Type Safe process.env

I've found myself copy and pasting the same TypeScript snippet to add type-safety for process.env.<X> references in my various projects. I figured I should just write a brief blog post to help myself with this in the future.

Use this snippet to override process.env types:

1declare global {
2  namespace NodeJS {
3    interface ProcessEnv {
4      // Replace `KEY` with your env variables!
5      KEY: string;
6    }
7  }
8}
9
10export {};

1declare global {
2  namespace NodeJS {
3    interface ProcessEnv {
4      // Replace `KEY` with your env variables!
5      KEY: string;
6    }
7  }
8}
9
10export {};

Recipe:

• Create a types.d.ts file at the root of the project
• Insert the above snippet
  • Make sure to replace KEY with your env variables!
• Add ./types.d.ts to the includes array in tsconfig.json