During use of DeepSeek Harness (DSH), manually adjusting model parameters and reasoning levels can often be cumbersome. The dsh-performance-slider plugin reproduces the interaction experience of the Codex desktop client, providing a set of 6-level performance sliders. Each level is bound to a specific model, reasoning level, and one of 31 character background images; dragging the slider completes all the switches.

Core Features

  • 6-level performance slider: Provides an intuitive 1–6 level switch in the DSH interface, with each level corresponding to a different performance combination.
  • Linkage between model and reasoning level: When switching levels, it automatically adjusts the underlying called model (such as deepseek-v4-flash or deepseek-v4-pro) and the reasoning level (such as off, low, high, max).
  • Visual background switching: Supports 31 local character cutout backgrounds; when the slider snaps, it automatically switches to the corresponding visual theme.
  • Automatic installation: Supports automatic cordis patch installation, inserting the plugin entry into the dsh.bundle layer.
  • Standalone preview: Provides demo/index.html, allowing direct preview in a browser without installing the plugin.

Installation and Activation

Installing this plugin requires pnpm. Add the plugin to the dsh web profile with the following command:

dsh plugin --profile web add github:mobius/dsh-performance-slider

After installation completes, you must restart the dsh web service to apply the changes. The plugin declares dsh.bundle; the dsh plugin command will automatically handle the cordis patch, usually without manual configuration file modification.

Typical Usage

  1. Apply changes: After restarting the service, in any standard conversation, the slider appears above the input box (conversation.input.dock).
  2. Switch levels: Click levels 1–6, and the system will simultaneously switch the model, reasoning level, and one of the 31 character backgrounds.
  3. Package contract check: Run the static check script in the plugin directory to ensure the package contract conforms to DSH specifications:
    node scripts/check.mjs
  1. Standalone preview: Directly open demo/index.html to experience the drag slider and background switching effects without depending on the DSH environment.

Level Configuration

The mapping logic for levels is defined in the LEVELS array in lib/client.frames.js. Each item contains the model ID, reasoning level, and the corresponding background image token.

  • Model priority: When switching models, the plugin prioritizes selecting a provider/model that actually declares the reasoning level. If the current model does not support that level, it sequentially tries the fallback levels defined in effortFallbacks, finally falling back to the default level in the model catalog.
  • Storage mechanism: The user’s selection is written to the browser’s localStorage and a host-scoped cookie (port-agnostic). This means that even when using dsh web --port 0 to start a random port each time, the last selected level is automatically restored the next time it is opened.

Plugin Information

  • Maintainer: mobius
  • Category: Model reasoning
  • License: MIT

Related links:
* GitHub repository: https://github.com/mobius/dsh-performance-slider
* Plugin directory: https://www.skillhub.cn/plugins/mobius/dsh-performance-slider