"PORT": "type": "integer", "minimum": 1024, "maximum": 65535 , "DATABASE_URL": "type": "string", "format": "uri" , "DEBUG": "type": "boolean" , "LOG_LEVEL": "enum": ["debug", "info", "warn", "error"]
: Add .env.sample to your repository. This is the only environment-related file that belongs in version control.
: Compares .env against .env.example at runtime. If a key is missing from .env , the application refuses to boot and throws an explicit error message specifying exactly which variable is missing. .env.sample
The universal solution to this problem is the .env.sample file. What is a .env.sample File?
Always include a quick snippet in your project's README.md file instructing developers on how to use the sample file. The standard workflow across most operating systems is: If a key is missing from
New developers can clone the repository, copy the sample file, and immediately see what credentials they need to acquire to run the application locally.
A comprehensive .env.sample file reduces onboarding friction. New team members can get the application running in minutes by copying the template and filling in their personal values, rather than hunting through documentation or reverse-engineering configuration from error messages. The template answers questions like: What database do I need? What API keys must I obtain? What ports does the application expect? Always include a quick snippet in your project's README
When variables are grouped with descriptive comments explaining their purpose and expected format, the .env.sample file becomes self-documenting. This reduces the need for external wiki pages or README sections dedicated solely to environment variables. As one team put it: "The .env.example file serves as documentation for required environment variables and provides a starting point for local development configuration".
Add the key and its live value to your local .env file to test the feature.
Demystifying .env.sample: The Essential Guide to Secure Environment Management