Fan Control for Raycast

Control your Mac's fan RPM straight from Raycast — view live fan speed, set a manual RPM target, apply quiet/full profiles, or hand control back to macOS.

Works on Apple Silicon (verified path: M4). Powered by smctl, the open-source SMC control CLI.

How it works

Raycast extensions run in a sandboxed Node runtime and cannot talk to hardware directly. Writing fan targets to the SMC (System Management Controller) also requires root. This extension delegates both problems to smctl:

Raycast extension (TypeScript)
        │  execFile
        ▼
smctl CLI  ──XPC──►  smctld (root LaunchDaemon)  ──IOKit──►  SMC (fan keys)

• Reads (smctl sensors --json) need no daemon and no root — fan RPM and temperatures always work.
• Writes (smctl fan set, smctl fan profile) go through the smctld daemon, installed once with sudo.

smctl ships a thermal safety guard: if temperatures climb too high while fans are under manual control, it forces fans back to system control. Fans also return to macOS control if the daemon is stopped or uninstalled.

Setup

1. Install smctl:

   brew install leaperone/smctl/smctl
   sudo smctl daemon install
   

2. Install the extension (development mode):

   npm install
   npm run dev
   

   Raycast will pick up the extension automatically while ray develop is running. Use npm run build for a production build.

Commands

Command	What it does
Control Fans	List of fans with live actual/target RPM, supported range, and control mode. Actions: set manual RPM (per fan or all), quiet profile, full speed, back to auto.
Set Fan Speed	Quick command — type an RPM as argument, applies to all fans. Validates against the hardware range.
Set Fans to Auto	One keystroke to return fan control to macOS.

Preferences

• smctl Path — override the binary location if it's not in /opt/homebrew/bin or /usr/local/bin.

Troubleshooting

• "smctl is not installed" — run brew install leaperone/smctl/smctl.
• "smctld is not running" — writes need the daemon: sudo smctl daemon install (check with smctl daemon status).
• Fans stuck in manual mode you didn't set — another fan tool (or a previous smctl fan set) left a manual target. Use Set Fans to Auto.

License

MIT