I built Statusline: an open-source Codex usage monitor for desktop and mobile

Statusline started with a small interface detail I wanted to make more useful: Weekly limit: [███████████░░░░░░░░░] 53% left (resets 09:02 on 2 Sep) That line answers two practical questions: how much capacity is left, and when it resets. I wanted to keep that information visible while working—and make it accessible from my phone without opening a terminal. That became Statusline, an open-source desktop companion with native mobile apps and home screen widgets. The iPhone app is now available on the App Store. Desktop builds and Android are available in beta. What Statusline does Statusline reads usage information from your local Codex session and presents the remaining quota, reset time, and sample timestamp. The desktop companion also displays short-window usage and account-plan information when available. It lives in the menu bar on macOS or the system tray on Windows and Linux. Optional encrypted synchronization carries a minimal quota snapshot to the mobile apps and their widgets. The visual language, called Data Plane, grew out of the original terminal display: segmented meters, restrained typography, dark surfaces, and an amber accent. The interface is intentionally focused. Statusline monitors your personal Codex quota; it does not run coding tasks, manage conversations, or increase your usage limits. The architecture: shared protocol, native interfaces The project uses different technologies where they fit: Desktop: Tauri, Rust, and TypeScript. iPhone: SwiftUI and WidgetKit. Android: Kotlin, Jetpack Compose, and native app widgets. Relay: TypeScript, currently deployed on Cloudflare Workers with D1. Instead of sharing one UI implementation across every platform, the clients share a versioned synchronization contract. The data flow looks like this: Local Codex runtime │ │ Usage metadata over local stdio ▼ Desktop companion │ │ Encrypt snapshot with AES-256-GCM ▼ HTTPS relay │ │ Encrypted snapshot ▼ Native mobile app │ │ Decrypt, validate, and cache ▼ Home screen widget The desktop companion communicates with the local Codex App Server process. It normalizes the relevant usage information before deciding what to display locally and what to synchronize. The current mobile payload is deliberately small: remaining percentage, reset time, and the time of the reading. A Windows computer and an iPhone use the same pairing and snapshot protocol as a Linux computer and an Android phone. The synchronization flow does not require a shared iCloud account. The relay protocol specification and encryption interoperability fixture are versioned in the repository so the Rust, Swift, and Kotlin implementations can be checked against the same contract. Keeping account credentials out of synchronization A quota widget should not need your prompts, source code, or conversation history. Statusline does not require an OpenAI API key. The local Codex runtime manages its own authentication; Statusline does not copy its credential files or send those credentials to the relay. Device pairing separates authentication from encryption: The companion creates a relay channel and generates an encryption key locally. A single-use pairing QR transfers the pairing information and encryption key to the phone. The phone exchanges the temporary pairing token for a reader credential. The companion encrypts quota snapshots before uploading them. The relay never receives the encryption key. It stores the encrypted snapshot alongside the operational information needed to manage the channel, such as credential hashes and timestamps. That distinction matters: encrypted payloads do not mean the service has no metadata. The goal is to keep the quota contents and Codex credentials outside the relay's trust boundary. The pairing QR is also sensitive information. It should not appear in screenshots, public issue reports, or promotional videos. Supporting macOS users without a separate CLI installation One practical issue came up during development: some people use Codex through the desktop application and have never installed a standalone CLI. The latest macOS beta can discover the Codex executable bundled inside supported ChatGPT or Codex.app installations. That allows Statusline to use the existing local runtime without requiring a separate CLI installation. There are important boundaries to this support: Older desktop-app versions may not contain a compatible runtime. Session reuse depends on how the local Codex installation manages authentication. Windows and Linux currently retain their CLI-based discovery. If a session is unavailable, Statusline reports that state. It does not attempt to extract desktop cookies or silently migrate account credentials. The supported sources and troubleshooting steps are documented in the Codex runtime guide. A widget shows a snapshot, not a live connection One design decision I want to be explicit about is freshness. The widgets read a local cache populated by the mobile app. They display the most recently synchronized sample, not a continuously streaming connection to Codex. A new reading depends on the companion collecting and publishing it, the phone fetching it, and the operating system allowing the relevant work. That is why the sample timestamp matters alongside the percentage. A reading can still be useful when it is cached, but users should be able to understand how recent it is. Push-assisted background refresh is planned; it is not something the current release promises. Availability Platform Current availability iPhone Available on the App Store; requires iOS 17 or later Android Beta APKs and Google Play closed testing macOS Universal beta DMG and PKG installers, signed and notarized Linux Beta DEB, RPM, and AppImage packages with detached OpenPGP signatures Windows Beta NSIS and MSI installers; currently unsigned previews Windows signing remains unfinished. SmartScreen may warn about or block those installers. Signed checksums help verify file integrity, but they do not replace a trusted Windows publisher signature. The applications support English and Spanish, following the system language with English as the fallback. What comes next The first version focuses on Codex. The longer-term direction is a single view of capacity across coding agents. AGY, Claude Code, and GitHub Copilot are on the research roadmap, but they are not supported integrations today. The challenge is not simply adding more progress bars. A future adapter needs a reliable, authorized data source and a clear definition of what its numbers mean. Requests, tokens, credits, and subscription percentages should not be presented as interchangeable measurements. Other planned improvements include local usage history, low-capacity alerts, configurable multi-provider widgets, and a separately packaged Linux relay for self-hosting. These are directions, not delivery commitments. The public roadmap tracks the scope and constraints. Try it, or help improve it Statusline is available under the MIT license: Project website Source code and documentation Download for iPhone Desktop and Android beta downloads I'm particularly interested in feedback on initial setup, device pairing, and widget readability. I'm also looking for Android testers before the public Google Play release. If you use Codex and would like to try the Android app, leave a comment or get in touch through the project. What would make a quota monitor useful in your workflow: a simple remaining-capacity indicator, reset notifications, or usage history? Statusline is an independent project. It is not affiliated with, sponsored by, or endorsed by OpenAI.