</>
typescriptbeginner

Environment Variable Validation

Validate required environment variables at build time with type-safe access and descriptive errors.

typescript
function requireEnv(key: string): string {
  const value = process.env[key];
  if (!value) {
    throw new Error(
      `[env] Missing required environment variable: ${key}`
    );
  }
  return value;
}

export const env = {
  DATABASE_URL: requireEnv('DATABASE_URL'),
  NEXTAUTH_SECRET: requireEnv('NEXTAUTH_SECRET'),
  NEXTAUTH_URL: requireEnv('NEXTAUTH_URL'),
  STRIPE_SECRET_KEY: process.env.STRIPE_SECRET_KEY ?? '',
  ANALYTICS_ID: process.env.NEXT_PUBLIC_ANALYTICS_ID ?? '',
} as const;

// Validate at import time — fails fast during build
// import { env } from '@/lib/env';

Use Cases

  • App startup checks
  • CI pipeline validation
  • Config management

Tags

#environment#validation#config#typescript

Related Snippets

Similar patterns you can reuse in the same workflow.

typescriptbeginner

Environment Variable Validator

Validates required environment variables at startup and returns a typed config object or throws with missing keys.

#config#validation
pythonbeginner

Type-Safe Settings with Pydantic

Load and validate environment variables into a typed settings object using pydantic-settings with defaults.

#pydantic#settings
typescriptintermediate

Type-Safe API Route Handler

Next.js App Router route handler with input validation, typed responses, and proper error handling.

#api#route-handler
typescriptintermediate

Server Action with Form Validation

Next.js Server Action handling form submissions with validation, error messages, and redirect on success.

#server-actions#forms