.env.local.production

Not every framework supports this exact syntax. Here is the breakdown by ecosystem.

.env.*

If you mistakenly commit this file, you are committing secrets that are intended for production-like behavior—potentially including API keys that have broad permissions on your staging or live infrastructure. .env.local.production

On platforms like Vercel, you never use .env.production.local. You use their dashboard or CLI: Not every framework supports this exact syntax

vercel env add API_KEY production

The .env.production.local file is only for local testing of production builds. If you mistakenly commit this file, you are