Claude Red Bar (visual and audible notifier of task completion)

What happened

Claude Red Bar Brings a Visual and Audible Finish Line to Claude Code Sessions

A macOS developer has published claude-red-bar, a free open-source tool that paints a full-width colored bar across every screen and plays a chime the moment Claude Code stops working. The project, hosted at github.com/gregsramblings/claude-red-bar, is version 1.0 and targets macOS only, using Apple's AppKit framework and the macOS launchd service manager. It surfaced on Hacker News under the tag HN Claude/Codex/Fable, where it quickly attracted attention from developers who run long agentic coding sessions and want to know when they can return to the keyboard.

This piece explains exactly how the bar works, what it signals, and what a developer needs to set up and verify before relying on it. It is aimed at anyone running Claude Code locally — in a terminal or through an IDE extension — who wants an ambient signal rather than a modal notification.

How it works

Greg Ramblings (GitHub: gregsramblings) released version 1.0 of ccredbar, a lightweight macOS application that monitors Claude Code hook events and translates them into a full-width colored stripe along one edge of every attached monitor. The default position is the top edge, though position, thickness, and color are all adjustable from a persistent menu-bar icon. An optional completion chime, defaulting to the macOS system sound named Glass, plays the instant the bar clears — that is, when the last active Claude Code session finishes its turn. The repository carries no license fee, no runtime dependencies beyond the system Swift compiler and the macOS command-line utility plutil, and no requirement for Homebrew or jq.

The install path is three commands: clone the repository, enter the directory, and run install.sh. The script compiles the Swift app, registers a LaunchAgent so the bar restarts at login, starts the daemon immediately, and prints a ready-to-paste hooks block for the developer's Claude Code settings file at ~/.claude/settings.json.

The bar communicates through four Claude Code hook events. UserPromptSubmit fires when the developer sends a message, signaling the start of work and making the bar turn solid red. Stop fires when Claude finishes a turn, clearing the bar entirely. Notification fires when Claude needs an explicit response — a permission prompt or a structured AskUserQuestion tool call — causing the bar to pulse rather than stay solid. A fourth hook, tied to session lifecycle events, handles cleanup when a session exits.

Why it matters

The hook.sh script reads the hook type passed as a command-line argument (busy, waiting, or needs_input) and writes a state file or sends a signal to the running ccredbar daemon. One deliberate filter is built in: Claude Code emits an idle notification roughly every sixty seconds when a finished session is sitting open. hook.sh explicitly ignores the "waiting for your input" idle message so the bar never pulses for a dormant session. A plain conversational question at the end of a turn also does not pulse, because Claude Code has no distinct event for that case; only real prompts — permission requests and structured AskUserQuestion hooks — cause the pulsing state. The bar is click-through and floats above all windows, including fullscreen apps, on every macOS Space.

The core problem is attention management during long agentic runs. When Claude Code is running a multi-step task — writing files, running tests, calling tools — the developer has nothing useful to do at the terminal. Checking the window every thirty seconds is friction; missing a permission prompt for several minutes wastes the session's momentum. A room-visible red bar across every monitor solves the first problem, and the pulsing variant plus the Glass chime solves the second. The chime is particularly useful for developers who work with headphones or who switch to a different physical space while waiting.

Who is affected

The approach is also architecturally minimal. Because it hooks into Claude Code's own hook system rather than scraping output or polling a process table, the bar reflects the actual semantic state of the session: working, done, or blocked on input. No polling interval introduces a lag. No screen-reading component can misread terminal output. The signal is as fast as the hook system itself.

The tool is useful to any developer running Claude Code locally on a Mac — in a terminal session or through an IDE extension. It explicitly does not work with cloud sessions on claude.ai/code, because those sessions run on remote infrastructure and cannot reach a hook script on the developer's local machine. The macOS-only constraint is hard: the app uses AppKit for the overlay window and launchd for the run-at-login agent, and the README states there is no Windows or Linux build. Anyone running Claude Code on Linux or under a remote SSH session should check whether a comparable hook-based notifier exists for their platform, because this one will not install there.

Developers who already have a hooks key in their settings.json file need to merge the four new events into the existing object rather than replace the whole key. The install.sh script prints the block but does not modify the settings file automatically, so the merge step is manual. Builders using multiple concurrent Claude Code sessions should note that the bar aggregates state: if any session is still busy, the bar stays solid red even if other sessions have finished.

What to watch next

Because ccredbar is version 1.0 and macOS-only, the near-term questions are whether the developer adds Linux or Windows support and whether additional hook events in future Claude Code releases enable finer-grained states. The project currently has no CI, no test harness, and no packaged release — the install path requires Xcode Command Line Tools and compiles from source. A developer evaluating it for a team should verify that swiftc is available on the target machines and that the LaunchAgent plist path, which is derived from the clone location, does not break if the repository is moved after install.

The Hacker News thread at news.ycombinator.com/item?id=49516904 is the best place to follow community feedback on edge cases, particularly around multi-session behavior and the idle-notification filter. Anyone building similar tooling for other AI coding agents should study hook.sh closely: the pattern of filtering specific notification strings to avoid spurious state changes is a transferable technique for any hook-driven ambient display.