The first commercial AID system powered by the Loop algorithm — the same open-source algorithm the community built. A remarkably light, round pump with automated insulin delivery, Apple Watch bolusing, and a novel gravimetric dosing sensor.
Device specifications change frequently — always verify current information directly with the manufacturer before making any decisions. Full disclaimer.
New to twiist? Start here.
The DIY community built the Loop algorithm years before any company shipped automated insulin delivery. Tidepool brought that algorithm through the FDA, and Sequel Med Tech built a pump around it. twiist is the result: a commercial, FDA-cleared, fully supported AID system running the same algorithmic lineage as DIY Loop — no building, no GitHub, no Apple Developer account. It pairs that algorithm with unusual hardware: a small, round, lightweight pump and a gravimetric sensor that measures the actual mass of each insulin dose delivered.
twiist runs Tidepool Loop — the FDA-cleared version of the community-built Loop algorithm. It predicts glucose and adjusts insulin every 5 minutes. If you've followed DIY Loop, this is the same lineage in a supported commercial package.
twiist measures the actual mass of insulin delivered with each dose — a novel approach that weighs delivery rather than inferring it from motor rotations. Designed to catch occlusions and delivery failures more directly.
twiist is designed to let users bolus directly from an Apple Watch — one of the first commercial systems to offer wrist-based dosing. Useful for discretion and convenience.
The twiist pump is notably small and light — around 2 ounces — with a round form factor that differs from the rectangular pumps most people picture. Uses replaceable cartridges and standard infusion sets.
Scott has covered twiist and the Loop-to-commercial story on the Juicebox Podcast — including conversations tied to the Algorithm Pumping series. See the Algorithm Pumping series for Loop, twiist, and the broader AID landscape.
twiist takes the algorithm the community proved could work and puts it in a supported, FDA-cleared box — no building, no maintaining, no Apple Developer account. For people who wanted Loop but not the DIY project, that's the whole point.
— Juicebox Podcast twiist GuideTidepool Loop — the FDA-cleared interoperable automated glycemic controller (iAGC) derived from the open-source Loop algorithm. Adjusts basal every 5 minutes; automated correction. Standard pump settings (basal, ICR, ISF, DIA) still apply and still need your input.
Designed as an interoperable system. Compatible CGMs include Dexcom G6/G7, FreeStyle Libre 3 Plus, and Eversense 365 — confirm current cleared pairings before prescribing, as interoperability is expanding.
Patients who want the Loop algorithm in a supported commercial product. Those drawn to Apple Watch bolusing, a very light pump, or the interoperable ecosystem. Ages 6+.
Unlike the iLet, twiist uses standard programmable settings. Good basal/ICR/ISF/DIA input drives good outcomes. Your role in tuning is the same as with any programmable AID pump.
twiist behaves like the Loop algorithm because it is the Loop algorithm — so much of what applies to Loop applies here, with the important difference that twiist is supported, cleared, and doesn't require you to build or maintain anything.
The twiist EcosystemLight (~2 oz), round, cartridge-based, standard infusion sets.
Wrist bolusing and glucose viewing.
Primary controller for the algorithm, settings, and data.
Weighs each delivered dose to verify insulin delivery.
Patients coming from DIY Loop will recognize the algorithm's behavior — the same predictive basal adjustment lineage. The mental model transfers, which can make onboarding smoother for experienced loopers.
Existing Loop settings (basal, ICR, ISF, DIA) are a reasonable starting reference, but should be reviewed and confirmed rather than assumed. Hardware differences and the commercial algorithm's guardrails may warrant adjustment.
Unlike DIY, twiist has a manufacturer support line, warranty, and formal clearance. For patients who found DIY maintenance burdensome, this reduces the ongoing self-management overhead considerably.
twiist integrates with Tidepool for data review. Many clinics already use Tidepool for DIY Loop and other devices, so the review workflow may already be familiar to your team.
twiist is the clearest example of the diabetes community's open-source work becoming a regulated commercial product. Understanding how it got here explains what it is — and what still needs your clinical input.
Tidepool Loop (iAGC), FDA-cleared descendant of open-source Loop. Predictive basal adjustment every 5 minutes with automated correction. twiist system cleared 2024; broader availability 2025.
Standard programmable: basal, ICR, ISF, DIA, glucose targets. Clinician tuning drives outcomes. Contrast with iLet (no programmable settings).
Round, ~2 oz pump; replaceable cartridges; standard infusion sets; gravimetric delivery sensor. Apple Watch bolusing; iPhone as primary controller.
Interoperable: Dexcom G6/G7, FreeStyle Libre 3 Plus, Eversense 365 among cleared/expected pairings. Confirm current cleared list before prescribing.
Ages 6+. Especially suited to patients wanting Loop-style automation in a supported product, interoperable CGM choice, or Apple Watch dosing.
Integrates with Tidepool for review. Familiar to clinics already using Tidepool for DIY Loop and multi-device data aggregation.