# Environmental Variables In designing MERNKIT I wanted the platform to be as plug and play as possible. Therefore, the setup is almost entirely managed by setting environmental variables. For development, you will edit the .env file. For production you will edit the .env.production file. I will share documentation on how to setup MERNKIT on AWS at the end of the section. Your .env file will contain the following empty variables that must be filled out. I will put descriptions where your variable value should go. ``` REACT_APP_BACKEND_URL=http://localhost:5000 REACT_APP_COOKIEDOMAIN=localhost REACT_APP_STRIPE=STRIPE PUBLIC KEY ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.mernkit.com/front-end/environmental-variables.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.