It reads configured credential directories, refreshes the account list on each polling round, and shows a card for each quota window.
The tool reports current use and produces two projections: the percentage expected at reset if the current rate continues, and the point in the window at which the quota would run out. The article says Claude Code has a five-hour session limit and a weekly window; Kimi Code can have a monthly window, while Codex uses its own windows. Forecasts use the last hour of history for a session and the last three days for weekly or monthly windows.
Forecasts are withheld until history covers at least 5% of a window and at least 30 minutes: 8 hours 24 minutes for a weekly window and 36 hours for a monthly one. An optional work schedule can down-weight nights and weekends. The source does not establish forecast accuracy in real workloads or continuing compatibility: the data comes from undocumented endpoints, which the author says may break after updates.