ApexKit

ApexKit is a standalone iOS framework that integrates the APEX TruCare III insulin pump with LoopKit-based automated insulin delivery (AID) apps such as Trio.

It was extracted from Trio's in-app Apex pump driver so the same pump support can be reused in other LoopKit apps without copying app-specific code.

What it provides

• A PumpManagerUI implementation (ApexPumpManager) that can be registered as a pump plugin in any LoopKit-based app.
• Direct Bluetooth connection to the pump by serial number. The target device name is APEX + serial number, matching the pump's BLE advertisement.
• Read-only status updates (firmware/protocol version, battery, reservoir) on a heartbeat.
• Real treatment commands: temporary basal rate, cancel temp basal, suspend, resume, bolus (0.025 U steps) and cancel bolus. Each treatment uses its own BLE connection and performs the minimum initialization writes (SyncDateTime, NotifyAboutConnection) before the treatment command.
• Onboarding UI (serial number entry) and a settings page with pump status.

The packet construction, CRC16-Modbus validation and response parsing follow the documented TruCare III protocol (protocol version 4.12). Command vectors are covered by unit tests.

Project layout

Path	Purpose
Sources/ApexKit/ApexPumpProtocol.swift	BLE session config, command builder, packet parser
Sources/ApexKit/ApexPumpReadOnlyTransport.swift	Bluetooth read-only status transport
Sources/ApexKit/ApexPumpTreatmentTransport.swift	Bluetooth treatment transport
Sources/ApexKit/ApexPumpManager.swift	PumpManagerUI implementation
Sources/ApexKit/ApexPumpSetupViewController.swift	Onboarding + settings UI
Sources/ApexKit/ApexPumpTreatmentCommandTestViewController.swift	Debug treatment page
Sources/ApexKit/ApexBolusProgressEstimator.swift	Bolus progress reporting
Sources/ApexKit/ApexPumpDoseEntryExtensions.swift	Dose/event constructors
Sources/ApexKit/ApexLog.swift	Lightweight OSLog logging
Tests/ApexKitTests/ApexPumpIntegrationTests.swift	Behavior + packet vector tests
project.yml	XcodeGen project spec

Build and test

Requirements: Xcode with an iOS 17+ simulator, XcodeGen, and a LoopKit checkout next to this folder (../LoopKit/LoopKit.xcodeproj).

xcodegen generate
xcodebuild build-for-testing \
  -project ApexKit.xcodeproj \
  -scheme ApexKit \
  -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.5'
xcodebuild test-without-building \
  -project ApexKit.xcodeproj \
  -scheme ApexKit \
  -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.5'

The test suite covers packet vectors, response parsing, dose construction, manager behavior (accepted/rejected/busy/suspended/not-validated/zero/over-max), bolus cancel and progress, and the settings UI.

Integrate into another app

1. Add ApexKit/ApexKit.xcodeproj to your Xcode workspace.

2. Link and embed ApexKit.framework in your app target (embed with CodeSignOnCopy), and add a target dependency on the ApexKit target.

3. import ApexKit where needed.

4. Register the plugin:

   let pumpManagers: [PumpManager.Type] = [
       ApexPumpManager.self,
       // ...
   ]
   let pluginMap: [String: PumpManager.Type] = [
       ApexPumpManager.pluginIdentifier: ApexPumpManager.self,
       // ...
   ]

5. The app already embeds LoopKit.framework and LoopKitUI.framework (ApexKit links against both).

The integration steps above follow the same pattern used by Trio, where the workspace references ApexKit/ApexKit.xcodeproj and the app target links and embeds ApexKit.framework.

Behavior notes

• Connection mode is fixed direct Bluetooth; there is no broadcast mode or connection-method selector.
• Treatment commands are sent only after a read-only validation has succeeded (firmware/protocol version received).
• A bolus accepted by the pump is recorded as fully delivered so history and IOB count the dose.
• Logs contain command summaries and status only; device identity, serial numbers, keys and communication payloads are not written to shareable logs.
• Real-pump validation still requires an actual APEX pump; unit tests cover the protocol and manager logic but not hardware behavior.