Quick answer
Open Usage alerts in UsageAtlas, turn on a window, and pick how much remaining capacity should trigger it, such as 20%. You get one desktop notification per window per reset cycle, so a long Claude Code or Codex run does not stop without warning.
Set up an alert
- Download UsageAtlas and let it detect your tools.
- Open Usage alerts. It lists every tool that reports a usage window, such as Claude Code or Codex.
- Turn on a window and drag the dial to the remaining capacity that should trigger the alert.
- Leave UsageAtlas running in the tray or menu bar. It checks in the background.
Each rule belongs to one window. You can warn at 30% left on the Codex weekly window and at 10% left on the Claude five-hour window if that matches how you work.
Why one alert is enough
An alert that fires every few minutes gets muted by lunch. UsageAtlas sends one notification when remaining capacity drops to your threshold and stays quiet until the window resets.
When it fires, open Today to see the reset time and decide. Finish the task, switch tools, or wait. The guides for a Claude limit and a Codex limit cover what to do next.
Which tools can alert
Alerts need a provider that reports a window with a known allowance. Claude Code, Codex, Cursor, and connected tools such as GitHub Copilot, Kimi Code, and Factory usually qualify. Tools that only write local history, such as OpenCode or Muse Code, have no window to watch, so they show tokens but cannot alert.
Questions, answered
Can I get a notification before Claude Code hits its limit?
Yes. Set a remaining-capacity threshold on the five-hour or weekly window in UsageAtlas. A desktop notification fires once when the window drops to it.
Do alerts work when UsageAtlas is closed?
No. The app has to be running, but it can sit in the tray or menu bar and launch at login.
Will I get repeated alerts in the same window?
No. Each rule fires once per reset cycle, then waits for the next window.