.env

You can access environment variables set in a .env file in your project root using bud.env.

Precedence

Environment variables are sourced from .env files recursively, starting with the project root directory. The closer the file is to the project root, the higher priority it has.

So, if you have an .env file in your project root and another in the parent directory, and both contain a value for the same key, the value from the project root will be used.

Expansion

bud.js supports expansion of environment variables. For example:

PUBLIC_API_ORIGIN=https://api.example.com
PUBLIC_API_URL=${PUBLIC_API_ORIGIN}/endpoint

Public variables

Any environment variables that are prefixed with PUBLIC_ will be available to your application code. When using variable values in your application you must remove the PUBLIC_ prefix.

For example, setting PUBLIC_API_URL:

PUBLIC_API_URL=https://api.example.com

Means API_URL can be used in your application code:

const request = fetch(`${API_URL}/endpoint`)

The replacement is static and happens at build time. It is not the same as defining a global.

For example, attempting to redefine it will cause a type error:

/**
 * Don't do this
 */
API_URL = 'https://api.example.com'

Configurable environment variables

Variable	Description	Related argument
BUD_BROWSERSLIST_UPDATE	Set to false in order to disable automatic updating of the browserslist database.	--browserslist-update
BUD_CACHE	Enable or disable bud.js caching	--cache
BUD_DEVTOOL	The devtool to use for builds	--devtool
BUD_ESM	Enable or disable bud.js ESM output (experimental)	--esm
BUD_HASH	Enable or disable output file hashing	--hash
BUD_HTML	Enable HTML templating; set to a string to specify the path to a template	--html
BUD_HOT	Enable or disable bud.js hot reloading	--hot
BUD_IMMUTABLE	Enable or disable automated updates of dependencies when using remote modules	--immutable
BUD_LAZY	Enable or disable lazy compilation of modules in development	--lazy
BUD_MINIMIZE	Enable or disable code minimization	--minimize
BUD_PATH_BASE	The path to the root directory of the bud.js project	--basedir
BUD_PATH_STORAGE	The path to the directory where bud.js stores its data and caches	--storage
BUD_PATH_INPUT	The path to the directory where bud.js looks for source files	--input
BUD_PATH_OUTPUT	The path to the directory where bud.js outputs build files	--output
BUD_PATH_PUBLIC	Directory to prepend to asset URLs (if assets are not served from web root)	--publicPath
BUD_PROXY_URL	The URL of the proxy server to use	--proxy
BUD_RUNTIME	Enable or disable generation of a runtime module	--runtime
BUD_SPLIT_CHUNKS	Enable or disable splitting of modules into discrete chunks (vendor, app, etc.)	--split-chunks

CLI

You can verify what environment variables are available to bud.js using the bud env command:

npm

npm run bud env

Yarn

yarn bud env

pnpm

pnpm run bud env