I made a small project called Flipper Codex Monitor. The premise fits on its intended screen: two bars for Codex usage limits, with labels showing when they reset.

Putting two percentages on a separate piece of hardware is a fairly elaborate way to look at two percentages. That is part of the charm.

On May 13, 2026, I posted a photo in my Telegram blog with a short caption: “Found a new use for the Flipper.” This was that use.

A Flipper Zero resting on a keyboard, with 5H and 1W usage bars on its orange screen.
From my blog, May 13, 2026. The values belong to the photo.

A small job for each side

The display covers the five-hour and weekly usage windows. A Rust backend on the computer reads the limits through the local Codex CLI app-server, formats reset times in the computer’s timezone, and sends a compact packet to the Flipper over Bluetooth Low Energy.

The packet is 21 bytes: percentages, reset labels, and a status byte. The Flipper does not need to parse JSON or work out timezones.

An outlined handheld screen with two progress bars connects to a desktop computer through a small packet arc.
The computer prepares the packet; the little screen only needs to display it.

The backend keeps the app-server process alive and is designed to transmit once per second. Most of the machinery lives on the computer; the Flipper’s job is to draw two bars.

Some inherited plumbing

This project builds on TheSainEyereg’s Flipper PC Monitor app and Rust backend, with Willy-JL’s BLE serial helper. The little monitor already had useful plumbing; I gave it a different thing to monitor.

The Codex version has a narrower job: account-limit information, with credentials staying on the computer. The roadmap keeps the same focus. It lists reconnect reliability, easier installation, and more tests among the next steps.

For now: two bars on an orange screen. The Flipper has a new job.