Config

kirbyup.config.js in the project root configures both the build and serve. The file is loaded with c12, so .ts, .mjs and .js all work. Neither .kirbyuprc nor a package.json key is read.

// kirbyup.config.js
import { defineConfig } from 'kirbyup/config'

export default defineConfig({
  alias: {},
  vite: {},
})

defineConfig(config)

Returns config unchanged. It exists for type hints and autocompletion.

alias

• Type: AliasOptions from Vite

Extra import aliases, merged after the built-in ~/ and @/. An object maps a prefix to a replacement, an array of { find, replacement } entries allows regular expressions. Entries apply in order, the first match wins.

Absolute paths resolve on the file system. Relative values are passed through as written, which is rarely what you want.

vite

• Type: InlineConfig from Vite

Merged into kirbyup's own config with Vite's mergeConfig. Arrays such as plugins are appended, everything else overrides.

kirbyup sets these options. Overriding the ones marked as fixed breaks the output.

Option	kirbyup default	Notes
resolve.alias	~/ and @/ to the entry file's folder	Extend via alias
plugins	Vue, Vue JSX, auto-imports, vue mapped to the Panel's global	Yours are appended
envPrefix	['VITE_', 'KIRBYUP_']	See Env Variables
build.lib	IIFE from the entry file	Fixed
build.minify	true for production, false for watch builds
server.port	--port, default 5177	Config wins over the flag
server.origin	Derived from server.host, server.https and the port	The URL written into index.dev.mjs
server.strictPort	true	Fails instead of picking another port

Set server.origin when the Panel cannot reach the dev server under the derived URL, for example on another host or behind a proxy.