. In large projects, a new developer joining the team needs to know which environment variables are required to get the app running. Bootstrapping Environments : Instead of forcing every developer to manually copy a .env.example .env.local .env.default.local
If using Vite, variables must be prefixed with VITE_ to be exposed to the client-side. Create .env.default.local . Add: VITE_API_URL=http://localhost:3000 Access: import.meta.env.VITE_API_URL In Docker Compose
Your team uses a feature flag service (LaunchDarkly, Flagsmith). In production, flags are remote. But during local development, you want certain flags to be "on" by default.
You keep .env in .gitignore . Great. But what happens when a junior developer runs git add . and accidentally commits their local .env with production AWS keys? It has happened to every engineering team. The blast radius is massive. .env.default.local
Consider a BLACKLISTED_IPS variable.
Comparison Table: .env vs. .env.local vs. .env.default.local Committed to Git? Default configuration for all users. .env.local General overrides for your machine. No (Ignored) .env.default.local Specific development/local overrides. No (Ignored) .env.example Template showing required variables. Best Practices for Using .env Files
: Production builds should never load .env.local files. Set NODE_ENV=production to ensure these files are ignored. Create
@IsString() BUCKET_NAME!: string;
: Environment-specific settings.
export class Environment @IsPort() API_PORT!: number; But during local development, you want certain flags
The .env.default.local file is a highly specialized hybrid. It serves as a across all modes, but with a twist: depending on the specific tooling or team philosophy, it can either be committed to share team-wide local defaults or ignored to prevent personal machine overrides from leaking.
(Local Default): API_URL=https://localhost:8080 .env.local (Personal): API_KEY=secret_123
: Add .env.default.local and .env.local to your Git ignore list .