VINAC-FM
Acoustic proof for nearby, fresh, policy-bound approval
VINAC-FM is the local acoustic transport for SilentAuth approvals. It carries small cryptographically bound artifacts, proves an approval device was physically present, and fails closed without storing raw audio.
Where VINAC-FM Fits
The cloud decides whether proof is required. The local gateway performs the proof without turning audio into identity.
Cloud Intent
Agent submits action hash, context, project, and requested proof
Policy Decision
SilentAuth decides whether local physical proof is required
Gateway Proof
Mac Mini gateway handles the VINAC-FM challenge and proof metadata
Signed Receipt
Agent verifies the short-lived receipt before execution
How It Works
Five steps from cloud request to signed execution receipt
Approval Request
An agent or app asks the cloud platform to authorize a sensitive action. The request is hashed with subject, resource, context, nonce, and policy.
Band Negotiation
The local gateway chooses a consumer-compatible band and creates a short acoustic challenge for the nearby approval device.
Presence Capture
A receiver captures the response through a microphone or acoustic front end, then validates freshness and expected band behavior.
Proof Submission
The Mac Mini gateway submits a proof hash and metadata back to the cloud with its adapter token. Raw audio stays local.
Receipt Issued
SilentAuth signs a short-lived receipt bound to the action hash, policy hash, proof channel, gateway, and expiry.
Use Cases
High-Value Transactions
Require a nearby approval signal before wire transfers, crypto withdrawals, or large purchases
AI Agent Execution Gates
Bind sensitive agent actions to fresh local proof before issuing an execution receipt
Infrastructure Changes
Add a local physical-presence check before deployment or infrastructure mutations
Device Presence
Confirm that an authorized approval device was nearby without treating audio as biometric identity
Offline Approval
Let a Mac Mini gateway approve from cached policy bundles and sync receipts later
Key Ceremony Operations
Require a deliberate local proof step for secret rotation, HSM access, and CA operations
Protocol Specification Highlights
Integration
JavaScript SDK
import { SilentAuth } from '@silentauth/js';
const sa = new SilentAuth({ publicKey: 'pk_live_…' });
// Request a VINAC-FM 2.0 local proof challenge
const { sessionId } = await sa.verification.create({
proof: ['vinac_fm'],
});
// Emit acoustic challenge
await sa.vinac.emitChallenge(sessionId, {
band: 'compat_18khz',
duration: 3000,
});
// Listen and capture on the same or nearby device
const proof = await sa.vinac.captureResponse(sessionId);
const receipt = await sa.verification.complete(proof);Device Requirements
Availability
VINAC-FM local proof is available in Open Preview so teams can test the gateway workflow before paid plan separation returns. VINAC-FM 2.0 is the current protocol direction. See the roadmap
VINAC-FM is the transport layer for Logos Lexicon
Logos Lexicon is the semantic intent protocol that can ride above VINAC-FM. VINAC-FM proves local presence and freshness; Logos defines what the compact token means through a versioned logic library, with no executable command payload.
Learn about Logos LexiconThe local proof layer for AI execution
When cloud policy needs physical presence, VINAC-FM adds a fresh acoustic proof before a receipt can be issued.