CRITICAL RULES — VIOLATIONS WILL BREAK THE WORKFLOW:

1. Never run midscene commands in the background. Each command must run synchronously so you can read its output (especially screenshots) before deciding the next action. Background execution breaks the screenshot-analyze-act loop.
2. Run only one midscene command at a time. Wait for the previous command to finish, read the screenshot, then decide the next action. Never chain multiple commands together.
3. Allow enough time for each command to complete. Midscene commands involve AI inference and screen interaction, which can take longer than typical shell commands. A typical command needs about 1 minute; complex

   act

   commands may need even longer.

npx @midscene/harmony@1

• Install via DevEco Studio
• Or set

  HDC_HOME

  environment variable to point to the HDC directory

hdc version
hdc list targets

1. Connect to establish a session
2. Launch the target app and take screenshot to see the current state, make sure the app is launched and visible on the screen.
3. Execute action using

   act

   to perform the desired action or target-driven instructions.
4. Disconnect when done

1. Bring the target app to the foreground before using this skill: For best efficiency, launch the app using HDC (e.g.,

   hdc shell aa start -a EntryAbility -b <bundleName>

   ) before invoking any midscene commands. Then take a screenshot to confirm the app is actually in the foreground. Only after visual confirmation should you proceed with UI automation using this skill. HDC commands are significantly faster than using midscene to navigate to and open apps.
2. Be specific about UI elements: Instead of vague descriptions, provide clear, specific details. Say

   "the Wi-Fi toggle switch on the right side"

   instead of

   "the toggle"

   .
3. Describe locations when possible: Help target elements by describing their position (e.g.,

   "the search icon at the top right"

   ,

   "the third item in the list"

   ).
4. Never run in background: Every midscene command must run synchronously — background execution breaks the screenshot-analyze-act loop.
5. Batch related operations into a single

   act

   command: When performing consecutive operations within the same app, combine them into one

   act

   prompt instead of splitting them into separate commands. For example, "open Settings, tap Wi-Fi, and toggle it on" should be a single

   act

   call, not three. This reduces round-trips, avoids unnecessary screenshot-analyze cycles, and is significantly faster.
6. Summarize report files after completion: After finishing the automation task, collect and summarize all report files (screenshots, logs, output files, etc.) for the user. Present a clear summary of what was accomplished, what files were generated, and where they are located, making it easy for the user to review the results.

hdc shell aa start -a EntryAbility -b com.huawei.hmos.settings
npx @midscene/harmony@1 connect
npx @midscene/harmony@1 take_screenshot
npx @midscene/harmony@1 act --prompt "scroll down the settings list and tap About device"
npx @midscene/harmony@1 take_screenshot
npx @midscene/harmony@1 disconnect

npx @midscene/harmony@1 act --prompt "fill in the username field with 'testuser' and the password field with 'pass123', then tap the Login button"
npx @midscene/harmony@1 take_screenshot