---
icon: gear
title: Configuration Options
description: Using environment variable to configure a self-hosted instance of Rallly.
---
## Environment variables
An environment variable is a dynamic value that can be set outside of an application and is used to configure or customize the behavior of an application.
This page lists all environment variables supported by Rallly.
### Base Configuration
These variables need to be configured for Rallly to run and function properly.
Postgres database connection string
The base url where this instance is accessible, including the scheme (eg.
`http://` or `https://`), the domain name, and optionally a port.
A random 32-character secret key used to encrypt user sessions
Comma separated list of email addresses that are allowed to register and
login. Wildcard characters are supported. Example: Setting it to
`*@example.com` to allow anyone with a `@example.com` email address.
### Email Configuration
These variables need to be configured to let Rallly send out transactional emails.
This email is used as the sender for all transactional emails. If not set,
`SUPPORT_EMAIL` will be used instead.
This name is used as the sender name for all transactional emails. If not set,
`Rallly` will be used instead.
This email will be shown as the contact email for support queries.
The host address of your SMTP server
The port of your SMTP server
Set to "true" if SSL is enabled for your SMTP connection
The username (if auth is enabled on your SMTP server)
The password (if auth is enabled on your SMTP server)
Enable TLS for your SMTP connection
### Single Sign On (SSO)
Go to [Single Sign On](/self-hosting/single-sign-on) for information on how to configure SSO.