> ## Documentation Index
> Fetch the complete documentation index at: https://developers.authlete.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introspection Response for Expired Access Token

> Details on how Authlete handles requests with expired access tokens in its Introspection API and the resulting UNAUTHORIZED response.

When an resource server makes a request to Authlete's [/auth/introspection](/api-reference/introspection-endpoint/process-introspection-request)
API, and the request includes an expired access token, Authlete works as follows:

* To the first request: Authlete determines the token has been expired and then removes the token from its database.
* To the second and subsequent requests: Authlete determines the token doesn't exist. Because the token has been removed at the first request.

In either case, a value of "action" in a response from the API would be "UNAUTHORIZED".

See also:

* [JavaDoc for Class IntrospectionResponse](https://authlete.github.io/authlete-java-common/com/authlete/common/dto/IntrospectionResponse.html)