Protocol
csound-auv3-instrument-boundary names the governed scenario and its lifecycle.
Capability record · system boundary
Csound AUv3 Instrument Boundary
The Book explains how a Csound Audio Unit fits into the Fountain Coach host story: Reframe remains the MIDI2 peer and mediator, the iPad hosts the AUv3, and Csound produces the audio.
Open the Csound instrument record → · Read authoritative Governance Chapter 133 →
Signature illustration
One boundary, four distinct authorities.
The picture explains the relationship. It does not turn a design projection into an acceptance or release claim.
The story
MIDI2 carries the intention; Csound makes the sound.
Reframe and the iPad host are separate instruments. MIDI-CI establishes the peer relationship. The AUv3 adapter owns the explicit host event mapping. Csound owns DSP. Reframe's Store and the independent witness answer whether the declared scenario actually completed.
Host
reframe/audiounit.lifecycle is the instrument operation exposed at the boundary.
Evidence
A non-silent render, recording, Store receipt, AX result, and window identity must remain correlated.
Current catalog state
Designed, not released.
The Instruments catalog currently records this boundary as designed, not yet admitted or live-accepted. The Book therefore documents the semantic relationship and its proof obligations; it does not claim a released AUv3, AUM interoperability, certification, or universal hardware support.