DeepSeek Harness (DSH) supports plugin-based extension for the Web UI. When developing or debugging agents, font styles in editor and code areas directly affect the reading experience. Existing theme settings often cannot meet fine-grained customization needs, or require modifying underlying source code. The following section introduces a DSH plugin focused on font control.

What is This

dsh-font-plugin is a DeepSeek Harness plugin maintained by user wtksana. It overrides CSS variables to control the font family and ligature settings for editor body text and code areas in the Web UI.

Core Features

The plugin provides the following three core configuration options:

  1. Font Family : Editor: Overrides the CSS variable --dsw-font-family, affecting both UI text and Markdown body content.
  2. Font Family : Code: Overrides the CSS variable --ds-font-family-code, affecting code blocks, commands, and log areas.
  3. Font Ligatures: Supports three states:
    • Auto: Follows the theme default.
    • On: Enables ligatures.
    • Off: Disables ligatures.

Installation and Enabling

The plugin targets the web platform. After installation, it must be manually enabled in the Web UI.

  1. Install from npm:
    dsh plugin --profile web add dsh-font-plugin
  1. Install from GitHub:
    dsh plugin --profile web add github:wtksana/dsh-font-plugin
  1. Install for local development:
    dsh plugin --profile web add ./path/to/dsh-font-plugin

After installation is complete, starting dsh automatically calculates the revision number of the client package. If you modify the code locally, you need to restart dsh.

Typical Usage

Font Stack Configuration

Font names can be entered as a comma-separated list (e.g., MiSans, Microsoft YaHei, sans-serif). Quoting font names is optional; if a single name is provided, the system automatically adds quotes and fallback fonts.

Configuration via UI

  1. In DSH Web UI, open Settings → Plugins.
  2. Locate Plugin configuration.
  3. Expand the dsh-font-plugin card.
  4. Modify the fields and click Save.

Configuration via YAML

You can also directly edit the $DSH_HOME/settings.yaml file:

dsh-font:
  editorFont: MiSans
  codeFont: MiSans
  ligatures: auto

Save Behavior: Saving writes the exact value entered by you into the user-level configuration. Even if the value is equal to the official default, the existence of the field is considered an override. Clicking Reset clears the field and lets it fall back to the theme default.

Use Cases and Notes

  • Permissions and Dependencies: DSH plugins run with the permissions of the current process. Before installing, it is recommended to review the source code and license (this project is MIT licensed).
  • Font Weight and Size: Font weight and size are provided by the official DSH theme settings (Appearance) in versions 0.1.2 and later. This plugin only manages font family and ligatures; it does not modify weight or size.
  • Localization: UI text is localized into English and Chinese through the official ctx.locale mechanism.
  • Uninstallation: Running dsh plugin remove dsh-font-plugin removes both the plugin package and its patch layer.

Summary

This plugin provides non-invasive font customization for the Web UI through the standard DSH plugin configuration contract. Developers can quickly adjust the appearance of editor and code areas via the UI or a YAML file.