Loop is an open-source automated insulin delivery app for iPhone and Apple Watch. It reads glucose from a continuous glucose monitor (CGM), forecasts glucose from insulin, carbs and recent trends, and adjusts delivery on a compatible insulin pump. It is a stone resting on the boulders of work done by many others.

Loop is built on LoopKit, a set of frameworks for data storage, retrieval and calculation, and on LoopAlgorithm. Pump and CGM support comes from separate plugins, and the app is built from LoopWorkspace.

Please understand that this project:

• Is highly experimental
• Is not approved for therapy

_{Screenshots are from the iOS Simulator with simulated CGM and pump data.}

• Automated insulin delivery. Loop forecasts glucose several hours ahead and adjusts delivery with each new glucose reading, using either temporary basal rates or automatic boluses.
• Meal and correction boluses with a recommended amount and a forecast of where glucose is heading. Carb entries can include food type, absorption time and saved favorite foods.
• Presets that temporarily adjust insulin needs and correction range: pre-meal, your own custom presets, and built-in activity presets for walking, jogging, biking and strength training (which can be hidden). Presets can be scheduled, and in-app training explains how to use them.
• Statistics: GMI, average glucose, variability and time in range, an ambulatory glucose profile, and daily insulin totals split into basal, automatic bolus and manual bolus.
• Live Activity on the Lock Screen, in the Dynamic Island and on CarPlay.
• Apple Watch app with glucose and forecast, carb entry, bolus and presets.
• Alerts for glucose and device conditions, with urgent alerts that sound even when the phone is silenced or in a Focus.
• Data sharing with Apple Health, and upload to Nightscout and Tidepool through optional services.

• Pumps: Omnipod 5, Omnipod DASH and Omnipod Classic (Eros, with RileyLink); older Medtronic pumps (with RileyLink); Medtrum Nano (200U and 300U).
• CGMs: Dexcom G5, G6, ONE, G7 and ONE+; FreeStyle Libre 1, 2 and 2+ (through MiaoMiao or Bubble transmitters, or EU Libre 2 directly); FreeStyle Libre 3 and 3+; Eversense E3 and 365; and readings from Dexcom Share or Nightscout.

See Loop Docs for the exact models and requirements.

Please visit the Loop Docs for installation, algorithm, and other details. Loop is built from LoopWorkspace, in a web browser with GitHub Actions or on a Mac with Xcode.

For FAQs, how to contribute to open source aspects of Loop and other tips, refer to the Wiki.

Questions and discussion are welcome on Loop Zulip.

Please read the LICENSE and CODE_OF_CONDUCT