Environment Variables

.env Files

Create .env files in your project root:

VOLT_API_URL=https://api.example.com
VOLT_DEBUG=true

Only variables prefixed with VOLT_ are exposed to client code by default.

Accessing Variables

console.log(import.meta.env.VOLT_API_URL)
console.log(import.meta.env.MODE)  // "development" or "production"
console.log(import.meta.env.DEV)   // true/false
console.log(import.meta.env.PROD)  // true/false

Env Prefix

Configure env_prefix when migrating from Vite or when your app already uses a different public-env naming convention:

config :volt, env_prefix: "VITE_"

Multiple prefixes are also supported:

config :volt, env_prefix: ["VOLT_", "PUBLIC_"]

File Loading Order

Files are loaded in order, with later files overriding earlier ones:

1. .env
2. .env.local
3. .env.{mode} (e.g. .env.production)
4. .env.{mode}.local

The mode defaults to "production" for mix volt.build and "development" for the dev server. Override with --mode.