.env.development

Next.js supports .env.development natively but distinguishes between build-time and run-time variables. You must prefix browser-safe variables with NEXT_PUBLIC_.

# .env.development
NEXT_PUBLIC_GOOGLE_MAPS_KEY=dev_test_key_123
DATABASE_URL="postgresql://user@localhost:5432/dev_db"

You can create scripts that modify behavior based on the presence of .env.development.

// package.json
"scripts": 
    "dev": "node scripts/validate-dev-env.js && NODE_ENV=development nodemon src/index.js"

The validation script checks that required .env.development keys exist before the app starts.

| File | Git? | Typical use | |------|------|--------------| | .env.development | yes | shared dev defaults | | .env.development.local | no | local overrides | | .env | yes | base defaults (all envs) | | .env.production | yes | production only |

Use .env.development to make your npm run dev experience consistent, safe, and configurable.

file is a plain-text configuration file used by developers to store environment variables

specifically for a local or development environment. It allows you to run your application locally with settings (like database URLs or API keys) that differ from those used in production. .env.development Environment Specificity .env.development

: It prevents you from accidentally using production data (like a live customer database) while testing new features. Automation : Modern tools like Create React App

automatically load this specific file when you run commands like npm run dev

: By keeping sensitive credentials in a separate file, you can ensure they aren't hardcoded into your source code. Key Usage Guidelines Variable Prefixing

: Many frameworks require variables to have a specific prefix to be accessible in the browser (e.g., for Vite or REACT_APP_ for Create React App). File Priority : Most systems follow a specific "load order." For example, .env.development.local will usually override settings found in .env.development .gitignore .env.development

files containing real secrets to version control systems like GitHub. Instead, provide a .env.example .env.sample

file with the keys but no values so other developers know what they need to set up. Common File Structure An example .env.development file might look like this: You can create scripts that modify behavior based

# Specific to development environment PORT=3000 DB_URL=mongodb://localhost:27017/dev_db API_KEY=dev_secret_key_123 VITE_ANALYTICS_ID=UA-DEV-999 Use code with caution. Copied to clipboard Advanced Considerations Build-time vs. Run-time

: In frontend frameworks, these variables are often "inlined" during the build process, meaning they are baked into the JavaScript code. Local Overrides

: If you have specific settings just for your machine (like a different port), use a .env.development.local file, which should also be ignored by Git. sample research structure or more technical details on how specific frameworks like handle these files? How to secure your web applications (Part 1) — CPAS 3

The .env.development file is a specialized configuration file used in modern web development to store environment variables specifically for a local development workflow. By using this file, developers can define settings like local database URLs or API keys that differ from those used in staging or production environments. What is the Purpose of .env.development?

In many frameworks like React, Vite, and Next.js, the build tools automatically look for a .env.development file when you run a local development command (such as npm run dev). This allows you to:

Isolate Configurations: Keep local development settings separate from production secrets. The validation script checks that required

Automate Switches: Avoid manually changing variables every time you move from writing code locally to deploying it.

Team Collaboration: Share a standard set of non-sensitive development variables with your team via a template (often called .env.example). Common Use Cases

The .env.development file typically contains "safe" or local-only information. Key examples include:

API Endpoints: Pointing to a local server (e.g., http://localhost:3000) instead of a production domain.

Database Credentials: Using a local development database rather than the live production database.

Feature Flags: Enabling "debug mode" or experimental features only while building.

Mock Services: Credentials for sandbox environments or mock payment gateways (like Stripe’s test keys). Best Practices for Security and Efficiency Environment variables - Vercel