https://www.chess.com/news/view/published-data-api#pubapi-endpoint-player-is-online
This endpoint requires a large number of internal resources to maintain, and in the past week it has been used by only one clear developer script with a user-agent that helps us contact the developer. All other access to that endpoint appears to be tests, runaway scripts, or unidentified programs that could work better.
We propose to completely remove this endpoint. Current online status of a player will no longer be available in this API.
We would like to have one week of discussion here, so that developers can voice any thoughts or concerns. We will work directly with the developer who identifies his program in these calls to move him to the newer system. In addition, we will monitor this forum post for at least two months, and directly work with other developers who are impacted. We are unlikely to publish the new method publicly, since it is strictly beta testing at the moment.
Thank you. Please let us know if this impacts a program you are running, and any concerns you have.