Why your Clio token stopped working

If your Clio integration started returning 401 and you are trying to work out why, the first question is not about your code. It is which of Clio's two OAuth systems you are on, because they have different rules and most advice on the internet does not say which one it is describing. There are two, and they are not interchangeable Clio Manage is the older one. OAuth at app.clio.com/oauth , API at app.clio.com/api/v4 . Clio Platform is the newer one, covering Grow and the lead inbox among others. OAuth at auth.api.clio.com/oauth , API at api.clio.com . They differ on essentially every point that matters when a token dies. Manage Platform Access token lifetime 2,592,000s, 30 days 86,400s, 24 hours Refresh token expiry Documented as none No time expiry, but rotates Refresh token rotation Not documented, and the refresh sample returns no new refresh token Documented: rotates on every use, previous one revoked Revocation endpoint POST app.clio.com/oauth/deauthorize , Bearer auth POST auth.api.clio.com/oauth/revoke , Basic auth Treat the lifetime row as the documented default rather than a constant. Honour the expires_in you get back on each response instead of hardcoding 30 days, because there are field reports of accounts issuing much shorter access tokens, and a hardcoded assumption fails in a way that looks exactly like revocation. That rotation row is the one that decides your debugging. On Platform , every refresh gives you a new refresh token and kills the old one, so failing to persist the new value out of each response leaves you holding a dead token the next time you try. Clio's docs say it directly: store the new refresh token returned in each response. On Manage , the documented behaviour is a long-lived refresh token that does not expire and is not replaced. Their refresh response sample does not even include a refresh_token field. So on Manage, a token that suddenly stops working usually points somewhere else: revocation, or the wrong region. The region trap