Starting this evening, August 5 at 11:00 pm - 12:00 am UTC, we will be performing the first of a series of planned service interruptions of traffic to the XML/RPC API that is using Legacy API Keys for authentication. Other authentication methods are are NOT affected (OAuth, Personal Access Tokens, Service Account Keys). This is intended to help customers and developers identify previously unknown traffic using Legacy API Keys.
For details of the overall effort in sunsetting Legacy API Keys check out our migration guide.
Here is the current Brownout schedule. Note: dates and times are subject to change.