# What does the VARTA error `invalid_api_key` mean?

The catalogue reserves this code for a credential that is well-formed but not valid.


**HTTP status:** `401`  ·  **Type:** `authentication_error`

## What it means

The catalogue reserves this code for a credential that is well-formed but not valid.

## What causes it

Cause not yet documented — no code path in this codebase currently raises it. Today an unrecognised key surfaces as `unauthenticated` instead.

## What to do

Treat it the same as `unauthenticated`: check the key you're sending is current and correctly copied, with no extra whitespace.