MCP 服务器

AndroidBuilder MCP Server

Enables LLMs to interact with MIT App Inventor, AndroidBuilder, Kodular, or Niotron IDEs in real-time, controlling the Designer and Blocks workspace via Chrome DevTools Protocol.

README

AndroidBuilder MCP Server

An official Model Context Protocol (MCP) server that connects to running instances of MIT App Inventor, AndroidBuilder, Kodular, or Niotron, allowing LLMs to interact with the Designer and Blocks workspace in real-time via the Chrome DevTools Protocol.

Features

Tool	Description
`get_project_info`	Project name, active screen, view mode, IDE type, URL
`get_component_tree`	Full component hierarchy (name, type, uid, children) from Designer
`get_component_properties`	All property values for a specific component
`update_component_property`	Set a property using 3-strategy fallback (GWT API → top-frame → DOM)
`add_blocks`	Inject validated Blockly XML into the Blocks workspace
`get_blocks_xml`	Export the current workspace as Blockly XML
`clear_blocks`	Clear all blocks from the workspace
`switch_screen`	Navigate to a different screen
`list_screens`	List all screens in the project
`click_element`	Click an arbitrary CSS selector on the IDE page

Prerequisites

Node.js ≥ 18
Google Chrome / Chromium launched with remote debugging enabled

Setup

1. Launch Chrome with Debugging Port

Windows (PowerShell / CMD):

chrome.exe --remote-debugging-port=9222

macOS:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222

Open your IDE (androidbuilder.in, App Inventor, etc.) and load your project.

2. Configure MCP Client

Add this server to your MCP client configuration (e.g. claude_desktop_config.json):

{
  "mcpServers": {
    "androidbuilder-mcp": {
      "command": "node",
      "args": [
        "C:/Users/User/.gemini/antigravity-ide/scratch/androidbuilder-mcp/dist/index.js"
      ],
      "env": {
        "BROWSER_DEBUG_PORT": "9222",
        "ANDROIDBUILDER_DEBUG": "0"
      }
    }
  }
}

Environment Variables

Variable	Default	Description
`BROWSER_DEBUG_PORT`	`9222`	Chrome remote debugging port
`EVAL_TIMEOUT_MS`	`15000`	Max ms to wait for page evaluation
`ANDROIDBUILDER_DEBUG`	`0`	Set to `1` to enable verbose stderr logging

Tool Reference

`get_project_info`

No parameters required.

Returns:

{
  "projectName": "MyApp",
  "activeScreen": "Screen1",
  "isBlocksView": false,
  "isDesignerView": true,
  "ideType": "AndroidBuilder",
  "url": "https://androidbuilder.in/ode/..."
}

`get_component_tree`

Parameter	Type	Required	Description
`screenName`	string	No	Screen to inspect (default: active screen)

Returns:

{
  "screen": "Screen1",
  "tree": [
    {
      "name": "Screen1",
      "type": "Form",
      "children": [
        { "name": "Button1", "type": "Button" },
        { "name": "Label1", "type": "Label" }
      ]
    }
  ]
}

`get_component_properties`

Parameter	Type	Required	Description
`componentName`	string	Yes	Component name (e.g. `Button1`)

Note: Click the component in Designer view first to populate the Properties panel.

`update_component_property`

Parameter	Type	Required	Description
`screenName`	string	Yes	Screen owning the component (e.g. `Screen1`)
`componentName`	string	Yes	Component name (e.g. `Button1`)
`propName`	string	Yes	Property name (e.g. `Text`, `BackgroundColor`)
`propValue`	string	Yes	New value (e.g. `Hello`, `#FF0000`)

`add_blocks`

Parameter	Type	Required	Description
`xmlString`	string	Yes	Valid Blockly XML (must start with `<`)

Requires: Blocks view

`get_blocks_xml`

No parameters. Exports current workspace as XML.

`clear_blocks`

No parameters. Clears all blocks (irreversible via MCP).

`switch_screen`

Parameter	Type	Required	Description
`screenName`	string	Yes	Target screen (e.g. `Screen2`)

`list_screens`

No parameters. Returns all screen names in the project.

`click_element`

Parameter	Type	Required	Description
`selector`	string	Yes	CSS selector of element to click

Troubleshooting

`Failed to connect to Chrome CDP`

Chrome was not started with --remote-debugging-port=9222
Another process is using port 9222
Check BROWSER_DEBUG_PORT env var

`No active AndroidBuilder/App Inventor tab found`

Open a project in the IDE before calling any tool
The IDE page must be fully loaded, not just navigated to

`Component tree (.gwt-Tree) not found`

You are in Blocks view — switch to Designer view

`Blockly is not available`

You are in Designer view — switch to Blocks view

Tools hang / timeout

Increase EVAL_TIMEOUT_MS (default 15000ms)
Reload the IDE page and try again

Development

# Build
npm run build

# Run with debug logging
ANDROIDBUILDER_DEBUG=1 node dist/index.js

# Run with custom port
BROWSER_DEBUG_PORT=9223 node dist/index.js