Skip to main content
Configure your app to use its deployment URL for redirects and absolute links. Add the deployment hostnames to its allowed-host list. Before you start, identify the HTTP service, its container port, and the settings your app uses for its base URL.

​
Expose the main HTTP service

Add an entry without label for the main hostname and custom-domain target. Replace app and 3000 with your service name and container port. Configure your app to listen on 0.0.0.0.
Replace APP_URL and APP_ALLOWED_HOSTS with your app’s environment variable names. Adapt the comma-separated hostname list if your app expects another format. Zenith terminates TLS at the HTTP ingress. web: false does not create a raw TCP or UDP endpoint. See the expose reference for all fields.

​
Track verified domain changes

Use ZENITH_PUBLIC_URL for the base URL and ZENITH_PUBLIC_HOSTNAMES for a hostname allowlist. See the URL built-ins for variants with ports and multiple URLs. An unverified custom domain does not replace the public URL. Aliases and templates resolve again when Zenith renders the deployment, so they track verified domain changes. A stored input.default_template keeps its initial value instead.

​
Add a labelled endpoint

Use a unique label for an additional HTTP endpoint. This example exposes an API alongside the main app:
A labelled endpoint has its own canonical Zenith URL. Use ZENITH_PUBLIC_URL_<LABEL> instead of constructing its hostname. Convert the label to uppercase and replace hyphens with underscores. For example, admin-api becomes ZENITH_PUBLIC_URL_ADMIN_API.

​
Check redirects and host validation

Open the returned deployment URL and check generated links and redirects. If you use a verified custom domain, repeat the checks there. Configure your app to accept the intended hostnames and use the correct public URL for callbacks. For Zenith identity callbacks on either origin, follow Sign in with Zenith.