Alfresco web service through "web scripts"

I have a folder structure in Alfreco 4.0, with folders and several article published to each folder. Need to create a simple web service through alfresco-web-script ([login to view URL]) in alfresco so i can fetch article fields. The web service will be called through REST URL in the form: http://<alfresco-host>/<folder-name>/<article-name> The webscript should then return content-data for the requested article as json.