What Is an Open Source Wearable API and When Does It Make Sense

Key Takeaways

• An open source wearable API gives you access to the integration code itself, not just the API endpoint. You can read it, fork it, audit it, and run it on your own infrastructure.
• Open Wearables is MIT-licensed and self-hosted. Your users' data stays on your infrastructure with no third-party data custody.
• The platform goes beyond raw data aggregation: it includes open algorithms for health scoring and an AI reasoning layer built on top of the unified data model.
• Open source makes sense when: data ownership matters, you need to customize the integration, compliance requires auditability, or you want to build intelligence on top of the data layer.
• Open Wearables is already running in production in applications built on top of it.

When developers look for wearable integrations, most discover SaaS APIs first. They are easy to find, well-documented, and let you make your first API call quickly. Open source alternatives exist but are less visible. The question is not which one is better, but which one fits your situation.

This article explains what an open source wearable API actually is, how Open Wearables specifically works, and the practical cases where this approach makes sense.

What "Open Source Wearable API" Actually Means

A SaaS wearable API gives you an endpoint to call. The integration code that connects to Garmin, Polar, or Oura lives on someone else's servers. You send a request, they return data. You never see how it works.

An open source wearable API gives you the integration code itself. You deploy it on your own infrastructure. You can read every line that handles the Garmin OAuth flow, the Polar webhook registration, the Oura data normalization. You can change it, extend it, fork it, and run it wherever you want.

Open Wearables is MIT-licensed. The full source is at github.com/the-momentum/open-wearables. Every provider integration, every data normalization step, every algorithm is in the repository.

What Open Wearables Is

Open Wearables is a self-hosted health intelligence platform. It connects wearable devices, normalizes the data into a unified model, and exposes it through a single REST API. On top of that data layer, it provides open algorithms for health scores and an MCP server that gives AI assistants structured access to health data.

When you deploy Open Wearables, wearable data from connected providers flows into your PostgreSQL instance. Your application queries one API regardless of which device a user has. A workout from Garmin and a workout from Polar come back in the same EventRecord format, with the same field names, the same units, the same timestamp format.

The current list of supported providers is at docs.openwearables.io/provider-setup.

What You Can Do With the Source Code

MIT license means you can:

• Read it: every OAuth flow, every webhook handler, every normalization step is visible. If you want to understand exactly how Garmin data is processed before it reaches your API, you can read the code.
• Fork it: take the repository, modify it for your use case, and run your version.
• Extend it: add custom provider integrations, custom data types, or proprietary processing logic on top of the existing foundation. For teams that need a provider not yet in the community version, Momentum can build custom integrations as a commercial service.
• Audit it: compliance and security teams can review exactly what happens to user data. There is no black box.

When Open Source Makes Sense

• Data ownership is a requirement. Some use cases, particularly in healthcare, require that user health data never passes through a third party's infrastructure. Self-hosting is the only way to guarantee this. SaaS APIs store data on their servers by design.
• You need to build intelligence on top of the data. Open Wearables goes beyond data aggregation. The open health score algorithms and AI reasoning layer are designed to be extended and customized for specific domains. If you are building a coaching product, a clinical monitoring tool, or a corporate wellness platform, the intelligence layer matters as much as the data layer.
• Compliance requires auditability. If a compliance team, clinical reviewer, or data governance committee needs to verify what happens to user data, open source gives them the code. A closed-source SaaS API cannot provide this.
• You need to customize the integration. If a provider is not yet supported, or if you need to handle data types that Open Wearables does not expose by default, you can add this yourself or work with Momentum to build it.
• You are already managing infrastructure. If your product already runs on self-managed infrastructure, adding Open Wearables to your Docker Compose stack is a smaller lift than it sounds.

Related articles

• How to Handle OAuth, Webhooks, and Token Refresh Across Multiple Wearable Providers
• How to Give Your LLM Access to Wearable Data
• How to Build a HIPAA-Compliant Health App That Uses Wearable Data
• What wearable app development actually looks like in 2026
• How to Add Wearable Support to an Existing Health App in Days, Not Months
• How to Build an AI Agent That Reasons Over Health Data

FAQ

Is Open Wearables production-ready?

Yes. The platform is already running in production in applications built on top of it. The wearable data integration layer is stable and actively maintained. Check the GitHub releases page for the current version and changelog.

How long does it take to set up?

The Docker Compose stack can be running in minutes. Provider credential setup takes longer: most providers issue credentials immediately through a self-service developer portal, but Garmin's developer program is currently not accepting new applications. Plan your integration timeline around the providers you need to support.

Can I add a provider that Open Wearables does not support yet?

Yes. The repository includes documentation for adding new providers. The architecture uses a strategy pattern, so each provider is a self-contained implementation. You can contribute the provider back to the open source project, keep it in your fork, or work with Momentum to build a custom integration.

What happens if I need help?

Community support is available through Discord and GitHub Issues. For enterprise support with SLA guarantees and dedicated implementation help, Momentum offers commercial services. Details at openwearables.io/pricing.

Does Open Wearables work alongside existing integrations?

Yes. You can deploy Open Wearables for new provider integrations while keeping existing direct integrations in place. The unified API means you can gradually migrate without a full cut-over.