This guide explains the key environment variables used to configure organizations in your Cal.com self-hosted instance.

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RESERVED_SUBDOMAINS

This is a comma-separated list of subdomains that are not allowed to be used as organization slugs. For example, if you set RESERVED_SUBDOMAINS="app,auth,help", then the domains app.cal.com, auth.cal.com and help.cal.com are reserved for use by the Cal.com instance. This means you cannot create an organization with the slug app, auth or help.

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ALLOWED_HOSTNAMES

This is a comma-separated list of domains on whose subdomains the booking pages and dashboard are allowed to work. Examples: If ALLOWED_HOSTNAMES="cal.com,cal.dev", then:
  • acme.cal.com is a valid organization booking domain and WEBAPP_URL can be set to http://app.cal.com
  • dunder.cal.dev is also a valid organization subdomain and WEBAPP_URL can be set to http://app.cal.dev
If ALLOWED_HOSTNAMES="cal.domain.tld", then:
  • WEBAPP_URL should be set to http://app.cal.domain.tld
  • Valid organization domains include: acme.cal.domain.tld, dunder.cal.domain.tld, xxxx.cal.domain.tld
Make sure your DNS is properly configured to point organization subdomains to your Cal.com instance.