I'm a contributor to Trio, an open-source automated insulin delivery (AID) app for iOS/watchOS maintained by the Nightscout Foundation. I'm posting at the recommendation of the engineering team via Feedback Assistant FB22619409 (Developer Support case 102865854185).
The goal
We're prototyping direct BLE connectivity between the Trio watchOS extension and the Dexcom G7 CGM sensor — eliminating dependence on iPhone-to-Watch relay via WatchConnectivity. For an AID app, stale CGM data affects insulin dosing decisions; this is a patient safety concern.
The entitlements needed
To maintain a BLE connection to the G7 while backgrounded and with the display off/wrist lowered, the WatchKit extension requires:
com.apple.developer.bluetooth-central-backgroundcom.apple.developer.bluetooth-central-screen-off-scanning
What I've confirmed
Both entitlements are present on Dexcom's shipping G7 WatchKit extension (com.dexcom.g7app.watchkitapp.watchkitextension), verifiable via:
codesign -d --entitlements :- \
"Dexcom G7.app/Watch/G7Watch.app/PlugIns/G7Watch Extension.appex"
Output includes:
com.apple.developer.bluetooth-central-background = true
com.apple.developer.bluetooth-central-screen-off-scanning = true
These are not self-service capabilities exposed through Xcode or the developer portal for our account:
- Xcode → Trio Watch App target → Signing & Capabilities → + Capability → searching
com.apple.developer.bluetooth-central-backgroundreturns No Matches - Certificates, Identifiers & Profiles → WatchKit Extension App ID (
org.nightscout.5QE6TMMEH2.trio.watchkitapp.watchkitextension) → the entitlement does not appear under Capability Requests
A screen recording demonstrating both is attached to FB22619409.
The May 16 Apple Feedback response noted that the entitlement was visible in an internal Xcode project — consistent with it being a restricted/managed entitlement not exposed through standard developer accounts.
My questions
- What is the correct process to request com.apple.developer.bluetooth-central-background for a watchOS extension App ID where it does not appear in Capability Requests?
- Is com.apple.developer.bluetooth-central-screen-off-scanning available through a private/managed entitlement process, and how do we enter that process?
- Is there a formal Apple program (e.g., MFi, HealthKit entitlements, or similar) applicable to CGM-connected medical apps that covers these entitlements?
Full account details, screen recording, and entitlement output are attached to FB22619409 / Developer Support case 102865854185.
Happy to provide a test build, full entitlement output, or additional context if needed.
Thank you