try spoof

grails-app/conf/application.groovy

@@ -45,6 +45,7 @@ grails.plugin.springsecurity.filterChain.chainMap = [
 	[pattern: '/**/images/**',   access: ['permitAll']],
 	[pattern: '/**/favicon.ico', access: ['permitAll']],
  	[pattern: "/login/auth",     access: ["permitAll"]],
+ 	[pattern: "/spoof/**",       access: ["permitAll"]],
  	[pattern: "/person/**" ,     access: ['ROLE_ADMIN']], // cannot use constant here :-(
  	[pattern: "/room/**"   ,     access: ['ROLE_ADMIN']],
  	[pattern: "/**"        ,     access: ['ROLE_ADMIN', 'ROLE_GUEST']],

grails-app/controllers/rooms/SpoofController.groovy

@@ -0,0 +1,23 @@
+package rooms
+
+class SpoofController {
+
+    final SAFARI  = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.1.2 Safari/605.1.15'
+    final CHROME  = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'
+    final FIREFOX = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:120.0) Gecko/20100101 Firefox/120.0'
+
+
+    def index() {
+        String result = '<pre>';
+
+        result += '\n' + 'Headers:'
+        request.getHeaderNames()
+            .each { headerName -> result += '\n' +  "${headerName}: ${request.getHeader(headerName)}" }
+
+
+        result += '</pre>'
+        render text: result.toString()
+
+
+    }
+}