Health Data Relay

Health Data Relay reads your health data on your phone and delivers it, in any format, to destinations you choose: your own server, a dashboard, MQTT, email, files or your calendar, when you tap Run or on a schedule. Nothing leaves the phone except to those destinations.

Docs and screenshots: health-data-relay.lgtm.page

• Exact incremental sync. Days that changed are re-sent in full; a receiver ends up with what the phone has, deletions included.
• One open schema. docs/schema.md, in Apple Health's own terms, versioned by name (apple-push/1).
• Or any format. Templates are text files that write JSON, CSV, Markdown, HTML, GPX or anything else.
• Pipelines, not a service. You add pipelines, each running when you tap Run or on a schedule, to destinations you choose; the app has no backend of its own.

Platforms

Directory	Platform	State
ios/	iPhone and iPad (iOS 17+), SwiftUI, HealthKit	v1
ios/HealthDataRelayMac	Mac dashboard, reading a phone's server	v1
ios/	Vision Pro	compiled, never run
android/	Android, Health Connect	later

Each platform lives in its own directory and shares no code with the others. What they share is the contract at the top level.

Where it stands against Health Auto Export, with the evidence for each feature: docs/parity-audit.md.

The contract

• docs/schema.md: the body every platform sends and every receiver accepts.
• docs/design.md: the behaviour every platform implements: which days are sent, batching, retries, triggers.
• docs/receivers.md: how to write a receiver.
• fixtures/: push-two-days.json, the canonical example batch, and empty-push.json, the connection test. Both are in canonical JSON (node tools/canonical.mjs --check fixtures/*.json).
• tools/receiver.mjs: a throwaway local receiver (Node, no dependencies) that every platform is tested against.

The site (site/) is built from these docs; see site/README.md.

A platform is done when, for the fixture's synthetic data, it emits fixtures/push-two-days.json byte for byte, and its pushes are accepted by tools/receiver.mjs.

node tools/receiver.mjs --token secret --out /tmp/pushes   # listens on :8787
curl -H 'Authorization: Bearer secret' --data-binary @fixtures/push-two-days.json http://localhost:8787/