Manifest format

Roger Wang edited this page Mar 23, 2016 · 68 revisions

NOTE: some content in this wiki applies only to 0.12 and earlier versions. For official documentation on 0.13 and later, see

Every app package should contain a manifest file named package.json, it will tell nwjs how to open the app and control how the browser behaves.

Quick Start

  "main": "index.html",
  "name": "nw-demo",
  "description": "demo app of node-webkit",
  "version": "0.1.0",
  "keywords": [ "demo", "node-webkit" ],
  "window": {
    "title": "node-webkit demo",
    "icon": "link.png",
    "toolbar": true,
    "frame": false,
    "width": 800,
    "height": 500,
    "position": "mouse",
    "min_width": 400,
    "min_height": 200,
    "max_width": 800,
    "max_height": 600
  "webkit": {
    "plugin": true

Basic Format

package.json should be written in the format of JSON.

Required Fields

Each package must provide all the following fields in its package descriptor file:


(string) which page should be opened when node-webkit starts.

You can specify a URL here. You can also specify just a filename (such as index.html) or a path (relative to the directory where your package.json resides).

Note that you should not use parameters after a filename (such as index.html?foo=bar) because they'll be treated as parts of the file's path (for example, index.html?foo=bar/baz is a file baz in a directory named index.html?foo=bar) and that's probably not what you expect. When you need to pass some parameters to a local application, use a URL with the App protocol.


(string) the name of the package. This must be a unique, lowercase alpha-numeric name without spaces. It may include "." or "_" or "-" characters. It is otherwise opaque.

name should be globally unique since node-webkit will store app's data under the directory named name.

Features Control Fields

Following fields control which features node-webkit should provide and how node-webkit should open the main window.


(boolean) set nodejs to false will disable Node support in WebKit.


since v0.3.1

(string) specify the path to a node.js script file, it will be executed on startup in Node context. This script will have same runtime environment with normal node.js binary. The script is ensured to run before the first DOM window load starting from v0.3.3. See here for more information.


(boolean) by default node-webkit only allows one instance of your app if your app is a standalone package (packaged with instructions of How to package and distribute your apps), if you want to allow multiple instances of your app running at the same time, specify this to false.
Starting from v0.10.0-rc1, it's also effective if your application is started from unpacked folders.


(object) controls how the main window looks, see Window Subfields below.


(object) controls what features of WebKit should be on/off, see WebKit Subfields below.


since v0.3.7

(string) Override the User-Agent header in HTTP requests made from the application. The following placeholders are available:

  • %name: replaced by the name field in the manifest.
  • %ver: replaced by the version field in the manifest, if available.
  • %nwver: replaced by the version of node-webkit.
  • %webkit_ver: replaced by the version of WebKit engine.
  • %osinfo: replaced by the OS and CPU information you would see in browser's user agent string.


since v0.3.7

(string) Enable calling Node in remote pages. The value controls for which sites this feature should be turned on. The format is the same with the "proxy bypass rules" of the browser:

It's a rule set, which rules are separated by , or ;. Each rule can be any of the following:

  // (1) [ URL_SCHEME "://" ] HOSTNAME_PATTERN [ ":" <port> ]
  //   Match all hostnames that match the pattern HOSTNAME_PATTERN.
  //   Examples:
  //     "", "*", "*", "*",
  //     "https://x.*"
  //   Match a particular domain suffix.
  //   Examples:
  //     "", ".com", ""
  // (3) [ SCHEME "://" ] IP_LITERAL [ ":" PORT ]
  //   Match URLs which are IP address literals.
  //   Conceptually this is the similar to (1), but with special cases
  //   to handle IP literal canonicalization. For example matching
  //   on "[0:0:0::1]" would be the same as matching on "[::1]" since
  //   the IPv6 canonicalization is done internally.
  //   Examples:
  //     "127.0.1", "[0:0::1]", "[::1]", "http://[::1]:99"
  //   Match any URL that is to an IP literal that falls between the
  //   given range. IP range is specified using CIDR notation.
  //   Examples:
  //     "", "fefe:13::abc/33".
  // (5)  "<local>"
  //   Match local addresses. The meaning of "<local>" is whether the
  //   host matches one of: "", "::1", "localhost".


since v0.4.0

(string) Specify chromium (content shell) command line arguments. It will be useful if you want to distribute the app with some custom chromium args. For example, if you want to disable the GPU accelerated video display, just add "chromium-args" : "--disable-accelerated-video". If you want to add multiple arguments, separate each two arguments by space. This field can take a number of flags in one argument as well, via enclosing them in single quotation marks.

A list of Chromium's command line arguments is available at


since v0.4.1

(string) Specify the flags passed to JS engine(v8). e.g. turn on Harmony Proxies and Collections feature:

  "name": "nw-demo",
  "main": "index.html",
  "js-flags": "--harmony_proxies --harmony_collections"

inject-js-start / inject-js-end

since v0.9.0 and v0.8.5

(string) a local filename, relative to the application path, used to specify a JavaScript file to inject to the window.

