Preface

When running long tasks with DeepSeek Harness (command name dsh), the main session quickly accumulates large blocks of code, error messages, and explanations. The actual point you’re stuck on is often just a small part of it: a single tool output, a piece of implementation explanation, or a single line of assumption.

If you directly follow up in the main input box, new questions will mix into the current task’s context; opening a new session will discard the prefix from that round of conversation just now.

The official DeepSeek Harness repository states this directly: Everything is a Plugin. Models, tools, sessions, and interfaces can all be replaced with community plugins. dsh-side-chat handles one aspect of session interaction: select text from a completed message in the web client, and follow up in a dedicated right-side sidebar, leaving the main conversation untouched.

First, we need to clarify the sources. DeepSeek Harness is open-sourced by DeepSeek AI, with the repository at deepseek-ai/deepseek-harness. It is currently in developer preview, and its interfaces are subject to change. The plugin directory introduced below, deepseek-harness-plugin.com, is a community site with no official affiliation to DeepSeek / Fang Technology, and should not be treated as an official app store. This article is collated after cross-checking with the directory’s detail page, the plugin’s GitHub repository (including Chinese and English READMEs, package.json, and CHANGELOG).

What is this

dsh-side-chat is a session and message plugin for the DeepSeek Harness Web Client, maintained by GitHub user AHGGG, licensed under MIT, primarily written in TypeScript. Its npm package name is @ahggg/dsh-side-chat, and the current repository version is 0.6.1 (CHANGELOG date 2026-08-17). As of August 18, 2026, the GitHub repository has 12 stars.

The problem it solves can be summed up in one sentence: launch a focused sidebar conversation targeting selected text without leaving or modifying the current main session.

Both the directory page and the repository README clearly state that this release exactly matches @deepseek-ai/dsh@0.1.0-rc.6. The peerDependencies in package.json are also pinned to 0.1.0-rc.6, and the client platform is web. Before switching to other dsh versions, check if the repository has been updated accordingly.

Core Features

Select Text with Three Entry Points

After the main session completes at least one round, selecting text within the same completed user or assistant message will bring up three actions (the repository’s English and Chinese READMEs use English button copy):

  1. Add to chat: Add an optional annotation first, then attach the selected passage to the main session input box. Existing drafts will be preserved; multiple numbered text segments and their respective annotations can be grouped into a single annotation capsule.
  2. More details: Immediately send a request for explanation.
  3. Ask in side chat: Write your own focused question to continue the conversation in the right sidebar.

When entering text manually, press Enter to send, and Shift+Enter to create a new line. Press Esc or click the × to close after finishing. While the assistant’s reply is being generated, the send icon will change to a stop button. The assistant’s replies use DSH’s built-in Markdown rendering.

There is a model selector next to the send button to choose the provider/model and available inference tiers. This selection belongs exclusively to the Side Chat and will not alter the main session’s model; after saving, it will be used as the global default for the next time the Side Chat is opened. Model and inference controls were added starting in CHANGELOG 0.6.0, and the last selected options will be remembered.

The main session will remain on the page and will not be switched to a child Session.

First Send Creates a Real Session Fork

The first time you send a message in the sidebar, the plugin will create a real DSH Session fork at the selected message. The child inherits the full event prefix, preset, and workspace. The initial model prioritizes the most recently accepted Side Chat selection; if no saved selection exists, it will take a snapshot of the main session configuration. Subsequent changes to the model or inference tier will only affect subsequent steps of the child session.

The README notes: keeping the prefix unchanged is beneficial for prompt cache reuse by vendors, but cache hits are not guaranteed.

When closing the sidebar, the plugin will cancel any running tasks, archive the child Session, and release the corresponding Agent. The child’s history on disk will not be deleted, so the child and the copied full prefix will occupy normal DSH Session storage.

Annotations Can Be Sent Back to the Main Input Box

The Add to chat path is separate from sidebar follow-up questions. After saving an annotation, the selected text will appear in the main session composer; you can hover over the capsule and click × to remove it before sending, and the same capsule will appear above your user message after sending. Hovering over N annotations will preview each selected text segment and its corresponding annotation.

