#Get started: HarmonyOS · Playground · ChatGPT subscription

These are the setup steps for Midscene on HarmonyOS with Playground and a ChatGPT subscription. To choose another combination, change the answers below or see all setup paths.

Step 1

#Connect the HarmonyOS device

Midscene uses hdc on your computer to communicate with the target HarmonyOS NEXT device. If hdc is already installed and your device is connected, skip directly to Verify the device connection.

#Install HDC

HDC (HarmonyOS Device Connector) is the official command-line tool for communicating with HarmonyOS devices. Install it using either of the following methods:

• Via DevEco Studio (recommended)
• Via the standalone HarmonyOS Command Line Tools

Run the following command to verify the installation:

hdc version

A version number in the terminal output confirms a working installation.

export HDC_HOME=/path/to/hdc/directory

#Enable debugging and connect the device

1. On your HarmonyOS device, open Settings > System > Developer options and enable USB debugging.
2. Connect the device to your computer using a USB cable that supports data transfer.
3. Keep the device unlocked and accept the debugging authorization prompt on the screen.

#Verify the device connection

Run the following command to check the connection status:

hdc list targets

A device ID in the output confirms that the device is connected and ready:

0123456789ABCDEF

If multiple devices are connected, note the target device ID so you can select it in Playground or your project configuration. If the output is empty or [Empty], check the USB cable, USB connection mode, USB debugging toggle, and the authorization prompt on the device.

Step 2

#Sign in with your ChatGPT subscription

The login command needs Node.js ^20.19.0 || ^22.12.0 || >=24.0.0 and pnpm. Check that node -v works in your terminal. If pnpm is not installed yet, run npm install -g pnpm.

First, run the following command in your terminal:

pnpm dlx @midscene/cli model siwc login

Follow the terminal instructions to sign in to ChatGPT in your browser and authorize plan usage. You can choose a name for your Agent during authorization. Once authorized, the Agent appears on your ChatGPT usage page.

The command saves credentials to ~/.midscene/siwc.json. Complete this sign-in manually before first use.

Playground reads the credentials saved by this command. Keep the following lines at hand. You will paste them into Playground settings in a later step:

MIDSCENE_MODEL_AUTH_MODE="siwc"
MIDSCENE_MODEL_NAME="gpt-6-sol"
MIDSCENE_MODEL_FAMILY="gpt-6"

Available models depend on your ChatGPT account. For credentials and usage, see Use a ChatGPT subscription.

Step 3

#Launch Playground

Make sure Node.js (^20.19.0 || ^22.12.0 || >=24.0.0) is installed and node -v works in your terminal. The command below uses pnpm. If it is not installed yet, run npm install -g pnpm.

1. Start the HarmonyOS Playground CLI:

pnpm dlx @midscene/harmony-playground

2. In the Playground window that opens, click the gear icon in the top-right corner, paste your model configuration, and save.
3. If your browser does not open automatically, visit the local Playground URL printed in the terminal, and keep the terminal process running.
4. In the connection panel on the left, select your target HDC device (matching the ID from hdc list targets) and create the Agent.
5. Confirm that the preview area displays your device's current screen. If no screen appears, check the HDC connection and device debugging authorization first.

Step 4

#Run an action and verify the result

On your HarmonyOS device, open the system browser and complete any first-run prompts. Enter the following TodoMVC URL in the address bar:

https://todomvc.com/examples/react/dist/#/

Keep the device unlocked with the browser in the foreground.

1. In Playground, select aiAct, enter the following instruction, and run it:

Add a todo named "Try Midscene", then mark it as completed.

2. Once the completed todo item appears on the page, switch to aiAssert, enter the following assertion, and run it:

The list contains a todo named "Try Midscene", and it is marked as completed.

3. Confirm that the assertion passes and inspect the step-by-step screenshots in the results panel. At this point, HDC connectivity, screen capture, touch input, and model calls have all been verified together.

4. (Optional) Switch to aiQuery, enter the following query, and run it:

Return the visible todo items as {name: string, completed: boolean}[].

The result contains each todo item's name and completion status. aiQuery extracts data from the current UI without changing the page.

If execution fails, check the failed step and error message: for missing screenshots or unresponsive touch input, see the FAQ; for model request errors, see Verify model connectivity.

After verification, delete the "Try Midscene" item in TodoMVC. If you plan to run the Midscene Test HarmonyOS example next, switch to the All filter and make sure the list is completely empty (including completed items), as the example template checks for an empty list before running and does not overwrite existing items.

Step 5

#Next steps

• Explore more examples: Showcases includes demo videos and full execution reports across platforms.

• Write repeatable cases: Create a Midscene Test project with the same platform and model. Cases are YAML files that you can run locally or in CI.

• Add to Vitest: Call Midscene from your Vitest tests with the same platform and model.

• Learn how Midscene works: The Basics explains the vision-based approach and when to use aiAct, instant actions, and insight APIs.

Want to try another platform or way to use Midscene? Back to top to change your selections.