Preface

When having long conversations with agents in DeepSeek Harness (DSH), the main thread often accumulates a lot of context. You might want to follow up on a specific reply for more details without switching away from the main conversation or pasting large blocks of text again. Common approaches include copying selected text, starting a new conversation, or pasting the entire section into the input box—the main interface remains, but your focus is already interrupted.

Below, we introduce the community plugin dsh-side-chat (maintainer AHGGG, GitHub repository AHGGG/dsh-side-chat). It provides a Side Chat similar to Codex within the DSH Web client: select text from completed messages, initiate a focused follow-up in a sidebar, while the main conversation stays visible and uninterrupted.

What is This

@ahggg/dsh-side-chat is a plugin for DSH’s Web client, currently at version 0.7.2 under the MIT license. Categorized as a “client-side” plugin in the SkillHub community directory, as of 2026-08-26, it has 12 stars and 2 forks on GitHub.

The core problem it solves is: without leaving the current main conversation, you can ask follow-up questions, seek explanations, or annotate selected text snippets, and later merge sidebar discussions back into the main input box when needed.

Core Features

Select and Act

After at least one round in the main conversation, you can select text within completed user or assistant messages. On desktop, an action bar appears after selection; on mobile or tablet, long-press to select, and the action bar appears below the selection (the browser’s native selection bar is above).

Available actions include:

  • Add to chat: Adds the selected snippet (with optional annotations) to the annotation capsule in the main input box.
  • More details: Immediately sends an explanation request.
  • Ask in side chat: Writes a focused question in the sidebar.

When sending for the first time in the sidebar, DSH forks a real sub-Session at the selected message. The sub-Session inherits full event prefixes, presets, and workspace; the model and reasoning strength can be configured independently of the main conversation and only affect subsequent steps in the sidebar.

Sidebar replies use DSH’s native Markdown rendering. After a reply, click Add to conversation to attach the sidebar’s user/assistant history as a conversation reference to the main input box; clicking again refreshes the reference instead of duplicating it.

Annotation Capsule

Add to chat preserves existing drafts in the main input box, allowing you to collect multiple numbered snippets, each with independent annotations. Hovering over the annotation capsule before sending previews all snippets; click × to remove. After sending, the capsule appears above the user message.

Other Interaction Details

  • Press Enter to send, Shift+Enter for a new line.
  • The model control next to the send button only applies to the sidebar and does not affect the main conversation; the selection becomes the global default for the next sidebar session.
  • During a reply, the send icon changes to a stop button.
  • Press Esc or click × to close the sidebar.

Installation and Enabling

The plugin’s README requires installing DSH 0.1.0-rc.7 first and refreshing the registry metadata for that package before adding the plugin to avoid pnpm reusing an old latest value. The package.json file’s dshCompatibility.testedVersions lists 0.1.0-rc.7 and 0.1.1-rc.2.

Execute the following in PowerShell:

npm install --global @deepseek-ai/dsh@0.1.0-rc.7
pnpm cache delete "@ahggg/dsh-side-chat"
dsh plugin --profile web add @ahggg/dsh-side-chat@latest

Navigate to the project directory where you want the agent to work, then start DSH Web:

cd E:\path\to\your-project
dsh web --port 3080

Open the URL printed in the terminal; the plugin will automatically load in the Web client.

When upgrading, clear the cache first, then update, and restart DSH:

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

To remove the plugin:

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

Typical Usage

After completing the installation steps, use the sidebar as follows:

  1. Complete at least one round of Q&A in the main conversation.
  2. Select text within a completed message.
  3. Click Ask in side chat to write a focused question, or click More details to request an explanation directly, or click Add to chat to attach the snippet (with optional annotations) to the main input box.
  4. After entering your question in the sidebar, press Enter to send.
  5. Once the sidebar reply stabilizes, click Add to conversation to bring this discussion as a reference back to the main input box.
  6. After finishing, press Esc or click × to close the sidebar.

If using Add to chat with annotations, press Enter or click Save to save; click Cancel or click outside the selection to discard.

Sessions and Side Effects

Closing the sidebar stops ongoing work, archives the sub-Session, and releases its Agent, but does not delete the sub-Session history from disk. The sub-Session and copied prefixes occupy normal DSH Session storage.

The parent and child sessions share the same workspace. File modifications, command executions, and other tool side effects in the sidebar are real and will not roll back after closing the panel.

Current limitations listed in the README:

  • The selection must be within a single completed message.
  • Attachments and the /side command are not yet supported.
  • A closed sidebar cannot be reopened from the panel.
  • There is no automatic history cleanup or “retain as normal conversation” operation.
  • Archived sub-Sessions may briefly appear in the normal session list.

Use Cases and Considerations

Suitable for DSH users who need to follow up on specific content in long conversations without interrupting the main thread. The sidebar model can be switched independently, making it convenient to use different reasoning strengths for quick clarification on selected snippets.

Please note before installation:

  • The plugin runs with the permissions of the current dsh process; tool calls in the sidebar, like those in the main conversation, will make real changes to the workspace.
  • Before installation, review the GitHub source code and the MIT license to ensure it fits your usage environment.
  • The SkillHub community directory (skillhub.cn/plugins/AHGGG/dsh-side-chat) is an independent site with no official affiliation with DeepSeek or High-Flyer.

Conclusion

dsh-side-chat integrates “select—follow up—merge” into the sidebar of the DSH Web client, keeping the main conversation always visible. If you often perform deep dives on specific outputs in long sessions, you can follow the README steps to install and try it out.