Where Claude's usage limits went: from SSE to protobuf frames (claude-monitor.com)

In a recent update, Claude Monitor, an open-source browser extension, has adapted to significant changes in how Claude.ai provides usage limits through its API. Initially reliant on a JSON endpoint, the extension now utilizes a Connect protocol using protobuf frames to retrieve real-time data about usage limits, including rolling session and weekly caps. This transition occurred in October 2023 and affects how the extension reads limits and reset times, including adjustments to handle nuances like jitter in reset times and different representations of utilization percentages. This shift is significant for the AI/ML community as it highlights the ongoing evolution of API designs in machine learning platforms, emphasizing the importance of maintaining flexibility in open-source tools. It also raises awareness about the challenges of building upon undocumented APIs due to changing data formats and the need for developers to adapt their integration methods frequently. Key changes include switching from a fractional utilization model to a double-type representation and implementing a new streaming mechanism for data retrieval, which could have broader implications for other developers building applications that interact with similar services.