Environment Variables

Default environment variables:

• .env

• docker-compose

Database

Variable	Description	Example
DB_HOST	The address of your mongodb database.	127.0.0.1
DB_PORT	The port of your mongodb database. When using docker set this to 27017.	27017
DB_USER	Your mongodb database username.	admin
DB_PASSWORD	Your mongodb password. Generate a secure one using a tool like 1password.

Security

Variable	Description	Example
JWT_KEY	The key used to verify and sign login-sessions. Use a site like 1password to generate a 32 character password.
USE_HTTPS	If your Lynx installation will be at https://mydomain.com - this does not provide an SSL certificate, it only changes how cookies are handled.	true
CORS	Your allowed CORS origin(s), * for any (default).	*

Link Creation

Variable	Description	Example
URL_LENGTH	The length of your automatically generated slugs.	8
URL_SET	The type of characters your automatically generated slug will use.	standard
URL_ONLY_UNIQUE	Wether each new url has to be unique, e.g. if a link already redirects to https://example.com new links created cannot link to the same destination.	false

Umami

Lynx comes with full support for Umami, both standard tracking and events.

Variable	Description	Example
UMAMI_SITEID	Your umami site ID, blank to disable.	224d86da-1209-4b8b-ad98-b24d300efa55
UMAMI_URL	The URL to your umami instance.	https://analytics.umami.is/script.js

For Umami to track links being used, FORCE_FRONTEND_REDIRECT will need to be set to true. This may slightly increase redirect times.

Backups

Variable	Description	Example
BACKUP	Wether to create backups or not. They will be in ./backups or /app/backups for Docker	true
BACKUP_SCHEDULE	When to create backups. Use crontab.guru to create	0 * * * *
BACKUP_COUNT	How many backups to keep. 1 will make a backup file called backup.json, -1 will keep every backup.	5

Other

Variable	Description	Example
NODE_ENV	What node environment to use, use production for any production use and/or when using in docker.	production
FORCE_FRONTEND_REDIRECT	Use the frontend to redirect instead of express, useful for hiding embeds on discord for all your rickrolling needs	false
ENABLE_REGISTRATION	Whether or not to allow registration. If not accounts exist you will be allowed to register either way. This first account will also be an admin account.	false
DOMAIN	Your Lynx installation domain	http://example.com
DEMO	Whether or not to enable the demo mode. In this mode features will be limited and links will be deleted after 10 minutes.	false
EXPRESS_PORT	The port to use internally for the backend.	3000
URL_REGEX	The URL_REGEX to use, I recommend using a custom one, like in the example (which adds support for twitter://user?screen_name=jackba_ links).	https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)|twitter:\/\/user\?screen_name=[a-zA-Z0-9_]+