diff --git a/tools/api-checker/config/gwt22_23userApi.conf b/tools/api-checker/config/gwt22_23userApi.conf
index b752dd0..3c94955 100644
--- a/tools/api-checker/config/gwt22_23userApi.conf
+++ b/tools/api-checker/config/gwt22_23userApi.conf
@@ -15,7 +15,7 @@
 :**/server/**\
 :**/tools/**\
 :com/google/gwt/regexp/shared/**\
-:com/google/gwt/autobean/shared/impl/StringQuoter.java\
+:com/google/gwt/autobean/**/impl/**\
 :com/google/gwt/autobean/shared/ValueCodexHelper.java\
 :com/google/gwt/core/client/impl/WeakMapping.java\
 :com/google/gwt/core/ext/**\
@@ -82,7 +82,7 @@
 :**/tools/**\
 :user/src/com/google/gwt/regexp/shared/**\
 :user/src/com/google/gwt/autobean/shared/ValueCodexHelper.java\
-:user/src/com/google/gwt/autobean/shared/impl/StringQuoter.java\
+:user/src/com/google/gwt/autobean/**/impl/**\
 :user/src/com/google/gwt/core/client/impl/WeakMapping.java\
 :user/src/com/google/gwt/junit/*.java\
 :user/src/com/google/gwt/junit/client/GWTTestCase.java\
diff --git a/user/src/com/google/gwt/autobean/client/impl/AbstractAutoBeanFactory.java b/user/src/com/google/gwt/autobean/client/impl/AbstractAutoBeanFactory.java
index 5aa2baf..ce068ca 100644
--- a/user/src/com/google/gwt/autobean/client/impl/AbstractAutoBeanFactory.java
+++ b/user/src/com/google/gwt/autobean/client/impl/AbstractAutoBeanFactory.java
@@ -28,31 +28,20 @@
  */
 public abstract class AbstractAutoBeanFactory implements AutoBeanFactory,
     EnumMap {
-  /**
-   * Implementations generated by subtypes. Used to implement the dynamic create
-   * methods.
-   */
-  protected interface Creator {
-    AutoBean<?> create();
 
-    AutoBean<?> create(Object delegate);
-  }
-
-  protected final Map<Class<?>, Creator> creators = new HashMap<Class<?>, Creator>();
   protected Map<Enum<?>, String> enumToStringMap;
   // This map is almost always one-to-one
   protected Map<String, List<Enum<?>>> stringsToEnumsMap;
+  private JsniCreatorMap creatorMap;
 
-  @SuppressWarnings("unchecked")
   public <T> AutoBean<T> create(Class<T> clazz) {
-    Creator c = creators.get(clazz);
-    return c == null ? null : (AutoBean<T>) c.create();
+    maybeInitializeCreatorMap();
+    return creatorMap.create(clazz, this);
   }
 
-  @SuppressWarnings("unchecked")
   public <T, U extends T> AutoBean<T> create(Class<T> clazz, U delegate) {
-    Creator c = creators.get(clazz);
-    return c == null ? null : (AutoBean<T>) c.create(delegate);
+    maybeInitializeCreatorMap();
+    return creatorMap.create(clazz, this, delegate);
   }
 
   /**
@@ -86,8 +75,17 @@
     return toReturn;
   }
 
+  protected abstract void initializeCreatorMap(JsniCreatorMap creatorMap);
+
   protected abstract void initializeEnumMap();
 
+  private void maybeInitializeCreatorMap() {
+    if (creatorMap == null) {
+      creatorMap = JsniCreatorMap.createMap();
+      initializeCreatorMap(creatorMap);
+    }
+  }
+
   private void maybeInitializeEnumMap() {
     if (enumToStringMap == null) {
       enumToStringMap = new HashMap<Enum<?>, String>();
diff --git a/user/src/com/google/gwt/autobean/client/impl/ClientPropertyContext.java b/user/src/com/google/gwt/autobean/client/impl/ClientPropertyContext.java
new file mode 100644
index 0000000..c89ae2d
--- /dev/null
+++ b/user/src/com/google/gwt/autobean/client/impl/ClientPropertyContext.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.autobean.client.impl;
+
+import com.google.gwt.autobean.shared.AutoBeanVisitor.CollectionPropertyContext;
+import com.google.gwt.autobean.shared.AutoBeanVisitor.MapPropertyContext;
+import com.google.gwt.autobean.shared.AutoBeanVisitor.ParameterizationVisitor;
+import com.google.gwt.autobean.shared.AutoBeanVisitor.PropertyContext;
+import com.google.gwt.core.client.JavaScriptObject;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Provides base methods for generated implementations of PropertyContext.
+ */
+public final class ClientPropertyContext implements PropertyContext,
+    CollectionPropertyContext, MapPropertyContext {
+
+  /**
+   * A reference to an instance setter method.
+   */
+  public static final class Setter extends JavaScriptObject {
+    /**
+     * Create a trivial Setter that calls {@link Map#put(Object, Object)}.
+     */
+    public static native Setter mapSetter(Map<String, Object> values, String key) /*-{
+      return function(value) {
+        values.@java.util.Map::put(*)(key, value);
+      };
+    }-*/;
+
+    protected Setter() {
+    }
+
+    public native void call(Object instance, Object value) /*-{
+      this.call(instance, value);
+    }-*/;
+  }
+
+  private final Object instance;
+  private final int[] paramCounts;
+  private final Class<?>[] paramTypes;
+  private final Setter setter;
+  private final Class<?> simpleType;
+
+  public ClientPropertyContext(Object instance, Setter setter, Class<?> type) {
+    this.instance = instance;
+    this.setter = setter;
+    this.simpleType = type;
+    this.paramTypes = null;
+    this.paramCounts = null;
+  }
+
+  public ClientPropertyContext(Object instance, Setter setter,
+      Class<?>[] types, int[] paramCounts) {
+    this.instance = instance;
+    this.setter = setter;
+    this.simpleType = null;
+    this.paramTypes = types;
+    this.paramCounts = paramCounts;
+
+    /*
+     * Verify input arrays of same length and that the total parameter count,
+     * plus one for the root type, equals the total number of types passed in.
+     */
+    if (ClientPropertyContext.class.desiredAssertionStatus()) {
+      assert types.length == paramCounts.length : "Length mismatch "
+          + types.length + " != " + paramCounts.length;
+      int count = 1;
+      for (int i = 0, j = paramCounts.length; i < j; i++) {
+        count += paramCounts[i];
+      }
+      assert count == types.length : "Mismatch in total parameter count "
+          + count + " != " + types.length;
+    }
+  }
+
+  public void accept(ParameterizationVisitor visitor) {
+    traverse(visitor, 0);
+  }
+
+  public boolean canSet() {
+    return setter != null;
+  }
+
+  public Class<?> getElementType() {
+    if (paramTypes == null || paramTypes.length < 2) {
+      return null;
+    }
+    if (List.class.equals(paramTypes[0]) || Set.class.equals(paramTypes[0])) {
+      return paramTypes[1];
+    }
+    return null;
+  }
+
+  public Class<?> getKeyType() {
+    if (paramTypes == null || paramTypes.length < 3) {
+      return null;
+    }
+    if (Map.class.equals(paramTypes[0])) {
+      return paramTypes[1];
+    }
+    return null;
+  }
+
+  public Class<?> getType() {
+    return simpleType == null ? paramTypes[0] : simpleType;
+  }
+
+  public Class<?> getValueType() {
+    if (paramTypes == null || paramTypes.length < 3) {
+      return null;
+    }
+    if (Map.class.equals(paramTypes[0])) {
+      return paramTypes[2];
+    }
+    return null;
+  }
+
+  public void set(Object value) {
+    setter.call(instance, value);
+  }
+
+  private int traverse(ParameterizationVisitor visitor, int count) {
+    if (simpleType != null) {
+      visitor.visitType(simpleType);
+      visitor.endVisitType(simpleType);
+      return 0;
+    }
+
+    Class<?> type = paramTypes[count];
+    int paramCount = paramCounts[count];
+    ++count;
+    if (visitor.visitType(type)) {
+      for (int i = 0; i < paramCount; i++) {
+        if (visitor.visitParameter()) {
+          count = traverse(visitor, count);
+        }
+        visitor.endVisitParameter();
+      }
+    }
+    visitor.endVisitType(type);
+    return count;
+  }
+}
diff --git a/user/src/com/google/gwt/autobean/client/impl/JsniCreatorMap.java b/user/src/com/google/gwt/autobean/client/impl/JsniCreatorMap.java
new file mode 100644
index 0000000..67f34fe
--- /dev/null
+++ b/user/src/com/google/gwt/autobean/client/impl/JsniCreatorMap.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.autobean.client.impl;
+
+import com.google.gwt.autobean.shared.AutoBean;
+import com.google.gwt.core.client.JavaScriptObject;
+import com.google.gwt.core.client.JsArray;
+
+/**
+ * Used in prod-mode code to create instances of generated AutoBean subtypes via
+ * JSNI references to their constructor methods.
+ */
+public final class JsniCreatorMap extends JavaScriptObject {
+  public static JsniCreatorMap createMap() {
+    return JavaScriptObject.createObject().cast();
+  }
+
+  /*
+   * Structure is a string map of class literal names to the no-arg and one-arg
+   * constructors of a generated AutoBean subtype.
+   */
+  protected JsniCreatorMap() {
+  }
+
+  public void add(Class<?> clazz, JsArray<JavaScriptObject> constructors) {
+    assert constructors.length() == 2 : "Expecting two constructor references";
+    set(clazz.getName(), constructors);
+  }
+
+  public <T> AutoBean<T> create(Class<T> clazz, AbstractAutoBeanFactory factory) {
+    JsArray<JavaScriptObject> arr = get(clazz.getName());
+    if (arr != null && arr.get(0) != null) {
+      return invoke(arr.get(0), factory, null);
+    }
+    return null;
+  }
+
+  public <T> AutoBean<T> create(Class<T> clazz,
+      AbstractAutoBeanFactory factory, Object delegate) {
+    JsArray<JavaScriptObject> arr = get(clazz.getName());
+    if (arr != null) {
+      assert arr.get(1) != null : "No delegate-based constructor";
+      return invoke(arr.get(1), factory, delegate);
+    }
+    return null;
+  }
+
+  private native JsArray<JavaScriptObject> get(String key) /*-{
+    return this[key];
+  }-*/;
+
+  private native <T> AutoBean<T> invoke(JavaScriptObject fn, Object arg1,
+      Object arg2)/*-{
+    return fn(arg1, arg2);
+  }-*/;
+
+  private native void set(String key, JsArray<JavaScriptObject> arr) /*-{
+    this[key] = arr;
+  }-*/;
+}
diff --git a/user/src/com/google/gwt/autobean/rebind/AutoBeanFactoryGenerator.java b/user/src/com/google/gwt/autobean/rebind/AutoBeanFactoryGenerator.java
index 3c4efdf..509cadc 100644
--- a/user/src/com/google/gwt/autobean/rebind/AutoBeanFactoryGenerator.java
+++ b/user/src/com/google/gwt/autobean/rebind/AutoBeanFactoryGenerator.java
@@ -16,6 +16,8 @@
 package com.google.gwt.autobean.rebind;
 
 import com.google.gwt.autobean.client.impl.AbstractAutoBeanFactory;
+import com.google.gwt.autobean.client.impl.ClientPropertyContext;
+import com.google.gwt.autobean.client.impl.JsniCreatorMap;
 import com.google.gwt.autobean.rebind.model.AutoBeanFactoryMethod;
 import com.google.gwt.autobean.rebind.model.AutoBeanFactoryModel;
 import com.google.gwt.autobean.rebind.model.AutoBeanMethod;
@@ -25,12 +27,10 @@
 import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.autobean.shared.AutoBeanUtils;
 import com.google.gwt.autobean.shared.AutoBeanVisitor;
-import com.google.gwt.autobean.shared.AutoBeanVisitor.CollectionPropertyContext;
-import com.google.gwt.autobean.shared.AutoBeanVisitor.MapPropertyContext;
-import com.google.gwt.autobean.shared.AutoBeanVisitor.PropertyContext;
 import com.google.gwt.autobean.shared.impl.AbstractAutoBean;
 import com.google.gwt.autobean.shared.impl.AbstractAutoBean.OneShotContext;
-import com.google.gwt.autobean.shared.impl.AbstractPropertyContext;
+import com.google.gwt.core.client.JavaScriptObject;
+import com.google.gwt.core.client.JsArray;
 import com.google.gwt.core.client.impl.WeakMapping;
 import com.google.gwt.core.ext.Generator;
 import com.google.gwt.core.ext.GeneratorContext;
@@ -44,7 +44,6 @@
 import com.google.gwt.core.ext.typeinfo.JPrimitiveType;
 import com.google.gwt.core.ext.typeinfo.JType;
 import com.google.gwt.core.ext.typeinfo.TypeOracle;
-import com.google.gwt.dev.generator.NameFactory;
 import com.google.gwt.editor.rebind.model.ModelUtils;
 import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
 import com.google.gwt.user.rebind.SourceWriter;
@@ -308,32 +307,75 @@
    * Write an instance initializer block to populate the creators map.
    */
   private void writeDynamicMethods(SourceWriter sw) {
-    sw.println("{");
+    List<JClassType> privatePeers = new ArrayList<JClassType>();
+    sw.println("@Override protected void initializeCreatorMap(%s map) {",
+        JsniCreatorMap.class.getCanonicalName());
     sw.indent();
     for (AutoBeanType type : model.getAllTypes()) {
       if (type.isNoWrap()) {
         continue;
       }
-      sw.println(
-          "creators.put(%s.class, new Creator() {",
-          ModelUtils.ensureBaseType(type.getPeerType()).getQualifiedSourceName());
-      if (type.isSimpleBean()) {
-        sw.indentln("public %1$s create() { return new %1$s(%2$s.this); }",
-            type.getQualifiedSourceName(), simpleSourceName);
+      String classLiteralAccessor;
+      JClassType peer = type.getPeerType();
+      String peerName = ModelUtils.ensureBaseType(peer).getQualifiedSourceName();
+      if (peer.isPublic()) {
+        classLiteralAccessor = peerName + ".class";
       } else {
-        sw.indentln("public %1$s create() { return null; }",
-            type.getQualifiedSourceName());
+        privatePeers.add(peer);
+        classLiteralAccessor = "classLit_" + peerName.replace('.', '_') + "()";
       }
-      // public FooAutoBean create(Object delegate) {
-      // return new FooAutoBean((Foo) delegate); }
-      sw.indentln("public %1$s create(Object delegate) {"
-          + " return new %1$s(%2$s.this, (%3$s) delegate); }",
-          type.getQualifiedSourceName(), simpleSourceName,
-          type.getPeerType().getQualifiedSourceName());
-      sw.println("});");
+      // map.add(Foo.class, getConstructors_com_foo_Bar());
+      sw.println("map.add(%s, getConstructors_%s());", classLiteralAccessor,
+          peerName.replace('.', '_'));
     }
     sw.outdent();
     sw.println("}");
+
+    /*
+     * Create a native method for each peer type that isn't public since Java
+     * class literal references are scoped.
+     */
+    for (JClassType peer : privatePeers) {
+      String peerName = ModelUtils.ensureBaseType(peer).getQualifiedSourceName();
+      sw.println(
+          "private native Class<?> classLit_%s() /*-{return @%s::class;}-*/;",
+          peerName.replace('.', '_'), peerName);
+    }
+
+    /*
+     * Create a method that returns an array containing references to the
+     * constructors.
+     */
+    String factoryJNIName = context.getTypeOracle().findType(
+        AutoBeanFactory.class.getCanonicalName()).getJNISignature();
+    for (AutoBeanType type : model.getAllTypes()) {
+      String peerName = ModelUtils.ensureBaseType(type.getPeerType()).getQualifiedSourceName();
+      String peerJNIName = ModelUtils.ensureBaseType(type.getPeerType()).getJNISignature();
+      /*-
+       * private native JsArray<JSO> getConstructors_com_foo_Bar() {
+       *   return [
+       *     BarProxyImpl::new(ABFactory),
+       *     BarProxyImpl::new(ABFactory, DelegateType)
+       *   ];
+       * }
+       */
+      sw.println("private native %s<%s> getConstructors_%s() /*-{",
+          JsArray.class.getCanonicalName(),
+          JavaScriptObject.class.getCanonicalName(), peerName.replace('.', '_'));
+      sw.indent();
+      sw.println("return [");
+      if (type.isSimpleBean()) {
+        sw.indentln("@%s::new(%s),", type.getQualifiedSourceName(),
+            factoryJNIName);
+      } else {
+        sw.indentln(",");
+      }
+      sw.indentln("@%s::new(%s%s)", type.getQualifiedSourceName(),
+          factoryJNIName, peerJNIName);
+      sw.println("];");
+      sw.outdent();
+      sw.println("}-*/;");
+    }
   }
 
