Introduction

DeepSeek Harness (DSH) uses a plugin-based architecture that allows developers to extend its functionality. During agent development, debugging specific steps or retrying completed operations is a common requirement. dsh-session-rerun is designed to address this pain point by providing the ability to inspect historical steps and re-execute them without affecting the original session data.

Plugin Overview

This is a Web plugin for DeepSeek Harness, maintained by user liuyangdongdong. It is mainly used to inspect and replay completed session steps, helping developers analyze model responses, tool call results, and elapsed time during execution.

Core Features

  1. Session Timeline Grouping: Groups the persistent session timeline by turn and step, making it easier to trace the interaction flow.
  2. Detailed Status Display: Displays model responses, tool calls, skill usage, failure states, and the elapsed time for each step.
  3. File Reference Markers: Shows compact badges for script and Markdown filenames on the right side of a step, making it easier to locate related files.
  4. Top-Level Step Replay: Replays selected top-level steps in a new session without modifying the source session.
  5. Subagent Step Replay: Replays selected subagent steps in the original workspace via a new main session. The new main session only rebuilds the delegated call, waits for the new subagent result, and then continues execution.

Install and Enable

Installing the plugin requires the DeepSeek Harness CLI.

  1. Install the plugin:
    npx @deepseek-ai/dsh plugin --profile web add github:liuyangdongdong/dsh-session-rerun
  1. Start the Web UI:
    npx @deepseek-ai/dsh web
  1. After installing or replacing the plugin, you must restart the running Web process for the plugin to take effect.

Typical Usage

In the Web UI, the plugin displays historical session steps. Developers can click a specific step to replay it:
* For a regular step, the new agent receives the persistent history before the selected step and the user input recorded for that step.
* For a subagent step, the plugin creates a new main session and a new sub session. The sub session replays the selected step, while the main session rebuilds the delegated call and waits for the sub session result.

Use Cases and Cautions

Applicable Scenarios

  • You need to review a completed session and verify its results.
  • You need to adjust the input or parameters of a specific step.
  • You need to analyze the specific parameters and return values of tool calls.

Cautions

  • Data Safety: The plugin never modifies the source session; replay operations generate a new session.
  • Nesting Limitation: Nested subagent replay is intentionally not supported.
  • Step Integrity: The replayed step must exist and have a matching step/end event.
  • Developer Preview: DeepSeek Harness is in developer preview, and peer dependency versions may need to move with upstream releases.

Summary

dsh-session-rerun provides DeepSeek Harness users with a practical tool for inspecting and replaying historical session steps. Through a clear interface and flexible replay mechanism, it helps improve the efficiency of agent development and debugging.