---
title: Environment Variables for Development
description: Complete guide to environment variables for Chatwoot development and testing
sidebarTitle: Environment Variables
---

# Environment Variables for Development

This guide covers environment variables specifically for development and testing environments. For production environment variables, see the [Self-hosted Environment Variables](../../self-hosted/configuration/environment-variables) guide.

### Use letter opener instead of mailhog/SMTP

Set the following variable to open emails in letter opener instead of SMTP

```bash
LETTER_OPENER=true
```