Zendesk OAuth refresh token invalid_grant — What it means & how to fix it
Blog post from Nango
Integrating with Zendesk using OAuth 2.0 can lead to refresh token failures, often manifesting as an "invalid_grant" error, which can disrupt ticket synchronization, Help Center ingestion, and background jobs. Such failures typically arise from token lifecycle issues, such as using outdated tokens due to token rotation, concurrency problems, token expiration, or mismatches in client credentials or subdomain. To address these issues, it is essential to persist the latest refresh tokens, ensure atomic token persistence, handle refresh concurrency by allowing only one refresh request per connection, and reauthorize when a refresh token is invalid, expired, or revoked. Preventative measures include tracking refresh token expiry, storing tenant identity, and providing a user-friendly reconnection process. For those seeking to bypass these complexities, Nango offers an open-source API auth solution that automates OAuth access token refreshing and rotation, provides webhooks for revoked tokens, and includes built-in error handling for OAuth edge cases, allowing developers to focus on product features instead of token lifecycle management.