

Audia & audia-tap
A macOS menu-bar app for real-time, per-app audio routing, plus an OSS CLI that pipes raw PCM straight into local AI models.
Why it was hard
A process tap is only the starting point. We built a routing engine around private stacked aggregate devices and physical outputs, using the system-audio permission path. Real-time HAL callbacks handle volume ramps and 10-band EQ, while dual taps crossfade between devices.
- Driver-free
- Audio capture
- 10-band
- Equalizer
- Crossfaded
- Device switching
How it works
Per-app audio
Spotify, Zoom, any process
Core Audio HAL tap
Process-level intercept, no driver
SPSC ring buffer
Lock-free sample transfer
SIMD DSP
10-band EQ, volume ramps
Routed output
Physical outputs, dual-tap crossfades