.env.development.local _verified_

.env.development (committed): REACT_APP_API_URL=https://staging-api.example.com FEATURE_X=false

The .local suffix implies a physical developer machine. Never upload .env.development.local to a cloud VM, Docker container, or PaaS like Heroku or Vercel. Use the platform's native environment variable configuration panel instead. .env.development.local

: Variables in this file are only loaded when the application is running in "development" mode (e.g., npm run dev Security & Privacy : It is intended to be kept local to your machine and must never be committed to version control (Git). Loading Priority (Hierarchy) .env.development.local