JAPK Asset Package Format

JAPK is JadeView's proprietary application packaging format. It bundles all of your front-end resources — HTML, CSS, JavaScript, images, and more — into a single .japk file, much like an archive. The benefits of using JAPK:

• Simple distribution: Just send a single file instead of transferring a pile of scattered files
• Fast loading: JadeView can read resources directly from inside the package, with no need to extract to a temporary directory
• Source protection: Combined with JadePack, content can be protected through obfuscation and signature

Electron ASAR vs. JadePack

For JadePack downloads and details, see JadePack.

JadePack Build Tool

JadePack is the graphical build tool officially released by JadeView, designed specifically for building and protecting JAPK asset packages:

• One-click build: Operate through a graphical interface to easily package a front-end project into a JAPK
• Content obfuscation: Even without signing, file content is protected with a 3-layer reversible transform (XOR + byte permutation + bit rotation), so it is not a plaintext package
• Signature protection: Supports signing the JAPK to verify its origin and integrity and prevent tampering
• Unpack support: Supports storing selected files as "unpacked" for convenient native module loading

JadeView is fully compatible with the Electron ASAR format, which means:

• Packages created with Electron ASAR can be loaded and run directly by JadeView
• No additional conversion or processing steps are required
• Full interoperability with the Electron ecosystem

Loading a JAPK Package

Use the set_protocol_service_path API to load a JAPK package. For details, see Core API - Local Protocol Service.

Example

#include "JadeView.h"

// Use a JAPK file
void load_japk_example() {
  char url_buffer[256];
  const char* japk_path = "C:\\path\\to\\your\\app.japk";
  
  int32_t result = set_protocol_service_path(
    japk_path,
    url_buffer,
    sizeof(url_buffer),
    0  // hot_reload: 0 = disable hot reload
  );
  
  if (result == 1) {
    printf("Protocol URL: %s\n", url_buffer);
    // Navigate using url_buffer
  }
}

Command-Line Packaging Tutorial (Electron ASAR)

If you don't have any Node.js development experience yet, don't worry — this section starts from scratch and teaches you step by step how to package web files into a JAPK file from the command line.

What is ASAR?

ASAR (Atom Shell Archive) is a file packaging format that merges all the files in a folder (HTML, CSS, JS, images, etc.) into a single file. This file is like a .zip archive, the difference being that JadeView can read web pages directly from inside it without extracting.

@electron/asar is a command-line tool for creating and unpacking ASAR files. It is free.

Step 0: Install Node.js

Node.js provides a command-line tool called npm, which we'll use to install @electron/asar.

1. Open your browser and visit https://nodejs.org
2. Download the LTS (Long-Term Support) version; Windows users are recommended to choose the .msi installer
3. Double-click to install and just keep clicking "Next" (keep the default options)
4. After installation, press Win + R, type cmd, and press Enter to open the Command Prompt
5. Enter the following command to verify the installation succeeded:

node --version

If you see a version number like v20.x.x, the installation was successful.

Step 1: Install the Packaging Tool

Enter the following command in the Command Prompt (only needs to be run once; after a global install it is permanently available):

npm install -g @electron/asar

• npm install: tells npm to install a tool
• -g: global install, usable from any directory after installation
• @electron/asar: the name of the tool to install

Verify that the installation succeeded:

asar --version

Seeing a version number means it's OK.

Step 2: Prepare Your Web Project

Place your web files into a folder. Suppose your project is called my-app, for example:

my-app/
├── index.html          ← entry page (required)
├── src/
│   ├── renderer.js     ← JS script
│   └── styles.css      ← stylesheet
└── assets/
    └── icon.png        ← image resource

Step 3: Package

In the Command Prompt, first navigate to the directory containing my-app, then run:

asar pack my-app app.japk

What this command means:

• asar pack: tells the tool "I want to package"
• my-app: the name of the folder to package
• app.japk: the name of the generated file (it can be any name; the .japk extension is a convention)

After running it, an app.japk file is generated in the current directory — this is the JAPK package you need.

Verifying the Packaging Result

To see which files are in the package, use the following command to list its contents:

asar list app.japk

It will output something like:

/index.html
/src/renderer.js
/src/styles.css
/assets/icon.png

Advanced Usage

Excluding Certain Files (e.g., .node native modules)

Some files (such as .node native modules) cannot be packaged and need to stay outside the package to be loaded separately:

asar pack my-app app.japk --unpack "*.node"

• --unpack "*.node": all files with the .node extension are not packaged but placed separately in the app.japk.unpacked folder

Generating to a Specified Directory

asar pack my-app ./dist/app.japk

• Generates app.japk into the dist folder under the current directory

Unpacking (Extracting Files from the Package)

If you want to restore the files inside a JAPK:

asar extract app.japk ./extracted

• Extracts the contents of app.japk into the extracted folder

Important Notes

Electron ASAR creates plaintext packages, and unsigned packages created by JadePack are also obfuscated packages.

JAPK built with Electron ASAR:

• File content is entirely plaintext, without any encryption or obfuscation
• Anyone can directly view the package contents
• The file's origin and integrity cannot be verified
• Not suitable for production environments or scenarios requiring security protection

Unsigned JAPK built with JadePack:

• Uses a 3-layer reversible transform (XOR + byte permutation + bit rotation) to protect file content (not plaintext)
• Provides basic content protection
• But does not include signature information, so the origin cannot be verified
• Suitable for scenarios that need basic protection but not signing

Recommended approach: Use JadePack's graphical build center to create signed JAPK packages, which provide complete security protection, identity verification, and integrity checking.

Related Resources

• https://github.com/electron/asar
• https://www.electronjs.org/docs/latest/tutorial/asar-archives