QUANTANITY.
Data Ingestion

APPLE HEALTHKIT EXPORT

Extracting raw, unaggregated telemetry from the iOS ecosystem for local analysis. Bypassing the native Health app's smoothed curves and constrained visualizations.

The Extraction Protocol

Apple allows for a complete, localized XML export of all HealthKit data. This file is large, dense, and requires programmatic parsing. It is the only way to access the raw timestamped values for metrics like HRV (SDNN) and resting heart rate without third-party middleware.

Step 1: Initiation

  1. Open the Health app on the host iOS device.
  2. Navigate to the User Profile (top right icon).
  3. Scroll to the absolute bottom and select Export All Health Data.
  4. Acknowledge the warning regarding file size and processing time.

Step 2: Transfer and Extraction

The resulting artifact is a `.zip` archive containing `export.xml` and route data. AirDrop this archive to a secure local machine. Do not use unencrypted cloud transit.

<Record type="HKQuantityTypeIdentifierHeartRateVariabilitySDNN"
        sourceName="Apple Watch"
        sourceVersion="9.4"
        device="<<HKDevice: 0x280e2b480>, name:Apple Watch..."
        unit="ms"
        creationDate="2023-11-04 06:12:33 -0500"
        startDate="2023-11-04 06:11:32 -0500"
        endDate="2023-11-04 06:12:32 -0500"
        value="48.243"/>

Step 3: Parsing Strategy

Because `export.xml` frequently exceeds 1GB, DOM-based parsers will fail via memory exhaustion. You must utilize a stream-based parser (SAX) or a high-performance parsing utility to iterate through the `<Record>` nodes, filtering for the required `type` attributes (e.g., `HKQuantityTypeIdentifierRestingHeartRate`).