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

# Check designs against your principles

> Ask your agent to check a design against your saved principles, then save the check and run it again later.

Rivet can check a design against rules you've already saved, like your motion or typography principles. Your agent runs the check and tells you what passed and what didn't.

Your principles are saved instructions. To save some, point your agent at a Markdown file:

> "Save docs/motion.md as my motion principles."

## Ask for a check

> "Verify this direction follows my motion principles."

Your agent finds your saved principles, checks the app, and reports pass, fail, or couldn't verify for each rule. Missing evidence counts as couldn't verify, not a pass. Your agent reports failures without changing your app.

## Save it for next time

After the report, your agent offers to save the check. Saved checks belong to your Rivet account on this computer, so they work across projects and chats. They don't sync to other machines.

> "Run my saved motion check on this page."

Saved checks run only when you ask. Saving one doesn't add an automatic gate.

## When a check goes stale

If you edit the principles, the saved check is marked stale. Rivet won't run a stale check. Your agent updates it before running it again.

## Code checks (advanced)

A check can include Node code that Rivet runs locally with `rivet context verify`. It runs with your own permissions, not in a sandbox, so only save code you trust. Rivet doesn't install dependencies for it.

See the [CLI reference](/mcp-guide.md#cli-commands) for the `rivet context` commands.

## Next

> **[Comparing variants](/comparing-variants.md)**
>
> Review your directions side by side.


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