# Rewind, History and Quantities

Seeing what a report said an hour ago, what changed since, and how much of it there is.

Source: https://salidium.com/docs/rewind

A report shows a session as it stands. These three answer the questions that are about time rather than about now.

## Rewind

Rewind puts a scrubber at the foot of the session. Drag it and the page becomes the session as it stood at that moment, with everything later hidden.

![The Salidium rewind scrubber under a report, with marks for checks and commits along the track.](https://salidium.com/docs/rewind-light-afae774c.png)

The track is one step per change, not per minute. A mark is a check or a commit, red where a check failed, and marks too close to draw apart are merged into one that takes the worst outcome in it.

## History

History lists every change Salidium derived, oldest first, each with the kind of change it was and how it is known. It is a log, so it sits at the bottom where the newest entry is. Open it as a table across the page and it gains a How we know column.

![The Salidium history table, listing each change with when it happened, its kind, what changed, and a How we know column.](https://salidium.com/docs/history-light-bb6204b9.png)

The filter narrows it to any of seven kinds: status, what changed, why, how, checks, left to do, needs review. When you come back to a session that moved while you were away, Salidium offers the changes since you last had it open, and History opens scoped to them.

## Quantities

Measured totals beside the session, and only the ones that were observed.

![The Salidium quantities rail, showing changes, activity, model usage and the latest check.](https://salidium.com/docs/quantities-light-36a25eaf.png)

- **Changes**: Files, added, removed.
- **Activity**: Duration, commits, turns.
- **Model**: Responses, input, output, cache read, cache write.
- **Latest check**: The method, the outcome, the time.
- **Data handling**: Credential-shaped strings redacted, records that could not be read, context compactions.

> No figure appears in currency. That would be Salidium's arithmetic over a price table it does not carry, and on a subscription no amount is charged.