Monitoring System Events with Endpoint Security

At a glance

Project structure

Source bundle/
├── SampleEndpointApp/
│   ├── main.m
│   ├── AppDelegate.m
│   ├── ViewController.m
│   ├── AppDelegate.h
│   └── ViewController.h
├── Extension/
│   ├── auth_demo.c
│   ├── notify_demo.c
│   ├── Extension.entitlements
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── SampleEndpointApp.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: C, C/Objective-C header, Objective-C.
• The verified tree contains 8 project/configuration file(s) and 2 source declaration(s).

Overall architecture

flowchart LR
    User["Install action"] --> App["SampleEndpointApp"]
    App --> Manager["OSSystemExtensionManager"]
    Manager --> Extension["Extension target"]
    Extension --> Client["es_client_t event loop"]
    Client --> ES["EndpointSecurity APIs"]

Reference code

SampleEndpointApp/ViewController.m:28 — the app submits the activation request

    OSSystemExtensionRequest *req = [OSSystemExtensionRequest activationRequestForExtension:@"com.example.apple-samplecode.SampleEndpointApp.Extension" queue:dispatch_get_main_queue()];
    req.delegate = (id<OSSystemExtensionRequestDelegate>)self;

    [[OSSystemExtensionManager sharedManager] submitRequest:req];
    self.currentRequest = req;

Extension/auth_demo.c:136 — the selected extension entry creates and subscribes its client

es_client_t *client;
es_new_client_result_t result = es_new_client(&client, ^(es_client_t *c, const es_message_t *msg) {
    handle_event(c, msg);
});

Interpretation

The app and extension are separate lifecycle boundaries. The app retains the in-flight activation request; after launch, the system extension creates the Endpoint Security client and stays in its dispatch loop. The target includes exactly one of auth_demo.c or notify_demo.c, so those files are alternative extension entries rather than cooperating runtime layers.

Ownership and state

classDiagram
    ViewController o-- OSSystemExtensionRequest : currentRequest
    ViewController o-- NSButton : installButton
    ViewController o-- NSTextView : textView

Ownership evidence

SampleEndpointApp/ViewController.m:12 — stored dependency or nearest verified ownership anchor

@interface ViewController ()

@property (strong) OSSystemExtensionRequest *currentRequest;
@property (weak) IBOutlet NSButton *installButton;
@property (unsafe_unretained) IBOutlet NSTextView *textView;

@end

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

SampleEndpointApp/AppDelegate.h:9 — representative type boundary

@interface AppDelegate : NSObject <NSUserNotificationCenterDelegate>

@end

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

SampleEndpointApp/ViewController.m:12 — representative boundary

@interface ViewController ()
// ...
@property (strong) OSSystemExtensionRequest *currentRequest;
// ...
@end

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: Controller: ViewController; Delegate: AppDelegate.
• Protocols: no local protocol declaration in the scanned source.
• Methods: applicationDidFinishLaunching, applicationWillTerminate, installExtension, viewDidLoad, setRepresentedObject, logText, logWithFormat, logError.
• Files: SampleEndpointApp/AppDelegate.m, SampleEndpointApp/ViewController.m, SampleEndpointApp/AppDelegate.h, SampleEndpointApp/ViewController.h.

Architecture takeaways

• SampleEndpointApp owns installation UI and request state; macOS owns extension activation and launch.
• The selected C entry owns the Endpoint Security client until its dispatch loop ends; authorization and notification demos are build alternatives.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation