Issue Summary

• Loop expects events that are not finalized to have isMutable true.
• Loop expects to have deliveredUnits provided for each finalized event, it should be nil when event is not finalized; although units (TBR U/hr or requested bolus) should be provided.
• The MedtrumKit pump manager is not finalizing temp basal event and is not providing the deliveredUnits for each finalized temp basal event.

Overview

Examine cycle by cycle a few events looking at Pump Event Details and Apple Health. The issues are most obvious when running with Dosing Strategy using Temp Basal Mode only.

Summarize problems:

• Each successive temp basal event overwrites the previous one when looking at Loop Pump Event history
• Apple Health history appears to be reporting each temp basal as if it were the indicated duration but at the scheduled basal rate
• Examine automatic, isMutable and deliveredUnits for the MedtrumKit pump manager when a Temp Basal Rate is in-progress
  • automatic is reported as nil when it should be true
  • isMutable: true is correct, but because each successive TBR overwrites the previous one in event history, we never see the finalized TBR result
  • deliveredUnits should be nil (and it is) until the event is finalized but we don't see the finalized event
• Examine automatic, isMutable and deliveredUnits for the MedtrumKit pump manager for bolus events
  • automatic value is correct
  • isMutable value is correct
  • deliveredUnits should be nil until the event is finalized, but they are correct

Main Loop Screen

Only the currently running TBR appears on the Loop plot. All previous TBR records are overwritten by current one.

Test Details

Delete Loop from phone to begin with a clean slate.

Configuration

• SE 3rd gen phone running iOS 26.3
• LoopWorkspace URL: https://github.com/marionbarker/LoopWorkspace
• branch: feat/add_all_managers (includes 2 private repo: OmnipodKit and TandemKit)
• MedtrumKit commit: f21d808
  • Realized part way through the test, there is a newer version in MedtrumKit, but it does not make a difference, same issues
• modifications: add pretty-print pump events PR for Loop (PR 2403) and LoopKit (PR 586)
• leave Apple Health alone (so loop will read in that information) but will start fresh for pump data
• use default Loop settings, Scheduled Basal 1.2 U/hr, target 105-110, 15 g/U, 50 mg/dL/U

Narrative - examine Pump Event in real time

Dosing Strategy: Temp Basal Only

Date: 2026-02-12, PST (UTC -8)

• add Nightscout as a Service
• add CGM SImulator, sine wave 110 +/- 20 and upload to Nightscout
• Add Medtrum:
  • attach pump base
  • start priming
  • activate

That's enough for the Temp Basal Test.

• share the text file and prepend the date time stamp to each filename - uploaded at end of this comment

I got part-way through this test and realized I do not have the latest commit for MedtrumKit.

Start over at 16:20 using Medtrum commit: 27b9b68

Restart Test

Do not bother starting with a fresh build on the phone, just build newest commit onto existing app.

First loop after building with latest MedtrumKit commit.
Leave Loop set to Temp Basal Only, Closed Loop enabled

Nightscout

Nightscout plots look fine because they go by the uploaded temp basal values.

Apple Health

❌ Apple Health appears to be reporting a value equal to the scheduled basal rate for each duration. Not what is expected from the TBR values

(1.2 U/hr is 0.1 for 5 minutes, 0.2 for 10 minutes and 0.3 for 15 minutes).

Switch to Automatic Bolus

✅ All bolus pump events are correct with the exception that deliveredUnits should be nil when isMutable is true.

Pump Event text files

These Pump Event details text files were shared from the Loop phone. All Temp Basal files were in progress. The Bolus files are noted as in-progress or completed.

PumpEvent-txt-files.zip

Share one of these as a screenshot.