Developers building fitness apps now have a ready‑made OAuth2 PKCE flow for Garmin Connect inside a React Native project. The tutorial walks through creating an Expo app, registering a Garmin developer account, and configuring a deep‑link scheme that returns users to the app after authentication for mobile development.

Once the app skeleton is in place, the guide introduces expo-crypto to generate a secure code_verifier and code_challenge, then builds an authorization URL with client_id and redirect_uri. Users click a button that launches expo-web-browser, which opens Garmin’s consent screen in a native session for secure authentication flows today.

After the user authorizes, the app captures the authorization code from the callback, exchanges it for an access_token and refresh_token, and stores the payload in AsyncStorage. A background timer refreshes the token five minutes before expiry, keeping the session alive without user intervention for continuous data sync operations.

The repository also demonstrates a clean UI with a connect button, token details toggle, and a disconnect endpoint that calls Garmin’s /user/registration DELETE API. By following this pattern, teams can quickly add Garmin data to dashboards, analytics pipelines, or health‑tracking features for scalable mobile applications today.