The validation script checks that required .env.development keys exist before the app starts.
Nothing is worse than a silent failure because a variable was misspelled in .env.development . Use a validation library early in your bootstrapping process.
The Definitive Guide to .env.development in Modern Web Development
VUE_APP_API_URL=https://api.myapp.com VUE_APP_DEBUG=false .env.development
// ❌ Dangerous - could expose env vars app.use((err, req, res, next) => res.status(500).json( error: err.message, env: process.env ); );
# .env.development # Server-only (never exposed to client) DATABASE_URL=postgresql://localhost:5432/myapp_dev API_SECRET=dev-secret-key
commit .env.development to Git. Add it to your .gitignore file immediately. The validation script checks that required
A variable has a different value than what's defined in .env.development .
The .env.development file is an essential tool for modern development workflows. It enables environment-specific configuration, supports team collaboration through committed defaults, and helps prevent the accidental use of development settings in production environments.
| File Name | Purpose | Git Status | Load Conditions | |-----------|---------|------------|-----------------| | .env | Global default configuration for all environments | Commit (template values only) | Always loaded | | .env.local | Local overrides for all environments (except test) | (gitignored) | All environments except test | | .env.development | Development-specific defaults | Commit (safe defaults) | Development mode only | | .env.development.local | Local overrides for development only | Ignore (gitignored) | Highest priority in dev | | .env.production | Production-specific defaults | Commit (safe defaults) | Production mode only | | .env.test | Testing-specific configuration | Commit | Test mode only | The Definitive Guide to
// ✅ Safe - redact sensitive information app.use((err, req, res, next) => const requestId = crypto.randomUUID(); console.error( [$requestId] $err.message ); res.status(500).json( error: message: 'Internal server error', requestId ); );
In modern web development, .env.development is a configuration file used to store non-sensitive
The syntax inside a .env.development file is simple and universal: