Using environment variables

Astro uses Vite’s built-in support for environment variables, and lets you use any of its methods to work with them.

Note that while all environment variables are available in server-side code, only environment variables prefixed with PUBLIC_ are available in client-side code for security purposes.


In this example, PUBLIC_ANYBODY (accessible via import.meta.env.PUBLIC_ANYBODY) will be available in server or client code, while SECRET_PASSWORD (accessible via import.meta.env.SECRET_PASSWORD) will be server-side only.

Astro includes a few environment variables out-of-the-box:

  • import.meta.env.MODE: The mode your site is running in. This is development when running astro dev and production when running astro build.
  • import.meta.env.PROD: true if your site is running in production; false otherwise.
  • import.meta.env.DEV: true if your site is running in development; false otherwise. Always the opposite of import.meta.env.PROD.
  • import.meta.env.BASE_URL: The base url your site is being served from. This is determined by the base config option.
  • import.meta.env.SITE: This is set to the the site option specified in your project’s astro.config.

Environment variables can be loaded from .env files in your project directory.

You can also attach a mode (either production or development) to the filename, like .env.production or .env.development, which makes the environment variables only take effect in that mode.

Just create a .env file in the project directory and add some variables to it.

# This will only be available when run on the server!
# This will be available everywhere!

For more on .env files, see the Vite documentation.

You can also add environment variables as you run your project:

POKEAPI= npm run dev

Instead of using process.env, with Vite you use import.meta.env, which uses the import.meta feature added in ES2020.

For example, use import.meta.env.PUBLIC_POKEAPI to get the PUBLIC_POKEAPI environment variable.

// When import.meta.env.SSR === true
const data = await db(import.meta.env.DB_PASSWORD);

// When import.meta.env.SSR === false
const data = fetch(`${import.meta.env.PUBLIC_POKEAPI}/pokemon/squirtle`);

By default, Astro provides type definition for import.meta.env in astro/client.d.ts.

While you can define more custom env variables in .env.[mode] files, you may want to get TypeScript IntelliSense for user-defined env variables which are prefixed with PUBLIC_.

To achieve this, you can create an env.d.ts in src/ and configure ImportMetaEnv like this:

interface ImportMetaEnv {
  readonly DB_PASSWORD: string;
  readonly PUBLIC_POKEAPI: string;
  // more env variables...

interface ImportMeta {
  readonly env: ImportMetaEnv;