x-api-key is accepted as an alternative for clients that cannot set an Authorization header.
Environments
A key is valid in one environment only. Using a sandbox key against production returns
api_key_invalid.
Keeping keys safe
- Call the API from your server. Public clients get scoped tokens, never a secret key.
- Store keys in your secret manager or environment, never in source control.
- Rotate on a schedule and immediately on suspected exposure. Rotation is instant and the old key stops working.
- Requests over plain HTTP are rejected, not redirected. Any key sent that way is compromised, so rotate it.

