What does the VARTA error `invalid_api_key` mean?

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.