> ## Documentation Index
> Fetch the complete documentation index at: https://docs.devic.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Versions and usage

> Every edit to a document is kept, comparable and revertible — and you can always see who is relying on it.

Knowledge that agents act on is not something you want to change blindly. Devic keeps the history for you, and tells you who depends on a page before you touch it.

***

## A version per change

Every time a document's content changes, Devic stores a new version. Nothing to enable, nothing to remember.

<img src="https://mintcdn.com/devic/TaMbtKJRXl9eU5LD/images/knowledge/versions.png?fit=max&auto=format&n=TaMbtKJRXl9eU5LD&q=85&s=fba06d200d088999ce538a2bad06c6ba" alt="Version history of a document" width="2042" height="1474" data-path="images/knowledge/versions.png" />

Each version records what changed — lines added and removed — so the history reads as a list of edits rather than a list of timestamps.

<Steps>
  <Step title="Open the history">
    From the document, open its version history.
  </Step>

  <Step title="Compare">
    Pick a version to see its content and what changed against the one before it.
  </Step>

  <Step title="Revert">
    Restoring an old version does not erase anything: it writes the old content as a **new** version. The history stays complete, and the revert itself is part of it.
  </Step>
</Steps>

<Note>
  Renaming a document, moving it or editing its properties does not create a version. Only content does.
</Note>

***

## Who is using this document

Before you edit — and certainly before you delete — check the usage panel. It lists the agents and assistants that have this document attached, directly or through a folder.

<img src="https://mintcdn.com/devic/TaMbtKJRXl9eU5LD/images/knowledge/usage.png?fit=max&auto=format&n=TaMbtKJRXl9eU5LD&q=85&s=67d47b53b75f66516db307cf5ec7e9c0" alt="Document usage" width="1076" height="1048" data-path="images/knowledge/usage.png" />

It is the difference between "this page looks stale" and "this page is quoted by the support assistant forty times a day".

***

## Deleting

Deleting a document removes it from every agent and assistant that referenced it, and takes its subdocuments with it — the whole tree below the document goes.

<Warning>
  Deleting a folder leaves the documents inside it unfiled unless you explicitly ask for them to go too. Deleting a **document**, on the other hand, always takes its subdocuments with it. The two differ on purpose: a folder is a container, a subdocument is part of its parent.
</Warning>

***

## Through the API

The same history is available programmatically, which is what makes it usable from a pipeline that keeps Devic in step with a repository:

| Call                                                                                                            | Purpose                              |
| --------------------------------------------------------------------------------------------------------------- | ------------------------------------ |
| [`GET /v1/documents/{id}/versions`](/api-reference/endpoint/get-api-v1-documents-id-versions)                   | List the versions of a document.     |
| [`GET /v1/documents/{id}/versions/{version}`](/api-reference/endpoint/get-api-v1-documents-id-versions-version) | Read one version.                    |
| [`POST /v1/documents/{id}/revert/{version}`](/api-reference/endpoint/post-api-v1-documents-id-revert-version)   | Restore a version as the newest one. |
| [`GET /v1/documents/{id}/usage`](/api-reference/endpoint/get-api-v1-documents-id-usage)                         | Who references this document.        |