Introduction

In DeepSeek Harness (DSH), the main session, sub-agent, and plan execution serve different purposes. The main session typically handles the current conversation, the sub-agent executes derived tasks, and plan execution triggers a specific run upon approval.

If the main session model is fixed for every stage, it is easy to encounter task mismatches and require repeated manual model switching. dsh-model-switch is a DSH plugin designed to select appropriate models for the main session, sub-agent, and plan execution individually. It adds model selection capabilities to the Settings, Plan Approval, and Sub-agent Information Display sections.

What is it

lincong1987/dsh-model-switch is a plugin for DeepSeek Harness, authored by lincong1987, and is licensed under MIT.

It solves the problem of allowing the main session to continue using the current model while configuring a different model for the sub-agent or plan execution within the same DSH environment. The plugin saves default settings, reducing the overhead of manual switching before every task. It also allows direct confirmation or modification of the execution model during plan approval.

Core Features

The following lists the capabilities explicitly provided by the plugin:

  • Select appropriate models separately for sub-agent and plan execution.
  • Keep the main session’s current model while using another model for the sub-agent or plan execution.
  • Save model default settings to avoid repeated switching before every task.
  • Confirm or modify the execution model in the plan approval panel.
  • Display the model, context window, and reasoning effort used by the sub-agent.
  • Restore the original model of the main session after plan execution.
  • Support Follow main model or Custom configuration.
  • The Custom mode allows selecting a model and reasoning effort.

Here, Follow main model uses the current session model, while Custom allows for the separate selection of a model and reasoning effort.

Installation and Enablement

This plugin is not published as an npm package. Do not use @lincong1987/dsh-model-switch.

The official installation command is as follows:

dsh plugin --profile web add github:lincong1987/dsh-model-switch

This command targets the web profile. Restart DSH after installation is complete.

The following conditions must be met before enabling:

  • DeepSeek Harness 0.1.1-rc.2 or higher.
  • Node.js ^22.19.0 or >=24.

The plugin’s settings are written to the host settings document and stored via a model-switch namespace registered by the plugin.

Typical Usage

  1. Open Settings → Model switch.
  2. Configure Subagent model and Plan execution model:
    • Follow main model uses the current session model.
    • Custom allows selecting a model and reasoning effort.
  3. When reviewing the plan, confirm or modify the execution model before selecting Approve.

The model selected in the plan review panel takes precedence over the saved plan execution settings.

If the plugin needs to be reinstalled after a DSH update, use --force to reinstall:

dsh plugin --profile web add --force github:lincong1987/dsh-model-switch

Restart DSH after reinstalling.

Applicable Scenarios and Notes

Suitable for scenarios where you use the main session, sub-agent, and plan execution simultaneously in DSH and wish to use different models at different stages. It is especially suitable for workflows that require saving default model settings, avoiding repeated manual switching, and confirming the execution model before approving plans.

Please note:

  • This plugin runs with the permissions of the current DSH process. You should check the source code, license, and dependency sources before installing.
  • Sub-agent model switching applies to in-process sub-agents, such as spawn and fork.
  • External process agents may manage models independently and are not necessarily controlled by this plugin.
  • DSH is still in developer preview, and it is recommended to backup ~/.dsh before upgrading across versions.
  • The README mentions that rc.8 modified the SQLite storage format in an incompatible way.
  • Only one plugin add can run at a time in Desktop.
  • If Desktop shows another plugin install recovery transaction is pending, you need to quit Desktop, clean up, and retry.

Conclusion

The value of dsh-model-switch lies in transforming “what model to use at each stage” from a temporary operation into a saveable and reviewable configuration: the main session retains its current model, while the sub-agent and plan execution switch as needed, and the main session’s original model is restored after plan execution.

  • GitHub: https://github.com/lincong1987/dsh-model-switch
  • Directory page: No verifiable link provided