harmonyos-device-automation

$2c

MIDSCENE_MODEL_API_KEY="your-api-key"

MIDSCENE_MODEL_NAME="model-name"

MIDSCENE_MODEL_BASE_URL="https://..."

MIDSCENE_MODEL_FAMILY="family-identifier"

Example: Gemini (Gemini-3-Flash)

MIDSCENE_MODEL_API_KEY="your-google-api-key"

MIDSCENE_MODEL_NAME="gemini-3-flash"

MIDSCENE_MODEL_BASE_URL="https://generativelanguage.googleapis.com/v1beta/openai/"

MIDSCENE_MODEL_FAMILY="gemini"

Example: Qwen 3.5

MIDSCENE_MODEL_API_KEY="your-aliyun-api-key"

MIDSCENE_MODEL_NAME="qwen3.5-plus"

MIDSCENE_MODEL_BASE_URL="https://dashscope.aliyuncs.com/compatible-mode/v1"

MIDSCENE_MODEL_FAMILY="qwen3.5"

MIDSCENE_MODEL_REASONING_ENABLED="false"

# If using OpenRouter, set:

# MIDSCENE_MODEL_API_KEY="your-openrouter-api-key"

# MIDSCENE_MODEL_NAME="qwen/qwen3.5-plus"

# MIDSCENE_MODEL_BASE_URL="https://openrouter.ai/api/v1"

Example: Doubao Seed 2.0 Lite

MIDSCENE_MODEL_API_KEY="your-doubao-api-key"

MIDSCENE_MODEL_NAME="doubao-seed-2-0-lite"

MIDSCENE_MODEL_BASE_URL="https://ark.cn-beijing.volces.com/api/v3"

MIDSCENE_MODEL_FAMILY="doubao-seed"

Commonly used models: Doubao Seed 2.0 Lite, Qwen 3.5, Zhipu GLM-4.6V, Gemini-3-Pro, Gemini-3-Flash.

If the model is not configured, ask the user to set it up. See Model Configuration for supported providers.

HDC Setup

HDC (HarmonyOS Device Connector) must be installed and accessible. Common setup:

• Install via DevEco Studio

• Or set HDC_HOME environment variable to point to the HDC directory

Verify HDC is working:

hdc version

hdc list targets

Commands

Connect to Device

npx -y @midscene/harmony@1 connect

npx -y @midscene/harmony@1 connect --deviceId 0123456789ABCDEF

Launch an App or URL

Use the dedicated launch step when you want a deterministic starting point before the rest of the task:

npx -y @midscene/harmony@1 launch --uri com.huawei.hmos.settings

npx -y @midscene/harmony@1 launch --uri com.huawei.hmos.camera

npx -y @midscene/harmony@1 launch --uri https://www.example.com

Run a Raw HarmonyOS Shell Command

Use this when the task needs lower-level device control that is not best expressed as a visible UI interaction:

npx -y @midscene/harmony@1 runhdcshell --command "hidumper -s RenderService -a screen"

This is forwarded to hdc shell on the connected device. In practice, the underlying command is hdc -t <deviceId> shell hidumper -s RenderService -a screen.

Take Screenshot

npx -y @midscene/harmony@1 take_screenshot

After taking a screenshot, read the saved image file to understand the current screen state before deciding the next action.

Perform Action

Use act to interact with the device and get the result. It autonomously handles all UI interactions internally — tapping, typing, scrolling, swiping, waiting, and navigating — so you should give it complex, high-level tasks as a whole rather than breaking them into small steps. Describe what you want to do and the desired effect in natural language:

# specific instructions

npx -y @midscene/harmony@1 act --prompt "type hello world in the search field and press Enter"

npx -y @midscene/harmony@1 act --prompt "long press the message bubble and tap Delete in the popup menu"

# or target-driven instructions

npx -y @midscene/harmony@1 act --prompt "open Settings and navigate to Wi-Fi settings, tell me the connected network name"

Assert Current Screen State

Use assert to verify that the current screen satisfies a natural language condition. It does not perform UI actions; it checks the visible screen state and passes only when the assertion is true. Use this for validation, QA checks, and final state verification after act.

npx -y @midscene/harmony@1 assert --prompt "there is a login button visible"

npx -y @midscene/harmony@1 assert --prompt "the settings screen shows Wi-Fi and Bluetooth options"

npx -y @midscene/harmony@1 assert --deviceId 0123456789ABCDEF --prompt "the app shows a successful login message"