   private void writeEnumSetup(SourceWriter sw) {
@@ -574,12 +616,20 @@
    * Generate traversal logic.
    */
   private void writeTraversal(SourceWriter sw, AutoBeanType type) {
-    NameFactory names = new NameFactory();
+    List<AutoBeanMethod> referencedSetters = new ArrayList<AutoBeanMethod>();
     sw.println(
         "@Override protected void traverseProperties(%s visitor, %s ctx) {",
         AutoBeanVisitor.class.getCanonicalName(),
         OneShotContext.class.getCanonicalName());
     sw.indent();
+    sw.println("%s bean;", AbstractAutoBean.class.getCanonicalName());
+    sw.println("Object value;");
+    sw.println("%s propertyContext;",
+        ClientPropertyContext.class.getCanonicalName());
+    // Local variable ref cleans up emitted js
+    sw.println("%1$s as = as();", type.getPeerType().getQualifiedSourceName());
+    sw.println("%s<String, Object> values = this.values;",
+        Map.class.getCanonicalName());
 
     for (AutoBeanMethod method : type.getMethods()) {
       if (!method.getAction().equals(JBeanMethod.GET)) {
@@ -602,26 +652,24 @@
 
       // The type of property influences the visitation
       String valueExpression = String.format(
-          "%1$s value = (%1$s) %2$s.getAutoBean(as().%3$s());",
+          "bean = (%1$s) %2$s.getAutoBean(as.%3$s());",
           AbstractAutoBean.class.getCanonicalName(),
           AutoBeanUtils.class.getCanonicalName(), method.getMethod().getName());
       String visitMethod;
-      Class<?> propertyContextType;
+      String visitVariable = "bean";
       if (method.isCollection()) {
-        propertyContextType = CollectionPropertyContext.class;
         visitMethod = "Collection";
       } else if (method.isMap()) {
-        propertyContextType = MapPropertyContext.class;
         visitMethod = "Map";
       } else if (method.isValueType()) {
-        propertyContextType = PropertyContext.class;
-        valueExpression = String.format("Object value = as().%s();",
+        valueExpression = String.format("value = as.%s();",
             method.getMethod().getName());
         visitMethod = "Value";
+        visitVariable = "value";
       } else {
         visitMethod = "Reference";
-        propertyContextType = PropertyContext.class;
       }
+      sw.println(valueExpression);
 
       // Map<List<Foo>, Bar> --> Map, List, Foo, Bar
       List<JType> typeList = new ArrayList<JType>();
@@ -634,86 +682,99 @@
        * payloads to be interpreted as different types). The leading underscore
        * allows purely numeric property names, which are valid JSON map keys.
        */
-      String propertyContextName = names.createName("_"
-          + method.getPropertyName() + "PropertyContext");
-      sw.println("class %s extends %s implements %s {", propertyContextName,
-          AbstractPropertyContext.class.getCanonicalName(),
-          propertyContextType.getCanonicalName());
+      // propertyContext = new CPContext(.....);
+      sw.println("propertyContext = new %s(",
+          ClientPropertyContext.class.getCanonicalName());
       sw.indent();
-      sw.println("%s() {", propertyContextName);
-      sw.indent();
-      sw.print("super(new Class<?>[] {");
-      boolean first = true;
-      for (JType lit : typeList) {
-        if (first) {
-          first = false;
+      // The instance on which the context is nominally operating
+      sw.println("as,");
+      // Produce a JSNI reference to a setter function to call
+      {
+        if (setter != null) {
+          // Call a method that returns a JSNI reference to the method to call
+          // setFooMethodReference(),
+          sw.println("%sMethodReference(as),", setter.getMethod().getName());
+          referencedSetters.add(setter);
         } else {
-          sw.print(", ");
-        }
-        sw.print("%s.class",
-            ModelUtils.ensureBaseType(lit).getQualifiedSourceName());
-      }
-      sw.println("}, new int[] {");
-      first = true;
-      for (JType lit : typeList) {
-        if (first) {
-          first = false;
-        } else {
-          sw.print(", ");
-        }
-        JParameterizedType hasParam = lit.isParameterized();
-        if (hasParam == null) {
-          sw.print("0");
-        } else {
-          sw.print(String.valueOf(hasParam.getTypeArgs().length));
+          // Create a function that will update the values map
+          // CPContext.mapSetter(values, "foo");
+          sw.println("%s.mapSetter(values, \"%s\"),",
+              ClientPropertyContext.Setter.class.getCanonicalName(),
+              method.getPropertyName());
         }
       }
-      sw.println("});");
-      sw.outdent();
-      sw.println("}");
-      // Base method returns true.
-      if (!type.isSimpleBean() && setter == null) {
-        sw.println("public boolean canSet() { return false; }");
-      }
-      sw.println("public void set(Object obj) { ");
-      if (setter != null) {
-        // Prefer the setter if one exists
-        // as().setFoo((Foo) obj);
-        sw.indentln(
-            "as().%s((%s) obj);",
-            setter.getMethod().getName(),
-            ModelUtils.ensureBaseType(
-                setter.getMethod().getParameters()[0].getType()).getQualifiedSourceName());
-      } else if (type.isSimpleBean()) {
-        // Otherwise, fall back to a map assignment
-        sw.indentln("values.put(\"%s\", obj);", method.getPropertyName());
+      if (typeList.size() == 1) {
+        sw.println("%s.class",
+            ModelUtils.ensureBaseType(typeList.get(0)).getQualifiedSourceName());
       } else {
-        sw.indentln("throw new UnsupportedOperationException(\"No setter\");");
+        // Produce the array of parameter types
+        sw.print("new Class<?>[] {");
+        boolean first = true;
+        for (JType lit : typeList) {
+          if (first) {
+            first = false;
+          } else {
+            sw.print(", ");
+          }
+          sw.print("%s.class",
+              ModelUtils.ensureBaseType(lit).getQualifiedSourceName());
+        }
+        sw.println("},");
+
+        // Produce the array of parameter counts
+        sw.print("new int[] {");
+        first = true;
+        for (JType lit : typeList) {
+          if (first) {
+            first = false;
+          } else {
+            sw.print(", ");
+          }
+          JParameterizedType hasParam = lit.isParameterized();
+          if (hasParam == null) {
+            sw.print("0");
+          } else {
+            sw.print(String.valueOf(hasParam.getTypeArgs().length));
+          }
+        }
+        sw.println("}");
       }
-      sw.println("}");
       sw.outdent();
-      sw.println("}");
+      sw.println(");");
 
