How it works
OAuth access tokens expire, sometimes after an hour. Before or after expiry, the integration calls the platform's token endpoint with the refresh token. Many platforms rotate refresh tokens, issuing a new one each time and invalidating the old one. If two processes refresh at once, or a new refresh token is not saved, the connection breaks and the customer must reconnect.
Example
Two workers refresh the same QuickBooks Online connection at the same moment. One saves its new refresh token, the other overwrites it with a stale one, and the next sync fails.
In integrations
Unify Connect is designed to serialize refreshes per connection, store tokens in a separate vault and retry once on a 401 before marking a connection expired. Unify Monitor raises health alerts for expiring and expired tokens before they turn into support tickets. Broken token handling is a common cause of disconnected integrations. Each reconnect request costs customer trust, so treat refresh as critical infrastructure, not a helper function.