How to fix Cannot find name 'process'. Do you need to install type definitions for node? Try `npm i --save-dev @types/node` and then add 'node' to the types field in your tsconfig. in TypeScript

Open your terminal and install the official Node.js type definitions package. This provides TypeScript with all the type information needed to recognize Node.js globals.

npm install --save-dev @types/node

If you are using Yarn:

yarn add --dev @types/node

If you are using pnpm:

pnpm add --save-dev @types/node

Open your tsconfig.json file and ensure it includes "node" in the types array. If you don't have a types array, add one.

{
  "compilerOptions": {
    "lib": ["es2015", "dom"],
    "types": ["node"]
  }
}

Alternatively, if you want to be more explicit about which types to include, you can reference @types/node directly:

{
  "compilerOptions": {
    "types": ["node", "jest"]
  }
}

If you omit the "types" array entirely, TypeScript will include all @types packages found in node_modules, which works for most projects.

Your IDE may be caching the old TypeScript compilation results. Restart the TypeScript language server to pick up the new type definitions.

For VS Code:
- Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P)
- Search for "TypeScript: Restart TS Server"
- Press Enter

Alternatively, reload the entire window:
- Open the Command Palette
- Search for "Developer: Reload Window"
- Press Enter

For WebStorm/IntelliJ:
- Go to File > Invalidate Caches / Restart
- Choose "Invalidate and Restart"

After installing @types/node and restarting your IDE, you should be able to use Node.js globals without errors. Test by accessing the process object:

// Now this works without TypeScript errors
console.log(process.env.NODE_ENV);
console.log(process.cwd());
console.log(process.version);

// You can also use other Node.js globals
const filepath = require("path").join(__dirname, "file.txt");

If you still see errors, verify that @types/node was installed correctly by checking node_modules/@types/node exists.

If you have both Node.js server code and browser/frontend code in the same project, you may need separate tsconfig files. Create a tsconfig.node.json for server-side code:

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "module": "commonjs",
    "lib": ["es2015"],
    "types": ["node"]
  },
  "include": ["server/**/*"],
  "exclude": ["node_modules", "dist"]
}

Then reference it in your build tool configuration (for example, in tsup, esbuild, or webpack) when compiling server-side code. Keep your main tsconfig.json without Node.js types for frontend code to avoid bundling unnecessary type definitions.

Create React App intentionally excludes @types/node from browser code because process is not available in the browser. If you need to access environment variables in a Create React App project, use the REACT_APP_ prefix:

// Correct for Create React App
const apiKey = process.env.REACT_APP_API_KEY;

// Define in .env file
// REACT_APP_API_KEY=your_key_here

If you need process in backend code that runs outside Create React App (like a server file or build script), keep that code in a separate folder and use a separate tsconfig.node.json with @types/node included.