Stripe OAuth refresh token invalid_grant — What it means & how to fix it

Integrating with Stripe's API using OAuth 2.0 often encounters refresh token failures, commonly identified by the "invalid_grant" error, which can disrupt payment processing and account synchronization. This issue arises when the refresh token is invalid, expired, revoked, or stale after token rotation, requiring a systematic approach to troubleshooting and resolving these errors. Key strategies include ensuring the use of the latest refresh token, verifying correct request parameters, handling account disconnections, and preventing authorization code reuse. Refresh token concurrency can lead to race conditions, particularly in environments with multiple workers, necessitating single-flight and locking mechanisms to maintain token integrity. Additionally, proactive measures like refreshing tokens before expiration, monitoring for "invalid_grant" trends, and implementing a user-friendly re-authentication process can significantly reduce integration issues. Tools like Nango offer automated solutions for managing OAuth token lifecycles, allowing developers to focus on product features while handling token refresh complexities.