Bearer error="invalid_request" as responseContent.
action: OK is the field that
reports the outcome of the introspection: the access token exists and has not
expired, and the resource server should serve the protected resource.
responseContent is not a result — it is a prepared value for the
WWW-Authenticate header, for the case where the resource server decides to
reject the request anyway. Bearer error="invalid_request" is the simplest
string usable with 400 Bad Request, and it is what Authlete returns when
action is OK, because at that point the token is fine and the only thing
left to complain about is the request itself.
invalid_request alone.
Note also that responseContent is formatted for the Bearer token type
(RFC 6750). A service that uses a
different token type has to build the error response itself.
See also: