PEOPLE WITH DIABETES BUILT THEIR OWN ARTIFICIAL PANCREAS BECAUSE THE APPROVED ONE WAS YEARS AWAY
Patients reverse-engineered insulin pumps and built a closed-loop glucose control system rather than wait years for approved versions.
HealthOpen-hardware
- difficulty
- ●●●●○
- time
- a weekend-plus, then ongoing tuning with your clinical team
- license
- AGPL-3.0
- repo
- repo ACTIVE1,194 stars
●●●●○ · a weekend-plus, then ongoing tuning with your clinical team · AGPL-3.0 · 1,194 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
This is a patient-built closed-loop insulin delivery system: an Android app (AAPS) that talks to your insulin pump and continuous glucose monitor, usually directly over Bluetooth; only some older pumps need an extra radio bridge such as RileyLink. The software reads your glucose every few minutes, predicts where it is heading and adjusts insulin delivery. It grew out of the #WeAreNotWaiting movement, where patients and parents reverse-engineered pump communication and published it. You build the app yourself (the docs recommend a browser build), then work through the app's built-in objectives before closing the loop. The single biggest barrier is not the build itself; it is having a supported pump. AAPS works with a list of current Bluetooth pumps (Omnipod DASH, Dana, Accu-Chek, Medtrum and others) plus some older models via RileyLink, so check the compatibility list first. You also need a compatible CGM, a clinical team who will work with you, and the willingness to tune basal rates, insulin sensitivity factors and carb ratios yourself. This is not an approved medical device; every person who runs it does so at their own risk. If you have type 1 diabetes, a supportive endocrinologist and the determination to learn how closed-loop control works, this is as real as it gets. If you want a consumer product, use an approved system.
IN THE REPO
GOOD TO KNOW
- —AndroidAPS is the Android app that closes the loop; you build it yourself from source and it talks to the pump from your phone. OpenAPS (a separate Raspberry-Pi-based rig) and Loop (iOS) are sister projects.
- —This is not an approved medical device. Every person who runs it does so with their own clinical team and accepts full responsibility.
- —AndroidAPS is licensed AGPL-3.0: you may use and modify it, but modified versions you distribute or serve must stay open. It is not an approved medical device, and almost all users are patients building it for themselves.
- —You need a supported insulin pump (the docs list current Bluetooth pumps such as Omnipod DASH, Dana and Accu-Chek models, plus older pumps via RileyLink) and a compatible continuous glucose monitor.
- —The repository is actively developed as of August 2026. The broader #WeAreNotWaiting movement spans OpenAPS (reference design), AndroidAPS (Android app), Loop (iOS app), and RileyLink (radio hardware).
- —Safety documentation is extensive and assumes you understand diabetes management. This is not a set-and-forget system; it requires tuning, monitoring, and clinical oversight.
Parts to buy
4 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the AndroidAPS documentation front to back before buying anything (The docs assume you already understand diabetes management. If terms like basal rate, ISF, or carb ratio are new to you, this is not the right project yet.)
- 2.Check the pump compatibility list and secure a compatible pump(Most supported pumps connect over Bluetooth; a few older ones need a RileyLink-type bridge. Confirm your exact model and firmware on the list before you start.)
- 3.Join the community (the AndroidAPS Users Facebook group or the AAPS Discord) and ask questions(The learning curve is steep. The community is experienced and helpful, but you must do the work yourself.)
- 4.Get a RileyLink-compatible bridge only if your pump needs one(Most supported pumps talk to the phone directly over Bluetooth. Only the pumps marked RileyLink on the compatibility list need a bridge device.)
- 5.Set up Nightscout for remote monitoring(Nightscout is a separate project that hosts your glucose data in the cloud. It is optional but widely used.)
- 6.Work with your clinical team to set initial parameters, then tune in open-loop mode before closing the loop(Do not enable automated insulin delivery until you have verified every parameter in open-loop mode and discussed the plan with your endocrinologist.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The biggest trap is not the build — it is the pump. AAPS supports a specific list of pumps (many current Bluetooth models, some older ones via RileyLink), and an unsupported model or firmware will not loop. Check the compatibility list before you commit.
- This is not a project you build for someone else. It is a medical system that requires the person using it to understand how it works, how to tune it, and how to intervene when it does not. If you are building it for your child, you still need to understand it yourself.
- The documentation assumes you already know diabetes management. If you do not understand basal rates, insulin sensitivity factors, or carb ratios, you are not ready for this. Take a diabetes education course first.
- Closed-loop control is not set-and-forget. You will spend weeks tuning parameters, watching overnight graphs, and adjusting settings. This is normal and required.
- Your clinical team must be willing to work with you on this. If your endocrinologist is opposed, do not proceed — you need someone who can help you troubleshoot when something goes wrong.
- Building the app is the easy part: the docs recommend a browser build, with Android Studio or the command line as alternatives. The hard part is the weeks of tuning that follow, working through the app's objectives, and the responsibility of running a system that delivers insulin based on settings you control.
Is this legal?
AAPS is not an approved medical device. People build and run it for themselves at their own risk; the rules differ by country, so check yours and talk to your clinical team. You must not sell it or present it as an approved device.
How much does it cost?
The software is free. The costs are a supported insulin pump, a compatible CGM with its recurring sensor costs, an Android phone, and a RileyLink-type bridge only if your pump needs one. Prices depend heavily on your country and insurance.
Can I build this if I do not have diabetes?
No. This is a system for people with type 1 diabetes who already manage their condition and want tighter control. Do not build it for someone else unless you are their parent or caregiver and they cannot build it themselves.
What happens if the rig fails?
You fall back to manual pump control, exactly as you did before. The pump still works normally; the rig only sends it commands. Keep backup supplies and know how to manage your diabetes without the loop.
Is there an iPhone version?
Yes, it is called Loop. It is a separate project with the same principles but different code and a different build process.
How do I get help if something goes wrong?
Start with the AAPS documentation, then search and ask in the AndroidAPS Users Facebook group, and if that does not help, ask on the AAPS Discord; there are also country and language-specific groups. But you need to understand the system yourself — no one else can troubleshoot your insulin settings for you.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The #WeAreNotWaiting community has years of real-world experience with this system. If you are already managing type 1 diabetes, what would tighten your control the most: overnight basal adjustments, meal predictions, or just never forgetting a correction bolus?
#WeAreNotWaiting community
The OpenAPS project was started by patients and parents who reverse-engineered the radio protocols of older insulin pumps and published everything so others could build the same system. AndroidAPS, Loop, RileyLink, and Nightscout are all community-led projects under the same banner.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo agoedited
Practical notes from our verification: the project page links to the AndroidAPS repository (AGPL-3.0), the Android app that closes the loop by talking to your pump directly from the phone or through a RileyLink bridge, with documentation in the AAPS wiki. A full setup means a compatible pump, a CGM, an Android phone and optionally Nightscout or Tidepool for remote data. Pump compatibility is the first thing to check: the wiki keeps a Compatible Pumps list that covers current models such as Dana-i and DanaRS, Accu-Chek Combo and Insight, Omnipod DASH and Medtrum Nano, so you are not limited to old discontinued pumps — but if your pump is not on that list, the project is not for you yet. The second surprise is how much of the difficulty is not the build, but the weeks of tuning with your clinical team afterward. This is a patient-built system with serious documentation and a large active community, but it is not a product and it is not for everyone. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.