Handle token expiry, renewal and logout.
Access tokens expire. A refresh token may let the client request a replacement. Logout and revocation require separate actions.
Why this lesson?
A desktop app needs a new access token when the old one expires. It must also handle session cleanup when the user logs out.
Learning goal and prerequisites
Receive an expired-token error
The application programming interface (API) rejects an access token whose expiration time has passed. This does not always require the user to sign in again because the client may still hold a valid refresh token.
Inspect request, response, and claims
Try a failure scenario
↳ Change a condition
Read the detailed explanation
Why it exists, how it works, and where it fits
Tokens and sessions should not remain valid forever. Long-lived credentials make theft more damaging and make it harder for permission changes to take effect. A secure design gives each credential a purpose and a lifetime that matches how it will be used.
Access tokens are usually short-lived because they are presented to application programming interfaces (APIs). Refresh tokens can live longer because they are used only with the authorization server to obtain new access tokens. The client protects the refresh token more carefully and uses it when the access token expires.
When the client refreshes, the authorization server can recheck policy and issue a new access token with current limits. A user logout or administrative event may also require clearing the local session and revoking refresh capability. These controls reduce how long old authority can continue.
The important lesson is that expiration, refresh, revocation, and logout solve different parts of the lifecycle. Expiration limits time. Refresh restores approved access without another full sign-in. Revocation ends a token early. Logout ends a session. A complete design decides how those pieces interact.
Investigation
Inspect the traffic, select a diagnosis in the checkpoint, then reveal the repair.
Check your understanding
Pass the lesson quiz
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