-      sw.print("{");
-      sw.indent();
-      sw.println("%1$s %1$s = new %1$s();", propertyContextName);
-
-      // Call the visit methods
-      sw.println(valueExpression);
       // if (visitor.visitReferenceProperty("foo", value, ctx))
-      sw.println("if (visitor.visit%sProperty(\"%s\", value, %s))",
-          visitMethod, method.getPropertyName(), propertyContextName);
+      sw.println("if (visitor.visit%sProperty(\"%s\", %s, propertyContext)) {",
+          visitMethod, method.getPropertyName(), visitVariable);
       if (!method.isValueType()) {
         // Cycle-detection in AbstractAutoBean.traverse
-        sw.indentln("if (value != null) { value.traverse(visitor, ctx); }");
+        sw.indentln("if (bean != null) { bean.traverse(visitor, ctx); }");
       }
-      // visitor.endVisitorReferenceProperty("foo", value, ctx);
-      sw.println("visitor.endVisit%sProperty(\"%s\", value, %s);", visitMethod,
-          method.getPropertyName(), propertyContextName);
-      sw.outdent();
       sw.println("}");
+      // visitor.endVisitorReferenceProperty("foo", value, ctx);
+      sw.println("visitor.endVisit%sProperty(\"%s\", %s, propertyContext);",
+          visitMethod, method.getPropertyName(), visitVariable);
     }
     sw.outdent();
     sw.println("}");
+
+    for (AutoBeanMethod method : referencedSetters) {
+      JMethod jmethod = method.getMethod();
+      assert jmethod.getParameters().length == 1;
+
+      /*-
+       * Setter setFooMethodReference(Object instance) {
+       *   return instance.@com.example.Blah::setFoo(Lcom/example/Foo;);
+       * }
+       */
+      sw.println(
+          "public static native %s %sMethodReference(Object instance) /*-{",
+          ClientPropertyContext.Setter.class.getCanonicalName(),
+          jmethod.getName());
+      sw.indentln("return instance.@%s::%s(%s);",
+          jmethod.getEnclosingType().getQualifiedSourceName(),
+          jmethod.getName(),
+          jmethod.getParameters()[0].getType().getJNISignature());
+      sw.println("}-*/;");
+    }
   }
 }
diff --git a/user/src/com/google/gwt/autobean/rebind/model/AutoBeanFactoryModel.java b/user/src/com/google/gwt/autobean/rebind/model/AutoBeanFactoryModel.java
index b073335..1ec0452 100644
--- a/user/src/com/google/gwt/autobean/rebind/model/AutoBeanFactoryModel.java
+++ b/user/src/com/google/gwt/autobean/rebind/model/AutoBeanFactoryModel.java
@@ -19,10 +19,12 @@
 import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.autobean.shared.AutoBeanFactory.Category;
 import com.google.gwt.autobean.shared.AutoBeanFactory.NoWrap;
+import com.google.gwt.autobean.shared.impl.EnumMap.ExtraEnums;
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.typeinfo.JClassType;
 import com.google.gwt.core.ext.typeinfo.JEnumConstant;
+import com.google.gwt.core.ext.typeinfo.JEnumType;
 import com.google.gwt.core.ext.typeinfo.JGenericType;
 import com.google.gwt.core.ext.typeinfo.JMethod;
 import com.google.gwt.core.ext.typeinfo.JParameter;
@@ -35,7 +37,6 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -57,7 +58,7 @@
   private final List<AutoBeanFactoryMethod> methods = new ArrayList<AutoBeanFactoryMethod>();
   private final List<JMethod> objectMethods;
   private final TypeOracle oracle;
-  private final Map<JClassType, AutoBeanType> peers = new HashMap<JClassType, AutoBeanType>();
+  private final Map<JClassType, AutoBeanType> peers = new LinkedHashMap<JClassType, AutoBeanType>();
   private boolean poisoned;
 
   /**
@@ -100,6 +101,17 @@
       if (noWrapAnnotation != null) {
         processClassArrayAnnotation(noWrapAnnotation.value(), noWrapTypes);
       }
+
+      ExtraEnums extraEnumsAnnotation = factoryType.getAnnotation(ExtraEnums.class);
+      if (extraEnumsAnnotation != null) {
+        for (Class<?> clazz : extraEnumsAnnotation.value()) {
+          JEnumType asEnum = oracle.findType(clazz.getCanonicalName()).isEnum();
+          assert asEnum != null;
+          for (JEnumConstant value : asEnum.getEnumConstants()) {
+            allEnumConstants.put(value, AutoBeanMethod.getEnumName(value));
+          }
+        }
+      }
     }
 
     for (JMethod method : factoryType.getOverridableMethods()) {
diff --git a/user/src/com/google/gwt/autobean/rebind/model/AutoBeanMethod.java b/user/src/com/google/gwt/autobean/rebind/model/AutoBeanMethod.java
index d75e819..e936479 100644
--- a/user/src/com/google/gwt/autobean/rebind/model/AutoBeanMethod.java
+++ b/user/src/com/google/gwt/autobean/rebind/model/AutoBeanMethod.java
@@ -121,18 +121,23 @@
         map = toReturn.enumMap = new LinkedHashMap<JEnumConstant, String>();
       }
       for (JEnumConstant e : enumType.getEnumConstants()) {
-        String name;
-        PropertyName annotation = e.getAnnotation(PropertyName.class);
-        if (annotation == null) {
-          name = e.getName();
-        } else {
-          name = annotation.value();
-        }
+        String name = getEnumName(e);
         map.put(e, name);
       }
     }
   }
 
+  static String getEnumName(JEnumConstant e) {
+    String name;
+    PropertyName annotation = e.getAnnotation(PropertyName.class);
+    if (annotation == null) {
+      name = e.getName();
+    } else {
+      name = annotation.value();
+    }
+    return name;
+  }
+
   private JBeanMethod action;
   private JClassType elementType;
   private Map<JEnumConstant, String> enumMap;
diff --git a/user/src/com/google/gwt/autobean/shared/impl/AbstractPropertyContext.java b/user/src/com/google/gwt/autobean/shared/impl/AbstractPropertyContext.java
deleted file mode 100644
index b04b0e9..0000000
--- a/user/src/com/google/gwt/autobean/shared/impl/AbstractPropertyContext.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- * 
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy of
- * the License at
- * 
- * http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
-package com.google.gwt.autobean.shared.impl;
-
-import com.google.gwt.autobean.shared.AutoBeanVisitor.ParameterizationVisitor;
-import com.google.gwt.autobean.shared.AutoBeanVisitor.PropertyContext;
-
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-/**
- * Provides base methods for generated implementations of PropertyContext.
- */
-public abstract class AbstractPropertyContext implements PropertyContext {
-
-  private final Class<?>[] types;
-  private final int[] paramCounts;
-
-  protected AbstractPropertyContext(Class<?>[] types, int[] paramCounts) {
-    this.types = types;
-    this.paramCounts = paramCounts;
-  }
-
-  public void accept(ParameterizationVisitor visitor) {
-    traverse(visitor, 0);
-  }
-
-  public boolean canSet() {
-    return true;
-  }
-
-  /**
-   * @see com.google.gwt.autobean.shared.AutoBeanVisitor.CollectionPropertyContext#getElementType()
-   */
-  public Class<?> getElementType() {
-    assert types.length >= 2;
-    assert List.class.equals(types[0]) || Set.class.equals(types[0]);
-    return types[1];
-  }
-
-  /**
-   * @see com.google.gwt.autobean.shared.AutoBeanVisitor.MapPropertyContext#getKeyType()
-   */
-  public Class<?> getKeyType() {
-    assert types.length >= 2;
-    assert Map.class.equals(types[0]);
-    return types[1];
-  }
-
-  public Class<?> getType() {
-    return types[0];
-  }
-
-  /**
-   * @see com.google.gwt.autobean.shared.AutoBeanVisitor.MapPropertyContext#getValueType()
-   */
-  public Class<?> getValueType() {
-    assert types.length >= 2;
-    assert Map.class.equals(types[0]);
-    return types[2];
-  }
-
-  private int traverse(ParameterizationVisitor visitor, int count) {
-    Class<?> type = types[count];
-    int paramCount = paramCounts[count];
-    ++count;
-    if (visitor.visitType(type)) {
-      for (int i = 0; i < paramCount; i++) {
-        if (visitor.visitParameter()) {
-          count = traverse(visitor, count);
-        }
-        visitor.endVisitParameter();
-      }
-    }
-    visitor.endVisitType(type);
-    return count;
-  }
-}
diff --git a/user/src/com/google/gwt/autobean/shared/impl/EnumMap.java b/user/src/com/google/gwt/autobean/shared/impl/EnumMap.java
index d55d45f..3b53d1b 100644
--- a/user/src/com/google/gwt/autobean/shared/impl/EnumMap.java
+++ b/user/src/com/google/gwt/autobean/shared/impl/EnumMap.java
@@ -20,6 +20,13 @@
  * convert enum values to strings.
  */
 public interface EnumMap {
+  /**
+   * Extra enums that should be included in the AutoBeanFactory.
+   */
+  public @interface ExtraEnums {
+    Class<? extends Enum<?>>[] value();
+  }
+
   <E extends Enum<E>> E getEnum(Class<E> clazz, String token);
 