Installation and Activation

The installation command given by the community directory is as follows, run it in the DeepSeek Harness terminal:

dsh plugin add github:AHGGG/dsh-side-chat

The directory page also reminds users: for reproducible installations, you should pin the commit hash. As of August 18, 2026, the master branch of the repository corresponding to the 0.6.1 release commit is 81d62a07c35d6a301eeeaa27b793c868a6572fe6:

dsh plugin add github:AHGGG/dsh-side-chat#81d62a07c35d6a301eeeaa27b793c868a6572fe6

The repository README says to install to the web profile and pull @ahggg/dsh-side-chat from npm. Refresh the package’s registry metadata before adding to avoid pnpm reusing the old latest tag right after a new version is published:

npm install --global @deepseek-ai/dsh@0.1.0-rc.6
pnpm cache delete "@ahggg/dsh-side-chat"
dsh plugin --profile web add @ahggg/dsh-side-chat@latest

Then navigate to the actual project directory where you want the Agent to operate, and start the Web interface:

cd /path/to/your-project
dsh web --port 3080

Open the address printed by dsh, and the plugin will automatically load into the Web client. The package.json requires Node.js ^22.19.0 or >=24.0.0.

Upgrading and uninstalling (also from the repository README):

pnpm cache delete "@ahggg/dsh-side-chat"
dsh plugin --profile web update @ahggg/dsh-side-chat --latest

dsh plugin --profile web remove @ahggg/dsh-side-chat

The plugin runs with the permissions of the current dsh process and may execute code during installation. Please verify the source code repository and license before installing; do not search only by plugin name, confirm that the repository is AHGGG/dsh-side-chat and the package name is @ahggg/dsh-side-chat.

Typical Usage

Follow the steps from the repository README below, without making up additional interface screenshots or performance data.

  1. Confirm that your local machine is running dsh 0.1.0-rc.6 and that you have installed the plugin to the web profile per the previous section.
  2. Execute dsh web --port 3080 in the target project directory, and open the local address output in your browser.
  3. Complete at least one round of conversation in the main session so that completed user or assistant messages appear on the page.
  4. Drag to select a passage within the same message, such as a command output or a function description.
  5. If you just want to bring this passage back to the main input box and add your own note, click Add to chat, press Enter or Save to confirm; click outside the annotation box or Cancel to abort.
  6. If you want an explanation immediately, click More details.
  7. If you want to ask multiple follow-up questions around this passage without disrupting the main task, click Ask in side chat, type your question in the right sidebar, and press Enter to send. To switch the model or inference tier, use the control next to the send button—this only changes the sidebar, not the main session.
  8. After finishing, press Esc or click the × to close. The main session remains intact, and the child session in the sidebar will be archived.

The repository’s docs/assets/side-chat-demo.gif is the official demonstration animation, which you can view before installing to understand the interaction flow.

Applicable Scenarios and Notes

It is particularly suitable for these situations:
- The main task is still running, and you only want to do a local follow-up on a specific segment of output.
- You want to use a different model or inference tier in the sidebar while keeping the main session’s original configuration.
- You need to send multiple original text segments along with their annotations back to the main input box, rather than copying and pasting the entire history.

Please note the following boundaries, all from the repository README and not speculative:
- The selection must fall within the same completed message; you cannot select across messages or content that is still being generated.
- Attachments are not supported yet, and there is no /side command.
- You cannot reopen the original Side Chat from the panel after closing it; there is no automatic history cleanup, and no “save as normal session” option.
- Archived child sessions may briefly appear in the regular session list.
- The parent session and child session share the same workspace. File modifications, command executions, and other tool side effects generated in the sidebar are real, and closing the panel will not undo them.
- The child session’s history remains on disk and will occupy normal Session storage.

Additionally, DSH is still undergoing rapid iteration, and this plugin is pinned to 0.1.0-rc.6. If the sidebar fails to appear or throws errors after upgrading dsh, first check the repository for compatibility updates, rather than assuming the new version will work out of the box.

Summary

dsh-side-chat brings Codex-style sidebar follow-up questions to DeepSeek Harness’s web sessions: select a segment of a completed message, ask all detailed questions in a separate right-side session, and keep the main conversation uninterrupted. It is an MIT-licensed open-source plugin maintained by AHGGG, current version 0.6.1, and only compatible with the Web client of dsh 0.1.0-rc.6.

Read the source code and license before installing, and remember that the sidebar and main session share the same workspace — files modified in the sidebar will not be automatically restored when the panel is closed. The directory page and repository addresses are as follows:
- Directory page: https://deepseek-harness-plugin.com/zh-CN/plugins/dsh-side-chat/
- GitHub: https://github.com/AHGGG/dsh-side-chat
- DeepSeek Harness official repository: https://github.com/deepseek-ai/deepseek-harness