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

# Keep API keys private

> Give your site's server code API keys that stay hidden in Studio, the CLI, logs and the browser.

Your site's server code can now use payment, email and other API keys without
showing them to anyone. Mark a variable **Private** when you add it, and its
value stays hidden for good.

![Fimo's Variables settings with a public site URL shown and a private Stripe key hidden](https://assets.fimo.ai/cdn-cgi/image/width=2000,fit=scale-down,format=png/docs/studio/private-variables-2x-20261022b.png)

## Private for server code, public for the browser

Open **Settings** → **Advanced settings** → **Variables**, choose **Add
variable**, and turn on **Private** for a key such as `STRIPE_SECRET_KEY`.
Fimo never shows the value again, never writes it to an env file or the
browser bundle, and hides it from logs. Read it from your server code.

Keep public variables for values the browser may see, such as your site URL.
Each Environment holds its own value, so use a test key in Preview and the live
key in Production. You choose public or private when you add a variable; to
change it later, delete the variable and add it again.

`fimo vars pull` never pulls a private value. Add your own test value to
`.env.local` for local development.

[Manage variables](/docs/studio/variables.md)

## Variables or secrets

Secrets are for Fimo itself: webhook headers, schedules and agents. Your site
never receives them. If your site's code needs the key, use a private variable.

[Learn about secrets](/docs/studio/secrets.md)

[See all updates](/docs/changelog/overview.md)


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