Open Wearables vs Terra API
Open-Source Alternative
Terra locks your wearable data behind cloud infrastructure and usage-based pricing. Open Wearables gives you the same integrations, self-hosted and open source, with no usage-based fees.
One platform for wearable data and health intelligence.
Open Wearables is an open-source alternative to Terra API for teams that want the same wearable coverage without handing custody of health data to a vendor. It connects all major wearable providers through one unified REST API, normalizes and deduplicates readings into a single schema, and computes documented health scores on top: Sleep Score across duration, stages, consistency, and interruptions, and Resilience Score from heart rate variability. Because the platform is MIT licensed and self-hosted, cost tracks the infrastructure you run rather than your user count, and the scoring logic is open to audit and adjustment instead of being a black box. An MCP server exposes scores and trends to any LLM, so an AI reasons over interpreted health context. The tradeoff is honest: you operate FastAPI, PostgreSQL, Redis, and Celery yourself instead of consuming a managed endpoint. Built and maintained by Momentum.
Unified API
Connect wearable providers through a single REST API. One integration, all devices.
Open health scores
Sleep, HRV, recovery, VO2 max. Every algorithm published under MIT license and fully customizable.
AI-ready
MCP-compatible interface connects your LLM stack directly to wearable data. No proprietary intermediary.
Self-hosted
Docker Compose or one-click Railway. FastAPI, PostgreSQL, Redis, Celery. Your infra, your data.
Looking for a Terra API alternative? Open Wearables and Terra solve the same problem: connecting wearable devices to your application without building each integration from scratch. The difference is in the model. Terra is a managed cloud service. You call their API, your users' data flows through their infrastructure, and you pay for that convenience on a per-call basis. Open Wearables is an open-source platform you deploy yourself. Same integrations, same data types, but running on your servers, under your control, with no usage-based fees.
Side by side.
| Aspect | Terra | Open Wearables |
|---|---|---|
| Hosting | Cloud-only | Self-hosted. Your servers, your data. |
| Source code | Closed source | MIT licensed. Fully open. |
| Wearable providers | Broader provider count (incl. Fitbit, Withings, Coros, Peloton), aggregated under one plan | Garmin, Polar, Whoop, Strava, Apple Health, Samsung Health, Google Health Connect, Suunto, Oura |
| Health algorithms | Proprietary. No access to scoring logic or model internals. | Open algorithms: sleep, HRV, recovery, VO2 max. Auditable and customizable. |
| Data ownership | Data processed and stored on Terra's cloud infrastructure | Full. Data never leaves your infrastructure. |
| GDPR / HIPAA | Compliance is managed by Terra as a third-party data processor | Self-hosted by design. You control compliance. |
| Deployment | SaaS only: no self-hosted or on-prem option | Docker Compose or one-click Railway |
| License | Proprietary, closed source | MIT |
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Why teams choose Open Wearables as a Terra alternative.
The cost compounds with scale
Terra's pricing model combines a base monthly subscription with per-API-call credits. At low usage that may seem manageable. As your user base grows, so does every API call, every data sync, every webhook. The cost scales with your product's success, not with your infrastructure.
Open Wearables runs on your own servers. You pay for compute, not for data access. At 10,000 users, the difference is not marginal.
Closed algorithms mean black-box health scores
Terra processes health data and returns scores. What those scores mean, how they are weighted, and whether they fit your use case is not visible to you. For clinical tools, performance platforms, or any product where health decisions depend on the output, a black box is a liability.
Open Wearables publishes its health scoring algorithms. Sleep, recovery, strain, HRV, VO2 max. Every calculation is in the repository. You can audit it, customize it, or replace it entirely.
Your data stays where you put it
With Terra, wearable data flows through their cloud infrastructure before reaching your application. That means a third party processes your users' health data, with all the compliance complexity that entails.
Open Wearables is self-hosted by design, not by coincidence. Your infrastructure. Your database. No data leaves unless you send it.
No vendor lock-in
Terra is a SaaS. If their pricing changes, if they are acquired, if they deprecate an integration, you adapt on their timeline. Open Wearables is MIT-licensed. Fork it, modify it, run it forever. The source code does not disappear.
Who uses Open Wearables instead of Terra.
Wellness and consumer health apps
Connect multiple wearables, compute open health scores, and build personalized experiences without paying per user or explaining black-box outputs to your team.
Clinical and digital health platforms
Full data ownership and self-hosted architecture means wearable data never leaves your infrastructure. Designed for environments where GDPR and HIPAA compliance are non-negotiable.
Sports performance and coaching tools
Open algorithms for HRV, recovery, strain, and VO2 max. Customizable scoring that fits your methodology, not a vendor's proprietary model.
Corporate wellness programs
Self-hosted at any scale. Connect devices across a large workforce without infrastructure lock-in.
Who is the Terra alternative for?
Open Wearables
Open Wearables fits teams that need full data ownership, want to customize health scoring, or are building for regulated environments (GDPR, HIPAA). It requires running your own infrastructure, which means your team needs to be comfortable with Docker or a managed platform like Railway.
Terra
Terra fits teams that want a fully managed service and prefer not to operate their own infrastructure. If your priority is getting to market fast without any DevOps overhead, and usage-based pricing is acceptable at your scale, Terra is a reasonable choice.
If you are evaluating which fits your situation, the docs and a quick demo call are the fastest way to find out.
How to get started.
Open Wearables is open-source and available on GitHub. To get started, you deploy the platform on your own infrastructure using Docker Compose or one-click Railway, and connect it to the wearable providers you need.
One important note: each wearable provider (Garmin, Whoop, Oura, Strava and others) requires its own developer credentials. You will need to apply for API access directly with each provider. Open Wearables handles the authentication flow, data normalization, and unified API layer, but the provider keys are yours to obtain.
See supported wearable providers: Garmin, Oura, Whoop, Strava and more →
Common questions.
Does Open Wearables support the same wearable providers as Terra?
Open Wearables currently integrates with Garmin, Polar, Whoop, Strava, Apple Health, Samsung Health, Google Health Connect, Suunto, and Oura. The full provider list is in the docs.
Is Open Wearables production-ready?
Yes. The wearable data layer is production-ready and used by healthtech teams in production. Open Wearables runs on FastAPI, PostgreSQL 18, Redis 8, and Celery, deployed via Docker Compose, with an architecture designed for horizontal scaling. Health scores are available now: Sleep Score computes a nightly 0-100 value across four pillars (duration, stages, consistency, interruptions), and Resilience Score measures autonomic nervous system stability weekly through heart rate variability. Check the GitHub releases for the current status of each component.
What does self-hosting actually require?
Docker Compose for a standard setup, or one-click deploy on Railway. The stack is FastAPI, PostgreSQL, Redis, and Celery. If you can run a containerized backend, you can run Open Wearables.
Who maintains Open Wearables?
Open Wearables is built and maintained by Momentum, a healthtech software house with 10 years of experience. It is open-source and MIT-licensed, backed by a commercial team with long-term skin in the game.
What if I need custom integrations or enterprise support?
The core platform is free and open-source. Momentum offers paid services on top: custom integrations, specialized ML models, enterprise deployment with SLA-backed support, and BAA for HIPAA-covered environments. Book a demo to discuss your requirements.
Open Wearables is built and maintained by Momentum, a healthtech software house with 10 years of experience. The platform is MIT-licensed and actively maintained. Momentum offers commercial services on top for teams that need custom integrations, enterprise deployment, or SLA-backed support.
Stop paying per API call.
Deploy Open Wearables on your infrastructure. MIT licensed. Self-hosted.