.env.development.local

Most modern frameworks utilize a library called dotenv-flow or a similar custom mechanism to load multiple .env files in a specific order of priority. If the same variable is defined in multiple files, the file with the highest priority overrides the others.

# ============================================================ # ENVIRONMENT: DEVELOPMENT (Local Overrides) # ============================================================ # This file takes precedence over .env.development and .env. # Use this for secrets or machine-specific configuration. # !! DO NOT COMMIT THIS FILE TO GIT !! # ============================================================ .env.development.local

Environment variables are injected into your application when the process starts. If you modify a value inside .env.development.local , the changes will not take effect automatically through hot-module reloading. You your development server (e.g., cancel the terminal process and run npm run dev again). Pitfall 3: Mixing Client and Server Secrets Most modern frameworks utilize a library called dotenv-flow