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

# Environment Variables for Development

> Complete guide to environment variables for Chatwoot development and testing

# 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 theme={null}
LETTER_OPENER=true
```