   String getToken(Enum<?> e);
diff --git a/user/src/com/google/gwt/requestfactory/rebind/RequestFactoryGenerator.java b/user/src/com/google/gwt/requestfactory/rebind/RequestFactoryGenerator.java
index d8ff630..5c1d109 100644
--- a/user/src/com/google/gwt/requestfactory/rebind/RequestFactoryGenerator.java
+++ b/user/src/com/google/gwt/requestfactory/rebind/RequestFactoryGenerator.java
@@ -21,21 +21,27 @@
 import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.autobean.shared.AutoBeanFactory.Category;
 import com.google.gwt.autobean.shared.AutoBeanFactory.NoWrap;
+import com.google.gwt.autobean.shared.impl.EnumMap.ExtraEnums;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.core.ext.Generator;
 import com.google.gwt.core.ext.GeneratorContext;
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.typeinfo.JClassType;
+import com.google.gwt.core.ext.typeinfo.JEnumType;
 import com.google.gwt.core.ext.typeinfo.JMethod;
 import com.google.gwt.core.ext.typeinfo.JParameter;
+import com.google.gwt.core.ext.typeinfo.JParameterizedType;
+import com.google.gwt.core.ext.typeinfo.JType;
 import com.google.gwt.core.ext.typeinfo.JTypeParameter;
 import com.google.gwt.core.ext.typeinfo.TypeOracle;
 import com.google.gwt.editor.rebind.model.ModelUtils;
 import com.google.gwt.requestfactory.client.impl.AbstractClientRequestFactory;
+import com.google.gwt.requestfactory.rebind.model.AcceptsModelVisitor;
 import com.google.gwt.requestfactory.rebind.model.ContextMethod;
 import com.google.gwt.requestfactory.rebind.model.EntityProxyModel;
 import com.google.gwt.requestfactory.rebind.model.EntityProxyModel.Type;
+import com.google.gwt.requestfactory.rebind.model.ModelVisitor;
 import com.google.gwt.requestfactory.rebind.model.RequestFactoryModel;
 import com.google.gwt.requestfactory.rebind.model.RequestMethod;
 import com.google.gwt.requestfactory.shared.EntityProxyId;
@@ -52,8 +58,12 @@
 import com.google.gwt.user.rebind.SourceWriter;
 
 import java.io.PrintWriter;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 /**
  * Generates implementations of
@@ -62,6 +72,72 @@
  */
 public class RequestFactoryGenerator extends Generator {
 
+  /**
+   * Visits all types reachable from a RequestContext.
+   */
+  private static class AllReachableTypesVisitor extends
+      RequestMethodTypesVisitor {
+    private final RequestFactoryModel model;
+
+    public AllReachableTypesVisitor(RequestFactoryModel model) {
+      this.model = model;
+    }
+
+    void examineTypeOnce(JClassType type) {
+      // Need this to handle List<Foo>, Map<Foo>
+      JParameterizedType parameterized = type.isParameterized();
+      if (parameterized != null) {
+        for (JClassType arg : parameterized.getTypeArgs()) {
+          maybeVisit(arg);
+        }
+      }
+      JClassType base = ModelUtils.ensureBaseType(type);
+      EntityProxyModel peer = model.getPeer(base);
+      if (peer == null) {
+        return;
+      }
+      peer.accept(this);
+    }
+  }
+
+  /**
+   * Visits all types immediately referenced by methods defined in a
+   * RequestContext.
+   */
+  private abstract static class RequestMethodTypesVisitor extends ModelVisitor {
+    private final Set<JClassType> seen = new HashSet<JClassType>();
+
+    @Override
+    public void endVisit(RequestMethod x) {
+      // Request<Foo> -> Foo
+      maybeVisit(x.getDataType());
+      // InstanceRequest<Proxy, Foo> -> Proxy
+      if (x.getInstanceType() != null) {
+        x.getInstanceType().accept(this);
+      }
+      // Request<Void> doSomething(Foo foo, Bar bar) -> Foo, Bar
+      for (JType param : x.getDeclarationMethod().getParameterTypes()) {
+        maybeVisit(param.isClassOrInterface());
+      }
+      // setFoo(Foo foo) -> Foo
+      for (JMethod method : x.getExtraSetters()) {
+        maybeVisit(method.getParameterTypes()[0].isClassOrInterface());
+      }
+    }
+
+    abstract void examineTypeOnce(JClassType type);
+
+    void maybeVisit(JClassType type) {
+      if (type == null) {
+        return;
+      } else if (!seen.add(type)) {
+        // Short-circuit to prevent type-loops
+        return;
+      }
+      examineTypeOnce(type);
+    }
+  }
+
   private GeneratorContext context;
   private TreeLogger logger;
   private RequestFactoryModel model;
@@ -93,7 +169,7 @@
     factory.setSuperclass(AbstractClientRequestFactory.class.getCanonicalName());
     factory.addImplementedInterface(typeName);
     SourceWriter sw = factory.createSourceWriter(context, pw);
-    writeAutoBeanFactory(sw);
+    writeAutoBeanFactory(sw, model.getAllProxyModels(), findExtraEnums(model));
     writeContextMethods(sw);
     writeContextImplementations();
     writeTypeMap(sw);
@@ -102,7 +178,79 @@
     return factory.getCreatedClassName();
   }
 
-  private void writeAutoBeanFactory(SourceWriter sw) {
+  /**
+   * Find enums that needed to be added to the EnumMap that are not referenced
+   * by any of the proxies. This is necessary because the RequestFactory depends
+   * on the AutoBeanCodex to serialize enum values, which in turn depends on the
+   * AutoBeanFactory's enum map. That enum map only contains enum types
+   * reachable from the AutoBean interfaces, which could lead to method
+   * parameters being un-encodable.
+   */
+  private Set<JEnumType> findExtraEnums(AcceptsModelVisitor method) {
+    final Set<JEnumType> toReturn = new LinkedHashSet<JEnumType>();
+    final Set<JEnumType> referenced = new HashSet<JEnumType>();
+
+    // Called from the adder visitor below on each EntityProxy seen
+    final ModelVisitor remover = new AllReachableTypesVisitor(model) {
+      @Override
+      void examineTypeOnce(JClassType type) {
+        JEnumType asEnum = type.isEnum();
+        if (asEnum != null) {
+          referenced.add(asEnum);
+        }
+        super.examineTypeOnce(type);
+      }
+    };
+
+    // Add enums used by RequestMethods
+    method.accept(new RequestMethodTypesVisitor() {
+      @Override
+      public boolean visit(EntityProxyModel x) {
+        x.accept(remover);
+        return false;
+      }
+
+      @Override
+      void examineTypeOnce(JClassType type) {
+        JEnumType asEnum = type.isEnum();
+        if (asEnum != null) {
+          toReturn.add(asEnum);
+        }
+      }
+    });
+    toReturn.removeAll(referenced);
+    if (toReturn.isEmpty()) {
+      return Collections.emptySet();
+    }
+    return Collections.unmodifiableSet(toReturn);
+  }
+
+  /**
+   * Find all EntityProxyModels reachable from a given ContextMethod.
+   */
+  private Set<EntityProxyModel> findReferencedEntities(ContextMethod method) {
+    final Set<EntityProxyModel> models = new LinkedHashSet<EntityProxyModel>();
+    method.accept(new AllReachableTypesVisitor(model) {
+      @Override
+      public void endVisit(EntityProxyModel x) {
+        models.add(x);
+      }
+    });
+    return models;
+  }
+
+  private void writeAutoBeanFactory(SourceWriter sw,
+      Collection<EntityProxyModel> models, Collection<JEnumType> extraEnums) {
+    if (!extraEnums.isEmpty()) {
+      StringBuilder extraClasses = new StringBuilder();
+      for (JEnumType enumType : extraEnums) {
+        if (extraClasses.length() > 0) {
+          extraClasses.append(",");
+        }
+        extraClasses.append(enumType.getQualifiedSourceName()).append(".class");
+      }
+      sw.println("@%s({%s})", ExtraEnums.class.getCanonicalName(), extraClasses);
+    }
     // Map in static implementations of EntityProxy methods
     sw.println("@%s({%s.class, %s.class, %s.class})",
         Category.class.getCanonicalName(),
@@ -116,7 +264,7 @@
         AutoBeanFactory.class.getCanonicalName());
     sw.indent();
 