  • inject-js-start: The injecting JavaScript code is to be executed after any files from css, but before any other DOM is constructed or any other script is run.
  • inject-js-end: The injecting JavaScript code is to be executed after the document object is loaded, before onload event is fired. This is mainly to be used as an option of to inject JS in a new window.


since v0.11.1

containing a list of PEM-encoded certificates (i.e. "-----BEGIN CERTIFICATE-----\n...certificate data...\n-----END CERTIFICATE-----\n").
These certificates are used as additional root certificates for validation, to allow connecting to services using a self-signed certificate or certificates issued by custom CAs.


since v0.4.2

(string) Specify the path to the snapshot file to be loaded with the application. The snapshot file contains compiled code of your application. See Protect JavaScript source code with v8 snapshot.


since v0.6.1

(int) Number of mega bytes for the quota of the DOM storage. The suggestion is to put double the value you want.


since v0.7.3

(boolean) whether the default Edit menu should be disabled on Mac OS X. The default value is false. Only effective on Mac OS X. This is a workaround for a feature request and is expected to be replaced by something else soon

Window Subfields


(string) the default title of window created by node-webkit, it's very useful if you want to show your own title when the app is starting.


(int) the initial width/height of the main window.


(boolean) should the navigation toolbar be showed.


(string) path to window's icon


(string) be null or center or mouse, controls where window will be put


(int) minimum width/height of window


(int) maximum width/height of window


(boolean) show as desktop background window under X11 environment


since v0.3.0

(boolean) whether window is resizable

Beware, if resizable is set to false on OS X and frame is set to true, the user will still be able to make the window fullscreen. Set fullscreen to false to disable the fullscreen control.


since v0.3.4

(boolean) whether the window should always stay on top of other windows.


since v0.11.3

(boolean) whether the window should be visible on all workspaces simultaneously (on platforms that support multiple workspaces, currently Mac OS X and Linux).


since v0.3.0

(boolean) whether window is fullscreen

Beware, if frame is also set to false in fullscreen it will prevent the mouse from being captured on the very edges of the screen. You should avoid activate it if fullscreen is also set to true.


since v0.9.2

(boolean) whether the window is shown in taskbar or dock. The default is true.


since v0.3.0

(boolean) specify it to false to make the window frameless

Beware, if frame is set to false in fullscreen it will prevent the mouse from being captured on the very edges of the screen. You should avoid activate it if fullscreen is also set to true.


since v0.3.0

(boolean) specify it to false if you want your app to be hidden on startup


since v0.3.1

(boolean) whether to use Kiosk mode. In Kiosk mode, the app will be fullscreen and try to prevent users from leaving the app, so you should remember to provide a way in app to leave Kiosk mode. This mode is mainly used for presentation on public displays


since v0.11.2

(boolean) whether to turn on transparent window mode. The default is false.

_control the transparency with rgba background value in CSS. Use command line argument --disable-transparency to disable this feature completely. There is experimental support for "click-through" on the transparent region: add --disable-gpu argument to the command line. See the discussion here: _

WebKit Subfields

The following fields require node-webkit >= v0.3.0.


(boolean) whether to load external browser plugins like Flash, default to false.


(boolean) whether to load Java applets, default to false.


(boolean) whether to enable page cache, default to false.

Other Fields

The Packages/1.0 standard specifies many other fields package.json should provide. currently we don't make use of them, but you provide them still.


a brief description of the package. By convention, the first sentence (up to the first ". ") should be usable as a package title in listings.


a version string conforming to the Semantic Versioning requirements.


an Array of string keywords to assist users searching for the package in catalogs.


Array of maintainers of the package. Each maintainer is a hash which must have a "name" property and may optionally provide "email" and "web" properties. For example:

"maintainers":[ {
   "name": "Bill Bloggs",
   "email": "",
   "web": "",


an Array of hashes each containing the details of a contributor. Format is the same as for author. By convention, the first contributor is the original author of the package.


URL for submitting bugs. Can be mailto or http.


array of licenses under which the package is provided. Each license is a hash with a "type" property specifying the type of license and a url property linking to the actual text. If the license is one of the official open source licenses the official license name or its abbreviation may be explicated with the "type" property. If an abbreviation is provided (in parentheses), the abbreviation must be used.

"licenses": [
       "type": "GPLv2",
       "url": "",


Array of repositories where the package can be located. Each repository is a hash with properties for the "type" and "url" location of the repository to clone/checkout the package. A "path" property may also be specified to locate the package in the repository if it does not reside at the root. For example:

"repositories": [
            "type": "git", 
            "url": "",
            "path": "packages/mypackage"
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