Addresses and domains

A handle

Set on Settings › Handle, as in https://app.example.com/my-news. 3 to 40 lowercase letters, numbers and hyphens, starting with a letter; words the app uses are taken.

Changing it breaks links already mailed with the old one. The number keeps working.

A domain of its own

Set or cleared on Settings › Domain, such as news.example.com; the app's own host is refused. BASE_URL must be set.

Point the DNS at the server. With Kamal, add the domain to the proxy hosts and deploy. With Docker, append it to TLS_DOMAIN, as in app.example.com,news.example.com, and restart. A CDN or proxy in front must keep the Host header.

# config/deploy.production.yml
proxy:
  ssl: true
  hosts:
    - app.example.com
    - news.example.com

bin/kamal deploy -d production

What a domain serves

Only reader pages: the post list at /, posts, feed, sitemap, subscription page, confirm and unsubscribe links, tracked links, ratings and post files. The newsletter's mail links there.

Sign-in and admin screens answer only at BASE_URL and are a 404 on a domain, which sets no cookie.

Changing or clearing a domain breaks links in mail already sent.