Nano Banana Prompt Helper

Windows desktop wrapper and static WebApp for a local HTML prompt-configuration dashboard. The Windows app opens as a single .exe, uses Microsoft Edge WebView2 for modern browser rendering, includes a custom icon/logo/splashscreen, and exports the generated configuration as JSON.

About

Nano Banana Prompt Helper is a compact desktop tool for building structured image-generation prompt configurations. It combines an editable form-based dashboard with a live JSON preview, so prompt parameters can be adjusted, imported, copied, reset, and exported without manually editing raw JSON.

The project is built around a self-contained HTML app. The same interface is available as a static WebApp in web/ and as a lightweight Windows WebView2 wrapper in src/.

Screenshot

Features

• Single-file Windows executable output
• Static WebApp with the same design and core functions
• Embedded WebView2 wrapper for the HTML app
• Custom app icon, in-app logo, and centered splashscreen
• Dark technical dashboard UI
• Section navigation, search, live JSON preview, import, copy, download, and reset
• Motion-enhanced UI with reduced-motion accessibility support
• No backend server required

Repository Structure

.
|-- assets/
|   |-- AppIcon.ico
|   |-- Logo.png
|   `-- Splash.jpg
|-- docs/
|   |-- BUILD.md
|   `-- app-screenshot.png
|-- scripts/
|   `-- build.ps1
|-- src/
|   |-- NanoBananaPromptHelper.App.cs
|   `-- NanoBananaPromptHelper.html
|-- web/
|   |-- index.html
|   |-- Logo.png
|   `-- manifest.webmanifest
|-- .gitignore
`-- README.md

Requirements

• Windows 10 or newer
• Microsoft Edge WebView2 Runtime
• .NET Framework 4.x runtime
• Visual Studio 2022 Community or another installation that provides the WebView2 SDK DLLs

The current build script looks for csc.exe in the Windows .NET Framework folder and WebView2 DLLs in common Visual Studio / local package locations.

Build

Open PowerShell in the repository root and run:

powershell -ExecutionPolicy Bypass -File .\scripts\build.ps1

The executable will be created here:

dist-single\NanoBananaPromptHelper.exe

Optional: if WebView2 SDK files are stored somewhere else, pass the path:

powershell -ExecutionPolicy Bypass -File .\scripts\build.ps1 -WebView2SdkDir "C:\path\to\webview2"

Build & Run

1. Clone or download this repository.
2. Open PowerShell in the repository root.
3. Build the Windows app:

powershell -ExecutionPolicy Bypass -File .\scripts\build.ps1

4. Start the generated executable:

.\dist-single\NanoBananaPromptHelper.exe

WebApp

The static WebApp lives in:

web\index.html

Run it locally with any static file server. For example:

python -m http.server 8080 --directory web

Then open:

http://127.0.0.1:8080

The WebApp uses the same dashboard UI and JSON functions as the Windows app: search, form editing, live preview, import, copy, download, and reset.

To sync the WebApp from the Windows app HTML source after future UI edits, run:

powershell -ExecutionPolicy Bypass -File .\scripts\sync-web.ps1

GitHub Pages

The WebApp is published from the dedicated gh-pages branch. In GitHub, use this Pages setting:

Settings -> Pages -> Build and deployment
Source: Deploy from a branch
Branch: gh-pages
Folder: / (root)

After GitHub Pages finishes publishing, the WebApp will be available at:

https://twilight1971.github.io/nano-banana-prompt-helper/

To update the published WebApp after changing files in web/, run:

git subtree push --prefix web origin gh-pages

Development

Most of the UI lives in:

src\NanoBananaPromptHelper.html

The WebApp copy lives in:

web\index.html

The Windows wrapper lives in:

src\NanoBananaPromptHelper.App.cs

After editing the main HTML source, run scripts\sync-web.ps1 to update the WebApp copy, then run the Windows build script if you also need a fresh .exe.

Notes

• The generated .exe embeds the HTML app, logo, splash image, icon resources, and WebView2 loader files.
• At runtime the app extracts internal files into %LocalAppData%\NanoBananaPromptHelper\Runtime\<process-id>.
• dist/ and dist-single/ are build outputs and are intentionally ignored by Git.
• No generated .exe file is committed to the repository. Build locally with scripts/build.ps1.
• The WebApp is committed as static files under web/.

License

This project is licensed under the MIT License.