A free, open-source automated insulin delivery app for iPhone. Trio grew out of the FreeAPS X / OpenAPS lineage, runs the oref algorithm, and now supports Omnipod DASH, Omnipod Eros, and — in open beta — Omnipod 5 pods, plus Dexcom and Libre CGMs.
DIY systems are not FDA-approved and involve building and maintaining the app yourself. Specifications change frequently — always verify current information with the project's own documentation. Full disclaimer.
New to Trio? Start here.
Important: Trio is a free, open-source, do-it-yourself system. It is not FDA-approved, not sold by a company, and not prescribed. You build the app yourself and are responsible for maintaining it. This guide is educational; it is not instructions to build or use Trio, and not medical advice. Work with your care team and rely on the project's own documentation at triodocs.org.
Trio is a free, community-built automated insulin delivery (AID) app for iPhone. It grew out of the FreeAPS X project (itself derived from the OpenAPS / oref lineage) and was renamed and expanded by a volunteer community. Trio runs the oref algorithm to automate insulin delivery using CGM data, and it works with a range of pumps — including Omnipod DASH and Omnipod Eros pods, and, in open beta, Omnipod 5 pods. Because it's open-source and self-built, Trio offers deep customization, but it also carries the responsibilities of a DIY system: you build it, maintain it, and take on the risk.
Trio isn't downloaded from the App Store as a finished product. You compile the app yourself (typically with a Mac and Xcode, or a browser-based build method) and install it on your own iPhone. This is the defining feature — and responsibility — of a DIY system.
Trio runs the oref algorithm from the OpenAPS lineage — the same algorithmic family that pioneered DIY closed-loop. It predicts glucose and adjusts insulin using your settings, with options like Dynamic ISF for advanced users.
Trio supports Omnipod DASH and Omnipod Eros pods. As of the July 2026 open beta, it also supports Omnipod 5 pods (via the community's feat/o5 work) — expanding tubeless DIY options. Confirm current pump support in the project docs.
Trio works with Dexcom (G6, G7) and FreeStyle Libre sensors, among others, for the CGM data that drives its automation. Available CGM integrations evolve with the project.
Trio is the community's insulin-delivery app: free, open-source, and built by the people who use it. That openness buys deep customization — and asks you to take on building and maintaining it yourself.
— Juicebox Podcast Trio GuideFree, open-source DIY AID app for iPhone running the oref algorithm (OpenAPS/FreeAPS X lineage). Not FDA-approved, not manufacturer-supported. Patient builds and maintains it.
Omnipod DASH and Eros pods; Omnipod 5 pods in open beta (feat/o5). CGMs include Dexcom G6/G7 and FreeStyle Libre. Confirm current support in project docs.
Patients who want deep customization, tubeless DIY looping, and community support, and who are comfortable building/maintaining their own system. Often already engaged, tech-comfortable users.
Support the patient's glycemic goals regardless of the tool. Many settings (basal, ICR, ISF, targets) mirror standard therapy. You don't prescribe or build Trio, but you can help interpret data and set targets.
Trio gives you an unusual amount of control for an AID system — which is the point of DIY. Understanding the core settings and how the oref algorithm uses them is how you get good results while keeping the system safe.
Trio uses standard therapy settings — basal rates, insulin-to-carb ratio (ICR), insulin sensitivity factor (ISF), and glucose targets — as the foundation the algorithm builds on. Good foundational settings are essential before enabling advanced features.
Advanced options let the algorithm scale sensitivity (and optionally carb ratio) based on glucose and IOB. Powerful for experienced users, but layered on top of solid basics — not a substitute for them.
Settings like Max IOB, Max Basal, and safety thresholds cap how much the system can do. These guardrails matter enormously in a self-built system — they are the boundaries that keep automation within safe limits.
DIA is a user-set profile value that tells the algorithm how long insulin keeps working. It is not locked to a fixed number — you set it (commonly around 6–7 hours for modern rapid insulins), with a project-defined minimum. Set it to match your insulin, not a default.
feat/o5 branch work). This means the tubeless Omnipod 5 pod hardware can be driven by Trio's oref algorithm in a DIY context, in addition to the already-supported DASH and Eros pods. As open beta, it is early and evolving — anyone considering it should follow the project's own documentation and community channels for current status, stability, and instructions rather than relying on any third-party summary.Many Trio users are highly engaged and knowledgeable. You don't need to build or endorse the system to support the patient — focus on glycemic goals, data review, and safety. The core settings map to standard therapy concepts.
Trio users typically run Nightscout and/or share CGM data, giving rich data for review. Familiar metrics (time in range, patterns) apply. You can help interpret trends and adjust targets and settings collaboratively.
Reinforce safety limits (Max IOB, thresholds), site care, and having backup insulin delivery. Because it's self-maintained, discuss what the patient does if a build expires or a pump/CGM integration breaks.
Note in the chart that the patient uses a DIY system. You're supporting their care, not prescribing Trio. Direct build/technical questions to the project's documentation and community, keeping your role clinical.
Trio sits within the open-source AID movement that predates every commercial system. Understanding where it comes from and how it works explains both its capabilities and the responsibilities it carries.
feat/o5 work), alongside existing DASH and Eros support. Importantly, this is the community using the pod hardware with Trio's own algorithm — it is distinct from Insulet's commercial Omnipod 5 SmartAdjust system. As open beta, it is early, evolving, and not a finished or FDA-cleared product. Anyone interested should rely entirely on the project's own documentation and community channels for current status, stability, and instructions rather than any third-party description.OpenAPS → FreeAPS X → Trio. Runs oref (temp basal + optional SMB), with Dynamic ISF/CR options. Community-developed, iPhone-based. Not FDA-approved.
Omnipod DASH and Eros pods. Omnipod 5 pods in open beta (feat/o5, July 2026). Confirm current support and stability in project docs.
Dexcom G6/G7, FreeStyle Libre, among others. Integrations evolve with the project. CGM data drives 5-minute algorithm cycles.
Basal, ICR, ISF, targets; Max IOB/Max Basal/thresholds as safety limits; user-set DIA (commonly ~6–7h, project minimum enforced). Dynamic options for advanced users.
Volunteer community + documentation (triodocs.org), forums, Discord. No manufacturer warranty or help line. Patient self-maintains builds.
Support glycemic goals and data review; reinforce safety and backup plans; document DIY use. You don't prescribe or build Trio. Technical questions go to the project.