Introduction

DeepSeek Harness (DSH) preserves the exact arrival intervals for every token (dt) in session logs, but the upstream interface does not provide playback. This plugin provides an inline playback theater for replaying sessions in the browser with their original timing. It is maintained by ItBayMax and aims to solve the issue that precise timing information preserved in logs cannot be visualized in the interface.

Core Features

  • Original token timing playback: Assistant responses grow token by token according to the recorded millisecond intervals, rather than as static text.
  • Inline playback theater: Provides play, pause, step, speed, and jump controls within the DSH interface.
  • Transport controls: Supports play/pause, step (forward/backward), restart (preserving speed), jump (absolute position), and speed control (0.5x to 8x).
  • Silence handling: Configurable maximum silence cap (default 200ms - ∞). Compressed silences are displayed on the transport bar.
  • Comparison runs: Supports side-by-side comparison runs and highlights divergence points.
  • Tool calls: Tool calls are displayed as cumulative JSON plus the tool name.

Installation

Install the plugin using the official CLI:

dsh plugin --profile web add dsh-replay-theater

After restarting dsh web, a Theater tab appears next to the session page.

Usage

  • Control bar:
    • ▶ / ❚❚: Play or pause. Playback restarts from the beginning when it reaches the end.
    • ⏴ / ⏵: Step forward or backward by one token. Stepping pauses playback.
    • ⤾: Restart, keeping the current speed.
    • Jump: Jump to an absolute position.
    • Speed: 0.5× to 8×.
    • Max Pause: Compress silences longer than this value (200 ms … ∞). Set to ∞ to preserve real timing.
    • Load Earlier: Load older windows. The playback position is preserved.
  • Silence compression: When any silence is compressed, the transport bar indicates the amount compressed.
  • Comparison: Load a recorded session.jsonl alongside the active session, and the plugin reports where the two runs stop matching.

Technical Limitations

  • No random access: History is limited to backward paging, one window at a time.
  • Silence compression: Long silences are compressed by default (2000 ms cap). Set to ∞ to preserve real timing.
  • Active sessions: The window follows playback, and the position is preserved when frames are appended.
  • Granularity: Jump coordinates are based on attempt granularity.
  • Types: Types are mirrored, not imported.
  • Compatibility: Developed against dsh 0.2.0-rc.2.
  • File reading: Reads disk-generated files (v2+, currently v4).
  • Transient entries: Client transient entries are ignored.

Use Cases

Suitable for developers who need to analyze reasoning processes, streaming outputs, or debug agent behavior.

Conclusion

dsh-replay-theater allows developers to replay sessions with precise token timing for analysis and demonstration. For more details, refer to catalog_url or github_url.