Introduction

The core design philosophy of DeepSeek Harness (DSH) is “everything is a plugin.” When processing long conversations or complex agent orchestration, quickly locating earlier user requests is a common pain point. shl-session-history aims to solve this problem. It provides a miniature rail on the left side of the chat area, allowing developers to intuitively review past inputs and jump to them quickly.

What Is This?

This is a miniature history rail plugin positioned vertically centered on the left side of the chat area. Each conversation record is displayed as a short dash (or dot). Hovering over an entry shows a request summary, and clicking it jumps directly to the corresponding chat position.

Core Features

  • Visual Display: Entries are shown as short dashes by default and can be switched to the dot style in settings. Style changes take effect immediately and are persisted locally.
  • Interaction Feedback: On mouse hover, an entry expands and shows a wave-like gradient effect centered on the hovered point. A floating tooltip with the full request summary also appears.
  • Smart Navigation: Clicking a rail entry automatically scrolls the chat area to the corresponding user message. If the target turn has not been loaded, the plugin automatically clicks the “Load earlier” button until the correct position is reached.
  • Real-Time Updates: The rail refreshes automatically every 2 seconds and rebuilds the DOM only when the data changes, ensuring that hover interactions are not interrupted.
  • Content Filtering: System-injected messages are filtered automatically, so only genuine user requests are displayed.
  • Intelligent Hiding: If the rail is too close to or overlaps the chat content, it hides automatically to avoid obscuring text.
  • Custom Sizing: You can adjust entry spacing, dash length, dot size, and hover capsule length.

Installation and Enablement

This plugin is a bundle plugin. Its dependencies are provided by the host application runtime, so no manual npm dependencies need to be installed.

Run the following command in your terminal to install it:

dsh plugin --profile desktop add /path/to/shl-session-history

After installation, go to the “Plugins” card on the Settings page and find the “Session Rail” card. By default, the rail is enabled and appears alongside the session content.

Configuration and Usage

All configuration options are located in the “Plugin Configuration → Session Rail” card on the Settings page:

  1. Enable/Disable: Use the “Enable Rail” switch to control the main toggle.
  2. Style Switching: Click “Dash” or “Dot” to switch the visual style.
  3. Size Tuning: Drag the corresponding sliders to adjust parameters such as spacing, length, and size. The values take effect immediately.
  4. Automatic Hiding: Enabled by default; adjust it as needed.

Click any rail entry to jump to the position of the corresponding historical request.

Version History and Maintenance

  • v1.1.5: The positioning mechanism was refactored into “unique key direct lookup.” The host outputs an event ID for each message, and the client uses the kernel’s data-chat-anchor-key to locate the exact DOM node. This ensures that duplicated messages with the same content can still be uniquely located, and fixes misjudgments during paginated loading.
  • v1.1.4: Fixed the issue where same-prefix messages were incorrectly targeted. The matching logic was changed from includes to startsWith to prevent early messages in long sessions from being matched incorrectly.
  • v1.1.3: Fixed occasional problems where clicking an entry failed to locate the content. Added compatibility handling for paginated loading buttons and quoted messages.
  • v1.1.2: Fixed visual issues with the settings card in dark mode.

Summary

shl-session-history provides a lightweight, highly customizable session navigation solution. It solves the locating challenge in long conversations while keeping the interface clean and interactions smooth through automatic hiding and real-time refreshing. The plugin is released under the MIT license, and the source code is hosted on GitHub.

Project Link: https://github.com/sunyuhuirong/shl-session-history