diff --git a/resource/js-impl.js b/resource/js-impl.js
new file mode 100644
index 0000000..1d38740
--- /dev/null
+++ b/resource/js-impl.js
@@ -0,0 +1,20 @@
+var resourceType = MACHINE.modules['whalesong/resource/structs.rkt'].getNamespace()['struct:resource'];
+
+var makePrimitiveProcedure = plt.baselib.functions.makePrimitiveProcedure;
+
+var checkResource = plt.baselib.check.makeCheckArgumentType(
+    resourceType.predicate,
+    "resource");
+
+var getResourcePath = function(r) { return resourceType.accessor(r, 0); };
+var getResourceKey = function(r) { return resourceType.accessor(r, 1); };
+
+
+
+EXPORTS['resource->url'] = makePrimitiveProcedure(
+    'resource->url',
+    1,
+    function(MACHINE) {
+        var resource = checkResource(MACHINE, 'resource->url', 0);
+        return "res/" + String(getResourceKey(resource));
+    });