Environment Variables & Security

Managing secrets and public variables safely in Astro.

Edit Concept ✏️

Environment Variables & Security

Astro uses Vite’s environment variable handling but adds its own layer of security to prevent accidental leaks.

Variable Types

  • Private Variables: Defined in .env without a prefix. These are only available in the Astro frontmatter and API routes (server-side).
  • Public Variables: Prefixed with PUBLIC_ (e.g., PUBLIC_ANALYTICS_ID). These are accessible on both the server and the client.

Data Validation

Astro supports a cvs (config validation schema) for environment variables using the astro:env module (Astro 4.x+), allowing you to define types and default values for your variables.