Preface

The design philosophy of DeepSeek Harness (DSH) is “everything is a plugin.” For developers or regular users, adjusting the interface style while keeping system functionality stable usually requires modifying the source code directly or using complex developer tools. The dsh-x9-theme plugin provides an appearance customization solution through the official plugin mechanism, without requiring a frontend build and without affecting the DSH source code.

Introduction

dsh-x9-theme is a DeepSeek Harness WebUI theme plugin (bundle). It provides features such as preset styles, light/dark mode switching, independent style customization for individual sections, and background management, with support for configuration persistence and sharing.

Installation

Run the following command in the terminal to install the plugin:

dsh plugin --profile web add github:X9wd09ncc/dsh-x9-theme

After installation is complete, restart the DeepSeek Harness service.

Core Features

Preset Styles and Light/Dark Mode

The plugin provides multiple preset styles, including Aurora, Midnight, Sakura, and Forest. It also supports light/dark mode, allowing users to choose between Follow System, Light, or Dark.

Independent Section Styles

Areas such as the sidebar, input box, chat bubbles (User/AI), and page background can have independently customized styles, including effects such as frosted glass, neon outline, emboss, and gradient.

Background Customization

Supports local upload, local file path, URL link, or built-in gradient as the background.

  • Local path restrictions: The file extension must be in the whitelist (jpg/jpeg/png/gif/webp/avif/svg/bmp), and the file size must not exceed 8 MiB.
  • Upload mechanism: Locally uploaded images are stored in the plugin assets directory and will not be lost after restarting.

Custom CSS and Opacity

  • Per-section custom CSS: Provides an editor that displays the actual styles of the current section and allows direct modification without using F12. When namespace conflicts occur, the custom CSS has higher priority.
  • Four-area opacity: The opacity of the main area, sidebar, card overlay, and input area can be adjusted independently, with support for automatic reference values (automatically adjusted after enabling the background).

Configuration Persistence and Sharing

All settings are automatically written to config.json in the plugin directory. In the “Advanced” section of the settings panel, configurations can be imported or exported, making it convenient to share themes with others.

Activation and Updates

  • Activation: After modifying lib/client.js (browser-side), refresh the page to apply the changes; after modifying lib/index.js (Host routing), restarting the service is required.
  • Updates: Re-run the installation command to overwrite and update the plugin.

Notes

  1. Prerequisites: DeepSeek Harness must already be installed.
  2. Version compatibility: After a major DSH version upgrade, CSS class names may change, and custom CSS must be updated accordingly.
  3. Background mode: Background style layers (such as cyber grid and starry sky) are all dark-based; selecting one will automatically switch to dark mode to ensure readability.
  4. Configuration reset: Delete config.json in the plugin directory or click “Reset All” in the “Advanced” section of the panel to restore defaults.