In my scenario there is an AngularJs application served from UI server and there are multiple REST services consumed by AngularJs application.
How to secure both AngularJs and rest service using WSO2 identity server.
REST endpoints are consumed by other applications too.
You can secure REST services with OAuth2 where WSO2 Identity Server will be the Identity Provider (IDP). Please refer following tutorial which has full detailed description [1].
If you just want to secure the endpoint with less customizations, i would recommend you to take look on WSO2 API Manager product as well [2]. Here WSO2 API Manager will act as an API Proxy where your REST services will be the back end. API Manager will provide you publisher and store where you can publish your REST services as apps and by using Store clients can subscribe to them. Once they subscribe they will get OAuth tokens and for secure communication though API Manager. Apart from that API Manager will provide you tools to monitor and manage API life cycles as well. Please refer full documentation to get some idea about key concepts [3].
[1] http://wso2.com/library/articles/2014/02/securing-your-web-service-with-oauth2-using-wso2-identity-server-1/
[2] http://wso2.com/api-management/try-it/
[3] https://docs.wso2.com/display/AM190/Key+Concepts