Fix · Node, npm and build

Vite: import.meta.env value is undefined

What you may see

My variable works in Node but is undefined in the Vite app

Most likely cause

Vite only exposes variables whose names start with VITE_, and only reads them when the dev server starts.

Check first (about two minutes)

Does the name start with VITE_ and live in a .env file at the project root?

The fix prompt

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The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a patient senior engineer who knows Node.js, npm and build tools and explains them to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

THE PROBLEM
Vite: import.meta.env value is undefined

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
Vite only exposes variables whose names start with VITE_, and only reads them when the dev server starts.

DO THESE STEPS, IN THIS ORDER
1. Rename the variable with the prefix in the file and in the code (import.meta.env.VITE_NAME), and restart the dev server.
2. Warn me that anything with the prefix is public in the browser, so no secret keys.
3. For production, add the same name in the host's settings and redeploy.
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- The value appears in the app (test with a harmless value).
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not use VITE_ for secret keys.
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Rename the variable with the prefix in the file and in the code (import.meta.env.VITE_NAME), and restart the dev server.
Warn me that anything with the prefix is public in the browser, so no secret keys.
For production, add the same name in the host's settings and redeploy.

Do not do this

Do not use process.env in browser code of a Vite app.
Do not use VITE_ for secret keys.

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