-    for (EntityProxyModel proxy : model.getAllProxyModels()) {
+    for (EntityProxyModel proxy : models) {
       // AutoBean<FooProxy> com_google_FooProxy();
       sw.println("%s<%s> %s();", AutoBean.class.getCanonicalName(),
           proxy.getQualifiedSourceName(),
@@ -126,11 +274,18 @@
     sw.println("}");
 
     // public static final Factory FACTORY = GWT.create(Factory.class);
-    sw.println("public static final Factory FACTORY=%s.create(Factory.class);",
-        GWT.class.getCanonicalName());
+    sw.println("public static Factory FACTORY;", GWT.class.getCanonicalName());
 
     // Write public accessor
-    sw.println("@Override public Factory getAutoBeanFactory() { return FACTORY; }");
+    sw.println("@Override public Factory getAutoBeanFactory() {");
+    sw.indent();
+    sw.println("if (FACTORY == null) {");
+    sw.indentln("FACTORY = %s.create(Factory.class);",
+        GWT.class.getCanonicalName());
+    sw.println("}");
+    sw.println("return FACTORY;");
+    sw.outdent();
+    sw.println("}");
   }
 
   private void writeContextImplementations() {
@@ -155,6 +310,10 @@
           AbstractRequestFactory.class.getCanonicalName(),
           Dialect.class.getCanonicalName(), method.getDialect().name());
 
+      Set<EntityProxyModel> models = findReferencedEntities(method);
+      Set<JEnumType> extraEnumTypes = findExtraEnums(method);
+      writeAutoBeanFactory(sw, models, extraEnumTypes);
+
       // Write each Request method
       for (RequestMethod request : method.getRequestMethods()) {
         JMethod jmethod = request.getDeclarationMethod();
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/AcceptsModelVisitor.java b/user/src/com/google/gwt/requestfactory/rebind/model/AcceptsModelVisitor.java
new file mode 100644
index 0000000..e3fb75c
--- /dev/null
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/AcceptsModelVisitor.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.requestfactory.rebind.model;
+
+/**
+ * A common interface for model types.
+ */
+public interface AcceptsModelVisitor {
+  void accept(ModelVisitor visitor);
+}
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/ContextMethod.java b/user/src/com/google/gwt/requestfactory/rebind/model/ContextMethod.java
index ae6ce92..367f5b7 100644
--- a/user/src/com/google/gwt/requestfactory/rebind/model/ContextMethod.java
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/ContextMethod.java
@@ -26,7 +26,7 @@
 /**
  * Represents a service endpoint.
  */
-public class ContextMethod {
+public class ContextMethod implements AcceptsModelVisitor {
 
   /**
    * Builds a {@link ContextMethod}.
@@ -68,6 +68,15 @@
   private ContextMethod() {
   }
 
+  public void accept(ModelVisitor visitor) {
+    if (visitor.visit(this)) {
+      for (RequestMethod method : getRequestMethods()) {
+        method.accept(visitor);
+      }
+    }
+    visitor.endVisit(this);
+  }
+
   public Dialect getDialect() {
     return dialect;
   }
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/EntityProxyModel.java b/user/src/com/google/gwt/requestfactory/rebind/model/EntityProxyModel.java
index da85d8c..ffcae99 100644
--- a/user/src/com/google/gwt/requestfactory/rebind/model/EntityProxyModel.java
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/EntityProxyModel.java
@@ -21,7 +21,7 @@
 /**
  * Represents an EntityProxy subtype.
  */
-public class EntityProxyModel {
+public class EntityProxyModel implements AcceptsModelVisitor {
   /**
    * Builds {@link EntityProxyModel}.
    */
@@ -83,6 +83,15 @@
   private EntityProxyModel() {
   }
 
+  public void accept(ModelVisitor visitor) {
+    if (visitor.visit(this)) {
+      for (RequestMethod method : requestMethods) {
+        method.accept(visitor);
+      }
+    }
+    visitor.endVisit(this);
+  }
+
   public Class<?> getProxyFor() {
     return proxyFor;
   }
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/ModelVisitor.java b/user/src/com/google/gwt/requestfactory/rebind/model/ModelVisitor.java
new file mode 100644
index 0000000..a380da8
--- /dev/null
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/ModelVisitor.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.requestfactory.rebind.model;
+
+/**
+ * Implements traversal across a RequestFactory model.
+ */
+public class ModelVisitor {
+  public void endVisit(ContextMethod x) {
+  }
+
+  public void endVisit(EntityProxyModel x) {
+  }
+
+  public void endVisit(RequestFactoryModel x) {
+  }
+
+  public void endVisit(RequestMethod x) {
+  }
+
+  public boolean visit(ContextMethod x) {
+    return true;
+  }
+
+  public boolean visit(EntityProxyModel x) {
+    return true;
+  }
+
+  public boolean visit(RequestFactoryModel x) {
+    return true;
+  }
+
+  public boolean visit(RequestMethod x) {
+    return true;
+  }
+}
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/RequestFactoryModel.java b/user/src/com/google/gwt/requestfactory/rebind/model/RequestFactoryModel.java
index d634624..142fdfa 100644
--- a/user/src/com/google/gwt/requestfactory/rebind/model/RequestFactoryModel.java
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/RequestFactoryModel.java
@@ -53,7 +53,7 @@
 /**
  * Represents a RequestFactory interface declaration.
  */
-public class RequestFactoryModel {
+public class RequestFactoryModel implements AcceptsModelVisitor {
   static String badContextReturnType(JMethod method,
       JClassType requestInterface, JClassType instanceRequestInterface) {
     return String.format(
@@ -146,6 +146,18 @@
     }
   }
 
+  public void accept(ModelVisitor visitor) {
+    if (visitor.visit(this)) {
+      for (EntityProxyModel model : getAllProxyModels()) {
+        model.accept(visitor);
+      }
+      for (ContextMethod method : getMethods()) {
+        method.accept(visitor);
+      }
+    }
+    visitor.endVisit(this);
+  }
+
   public Collection<EntityProxyModel> getAllProxyModels() {
     return Collections.unmodifiableCollection(peers.values());
   }
diff --git a/user/src/com/google/gwt/requestfactory/rebind/model/RequestMethod.java b/user/src/com/google/gwt/requestfactory/rebind/model/RequestMethod.java
index 0761bcf..867764c 100644
--- a/user/src/com/google/gwt/requestfactory/rebind/model/RequestMethod.java
+++ b/user/src/com/google/gwt/requestfactory/rebind/model/RequestMethod.java
@@ -28,7 +28,7 @@
  * be a method declared in a RequestContext or a getter or setter on an
  * EntityProxy.
  */
-public class RequestMethod {
+public class RequestMethod implements AcceptsModelVisitor {
 
   /**
    * Builds a {@link ContextMethod}.
@@ -127,6 +127,13 @@
   private RequestMethod() {
   }
 
