macOS menu bar app that reads IOKit to show USB-C cable speed, power rating, charger PDO list, and charging bottleneck in plain English.
Key Takeaways
Uses three IOKit service families (AppleHPMInterfaceType10/11, IOPortFeaturePowerSource, IOPortTransportComponentCCUSBPDSOP) with no private APIs or helper daemons.
Per-port display includes e-marker chip vendor, negotiated PDO, active transports (USB2/USB3/Thunderbolt/DisplayPort), and PD Discover Identity response.
Charging diagnostic banners pinpoint the bottleneck: cable rating, charger headroom, or Mac power state.
E-marker data only appears on marked cables; sub-60W cables typically lack one. PD 3.2 EPR support is incomplete.
Requires macOS 14 Sonoma+; not App Store eligible because App Sandbox blocks the necessary IOKit reads.
Hacker News Comment Review
The author (sleepingNomad) shipped 16 releases in roughly 7 hours during the HN thread, adding CLI mode and standalone app mode in direct response to feedback.
Linux users flagged lsucpd as a comparable PD inspection tool; portability to non-Apple platforms is constrained by how macOS exposes IOKit vs. what sysfs/lsusb offer.
Several commenters hit “No USB-C ports detected” on valid setups, suggesting IOKit service enumeration misses some hub or dock configurations.
Notable Comments
@jareds: notes the app is a genuine accessibility win, replacing a visual USB tester for blind users sorting cable drawers.
@pimeys: ported equivalent functionality to a KDE Plasma 6 QML Plasmoid in 10 minutes and $2 using GPT-5.5, underlining how thin the platform-specific logic is.
