Developer tooling that speeds integrations

What small health app teams keep running into is not the artificial intelligence model. It is the plumbing: Apple Health data lives behind HealthKit inside an iPhone app, Garmin data sits behind Garmin Connect, and each source has its own approval flow, data format, and permissions model. (developer.apple.com, developer.garmin.com) Apple’s system is especially awkward for a weekend sprint because HealthKit is not a website feed you can just call from a server. Apple says apps need the HealthKit capability enabled in Xcode and must ask the user for permission to read or write health data on device. (developer.apple.com, developer.apple.com) Garmin has the opposite problem. Its Connect Health application programming interface can expose heart rate, sleep, respiration, pulse oximetry, and stress data, but Garmin says developers need approval for the program and commercial use requires a license fee. (developer.garmin.com) That is why a “unified application programming interface” keeps showing up in this corner of developer tooling. The pitch is simple: instead of writing one connector for Apple, another for Garmin, and another for Whoop, a team writes to one common schema and lets the middleware translate the messy parts. (github.com, openwearables.io) One of the newer examples is Open Wearables, an open-source project from The Momentum that says it connects Apple Health, Garmin, Whoop, Polar, Suunto, and Samsung Health Connect through standardized endpoints. The project’s GitHub page describes it as a unified API and developer portal for syncing data from multiple wearable platforms. (github.com, themomentum.ai) The company is aiming this directly at hackathons and tiny startup teams, not just enterprise buyers. In a March 2026 post about a healthcare hardware hackathon, The Momentum described events with roughly 15 teams, 5 people per team, and 36 to 48 hours to build working health applications using wearable hardware and artificial intelligence tools. (themomentum.ai) That time pressure changes what gets built. If one engineer spends a day wrestling with Apple permissions and another spends a day mapping Garmin sleep fields, a 2-day sprint is gone before anyone ships the actual coach, alert, or triage workflow. (developer.apple.com, developer.garmin.com) The extra layer is not just about collecting raw numbers. Open Wearables says it also computes health scores and supports “AI reasoning,” which is shorthand for turning streams like resting heart rate, sleep duration, and activity into prompts or features a model can use without every team inventing its own translation layer. (openwearables.io, github.com) This is why the first products built on top tend to be coaches and triage demos. A coaching app needs a clean daily picture of sleep, recovery, and training load, and a triage app needs a clean stream of vitals and trends, so both benefit when the integration work is compressed into one reusable backend. (themomentum.ai, github.com) There is already a market for this shortcut. ROOK sells a single API for Apple Watch, Garmin, Oura, and Whoop data, and The Momentum’s own FAQ frames Open Wearables as a self-hosted alternative to paid aggregators that can charge $1 to $3 per active user each month. (tryrook.io, themomentum.ai) So the story here is less “new sensor” and more “new shovel.” The teams trying to build an artificial intelligence health product in one weekend are buying back time from the integration layer, and that can be the difference between a demo that only works with one watch and a demo that works across the devices people already wear. (openwearables.io, themomentum.ai)