dsh-replay-theater

The DeepSeek Harness session log quietly carries a piece of data the UI has never surfaced: the real inter-arrival gap between every token. Upstream stores each token boundary as its own record on purpose, yet nothing in the harness ever plays that rhythm back. dsh-replay-theater closes that gap by turning the log into an interactive theater where the assistant answer grows token by token, with each pause matching the millisecond spacing recorded at generation time. You can play, pause, single-step one token forward or backward, scrub to any position, and dial speed anywhere from 0.5x to 8x. A max-pause ceiling compresses long silences for readability, or set it to infinity to preserve true wall-clock cadence. Tool calls appear as accumulating JSON with the tool name on the timeline, while scalar events such as step/start and tool/result ride on a dedicated marker rail so they never muddy the text stream.

Version 2 adds a side-by-side comparison mode: load two recorded session.jsonl files and the theater reports exactly where the two runs stop matching, with a seek coordinate for each side. The replay core is a pure, framework-free module, so the same logic runs in a headless CLI script without a browser or a Harness checkout. No call-site changes are needed if you later swap the structural type mirrors for real package imports.

This plugin fits three common workflows. First, debugging prompt behavior when you want to feel the generation rhythm and silence distribution rather than reading raw numbers. Second, comparing two runs of the same prompt, or outputs under different model parameters, to spot where they diverge. Third, auditing tool-call flows to see each argument field materialize in order. It does not replace ui-tool cards; it focuses on one thing the rest of the stack leaves untouched: cadence.