AndroidBuilder Server

Local Model Context Protocol server for MIT App Inventor, AndroidBuilder, Kodular, Niotron, and AppyBuilder. It connects to a Chrome/Chromium session through the Chrome DevTools Protocol and lets MCP clients inspect the Designer and Blocks workspaces.

The server is safe by default: read tools are available immediately, while write tools require explicit environment flags.

Tools

Requirements

• Node.js >=22.12
• Chrome or Chromium launched with remote debugging enabled

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

Open your App Inventor-family IDE and load the project in that Chrome session.

Install

npm install
npm run build

Run the server:

node dist/index.js

MCP Config

Use .mcp.json in this repository for local development:

{
  "mcpServers": {
    "androidbuilder-mcp": {
      "command": "node",
      "args": ["dist/index.js"],
      "env": {
        "BROWSER_DEBUG_PORT": "9222",
        "ANDROIDBUILDER_ALLOW_WRITE": "0"
      }
    }
  }
}

For clients that do not resolve relative paths from the repository root, replace dist/index.js with an absolute path.

Environment

Codex, Claude, and Antigravity

• Codex plugin manifest: .codex-plugin/plugin.json
• Portable MCP config: .mcp.json
• Open Agent Skill: skills/build-app-inventor-apps/SKILL.md

See docs/compatibility.md for client-specific setup notes.

Development

npm run build
npm test
npm pack --dry-run

npm test builds the server, runs a real MCP SDK smoke test, verifies write tools are gated, checks the no-Chrome error path, and validates package metadata.

Troubleshooting

• Failed to connect to Chrome CDP: start Chrome with --remote-debugging-port=9222.
• No active AndroidBuilder/App Inventor tab found: open a project in the debug Chrome session.
• Component tree (.gwt-Tree) not found: switch to Designer view.
• Blockly is not available: switch to Blocks view.
• Write tool rejected: restart the MCP server with ANDROIDBUILDER_ALLOW_WRITE=1.

Supported IDEs

• AndroidBuilder
• MIT App Inventor 2
• MIT App Inventor Code
• Niotron
• Kodular
• AppyBuilder

License

MIT