Introduction

DeepSeek Harness (DSH) adopts a plugin-based architecture. dsh-essential-tools (DET) is a permanent plugin maintained by LLYlab, aimed at turning DSH into an engineering-capable console. Through features such as browser control, project execution, version snapshots, and Virtual Dialogue Tree (VTD), it addresses pain points encountered by agents in real-world code development, including broken context, lack of execution environments, and inability to trace back historical operations.

Core Features

Browser Control

DET communicates with the DSH host through a Manifest V3 browser extension (Edge or Chrome). The extension connects via a local WebSocket bridge, with the default port 127.0.0.1:9123, allowing the model to operate the user’s already logged-in browser instance.

  • Permission Control: Users control permission toggles through the extension popup, and the model can only read the currently configured permission state.
    • off: No permission.
    • read: Can read page text, DOM, screenshots, URL, and title.
    • write: Can navigate, click, fill forms, and run programs, but cannot read page content.
    • on: Full read/write permission.
  • Security Mechanisms: The model must have network permission level 4 to initiate a connection; in non-full-permission modes, browser operations must go through DSH’s tools/pre-execute approval process.

Virtual Dialogue Tree (VTD)

VTD allows creating and managing conversation branches without copy-pasting into a new session.

  • Branching Operations: Editing or retrying any user message creates a real child branch session (origin: vtd-fork), leaving the original thread unchanged. Use the <N> selector to switch between branches.
  • Message Micro-versions: Records micro-versions such as baseline, edit, retry, and auto-switch, supporting rollback.
  • Real-time Rendering: Refresh rate is approximately 700ms during streaming and approximately 2.5s when idle, with auto-scrolling.

Engineering Tools

Provides project-level operations in the right-side toolbar of DSH.

  • Run: Automatically finds entry points (such as main, entry/run, or .sln files) and uses MSBuild to compile and run.
  • File Tree: Displays the workspace file structure, supporting preview and editing.
  • Snapshots and Rollback: Creates snapshot backups of program code. Snapshots contain only code files. Supports manual snapshots, rollback (after automatic backup), and deletion.

Global Plugin Manager

Provides cross-session plugin management capabilities.

  • Multi-level Enablement Strategy: Plugins have 5 levels: Globally Enabled, Dialogue AI May Auto-Enable, Dialogue AI Requires Approval to Enable, No New Enablements, and Globally Disabled.
  • Source and Security: Supports promoting plugins from running dialogues, searching or importing from the store via Manifest URL. Supports direct download or AI rewriting source code (det_global_plugin_github_rebuild); rewritten code is not executed and is used only for security checks.
  • Boot and Protection: The plugin loader supports hot-plugging. Built-in Boot Guard mechanism limits consecutive startup failures (default 2) to prevent malicious plugins from causing system boot failure.

Memory Layer and Audit

  • MDA (Mixing Dialogue Agent): Provides grouped memory for native, workspace, and model.
  • CDM (Cross Dialogue Memory): Supports listing and searching cross-dialogue memory.
  • Security Audit: Provides audit logs and security switches.

Usage Guide

Running a Project

Click ▶ Run in the right-side toolbar of DSH. The plugin automatically detects main, entry, or .sln files, calls MSBuild to compile, and starts the program.

Dialogue Branching and Retry

  1. Long-press any message in the dialogue and select Edit or Retry.
  2. After the AI modifies the content, a new hidden branch is generated.
  3. Use <N> to switch to that branch to view the result; the original dialogue is unaffected.

Managing Plugins

  1. Click 🧩 Plugins in the right-side toolbar to enter the Global Plugin Manager.
  2. Use det_global_plugin_set_enabled to switch a plugin’s enabled state, or use det_global_plugin_github_rebuild to securely import a plugin from GitHub.

Notes

  • Zero Configuration: Core features such as dialogue tree and message editing can run without configuring a project path.
  • Browser Dependency: Using browser control requires installing the extension and ensuring that the 127.0.0.1:9123 bridge works properly.
  • Permission Level: Network permission level must be 4 to start the browser control feature.
  • Snapshot Scope: Program snapshots contain only code files, not binary output or environment configuration.

References