Use a Reference Image for Precise Targeting

When the user provides a screenshot, icon, logo, or reference image and wants an exact visual match, prefer tap --locate instead of a generic act --prompt. Pass --locate as JSON. The prompt describes the target, images supplies named reference images, and convertHttpImage2Base64: true is useful when the image URL may not be directly accessible to the model.

npx -y @midscene/harmony@1 tap --locate '{

  "prompt": "tap the area contains the image",

  "images": [

    {

      "name": "target image",

      "url": "https://github.githubassets.com/assets/GitHub-Mark-ea2971cee799.png"

    }

  ],

  "convertHttpImage2Base64": true

}'

The same locate JSON shape also works for other commands that accept a locate parameter.

Disconnect

npx -y @midscene/harmony@1 disconnect

Consume Report Files

The generated HTML report is recommended for human reading first. It includes step-by-step execution details and replay videos for each operation, which makes it much easier to understand what happened and troubleshoot problems.

If another skill or tool needs to consume the report, first convert it with report-tool from the same platform CLI package. Prefer Markdown for LLM-based workflows. Use JSON when the report needs to be processed programmatically.

npx -y @midscene/harmony@1 report-tool --action to-markdown --htmlPath ./midscene_run/report/.../index.html --outputDir ./output-markdown

npx -y @midscene/harmony@1 report-tool --action split --htmlPath ./midscene_run/report/.../index.html --outputDir ./output-data

Workflow Pattern

Since CLI commands are stateless between invocations, follow this pattern:

• Connect to establish a session

• Launch the target app and take screenshot to see the current state, make sure the app is launched and visible on the screen.

• Execute action using act to perform the desired action or target-driven instructions, and use assert when you need to verify the resulting screen state.

• Disconnect when done

Best Practices

• 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.

• 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".

• 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").

• Never run in background: Every midscene command must run synchronously — background execution breaks the screenshot-analyze-act loop.

• **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.

• **Use assert for verification**: When the goal is to confirm that a screen state is true, use assert --prompt "..." instead of an act prompt. Keep assertions observable and specific, such as "the permission dialog is visible" or "the Save button is disabled".

• 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.

• **Prefer tap --locate when a reference image is provided**: If the user shares a screenshot, icon, or logo and wants that exact visual target, use tap --locate with a multimodal locate JSON object such as { "prompt": "...", "images": [...] } instead of relying only on act --prompt.

Example — App launch and interaction:

hdc shell aa start -a EntryAbility -b com.huawei.hmos.settings

npx -y @midscene/harmony@1 connect

npx -y @midscene/harmony@1 take_screenshot

npx -y @midscene/harmony@1 act --prompt "scroll down the settings list and tap About device"

npx -y @midscene/harmony@1 take_screenshot

npx -y @midscene/harmony@1 disconnect

Example — Form interaction:

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

npx -y @midscene/harmony@1 take_screenshot

Common HarmonyOS Bundle Names

App

Bundle Name

Settings

com.huawei.hmos.settings

Camera

com.huawei.hmos.camera

Gallery

com.huawei.hmos.photos

Calendar

com.huawei.hmos.calendar

Clock

com.huawei.hmos.clock

Calculator

com.huawei.hmos.calculator

Browser

com.huawei.hmos.browser

Weather

com.huawei.hmos.weather

Troubleshooting

Problem

Solution

HDC not found

Install via DevEco Studio or set HDC_HOME environment variable.

Device not listed

Check USB connection, ensure USB debugging is enabled in Developer Options, and run hdc list targets.

Command timeout

The device screen may be off or locked. Wake the device and unlock it.

API key error

Check .env file contains MIDSCENE_MODEL_API_KEY=<your-key>. See Model Configuration.

**@midscene/* dependency version is outdated**

Check local versions with npm ls @midscene/harmony @midscene/core @midscene/shared (or pnpm why @midscene/harmony). Compare with latest via npm view @midscene/harmony version, npm view @midscene/core version, and npm view @midscene/shared version. Upgrade if needed: npm i @midscene/harmony@latest @midscene/core@latest @midscene/shared@latest.

Wrong device targeted

If multiple devices are connected, use --deviceId <id> flag with the connect command.