Oauth2 token verification method for server-side app

Hi there, I use an external oauth2 server to provide custom security tokens to my application. My application basically makes a request to the oauth2 server in order to grab a security key to use it for future requests (This is something apart from access_token). So only requests those have a valid "X-AUTH-TOKEN" header can move on with the access token request. So, I want my server-side app to behave like a single page application which means I want to write only one method to check if the token is valid (and I don't want to use /verify endpoint of the oauth2 server) and re-send a token request to the oauth2 server if the token is revoked. I can verify the token in my second application from the cache (by setting expiration time as token expiration time) but this is not enough. I wanna raise an event in case of any token validation error and handle it without refactoring each single controller.