Developers integrating Spotify's Web API into a React app must now use the PKCE authentication flow, as the older implicit grant method was deprecated in 2025. A common hurdle is Spotify's new policy banning localhost as a redirect URI. The solution involves configuring the development server to run on the loopback address `127.0.0.1` instead.

The authentication process requires generating a random code verifier and its SHA-256 hashed code challenge. This challenge is sent to Spotify to obtain an authorization code, which is then exchanged for an access token. Storing these tokens in localStorage is a standard practice, though security-minded developers may seek alternatives.

Managing token expiration is critical for a smooth user experience. The author implements a token refresh mechanism, using a stored refresh token to obtain new access tokens automatically. This approach prevents API calls from failing due to expired credentials and is especially important when using data-fetching libraries like TanStack Query, which can trigger race conditions if not handled properly.