.env.development.local 2021 Info

# Example for Next.js NEXT_PUBLIC_API_URL=http://localhost:3000 Use code with caution. 4. Gitignore (Crucial!)

: Specifies the environment mode. These variables will only load when your application is running in development mode (usually triggered by NODE_ENV=development ).

gitignore to protect these files or provide for specific frameworks like Vite or Next.js?

By adopting these recommendations, developers can improve their development workflow and ensure that their applications behave as expected across different environments. .env.development.local

If you are just getting started with environment variables, I recommend reviewing your project's .gitignore file to ensure that your .env.development.local file is properly ignored.

Beyond security, the file offers a level of granular control that shared files like .env.development cannot. Imagine a scenario where a team is building an app that interacts with a payment processor. Most developers might use a shared "test" account defined in .env.development . However, a lead developer working on a specific edge case might need to use a different test account. By defining those keys in .env.development.local , they can override the team-wide settings without changing a single line of shared code. Conclusion

Since .env.development.local is never committed, new team members need to know which environment variables are required. The standard solution is to commit a .env.example (or .env.sample ) file that lists all expected variables with placeholder values（）: # Example for Next

Understanding this order lets you set broad defaults in shared files and safely refine them with local, untracked files. Many tools like dotenv-flow simplify this process, dynamically loading the appropriate environment files based on the current NODE_ENV .

This file acts as the ultimate override for development-specific variables. When you run your application in development mode (typically via npm run dev or yarn start ), the system looks for variables across several files. In frameworks like Next.js, .env.development.local holds the . The typical hierarchy (from highest to lowest priority) is:

| File Name | Environment Scope | Version Control | Primary Use Case | |---|---|---|---| | .env.development | Development only | Usually committed | Team-shared development defaults | | .env.development.local | Development only | (.gitignore) | Developer-specific local overrides | | .env.local | All environments (except test) | Never committed (.gitignore) | Machine-specific overrides across all modes | | .env.production.local | Production only | Never committed (.gitignore) | Deployment-specific production overrides | These variables will only load when your application

This essay explores the purpose, importance, and best practices surrounding the .env.development.local file in modern software development.

Create a file named .env.development.local in your project's root directory.

In your application code, you would access these variables seamlessly: javascript

Modern build tools (like Vite or Next.js) load multiple .env files simultaneously. If the same variable is defined in multiple files, the tool decides which value to use based on a strict priority order.

The rules are slightly different: