.env.local Free

Because .env.local can override anything, add a validation script at the start of your application. Use libraries like zod to ensure required variables exist.

In this example, when you run your application locally, it will use http://localhost:8000 as the API URL, overriding the default value provided in .env . This way, you can work against a local API without altering the committed configuration.

# .gitignore

Do not use spaces around the = sign. KEY = VALUE will often break the parser. Use KEY=VALUE . Summary

.env.local usually sits near the top of the priority chain. If you define API_URL in .env and a different value in .env.local , the application will use the value from .env.local . This allows developers to override defaults without altering the shared code. .env.local

# Database Configuration DATABASE_URL="postgresql://user:password@localhost:5432/mydb" # API Keys (Sensitive - Keep local only) STRIPE_SECRET_KEY="sk_test_4eC39HqLyjWDarjtT1zdp7dc" NEXT_PUBLIC_ANALYTICS_ID="UA-12345678-1" # Service URLs BACKEND_API_URL="http://localhost:4000/api" # Feature Flags ENABLE_NEW_DASHBOARD=true Use code with caution. Copied to clipboard Key Characteristics

For a deep dive into implementation and best practices, these resources are highly recommended: : Because

file. This prevents sensitive "secrets"—such as private AWS keys or Stripe tokens—from being exposed in the repository’s history. Instead of sharing the actual file, teams typically share a .env.example