Authentication fails for the following, which gets posted to mailchimp using CURL, where API_KEY is defined as a string containing my key. Similar code used to work just fine for mailchimp v2:
$params = array ('apikey' => API_KEY,
'email_address' => $email,
'status' => 'pending',
'merge_fields' => array ('fname' => $first_name,
'lname' => $last_name
)
);
The error is:
{"type":"http://kb.mailchimp.com/api/error-docs/401-api-key-missing",
"title":"API Key Missing",
"status":401,"detail":
"Your request did not include an API key.",
"instance":"(long number)"
}