Configuration

Configuration by example

Each config file ships beside an example file that lists every supported option, commented out with its default:

astro.config.mjs
astro.config.mjs.example
nitro.config.ts
nitro.config.ts.example

Changing a setting is uncommenting a line, not opening a documentation tab. The example file is never loaded — it’s a learning tool bundled with your exact version.

The `site` URL

The installer sets site in astro.config.mjs from your answer. Change it whenever your origin changes: canonical URLs, Open Graph tags, the RSS feed and sitemap output are all derived from it, and a feed full of links to the wrong origin is worse than no feed.

Environment variables

Variable	Default	What it does
`PUBLIC_API_BASE`	same origin	Base URL for the frontend’s preconfigured ofetch client (`src/lib/api.ts`)
`NITRO_LOG_LEVEL`	`3`	Server log level — `4` adds debug lines, `5` adds trace
`NITRO_UPSTREAM_URL`	httpbin demo	Where `/api/upstream` sends its outbound call
`ZN_API_PORT`	`3000`	Nitro dev port and the Astro proxy target, together

All are read from .env; a value already in the environment wins over the file, so a one-off override like NITRO_LOG_LEVEL=4 npm run dev works as expected.

Nitro version

nitro is pinned to an exact beta. Don’t widen it to a caret range — the v3 beta still renames APIs between releases.