We are using vertx oauth2 components to implement login with cognito using oauth2 authorization code grant. We could implement the scenario using existing APIs. But vertx expect token introspect path in it's oauth2 config. Otherwise there is no way to ask from cognito whether the provided token to the resource server is correct or not. Anyway we could not find any information on what is the token instrospect context path on cognito documentation.
OAuth2ClientOptions oAuth2ClientOptions = new OAuth2ClientOptions()
.setClientID("***************************")
.setIntrospectionPath("") //what should goes here
.setClientSecret("********************")
.setSite("*****************")
.setTokenPath("/oauth2/token")
.setAuthorizationPath("/oauth2/authorize")
.setFlow(OAuth2FlowType.AUTH_CODE)