Introduction

In the DeepSeek Harness (DSH) Web UI, if you want to adjust the width of the chat content area directly in the session header bar without entering the settings page, magicOF2/dsh-chat-width-customizer provides a header bar button. It is used to cycle through width tiers and synchronously widen the chat message area, the bottom input box (Composer), and the user bubbles.

The following introduces the plugin positioning, core functions, installation and enabling, and typical usage.

Plugin Positioning

The plugin name is:

magicOF2/dsh-chat-width-customizer

The maintainer is magicOF2, and the license is MIT. It targets the DSH Web UI, adding a width toggle button to the utility area of the session header bar. According to verified information, the plugin is registered in the following slot:

conversation.session.header.utilities

This is a pure incremental addition.

Core Functions

The verified functional points are listed below:

  • Click the header bar button to cycle through width tiers, with a range of 748 → 1600 px, without needing to enter the settings page.
  • Synchronously widen the chat message area, the bottom input box (Composer), and the user bubbles.
  • The width is a global state, consistent across sessions.
  • Real-time synchronization across tabs via storage events.
  • Actual width is automatically clamped based on the viewport, with a clamping rule of viewport width minus 24px and a lower limit of 320px; it is recalculated in real-time when the window is resized, while the button still displays the selected tier.
  • Selections are written to localStorage and restored after refreshing the page or reopening the browser.
  • Uses DSH theme CSS variables for automatic adaptation to light/dark modes.
  • Registered in the conversation.session.header.utilities slot, making it a pure incremental addition.

Default Width Tiers

The default tiers are:

[748, 896, 1024, 1152, 1280, 1440, 1600]

The unit is px. To customize the width tiers, you need to edit the PRESETS constant at the top of the following file:

lib/client.js

Installation and Enablement

First, use the GitHub installation command:

dsh plugin --profile web add https://github.com/magicOF2/dsh-chat-width-customizer.git

After installation, a restart is required:

dsh web

And perform a hard refresh in the browser:

Ctrl+Shift+R

After the steps above, the plugin loads automatically with the GUI; no manual enabling is required.

Typical Usage

  1. Open any session and click the “Width · NNNpx” button on the right side of the header bar.

  2. Click once to cycle to the next tier:

748 → 896 → 1024 → 1152 → 1280 → 1440 → 1600 → 748 …

  1. When switching sessions, the width and button display remain consistent.

  2. After refreshing the page, the previously selected width is automatically restored.

Compatibility and Runtime Boundaries

Verified compatibility with the following environments:

DeepSeek Harness 0.1.0-rc.6 and above (verified version in development environment)
Cordis 4.x

The declared peerDependencies in package.json are:

{
  "@deepseek-ai/cordis": "^4.0.1",
  "react": "^18.2.0"
}

This plugin only writes data to localStorage, does not rely on API Keys, and has no data upload. As a DSH plugin, the plugin runs with the permissions of the current dsh process; before installation, you should check the source code and the MIT license to confirm it fits your usage environment.

Links

Community directory page:

https://www.skillhub.cn/plugins/magicOF2/dsh-chat-width-customizer

GitHub:

https://github.com/magicOF2/dsh-chat-width-customizer