> ## Documentation Index
> Fetch the complete documentation index at: https://cortex-foundation-add13747-droid-2a5c5e50-docs-ferndesk-pro.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Origin check

> Attach media and ask whether it is authentic. Cortex waits for a verdict, and says so plainly when the check cannot run.

**Check origin** answers one question about a picture or a video you attach: does it look authentic, or does it carry the marks of generation or manipulation? It is an explicit ask on attached media — not something that runs silently on every image in a thread.

## Run a check

<Steps>
  <Step title="Attach the media">
    Choose **+ → Check origin** on the composer, or attach the file with **Attach file**. iPhone HEIC/HEIF photos are accepted.
  </Step>

  <Step title="Ask">
    *Is this photo authentic?* or *Was this generated?* The turn runs the origin check on the attachment.
  </Step>

  <Step title="Wait for the verdict">
    Cortex holds its reply until a verdict paints. You will not get a confident paragraph followed by a result that contradicts it.
  </Step>
</Steps>

## When the check cannot run

If origin check is unavailable on a deployment, the product says so instead of guessing. That is fail-closed behaviour, not a broken button: no verdict is still no verdict. Ask again later rather than reading silence as a result.

## What it is not

| It is                             | It is not                                             |
| --------------------------------- | ----------------------------------------------------- |
| A check on media **you attach**   | An automatic label on every generated picture         |
| A Chat turn                       | A Code tool or a Bot skill                            |
| A verdict about the file's origin | A statement about the truth of what the picture shows |

Pictures generated with [Cortex-Image-1](/chat/images) are ordinary Library files. If you want to know whether one of them reads as generated, attach it and ask — the check does not run on its own after generation.

## Sizes and formats

An origin check runs on an attachment, so the same upload limits apply as anywhere else in Chat and [Library](/chat/library). A file that was rejected at upload is never attached, so there is nothing for the check to read — attach a supported file or a smaller one. See [`payload_too_large`](/problems/payload_too_large) for the ceilings and [Library](/chat/library) for the failure states.

## Related

* [Library](/chat/library) — where attached and generated media live.
* [Image generation](/chat/images) — Cortex-Image-1.
* [Chat troubleshooting](/chat/troubleshooting) — what a check that cannot run means.
* [Security](/security/overview) — how Cortex handles your files.