+  public void accept(ModelVisitor visitor) {
+    if (visitor.visit(this)) {
+      // Empty
+    }
+    visitor.endVisit(this);
+  }
+
   public String getApiVersion() {
     return apiVersion;
   }
diff --git a/user/src/com/google/gwt/requestfactory/server/testing/InProcessRequestContext.java b/user/src/com/google/gwt/requestfactory/server/testing/InProcessRequestContext.java
index 7b0ad26..2f74d22 100644
--- a/user/src/com/google/gwt/requestfactory/server/testing/InProcessRequestContext.java
+++ b/user/src/com/google/gwt/requestfactory/server/testing/InProcessRequestContext.java
@@ -18,6 +18,7 @@
 import com.google.gwt.autobean.server.impl.BeanMethod;
 import com.google.gwt.autobean.server.impl.TypeUtils;
 import com.google.gwt.autobean.shared.AutoBean.PropertyName;
+import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.requestfactory.shared.InstanceRequest;
 import com.google.gwt.requestfactory.shared.JsonRpcContent;
 import com.google.gwt.requestfactory.shared.JsonRpcWireName;
@@ -183,4 +184,9 @@
     super(factory, dialect);
     this.dialect = dialect;
   }
+
+  @Override
+  protected AutoBeanFactory getAutoBeanFactory() {
+    return ((InProcessRequestFactory) getRequestFactory()).getAutoBeanFactory();
+  }
 }
diff --git a/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestContext.java b/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestContext.java
index 505de0a..501a9d6 100644
--- a/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestContext.java
+++ b/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestContext.java
@@ -17,9 +17,11 @@
 
 import static com.google.gwt.requestfactory.shared.impl.BaseProxyCategory.stableId;
 import static com.google.gwt.requestfactory.shared.impl.Constants.REQUEST_CONTEXT;
+import static com.google.gwt.requestfactory.shared.impl.Constants.STABLE_ID;
 
 import com.google.gwt.autobean.shared.AutoBean;
 import com.google.gwt.autobean.shared.AutoBeanCodex;
+import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.autobean.shared.AutoBeanUtils;
 import com.google.gwt.autobean.shared.AutoBeanVisitor;
 import com.google.gwt.autobean.shared.Splittable;
@@ -65,7 +67,7 @@
 /**
  * Base implementations for RequestContext services.
  */
-public class AbstractRequestContext implements RequestContext,
+public abstract class AbstractRequestContext implements RequestContext,
     EntityCodex.EntitySource {
   /**
    * Allows the payload dialect to be injected into the AbstractRequestContext
@@ -162,7 +164,7 @@
       Class<BaseProxy> target = (Class<BaseProxy>) invocations.get(0).getRequestData().getReturnType();
 
       SimpleProxyId<BaseProxy> id = getRequestFactory().allocateId(target);
-      AutoBean<BaseProxy> bean = getRequestFactory().createProxy(target, id);
+      AutoBean<BaseProxy> bean = createProxy(target, id);
       AutoBeanCodex.decodeInto(result, bean);
 
       if (callback != null) {
@@ -300,6 +302,7 @@
       }
     }
   }
+
   private class MyViolation implements Violation {
 
     private final BaseProxy currentProxy;
@@ -356,18 +359,16 @@
       WriteOperation.PERSIST, WriteOperation.UPDATE};
   private static final WriteOperation[] UPDATE_ONLY = {WriteOperation.UPDATE};
   private static int payloadId = 100;
-
   protected final List<AbstractRequest<?>> invocations = new ArrayList<AbstractRequest<?>>();
   private boolean locked;
-  private final AbstractRequestFactory requestFactory;
 
+  private final AbstractRequestFactory requestFactory;
   /**
    * A map of all EntityProxies that the RequestContext has interacted with.
    * Objects are placed into this map by being passed into {@link #edit} or as
    * an invocation argument.
    */
   private final Map<SimpleProxyId<?>, AutoBean<? extends BaseProxy>> editedProxies = new LinkedHashMap<SimpleProxyId<?>, AutoBean<? extends BaseProxy>>();
-
   /**
    * A map that contains the canonical instance of an entity to return in the
    * return graph, since this is built from scratch.
@@ -397,10 +398,24 @@
     checkLocked();
 
     SimpleProxyId<T> id = requestFactory.allocateId(clazz);
-    AutoBean<T> created = requestFactory.createProxy(clazz, id);
+    AutoBean<T> created = createProxy(clazz, id);
     return takeOwnership(created);
   }
 
+  /**
+   * Creates a new proxy with an assigned ID.
+   */
+  public <T extends BaseProxy> AutoBean<T> createProxy(Class<T> clazz,
+      SimpleProxyId<T> id) {
+    AutoBean<T> created = getAutoBeanFactory().create(clazz);
+    if (created == null) {
+      throw new IllegalArgumentException("Unknown proxy type "
+          + clazz.getName());
+    }
+    created.setTag(STABLE_ID, id);
+    return created;
+  }
+
   public <T extends BaseProxy> T edit(T object) {
     return editProxy(object);
   }
@@ -535,14 +550,14 @@
    */
   public boolean isValueType(Class<?> clazz) {
     return requestFactory.isValueType(clazz);
-  };
+  }
 
   /**
    * Called by generated subclasses to enqueue a method invocation.
    */
   protected void addInvocation(AbstractRequest<?> request) {
     dialect.addInvocation(request);
-  }
+  };
 
   /**
    * Invoke the appropriate {@code onFailure} callbacks, possibly throwing an
@@ -579,6 +594,12 @@
   }
 
   /**
+   * Returns an AutoBeanFactory that can produce the types reachable only from
+   * this RequestContext.
+   */
+  protected abstract AutoBeanFactory getAutoBeanFactory();
+
+  /**
    * Invoke the appropriate {@code onViolation} callbacks, possibly throwing an
    * {@link UmbrellaException} if one or more callbacks fails.
    */
@@ -633,7 +654,7 @@
     AutoBean<Q> bean = (AutoBean<Q>) returnedProxies.get(id);
     if (bean == null) {
       Class<Q> proxyClass = id.getProxyClass();
-      bean = requestFactory.createProxy(proxyClass, id);
+      bean = createProxy(proxyClass, id);
       returnedProxies.put(id, bean);
     }
 
@@ -656,7 +677,7 @@
     AutoBean<?> parent;
     if (stableId.isEphemeral()) {
       // Newly-created object, use a blank object to compare against
-      parent = requestFactory.createProxy(stableId.getProxyClass(), stableId);
+      parent = createProxy(stableId.getProxyClass(), stableId);
 
       // Newly-created objects go into the persist operation bucket
       operation.setOperation(WriteOperation.PERSIST);
@@ -665,7 +686,7 @@
       operation.setStrength(Strength.EPHEMERAL);
     } else if (stableId.isSynthetic()) {
       // Newly-created object, use a blank object to compare against
-      parent = requestFactory.createProxy(stableId.getProxyClass(), stableId);
+      parent = createProxy(stableId.getProxyClass(), stableId);
 
       // Newly-created objects go into the persist operation bucket
       operation.setOperation(WriteOperation.PERSIST);
@@ -1040,9 +1061,9 @@
       for (Object o : (Iterable<?>) arg) {
         retainArg(o);
       }
-    } else if (arg instanceof EntityProxy) {
+    } else if (arg instanceof BaseProxy) {
       // Calling edit will validate and set up the tracking we need
-      edit((EntityProxy) arg);
+      edit((BaseProxy) arg);
     }
   }
 
diff --git a/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestFactory.java b/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestFactory.java
index 25c202b..3c26cf4 100644
--- a/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestFactory.java
+++ b/user/src/com/google/gwt/requestfactory/shared/impl/AbstractRequestFactory.java
@@ -15,12 +15,8 @@
  */
 package com.google.gwt.requestfactory.shared.impl;
 
-import static com.google.gwt.requestfactory.shared.impl.Constants.STABLE_ID;
-
-import com.google.gwt.autobean.shared.AutoBean;
 import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.event.shared.EventBus;
-import com.google.gwt.requestfactory.shared.BaseProxy;
 import com.google.gwt.requestfactory.shared.EntityProxy;
 import com.google.gwt.requestfactory.shared.EntityProxyId;
 import com.google.gwt.requestfactory.shared.ProxySerializer;
@@ -52,27 +48,18 @@
   };
   private RequestTransport transport;
 
-  /**
-   * Creates a new proxy with an assigned ID.
-   */
-  public <T extends BaseProxy> AutoBean<T> createProxy(Class<T> clazz,
-      SimpleProxyId<T> id) {
-    AutoBean<T> created = getAutoBeanFactory().create(clazz);
-    if (created == null) {
-      throw new IllegalArgumentException("Unknown EntityProxy type "
-          + clazz.getName());
-    }
-    created.setTag(STABLE_ID, id);
-    return created;
-  }
-
   public <P extends EntityProxy> Request<P> find(final EntityProxyId<P> proxyId) {
     if (((SimpleEntityProxyId<P>) proxyId).isEphemeral()) {
       throw new IllegalArgumentException("Cannot fetch unpersisted entity");
     }
 
