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Bolus & cancel

Confirm every bolus

faBolus is experimental and not FDA-cleared. Always confirm the amount before you deliver.

Bolus entry
Enter units, or carbs + BG for a recommendation
Bolus confirmation dialog
Explicit confirm before anything is delivered
Delivering with a Cancel button
Cancel any time while it's delivering

Deliver a bolus

  1. Open the Bolus tab (enabled only when connected). It opens in your default mode (Carbs or Units) from Settings.
  2. Either enter units directly, or enter carbs (and optionally BG) — the recommendation updates automatically as you type, using the pump's own calculator (carb ratio, ISF, target, IOB) to suggest a dose. (There's no separate button to press; tapping anywhere on the carbs/units row focuses the field.)
  3. Adjust units with the stepper (step = your unit increment from Settings). The max-units clamp blocks anything over your pump's configured ceiling.
  4. Tap Bolus N U, then confirm the dialog.

Carbs are recorded on the pump

When you deliver a carb bolus, faBolus sends the carb amount (and BG, if entered) to the pump as part of the bolus, so the carbs show up on the pump graph / t:connect and feed Control-IQ's carb awareness. The delivered units are still computed by faBolus — the pump can't calculate a dose from carbs, so faBolus mirrors its calculator (carb ratio, ISF, target, IOB) and the carbs ride along as recorded metadata.

Carb boluses from a remote (single calculator + safety guard)

When you enter carbs on the Garmin remote, the host phone is the single calculator: it recomputes the dose from your carbs using its live settings and delivers that. The Garmin also sends the estimate it showed you, and the phone compares the two — if they differ by more than 0.10 U (a sign the remote was working from stale settings, IOB, or glucose) the bolus is not delivered; the remote shows "Dose changed since your estimate — reopen and confirm," and you retry with fresh data. Units-mode entries are delivered exactly as confirmed.

Cancel & partial delivery

While a bolus is delivering, a prominent Cancel button is available on the HUD and the bolus sheet. Tapping it sends a cancel to the pump, and the app reports the actual amount delivered before the stop — so a cancelled bolus tells you exactly how much went through.

From a remote

Your Garmin watch can request a bolus, but the phone stays in control — it is the single calculator and the only device that talks to the pump. You complete a hold-to-deliver confirmation on the wrist — tap 1 → 2 → 3 on a touchscreen (like the Venu 3S), or a two-button hold on a button-only device. The phone then recomputes the dose from the carbs, checks it against the estimate the watch showed (a divergence beyond the tolerance above is rejected, not delivered), and carries it out. There is not a second confirm tap on the iPhone for a Garmin request.

If the phone is unreachable, the watch shows a clean failure and nothing is delivered. Garmin bolusing is off by default and has its own switch, plus an optional 4-digit passcode you can require instead of the tap-to-confirm — see Garmin remote.

Under the hood (for the curious)

The signed delivery sequence

Via TandemKit: BolusPermissionRequest → (carb bolus only) best-effort RemoteCarbEntryRequest + RemoteBgEntryRequest to record the carbs/BG on the pump → InitiateBolusRequest (signed and insulin-delivery-gated; also carries bolusCarbs/bolusBG inline) → status polling until the bolus finishes or is cancelled → LastBolusStatus for the delivered amount. The carb/BG records are best-effort — a rejected record never blocks the bolus. Every outgoing message is asserted byte-exact against the pumpX2 cliparser oracle.

Recommendation reasoning

Under the recommended dose there's a collapsible Show reasoning breakdown: the carb + correction total and the active insulin (IOB) subtracted. Hide the whole breakdown with Settings → Bolus & entry → Show recommendation reasoning. (The enforced pump-max limit still caps the dose — see the max-units clamp above.)