Environment Variables

Reion loads environment variables automatically, so you do not need to install dotenv.

Supported Files

Reion reads env files from your project root in this order:

1. .env
2. .env.local
3. .env.[mode] (for example: .env.development)
4. .env.[mode].local (for example: .env.development.local)

mode comes from NODE_ENV.

• reion dev defaults to development
• reion start defaults to production

Precedence

• Shell/CI environment variables are preserved and are not overwritten.
• Later env files can override values from earlier env files.

Example

# .env
DATABASE_URL="postgres://localhost:5432/reion"
LOG_LEVEL=info

// src/router/ping/route.ts
import type { Context } from "reion";

export async function GET(ctx: Context) {
  return {
    database: process.env.DATABASE_URL,
    logLevel: process.env.LOG_LEVEL,
  };
}

Important Security Tips