> ## Documentation Index > Fetch the complete documentation index at: https://openwearables.io/docs/llms.txt > Use this file to discover all available pages before exploring further. # Polar API Integration > Connect Polar devices via AccessLink API with OAuth 2.0. Syncs workouts, sleep, daily activity, continuous HR, Nightly Recharge, and cardio load. Requires Client ID and Secret from Polar AccessLink Admin. **Need help with your Polar integration?** Pop into our [Discord](https://discord.gg/qrcfFnNE6H) if you have questions or want to discover how Open Wearables can solve your problems. ## Overview Polar provides access to exercise, daily activity, sleep, and heart rate data from Polar devices through the [AccessLink API](https://www.polar.com/accesslink-api). The integration uses OAuth 2.0 for authentication and pull-based syncing to fetch data. ### Supported data types | Data Type | Support | | ------------------------------------------------ | -------------------------------------------- | | Workouts / Exercises | Yes (with optional HR samples, zones, route) | | Sleep (with stages) | Yes | | Daily activity (steps, calories, activity zones) | Yes | | Continuous heart rate | Yes | | Nightly Recharge / Recovery | Yes | | Cardio Load | Yes | | Sleepwise Alertness | Yes (requires Polar Sleepwise subscription) | | Sleepwise Circadian Bedtime | Yes (requires Polar Sleepwise subscription) | | Body Temperature | Yes (requires Polar Elixir device) | | Sleep Skin Temperature | Yes (requires Polar Elixir device) | | SpO2 | Yes (requires Polar Elixir device) | | Wrist ECG | Yes (requires Polar Elixir device) | ### Data delivery | Method | Description | | ------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Polling (pull) — Exercises** | Open Wearables fetches exercises via the AccessLink v3 API (`/v3/exercises`). Returns all exercises available in Polar Flow for the connected user. | | **Polling (pull) — 24/7 data** | Sleep, daily activity, continuous HR, Nightly Recharge, cardio load, and Elixir/Sleepwise metrics are fetched via range endpoints covering the last 90 days. | | **Webhooks (push)** | Polar sends a lightweight notification on each event (exercise, sleep, activity, etc.). Open Wearables acknowledges immediately and enqueues a targeted sync for the affected data type. | Webhook delivery requires a registered webhook subscription and `POLAR_WEBHOOK_SIGNATURE_SECRET` set in your environment. See the configuration step below. ## What you need by the end * **App credentials**: Client ID + Client Secret from the Polar AccessLink admin panel * **Redirect URI** registered in your Polar application ## Prerequisites * A [Polar Flow](https://flow.polar.com) account ## Application walkthrough If you don't have one yet, create a free account at [flow.polar.com](https://flow.polar.com). This is the same account used by Polar device owners - no separate developer account is needed. Go to the [Polar AccessLink Admin](https://admin.polaraccesslink.com) and sign in with your Polar Flow credentials. Click **Create client** to start the registration process. You'll go through four tabs: **1. Contractual Information** * Fill in your organization details (name, address, country) * Toggle "I intend to integrate on behalf of a client or third-party organization" if applicable * Accept the AccessLink Limited License Agreement **2. Application Information** * **Application Name**: Your app name (e.g. "Open Wearables") * **Business contact (email)**: Your contact email * **Description**: Brief description of your application * **Application Web site**: Your app's website (optional) * **Authorization redirect URL**: Your OAuth callback URL - for local development use `http://localhost:8000/api/v1/oauth/polar/callback` * **Available data types**: Enable all three - **Exercise data**, **Daily activity data**, **Physical information data** **3. Check Information** Review the summary of your organization and application details, then click **Confirm**. **4. Credentials** After confirmation, you'll see your: * **Client ID** * **Client Secret** The Client ID and Client Secret are **shown only once**. Copy and store them immediately. If you lose them, you'll need to create new credentials from the Admin tool. Add the following to your `.env` file: ```bash theme={null} #--- Polar ---# POLAR_CLIENT_ID=your-polar-client-id POLAR_CLIENT_SECRET=your-polar-client-secret POLAR_REDIRECT_URI=http://localhost:8000/api/v1/oauth/polar/callback # Optional — required only if using webhooks (set automatically on first registration) POLAR_WEBHOOK_SIGNATURE_SECRET= ``` **Configuration details:** | Variable | Description | | -------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | `POLAR_CLIENT_ID` | Client ID from the Polar AccessLink Admin panel | | `POLAR_CLIENT_SECRET` | Client Secret from the Polar AccessLink Admin panel | | `POLAR_REDIRECT_URI` | Must match the Authorization redirect URL registered in your Polar application. For local dev: `http://localhost:8000/api/v1/oauth/polar/callback` | | `POLAR_WEBHOOK_SIGNATURE_SECRET` | HMAC-SHA256 signing secret returned by Polar on webhook creation. Returned once — save it immediately. Used to verify incoming webhook payloads. | The OAuth scope is hardcoded to `accesslink.read_all` which grants full read access to the AccessLink API. No additional scope configuration is needed. With credentials configured and your Open Wearables instance running, initiate the OAuth flow to connect a user's Polar account. **1. Get the authorization URL:** ```bash theme={null} curl -X GET "http://localhost:8000/api/v1/oauth/polar/authorize?user_id={user_id}&redirect_uri=http://localhost:3000/users/{user_id}" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" ``` **Response:** ```json theme={null} { "authorization_url": "https://flow.polar.com/oauth2/authorization?client_id=...&redirect_uri=...&response_type=code&scope=accesslink.read_all&state=...", "state": "abc123..." } ``` **2. Redirect the user** to the `authorization_url`. They will log in to Polar Flow and authorize your app. **3. Polar redirects back** to the callback URI configured in your `.env` (`POLAR_REDIRECT_URI`). Open Wearables automatically exchanges the authorization code for access tokens and registers the user with the Polar API. **4. Verify the connection** was created: ```bash theme={null} curl -X GET "http://localhost:8000/api/v1/users/{user_id}/connections" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" ``` You should see a connection with `"provider": "polar"` and `"status": "active"`. The `redirect_uri` parameter in the authorize call is where the **user** is sent after the flow completes (e.g., back to your app). This is separate from `POLAR_REDIRECT_URI` in your `.env`, which is the **server-side** OAuth callback that Polar sends the authorization code to. An initial sync is triggered automatically after a successful OAuth connection. To manually sync or fetch data: ```bash theme={null} # Sync all data types curl -X POST "http://localhost:8000/api/v1/providers/polar/users/{user_id}/sync?data_type=all" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" ``` Exercises are fetched from `/v3/exercises` which returns all exercises available in Polar Flow for the connected user (no date filter). 24/7 data (sleep, activity, HR, etc.) is fetched over a 90-day lookback window using range endpoints. Once data has synced, fetch it via the Open Wearables API: ```bash theme={null} # Fetch workouts curl -X GET "http://localhost:8000/api/v1/users/{user_id}/events/workouts?start_date=2026-01-01T00:00:00Z&end_date=2026-02-01T00:00:00Z" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" # Fetch sleep records curl -X GET "http://localhost:8000/api/v1/users/{user_id}/events/sleep?start_date=2026-01-01T00:00:00Z&end_date=2026-02-01T00:00:00Z" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" # Fetch daily activity curl -X GET "http://localhost:8000/api/v1/users/{user_id}/events/daily-activity?start_date=2026-01-01T00:00:00Z&end_date=2026-02-01T00:00:00Z" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" ``` You can also fetch raw Polar exercise data with optional samples, zones, and route data: ```bash theme={null} # Fetch Polar exercises with HR samples and route curl -X GET "http://localhost:8000/api/v1/vendor-workouts/polar/users/{user_id}/workouts?samples=true&zones=true&route=true" \ -H "X-Open-Wearables-API-Key: YOUR_API_KEY" ``` If data is returned, your Polar integration is working end-to-end. ## Rate Limits Polar AccessLink API uses dynamic rate limits that scale with your registered user count: | Limit | Formula | | -------------- | -------------------------------- | | Per 15 minutes | 500 + (registered users x 20) | | Per 24 hours | 5,000 + (registered users x 100) | Rate limit headers are included in every response: `RateLimit-Usage`, `RateLimit-Limit`, `RateLimit-Reset`. ## Next Steps Explore the Open Wearables API endpoints. Understand the overall system architecture. ## Support **Need Help?** * Join our [Discord](https://discord.gg/qrcfFnNE6H) and ask a question. * Check [GitHub Discussions](https://github.com/the-momentum/open-wearables/discussions). * Check the [Polar AccessLink API Documentation](https://www.polar.com/accesslink-api). * Contact Polar developer support: [b2bhelpdesk@polar.com](mailto:b2bhelpdesk@polar.com)