---
title: "Variables, log rotation, JWTs and more - Cerbos v0.30"
description: "The v0.30 release of Cerbos is packed with new features such as variable validation, log rotation and configurable JWT skew support."
author: "Alex Olivier"
date: "2023-09-14T14:00:00.000Z"
canonical: "https://www.cerbos.dev/blog/variables-log-rotation-jwts-and-more-cerbos-v030"
image: "https://stylish-appliance-1c1cc1c30d.media.strapiapp.com/cover_image_e60353d3ec.jpg"
tags: ["documentation"]
source: "https://www.cerbos.dev/blog/variables-log-rotation-jwts-and-more-cerbos-v030"
---

# Variables, log rotation, JWTs and more - Cerbos v0.30

The [**v0.30 release**](https://docs.cerbos.dev/cerbos/latest/releases/v0.30.0.html) of Cerbos is packed with new features such as variable validation, log rotation and JWT skew support.

We have been working closely with users of Cerbos such as [**Envoy**](https://envoy.com/), [**Blockchain.com**](https://blockchain.com/), [**Utility Warehouse**](https://uw.co.uk/), [**9fin**](https://9fin.com/), and [**Salesroom**](https://www.salesroom.com/) on this release. We can’t wait to hear more about what you would like to see in future releases - join our [**Slack community**](https://community.cerbos.dev/) to join the conversation.

## **Variable validation**

[**Variables**](https://docs.cerbos.dev/cerbos/latest/policies/variables) used in policies are now checked at compile time to detect unknown variables and circular references. This change helps policy authors detect problems with policies early on during development time and enables the Cerbos engine to perform runtime optimizations as well.

## **Log rotation**

The` file `audit log driver now supports automatic log rotation based on file size and age. It also gains the ability to output to multiple destinations `(tee)` such as a file and `stdout`/`stderr` simultaneously.

## **Configurable JWT skew**

When working with JSON Web Tokens it is sometimes useful to have a small amount of skew allowed on time-based claims (`exp` and `nbf`) for cases when clocks may be slightly out of sync or a token has been cached.

  
Also with this release, you now export a policy store - particularly useful when working with database stores - and also compile policies in a zip/tar.gz archive.

You can find the full release notes for [**v0.30 on docs.cerbos.dev**](https://docs.cerbos.dev/cerbos/latest/releases/v0.30.0.html) and if you have any questions join our [**Slack community**](https://community.cerbos.dev/).