In order to use Sign in with Apple, I issued a JWT client according to the instructions and was able to connect without any problems, but suddenly an INVALID_CLIENT error started to occur.
The error was resolved by re-obtaining the JWT client token and resetting it.
The validity period of the JWT client token is 6 months and it has not expired yet, but I would like to know why I am getting an INVALID_CLIENT error.
Hi @yujid,
For us to begin investigating any issue with Sign in with Apple, we need more information from you. Please see the following post:
Gathering required information for troubleshooting Sign in with Apple authorization and token requests https://developer.apple.com/forums/thread/762831
However, the server logs are periodically purged, so you would need to have reproduced the issue recently in order for us to compare logs.
Cheers,
Paris X Pinkney | WWDR | DTS Engineer
Adding this for future readers: the client secret JWT has a hard maximum lifetime of 6 months (exp − iat ≤ 15777000 seconds), and it expires without any warning — web sign-in just starts returning invalid_client. If you rely on a statically generated secret, it needs to be regenerated at least every 6 months. This can be automated in CI (I maintain an open-source GitHub Action that does this on a schedule: github.com/oskar-makarov/apple-client-secret-rotator), or generate it dynamically server-side if your framework supports it.
