manifest.json

{
    "manifest_version": 2,
    "name": "__MSG_appName__",
    "version": "0.0.1",

    "default_locale": "en",
    "description": "__MSG_appDesc__",
    // "update_url": "http://path/to/updateInfo.xml",
    
    "app": {
        "background": {
            "scripts": ["scripts/background.js"]
        }
    },
    
    "icons": {
        "16": "icon/16x16.png",
        "32": "icon/32x32.png",
        "48": "icon/48x48.png",
        "64": "icon/64x64.png",
        "96": "icon/96x96.png",
        "128": "icon/128x128.png",
        "256": "icon/256x256.png"
    },
    
    "offline_enabled": true,
    
    "permissions": [
        "app.window",
        "clipboardRead",
        "clipboardWrite",
        "storage",
        {
            "fileSystem": [
                "write", 
                "retainEntries", 
                "directory"
            ]
        },
        {
            "socket": [
                "tcp-connect:*:*"
            ]
        }
    ],
    "file_handlers": {
        "text": {
            "title": "__MSG_appName__",
            "types": [
                "application/dart",
                "application/javascript",
                "application/json",
                "application/xml",
                "text/css",
                "text/dart",
                "text/html",
                "text/javascript",
                "text/json",
                "text/xml",
                "text/yaml", 
                "text/*"
            ],
            "extensions": ["coffee", "css", "htm", "html", "htmls", "js", "json", "manifest", "md", "shtml", "text", "textile", "txt", "xml", "yaml"]
        }
    }
}