A local-network prototype turning an iPhone into a Mac trackpad, keyboard and system-control interface through a shared Swift protocol and WSS.
Prototype
Swift
SwiftUI
Network.framework
Bonjour
CryptoKit
Keychain
XCTest
Original code-generated category illustration; not a product screenshot.
Overview
MacPilot comprises a SwiftUI iOS client, a macOS agent and a SharedCore protocol library. Bonjour discovers devices; WSS carries input events, system metrics, shortcuts and chunked file transfers. The agent uses native system APIs and requires macOS permissions. It remains a controlled-network prototype, with first-pairing authorization explicitly unresolved before any production use.
Problem and objectives
Controlling a Mac from an iPhone involves more than sending coordinates across a network. Touch gestures need translation into input events, devices need discovery, connections need state management and transferred file chunks need verification. Because the same channel enables powerful machine actions, device identity, operator approval and macOS Accessibility permissions are central design concerns alongside responsiveness and usability.
My role
Development of the native iOS/macOS client-agent architecture and shared communication components.
Solution approach
The SwiftUI client converts gestures into shared InputEvent models and connects to a Bonjour-discovered macOS agent over Network.framework WSS. An agent router dispatches messages to input, metrics, command and file handlers. CGEvent-based components apply input, while chunk and checksum models support file transfer. P256 challenge signatures and certificate pinning exist, but an unknown first peer currently bootstraps trust automatically. Explicit operator-approved pairing is therefore not established by the current handshake.
Implementation details
01
From gestures to native input events
TrackpadViewModel does not treat raw touches as final pointer coordinates. Normalization, speed-dependent gain and low-pass smoothing prepare pointer and scroll deltas; decaying momentum can continue generating scroll events after a gesture ends. On the agent, InputEventProcessor applies a token-bucket limit and dispatches accepted events on a userInteractive queue to mouse or keyboard handlers. This separates interaction tuning from native execution without establishing an unmeasured latency or perfectly smooth physical-device experience.
02
An explicit file-transfer protocol
File-transfer models carry transfer identity, chunk index, total chunk count, byte offset and checksum. ChunkedTransfer helpers handle 256 KB pieces, SHA-256 verification, byte ranges and progress through shared types. UI progress and agent validation can therefore refer to the same transfer concepts. Chunking bounds individual messages, but the splitFile helper collects chunks into an array, so not every path is constant-memory streaming. Physical-device acceptance remains a separate validation task.
03
Transport security versus first authorization
After Bonjour discovery, client and agent use WSS/TLS and P256 challenge signatures, with shared models defining message types on both sides. However, adding an unknown first public key to the trusted-device store is different from explicit operator approval. Likewise, AES-GCM envelope helpers in SharedCore do not establish mandatory use by the active router. The engineering boundary is to keep these distinctions visible: encrypted transport alone cannot determine whether the first peer is authorized.
