Architecture

How system requirements map to agent components, and what each platform dependency is used for.

Endpoint

# macOS
macOS 13+, root access
Network Extension approved
Keychain write access

# Windows
Windows 10 64-bit, SYSTEM
WinDivert driver installed
Cert store write access

Requirements by Component

Agent Core

LaunchDaemon / Service

macOS: LaunchDaemon plist

Windows: SentinelAgent service

Runs as root / SYSTEM

Bootstrap

Chain-of-trust validation

Signed binary verification

Spawns sentinel with --spawned-by-bootstrap

Network Monitor

macOS

Network Extension (kernel)

NETransparentProxyManager

System Extension approval required

Windows

WinDivert driver

Packet-level interception

Bundled in agent package

Certificate

macOS

Self-signed root CA

security add-trusted-cert

System Keychain write

Windows

Self-signed root CA

Cert:\LocalMachine\Root

Admin cert store write

Signed Binaries · Chain of Trust · Platform-native Auth · MDM / GPO Deployment

Operational State

LaunchDaemon runningSystem Extension activeRoot CA trustedBackend sync connectedWinDivert driver loadedService registered

QuilrAI

Component Dependency Map

Agent Component	macOS Requirement	Windows Requirement
sentinel (main agent)	root, signed binary	SYSTEM, Authenticode signed
bootstrap	root, signed binary	SYSTEM, Authenticode signed
sentinel-proxy	Network Extension entitlement, signed	WinDivert driver, signed
SentinelProxyExtension	System Extension approval	n/a
ipc-light-broker	Unix socket access	Named pipe access
sentinel-diagnostics	No special requirements	No special requirements

Security Model

The agent enforces a chain-of-trust before starting:

1. Bootstrap verifies its own code signature using OS APIs
2. Bootstrap verifies the sentinel agent binary against the manifest
3. Bootstrap spawns sentinel with --spawned-by-bootstrap and passes its PID via SENTINEL_BOOTSTRAP_PID
4. sentinel rejects startup if not spawned by bootstrap (exits with code 1)

This prevents the agent from running if tampered with or launched directly.

Installation Paths

Platform	Path	Contents
macOS app bundle	/Applications/SentinelProxy.app/Contents/MacOS/	All binaries
macOS support dir	/Library/Application Support/Sentinel/	Configs, certs, templates, logs
macOS daemon	/Library/LaunchDaemons/com.sentinel.agent	Service definition
Windows binaries	C:\Program Files\Sentinel\	All binaries
Windows cert	C:\Program Files\Sentinel\cert	Root CA
Windows service	SentinelAgent	Registered Windows Service

Update Flow

The agent self-updates via sentinel-updater, which the installer registers as a scheduled task or LaunchDaemon:

1. Checks the CDN for a new version every 30 minutes
2. Downloads and verifies the package (RSA-PSS + SHA-256)
3. Validates signatures in staging before stopping the running agent
4. Deploys from staging, starts the agent, runs a 30-second health check
5. Rolls back automatically on failure

The agent is never stopped until the staged package passes all verification checks.