> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/unified-api.md).

# Unified API

- [Overview](https://docs.tryterra.co/unified-api/getting-started.md): Discover the capabilities of Terra's Unified API, enabling you to access historical and current user health data from a multitude of health data sources.
- [Quickstart](https://docs.tryterra.co/unified-api/quickstart.md): Learn how to receive data events in just 3 steps
- [Integration setup](https://docs.tryterra.co/unified-api/integration-setup.md): Configure Terra API to receive your users' health & fitness data to your preferred destination (e.g. webhook, DB, etc).
- [Understanding sources and destinations](https://docs.tryterra.co/unified-api/integration-setup/understanding-sources-and-destinations.md)
- [Setting up data sources](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-sources.md)
- [Setting up data destinations](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations.md)
- [Webhooks](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/webhooks.md)
- [SQL database (Postgres, MySQL)](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/sql-database-postgres-mysql.md)
- [Supabase](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/supabase.md)
- [Cloud storage (S3, GCS, Azure Blob)](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/cloud-storage-s3-gcp.md)
- [Queuing services (SQS, Kafka)](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/queuing-services-sqs-kafka.md)
- [MongoDB](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/mongodb.md)
- [Firestore](https://docs.tryterra.co/unified-api/integration-setup/setting-up-data-destinations/firestore.md)
- [Customising data types](https://docs.tryterra.co/unified-api/integration-setup/customising-data-types.md): Customise the types of data events you wish to receive from your users (activity, sleep, etc).
- [Dedicated data source API keys](https://docs.tryterra.co/unified-api/integration-setup/dedicated-data-source-api-keys.md)
- [Understanding Terra environments](https://docs.tryterra.co/unified-api/integration-setup/understanding-terra-environments.md)
- [Per-user OAuth apps](https://docs.tryterra.co/unified-api/integration-setup/per-user-oauth-apps.md)
- [User authentication](https://docs.tryterra.co/unified-api/user-authentication.md): Securely connect your users' health data sources to your application via Terra.
- [Authentication flow](https://docs.tryterra.co/unified-api/user-authentication/authentication-flow.md)
- [Implementation (Terra widget)](https://docs.tryterra.co/unified-api/user-authentication/implementation-terra-widget.md)
- [Implementation (Custom UI)](https://docs.tryterra.co/unified-api/user-authentication/implementation-custom-ui.md)
- [Handling authentication events](https://docs.tryterra.co/unified-api/user-authentication/handling-authentication-events.md)
- [Customising authentication redirects](https://docs.tryterra.co/unified-api/user-authentication/customising-authentication-redirects.md)
- [Managing user health data](https://docs.tryterra.co/unified-api/managing-user-health-data.md): Access user health and fitness information from Terra and, where supported, write data back to connected services.
- [Receiving health data updates (events)](https://docs.tryterra.co/unified-api/managing-user-health-data/receiving-data-updates.md): Learn how to receive data update events to your app as soon as the user's data syncs to the cloud
- [Requesting historical health data (REST API requests)](https://docs.tryterra.co/unified-api/managing-user-health-data/requesting-historical-data.md): Learn how to request for historical data to be sent to your destination through the REST API
- [Writing data](https://docs.tryterra.co/unified-api/managing-user-health-data/write-data.md): Learn how to write data back to providers, and create a bi-directional data stream between your app and the various integrations you connect to
- [Mobile-only sources](https://docs.tryterra.co/unified-api/mobile-only-sources.md): Learn how to connect mobile-based integrations: Apple Health, Samsung Health, Google Fit
- [iOS (Swift)](https://docs.tryterra.co/unified-api/mobile-only-sources/ios-swift.md): The iOS SDK allows you to seamlessly send data from iOS to your backend or to your app directly!
- [Android (Kotlin)](https://docs.tryterra.co/unified-api/mobile-only-sources/android-kotlin.md): How to use the TerraAndroid SDK to connect mobile-based integrations?
- [React Native](https://docs.tryterra.co/unified-api/mobile-only-sources/react-native.md)
- [Flutter](https://docs.tryterra.co/unified-api/mobile-only-sources/flutter.md)
- [Activity Types Reference](https://docs.tryterra.co/unified-api/activity-types.md)
- [Troubleshooting](https://docs.tryterra.co/unified-api/debugging-faq.md)
- [Pricing](https://docs.tryterra.co/unified-api/pricing.md): This page outlines pricing for the Unified API on the Quick Start plan.
- [WHOOP](https://docs.tryterra.co/unified-api/whoop.md)
- [Dexcom](https://docs.tryterra.co/unified-api/dexcom.md)