: On your server (Heroku, Vercel, etc.), you set a single environment variable— DOTENV_KEY . When the app starts, it uses this key to decrypt the .env.vault file and load the required secrets into memory. Comparison: Dotenv Vault vs. Other Tools Export secrets as environment variables with Vault Agent
This file essentially acts as a bridge. It allows your application to read environment variables just like it would from a standard .env file, but it ensures that the source of truth is the encrypted vault, not a loose text file. .env.vault.local
To understand the .env.vault.local file, one must look at the failings of the traditional .env file. Historically, developers stored raw, plaintext keys in .env . This was fraught with risk: files were accidentally committed to Git, leaked in logs, or left exposed on unsecured hard drives. : On your server (Heroku, Vercel, etc