# Stop outdated AI answers when a document changes

Blog · Human page: https://quelvio.com/blog/when-a-document-changes · Machine view: https://quelvio.com/ai/blog/when-a-document-changes

## When a document changes, every answer follows

Each new version is compared with the last, and every change is logged. Agents ask what changed, and old answers are marked "source changed since".

Policies change. The trouble starts when agents keep quoting the old version.

Each new version of a document is compared with the last, sentence by sentence, and every change is logged: what was there, what replaced it, and when.

**Sample** · A change, on History

```text
What changed:
1 March 2026 · Travel and expenses policy · Meals · changed: "The daily meal allowance on business trips is 40 euros." → "The daily meal allowance on business trips is 45 euros."
```

## Agents ask what changed

Nothing is pushed into an agent. When an agent asks what has changed since a given time, it gets every change, and the lines it was given before are marked "served to you".

## Old answers are marked

An answer given before the change reads "source changed since". Opened again, it shows what was given at the time.

**Sample** · Past answers

```text
What is the daily meal allowance on business trips? · 20 February 2026 · source changed since
The daily meal allowance on business trips is 40 euros.
Travel and expenses policy · Meals · 1 January 2026 (stated) · in force · official
```

## Every version, kept

Every version is in Quelvio's history, with what changed between them, for 12 months.

[Knowledge →](https://quelvio.com/knowledge)

## Related

- [Human view of this page](https://quelvio.com/blog/when-a-document-changes)
- [All posts](https://quelvio.com/blog.md)
- [Everything for agents: llms.txt](https://quelvio.com/llms.txt)