you can also just use the normal java classes, its better documented
try{
var ctx=root.getContext();
var rrq=ctx.getRuntimeRequest();
var rrs=ctx.getRuntimeResponse();
var oerrq=rrq.orElse(null)
var oerrs=rrs.orElse(null)
if(oerrs==null){
...
}else{
var hsr=oerrs.getHttpServletResponse();
var c=new javax.servlet.http.Cookie('foo','bar')
hsr.addCookie(c);
}
}catch(e){
...
}
Not the documentation, but I managed to find some examples here: https://www.programcreek.com/java-api-examples/?api=com.mendix.m2ee.api.IMxRuntimeRequest