We Need a CatRun for the AI Era

#showdev #ai #macos #devtools

A 16-pixel hero in your macOS menu bar. Watches LLM traffic. That's it.

RunCat told us the CPU was busy. Nothing tells us the agent is.

You remember RunCat — the kitten in your menu bar that runs faster when your CPU is busy. Almost a decade old. Adorable. Useful. Asks nothing of you.

AI-native development needs the same thing for a different signal. Not CPU. Agent traffic. Is there a live LLM request flowing right now, or is everything quiet?

That's why I built AgentRunner.

We need a CatRun for the AI era. So I made one.

A 16-pixel hero in your macOS menu bar. Runs when your agent's actually working. Idle when it isn't. That's the whole UI.

Seven things it's built around

1. The menu bar is where you already glance. Same place as the clock. No extra tab, no extra window, no "I'll open the dashboard later."

2. Below the noise floor. <1% CPU, ~20MB RAM. Native SwiftUI. A monitor that becomes its own monitoring problem is a joke.

3. Flashy "live agent dashboards" don't last. Animated traffic, live token deltas, color-coded latency heatmaps — fun for a week, closed and forgotten by the next sprint. CatRun ran for a decade because it asked you nothing. Same spirit here.

4. Detailed analysis belongs in a different tool. Token spend, cache misses, run history — that needs report depth. That's what cc-token-saver is for, and it gets its own post next. AgentRunner = glance. cc-token-saver = report. Don't make one app try to be both.

5. Vendor-neutral by design. It watches LLM traffic, not Claude traffic. Claude Code, Codex, Cursor, Windsurf, local LLaMA via Ollama, any agent loop hitting a model endpoint over HTTPS. No API key, no per-vendor SDK.

6. Local-only. Zero telemetry. Detection happens on your machine. The app does not phone home. No analytics SDK, no event ping. An agent monitor that ships your data anywhere doesn't deserve trust.

7. Idle vs Active. Binary. That's the entire UI. CatRun gave us a kitten that ran when CPU spiked. AgentRunner gives you a 16-pixel hero that runs when LLM traffic flows. Same spirit. Useful. Small. Invisible until you glance at it.