGH" }).

If OS_VERSION is unavailable for deviceStreaming, do not reserve one.
Prompt the user for an alternative OS_VERSION.

Extract Parameters:

model_id: modelCode from device details. Required.

version_id: osVersion from device details. Required.

Reserve Device:

Rule: Explicit User Confirmation Required. Reserving a device incurs
billing charges and creates cloud resources. The agent MUST ALWAYS warn the
user explicitly about the billing costs that will be incurred on the active
Google Cloud project (e.g., ${PROJECT_ID}). You MUST STOP and ask for
explicit approval before proceeding with any session creation commands.

Then, run the API request with model_id and version_id to reserve the
device. Always rely on the exact curl command and instructions provided in
reserve_device.md.

Parse the response to get session_name (the session name, e.g.,
projects/${PROJECT_ID}/deviceSessions/session-xxxxxx). If reservation
fails, report the error.

Wait for Session to be Active:

While waiting for the device session to be provisioned, poll the session
status until "state" is "ACTIVE". See session_status.md for the exact
curl command.

Repeat this check every 5 seconds to prevent hitting API rate limit. If it
does not become active within 2 minutes (typically under 1 minute), report
failure and cancel the session. Once active, extract expireTime from the
session JSON response and convert it to the user's local time in a
human-readable format (e.g., "June 9, 2026 at 2:44 PM PDT").

Start Connection Forwarder: Start the ADB forwarder script to forward
connection to the remote device. Always rely on the exact command and
instructions provided in start_adb_forwarder.md. Ensure you record the
Command ID.

Wait for Online and Parse Port: Wait for the forwarder to be online and
extract the listening port. Always rely on the exact logic and instructions
provided in start_adb_forwarder.md.

Provide Instructions to User:

Once online, run adb -s localhost:{port} shell getprop ro.product.model to
retrieve the device model name. Then, print a message directly to the user
in the chat (do NOT create any artifact file) with the following
instructions:

Device is ready!

Device Model: {device_model}
OS Version: {version_id}
ADB Address: localhost:{port}
Session Expiration: {expire_time_human_readable_local}

Save Session State: Save the {session_name} and {command_id} in your
conversation memory/context so you can clean it up later.

Viewing the Device Screen of a Reserved Device

The coding agent can directly interact with the remote device using adb. Users
may use a utility to display the screen and manually control the reserved device
in DDP. See view_device.md for an example utility.

Stopping a Device Session

When the user asks to stop, cleanup, or release the device:

Identify Session: Retrieve the active {session_name} and
{command_id} from your context. If you don't have them, list active
sessions first (see helper command below) to find the session name.

Cancel Session via API: Cancel the session via the API. Always rely on
the exact curl command and instructions provided in cancel_session.md.

Terminate Connection Forwarder: Terminate the background process
matching {command_id} using your environment's process management
capability.

Confirm: Confirm to the user that the session has been cancelled and
resources released.

Change Device Session Expiration Time

When the user asks to change the expiration time of an active device session:

Rule: Explicit User Confirmation Required. Extending a device session
incurs additional billing charges and creates cloud resources. The agent MUST
ALWAYS warn the user explicitly about the extra billing costs that will be
incurred on the active Google Cloud project (e.g., ${PROJECT_ID}). You MUST
STOP and ask for explicit approval before proceeding with any session extension
commands.

Extract Parameters:

session_name: The active session name.

ttl: The new remaining duration (e.g., 3600s). Derive the ttl if
it's provided in another format.

Change Session via API: Change the session via the API using
updateMask=ttl. Always rely on the exact curl commands and instructions
provided in update_session_expiration.md.

Restart Connection Forwarder:

Run adb disconnect localhost:{port} to ensure the old forwarder
connection is closed.

Stop the old connection forwarder corresponding to {command_id}.

Start a new connection forwarder by following Step 5 in "Starting a
Device Session" (calculating the new --ttl duration in seconds and
storing the newly returned Command ID).

Confirm: Confirm to the user that the session duration has been updated
and the connection forwarder has been restarted with the new TTL.

Helper: List Active Sessions

To find active sessions if you lost context, always rely on the curl command and
instructions provided in list_sessions.md.

References

gcloud device-run CLI

Device Streaming API

describe_device.md

reserve_device.md

session_status.md

start_adb_forwarder.md

view_device.md

cancel_session.md

update_session_expiration.md

list_sessions.md