Glucose notifications as iOS Critical Alerts to bypass Silent/Focus modes

[railing236]

Feature Request

Trio glucose warning notifications currently deliver as standard iOS notifications, meaning they are silenced by Silent Mode, Do Not Disturb, and Focus modes. This creates a genuine safety risk — a user who misses an "Expected Low" alert while asleep or in a meeting may not have the opportunity to act in advance (myself all the time while outside).

iOS provides a dedicated Critical Alerts permission tier specifically designed for health and safety apps. Critical Alerts always play a sound and appear on the lock screen regardless of any silence or Focus settings the user has configured.

Requested behavior: Trio should request the criticalAlert entitlement from Apple and deliver at minimum the following notifications as Critical Alerts:

• Expected Low
• All glucose warning notifications (low, high, urgent low, rapid drop, etc.)

Why this matters

Scenario	Standard Notification	Critical Alert
Phone on Silent	❌ No sound	✅ Sound plays
Do Not Disturb	❌ Suppressed	✅ Delivered
Focus Mode (Sleep, Work)	❌ Suppressed	✅ Delivered
Lock screen	✅ Shows	✅ Shows

For most apps, silent mode is a preference. For a glucose monitoring app, a missed low alert at 3am is a medical event.

Proposed implementation notes

• Apple requires a special Critical Alerts entitlement (com.apple.developer.usernotifications.critical-alerts) — this must be applied for via Apple's entitlement request process
• Once granted, individual notifications can be flagged with UNNotificationSound.defaultCritical (or a custom critical sound)
• The feature should be opt-in per notification type in Trio Settings, allowing users to choose which alerts are elevated to Critical — not all Trio notifications should necessarily be critical
• Critical Alert volume can be set independently by iOS, separate from ringer volume

Expected behavior

1. Trio requests Critical Alerts permission on setup (or in notification settings)
2. User grants permission via the iOS system prompt
3. Glucose warning notifications (at minimum "Expected Low") arrive with sound regardless of Silent, DND, or Focus mode
4. Users can configure which notification types are elevated to Critical in Trio Settings → Notifications

Setup Information

Smartphone:

• Hardware: iPhone 11 Pro Max
• OS Version: 26.3

Pump:

• Manufacturer: Omnipod
• Model: Dash

CGM:

• Device: Dexcom G7
• Manager app: Dexcom App

Trio Version:

• Version Number: v0.6.0.43 (1) feat/garmin 97c76f7
• Repo: nightscout/Trio

Additional context

This is an established pattern in the diabetes app ecosystem — Dexcom, Loop, and similar apps already use or have requested the Critical Alerts entitlement for exactly this purpose. Implementing this would bring Trio in line with the safety standards users expect from a primary diabetes management tool, and is likely a meaningful factor for users choosing between AID systems.

[dnzxy]

Let me get back to you on this. To my knowledge this is not possible the way you think it is for OS-AID apps as it‘d require a per-bundle-id approval by Apple, and is actually not something used in the OS-AID ecosystem but only by commercial vendors (like Dexcom).

Additionally, Trio is an OS-AID system. Alerting for glucose readings are the responsibility of your CGM app of choice, so Dexcom, or xDrip4iOS, not Trio.

[dnzxy]

So, users/builders of Trio would need to individually reach out to Apple to get this approved for their build, then added.
We are not able to handle this, given on how Trio is distributed, thus closing this request.

[greyghost99]

@dnzxy I applied for critical notifications and was granted the entitlement from Apple and was curious on how to add it to Trio via browser build.

[dnzxy]

Genuinely no idea and I‘d have to google / research that as much as you would. Most notably adding the entitlement and then ensuring that it gets applied as a patch.

I believe @Sjoerd-Bo3 is using it + has it set up via browser build.

FWIW, as of dev of Trio you can actually override glucose alarms to break silence and DND, and you don’t specifically require the critical alert entitlement out of the box.

[greyghost99]

@dnzxy Ahh okay, I’ll do some research and see but if @Sjoerd-Bo3 could point me in right direction that would be appreciated thank you!

[Sjoerd-Bo3]

@greyghost99 I just got the entitlement myself today. So also needing to craft something to use it. I think we need some code for that first. Will come back on this, but that will be in PM on discord (find me there). because this will not come into the official Trio.