Preface

DeepSeek Harness uses a plugin-based architecture, and community plugins extend its native functionality. dsh-system-prompt focuses on editing and managing system prompts, addressing the difficulty of rolling back changes made directly on the settings page.

Plugin Overview

The plugin provides an entry point for editing system prompts on the DeepSeek Harness settings page, supporting restoration of default settings and undoing the last saved change.

  • Name: dsh-system-prompt
  • Maintainer: Ghpt6
  • License: MIT

Installation and Enablement

Use the following command to install the plugin:

npx @deepseek-ai/dsh plugin --profile web add github:Ghpt6/dsh-system-prompt

After installation, restart DeepSeek Harness Web and refresh the browser. Then go to the Settings → System Prompt page to use it.

Core Features

The plugin provides three operation modes:

  • Use Default: Does not override the system prompt; the current Harness, session preset, and loaded plugins assemble it automatically.
  • Append Instructions: Appends custom text at the end of the original system prompt, preserving the existing guidance.
  • Full Replacement: Replaces the entire system prompt body with custom text; the original tool usage guidance is also replaced.

Other features include:
* Prompt Source Selection: By default, it follows the current session and includes supplementary guidance from loaded plugins for read, write, edit, glob, grep, background tasks, and more. If the current session is empty and only one Host session is loaded, it automatically uses that session. With multiple sessions, you must select one manually.
* Load Full Default Prompt: Copies the full default prompt of the selected session into the editor area for confirmation or modification.
* Preview: Displays the prompt reassembled under the current configuration and provides a list of plugin section names.

Usage Instructions

  1. Edit and Save
    Select a mode (Use Default / Append Instructions / Full Replacement), and enter or modify the content in the text box. The input is a draft; changes take effect after clicking Save Changes.
  2. Load Default Content
    Click Load Full Default Prompt and Edit to copy the full default prompt of the current session into the editor area. After confirming the load, you still must manually click Save.
  3. Undo Changes
    Click Discard Unsaved Changes to reload the latest saved version.
  4. Restore Default
    Click Restore Default to clear the custom text and save, restoring the current Harness assembly result.
  5. Undo Last Save
    Click Undo Last Change to restore the previous saved version.

Technical Details and Limitations

  • Text Limit: The text supports a maximum of 100,000 UTF-16 code units and rejects blank content.
  • Template Support: The text is used literally; template variable expansion (such as {{example}}) is not supported.
  • Scope: Only processes the system prompt body; preserves tool schemas, filtering results from other plugins, and dynamic context. Full Replacement mode removes the tool guidance from the original prompt.
  • Configuration Effect: User-level settings, applying to sessions that share the same settings document. After saving, the committed settings are read when the next model request is assembled; no Host restart is required.
  • Environment Requirements: Verified with DSH 0.1.2-rc.1 (2026-09-08) and Node.js ^22.19.0 || >=24.0.0.
  • Special Limitations: Connections for remote browser memory/read-only settings cannot submit Host configuration.

Configuration and Uninstallation

The plugin’s configuration is stored under the dsh-system-prompt namespace in the DSH user settings document (typically <DSH_HOME>/settings.yaml).

dsh-system-prompt:
  schemaVersion: 1
  mode: append
  prompt: |-
    请始终使用中文回答。
  previous:
    mode: default
    prompt: ""

If you need to uninstall the plugin, run:

npx @deepseek-ai/dsh plugin --profile web remove dsh-system-prompt

After uninstallation, the plugin’s override is removed, but the user settings remain. Reinstallation will continue to use the previous settings.