I’ve been building a small tray app called Agent Context Monitor. It puts Claude Code and Codex usage limits and chat context in one window. I wanted to check how much room I had left without going into each chat separately.
There are three views: account usage with reset times, recent chats with their remaining context, and daily or weekly usage history. You can keep them in tabs or widen the window to see all three side by side. The tray indicator changes color as usage rises, with desktop alerts when a limit or an active chat is getting close to full.
The tricky part has been getting the readings right. Codex provides token counts and context-window data. Claude’s context window has to be estimated from the available metadata, so the app labels it as estimated. Old usage readings get greyed out instead of looking current. Limits a plan doesn’t report stay hidden.
Packaging brought its own fixes. The app needed to find Codex when launched from the Dock or Start menu, and read Claude’s login from the macOS Keychain. There are now installers for macOS, Windows, and Linux, plus install scripts.
It reads local chat metadata without storing messages. Account usage checks use the existing Claude Code login and installed Codex client. Usage history stays on your computer.
It’s free and open source. See the tool page for the screenshot and overview, or grab it from the GitHub repo.