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

Integrating with Airtable using OAuth 2.0 can lead to refresh token errors, typically appearing as "invalid_grant," which can disrupt sync jobs, backfills, or user-triggered updates. These errors often occur due to issues like not using the latest refresh token, as Airtable rotates tokens, or due to race conditions when multiple processes attempt to refresh a token simultaneously. Additionally, refresh tokens expire after 60 days of inactivity or can be revoked if a refresh request is rejected. To mitigate these issues, it is essential to implement best practices such as ensuring the use of the latest refresh token, verifying the refresh request, eliminating concurrency issues with distributed locking, and treating invalid_grant errors as a signal for re-authentication rather than repeatedly retrying. Tools like Nango can help manage OAuth token lifecycles by providing secure storage, automatic refreshes, and concurrency-safe logic, reducing the complexity of handling token lifecycle edge cases in production environments.