Introduction

In the conversation flow of DeepSeek Harness (DSH), verifying details, explaining code, or exploring alternatives often requires copying text, switching sessions, or forking the conversation, which can easily interrupt the current line of thinking. dsh-sidecar is a persistent sidecar follow-up plugin designed to provide a side-context follow-up experience similar to Codex. It lets you create independent child sessions for branch follow-ups without leaving the main conversation interface or polluting the main session history, and it automatically saves state for restoration at any time.

Plugin Overview

Name: srien11/dsh-sidecar
Description: DeepSeek Harness persistent sidecar follow-up plugin: branch follow-up without leaving the main conversation, with automatic saving and on-demand restoration.
Owner: Srien11
Category: Memory
License: MIT
Current status: 0.1.0-beta.0, targeting @deepseek-ai/dsh@0.1.5-rc.3

Core Features

Flexible follow-up entry points
Select any snippet of an AI response to start a follow-up directly beside the selection. If there is no selection, you can also continue asking about the entire content from the end of the response. While a response is still being generated, an “Ask about current output” option also appears next to the input box.

Independent and Persistent Child Session
Each new follow-up is conducted in an independent, persistent child session. Completed responses inherit context through native forking; in-progress responses freeze the visible history at the moment of click and hand it to an independent session, after which it no longer follows changes in the main conversation.

No interruption to the main flow
When verifying details, explaining code, or exploring alternatives, the main conversation remains unchanged. The plugin does not switch the current main session, nor does it append follow-up messages to the main conversation list.

Precise follow-up
Only valid selections within the current response are accepted, and the punctuation, line breaks, and code in the selected text are preserved exactly, avoiding recopying and pasting.

Floating window and interaction
The follow-up window is a freely draggable, resizable-in-eight-directions floating window that remembers its last position. The title bar displays a follow-up summary rather than a number. After focusing the left grip, use arrow keys to move the window, and Shift + arrow keys to resize it.

Original text highlighting and restoration
Original text that has been followed up remains highlighted in yellow. Click the highlight, or focus it and press Enter / Space, to restore that follow-up. The plugin records character offsets, accurately preserving locations for text that appears repeatedly.

Native integration
The plugin follows Harness’s Chinese and English interfaces and light/dark themes, and inherits the existing permission boundaries.

Installation and Activation

The current Beta has not yet been published to npm. Source installation requires Node.js ^22.19.0 || >=24.0.0, pnpm 11.7.0, and DeepSeek Harness 0.1.5-rc.3.

git clone https://github.com/Srien11/dsh-sidecar.git
cd dsh-sidecar
pnpm install
pnpm build
dsh plugin --profile web add link:D:\absolute\path\to\dsh-sidecar

After installation, restart the Web profile.

Usage Steps

  1. Open a session that is generating or already contains an AI response.
  2. While a response is still being generated, click “Ask about current output” next to the input box; the window will use the visible history at the moment of click.
  3. After the response is complete, if you need to target a specific snippet, select the text and click “Ask” that appears immediately beside the selection. You can also click “Ask” at the end of the response.
  4. After adding your question, press Enter to send and Shift + Enter for a new line. The main session remains selected and no messages are appended to it.
  5. Drag the window from anywhere on its title bar to move it away from the original text, drag the border or corner to resize it, and click “Reset” to return to the default position. Position and size are remembered.
  6. The dropdown at the end of the response lists all follow-ups for that response by summary, with the selected item highlighted. Original text that has been followed up remains highlighted in yellow; clicking the highlight returns you to the corresponding follow-up.

Use Cases and Notes

Isolation boundaries
This plugin guarantees conversation record isolation: follow-ups and responses only enter hidden child sessions, do not appear in the normal conversation list, and does not automatically write back, truncate, rename, or archive the parent session.

Side effects are not isolated
A child session and the parent session may still use the same workspace, file system, and external services. If the child session is allowed to call write-capable tools, those effects are also visible in the main workspace. Use Harness permission modes to control tool access.

Short Conclusion

dsh-sidecar provides DSH with stable side-branching capabilities, achieving precise context inheritance and restoration through child sessions and anchor records. For more details, see the official plugin catalog or the source repository.