     AbstractRequestContext context = new AbstractRequestContext(
-        AbstractRequestFactory.this, AbstractRequestContext.Dialect.STANDARD);
+        AbstractRequestFactory.this, AbstractRequestContext.Dialect.STANDARD) {
+      @Override
+      protected AutoBeanFactory getAutoBeanFactory() {
+        return AbstractRequestFactory.this.getAutoBeanFactory();
+      }
+    };
     return new AbstractRequest<P>(context) {
       {
         requestContext.addInvocation(this);
@@ -132,7 +119,11 @@
 
   /**
    * Implementations of EntityProxies are provided by an AutoBeanFactory, which
-   * is itself a generated type.
+   * is itself a generated type. This method knows about all proxy types used in
+   * the RequestFactory interface, which prevents pruning of any proxy type. If
+   * the {@link #find(EntityProxyId)} and {@link #getSerializer(ProxyStore)}
+   * were provided by {@link AbstractRequestContext}, this method could be
+   * removed.
    */
   protected abstract AutoBeanFactory getAutoBeanFactory();
 
diff --git a/user/src/com/google/gwt/requestfactory/shared/impl/ProxySerializerImpl.java b/user/src/com/google/gwt/requestfactory/shared/impl/ProxySerializerImpl.java
index 7e175c2..1e53bbb 100644
--- a/user/src/com/google/gwt/requestfactory/shared/impl/ProxySerializerImpl.java
+++ b/user/src/com/google/gwt/requestfactory/shared/impl/ProxySerializerImpl.java
@@ -17,6 +17,7 @@
 
 import com.google.gwt.autobean.shared.AutoBean;
 import com.google.gwt.autobean.shared.AutoBeanCodex;
+import com.google.gwt.autobean.shared.AutoBeanFactory;
 import com.google.gwt.autobean.shared.AutoBeanUtils;
 import com.google.gwt.autobean.shared.AutoBeanVisitor;
 import com.google.gwt.autobean.shared.Splittable;
@@ -141,6 +142,11 @@
   }
 
   @Override
+  protected AutoBeanFactory getAutoBeanFactory() {
+    return getRequestFactory().getAutoBeanFactory();
+  }
+
+  @Override
   SimpleProxyId<BaseProxy> getId(IdMessage op) {
     if (Strength.SYNTHETIC.equals(op.getStrength())) {
       return getRequestFactory().allocateSyntheticId(
diff --git a/user/test/com/google/gwt/requestfactory/client/RequestFactoryTest.java b/user/test/com/google/gwt/requestfactory/client/RequestFactoryTest.java
index b43e4ae..ad85e81 100644
--- a/user/test/com/google/gwt/requestfactory/client/RequestFactoryTest.java
+++ b/user/test/com/google/gwt/requestfactory/client/RequestFactoryTest.java
@@ -18,6 +18,8 @@
 import com.google.gwt.requestfactory.shared.EntityProxy;
 import com.google.gwt.requestfactory.shared.EntityProxyChange;
 import com.google.gwt.requestfactory.shared.EntityProxyId;
+import com.google.gwt.requestfactory.shared.OnlyUsedByRequestContextMethod;
+import com.google.gwt.requestfactory.shared.OnlyUsedInListProxy;
 import com.google.gwt.requestfactory.shared.Receiver;
 import com.google.gwt.requestfactory.shared.Request;
 import com.google.gwt.requestfactory.shared.RequestContext;
@@ -476,6 +478,22 @@
   }
 
   /**
+   * Tests that enum values used only as method parameters in a RequestContext
+   * are in the EnumMap. This test only applies to GWT-based clients.
+   */
+  public void testEnumOnlyUsedByRequestContext() {
+    delayTestFinish(DELAY_TEST_FINISH);
+    SimpleFooRequest ctx = simpleFooRequest();
+    ctx.receiveEnum(OnlyUsedByRequestContextMethod.FOO).fire(
+        new Receiver<Void>() {
+          @Override
+          public void onSuccess(Void response) {
+            finishTest();
+          }
+        });
+  }
+
+  /**
    * Check default value, a newly-set value, and a null value.
    */
   public void testEnumProperty() {
@@ -2217,6 +2235,15 @@
   }
 
   /**
+   * Test that a proxy only referenced via a parameterization is available.
+   */
+  public void testOnlyUsedInList() {
+    OnlyUsedInListProxy proxy = simpleFooRequest().create(
+        OnlyUsedInListProxy.class);
+    assertNotNull(proxy);
+  }
+
+  /**
    * Check if a graph of unpersisted objects can be echoed.
    */
   public void testUnpersistedEchoComplexGraph() {
diff --git a/user/test/com/google/gwt/requestfactory/server/SimpleFoo.java b/user/test/com/google/gwt/requestfactory/server/SimpleFoo.java
index d02ce15..4012b21 100644
--- a/user/test/com/google/gwt/requestfactory/server/SimpleFoo.java
+++ b/user/test/com/google/gwt/requestfactory/server/SimpleFoo.java
@@ -15,6 +15,7 @@
  */
 package com.google.gwt.requestfactory.server;
 
+import com.google.gwt.requestfactory.shared.OnlyUsedByRequestContextMethod;
 import com.google.gwt.requestfactory.shared.SimpleEnum;
 
 import java.math.BigDecimal;
@@ -258,6 +259,12 @@
     return string;
   }
 
+  public static void receiveEnum(OnlyUsedByRequestContextMethod value) {
+    if (value != OnlyUsedByRequestContextMethod.FOO) {
+      throw new IllegalArgumentException("Expecting FOO, received " + value);
+    }
+  }
+
   public static void receiveNullList(List<SimpleFoo> value) {
     if (value != null) {
       throw new IllegalArgumentException(
@@ -364,6 +371,9 @@
     return null;
   }
 
+  public static void returnOnlyUsedInParameterization(List<SimpleFoo> values) {
+  }
+
   public static SimpleFoo returnSimpleFooSubclass() {
     return new SimpleFoo() {
     };
diff --git a/user/test/com/google/gwt/requestfactory/shared/OnlyUsedByRequestContextMethod.java b/user/test/com/google/gwt/requestfactory/shared/OnlyUsedByRequestContextMethod.java
new file mode 100644
index 0000000..90d1c97
--- /dev/null
+++ b/user/test/com/google/gwt/requestfactory/shared/OnlyUsedByRequestContextMethod.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.requestfactory.shared;
+
+/**
+ * Ensures that enums used only by a method in a RequestContext are property
+ * emitted into the EnumMap used to encode values.
+ */
+public enum OnlyUsedByRequestContextMethod {
+  FOO, BAR;
+}
diff --git a/user/test/com/google/gwt/requestfactory/shared/OnlyUsedInListProxy.java b/user/test/com/google/gwt/requestfactory/shared/OnlyUsedInListProxy.java
new file mode 100644
index 0000000..a96aa9e
--- /dev/null
+++ b/user/test/com/google/gwt/requestfactory/shared/OnlyUsedInListProxy.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.gwt.requestfactory.shared;
+
+import com.google.gwt.requestfactory.server.SimpleFoo;
+
+/**
+ * This proxy type should only be used as the parameterization of a list type to
+ * ensure that proxy types reachable only through a parameterization can be
+ * created by a RequestContext.
+ */
+@ProxyFor(SimpleFoo.class)
+public interface OnlyUsedInListProxy extends ValueProxy {
+  String getUserName();
+}
diff --git a/user/test/com/google/gwt/requestfactory/shared/SimpleFooRequest.java b/user/test/com/google/gwt/requestfactory/shared/SimpleFooRequest.java
index 8fcc205..6afdd34 100644
--- a/user/test/com/google/gwt/requestfactory/shared/SimpleFooRequest.java
+++ b/user/test/com/google/gwt/requestfactory/shared/SimpleFooRequest.java
@@ -82,6 +82,8 @@
 
   Request<String> processString(String value);
 
+  Request<Void> receiveEnum(OnlyUsedByRequestContextMethod value);
+
   InstanceRequest<SimpleFooProxy, Void> receiveNull(String value);
 
   Request<Void> receiveNullList(List<SimpleFooProxy> value);
@@ -104,6 +106,9 @@
 
   Request<String> returnNullString();
 
+  Request<Void> returnOnlyUsedInParameterization(
+      List<OnlyUsedInListProxy> values);
+
   Request<SimpleFooProxy> returnSimpleFooSubclass();
 
   Request<SimpleValueProxy> returnValueProxy();