diff --git a/include/JSObjectProxy.hh b/include/JSObjectProxy.hh
index d66ac0d5..763e9160 100644
--- a/include/JSObjectProxy.hh
+++ b/include/JSObjectProxy.hh
@@ -74,6 +74,15 @@ public:
    */
   static PyObject *JSObjectProxy_get(JSObjectProxy *self, PyObject *key);
 
+  /**
+   * @brief Getter method (.sq_contains), returns whether a key exists, used by the in operator
+   *
+   * @param self - The JSObjectProxy
+   * @param key - The key for the value in the JSObjectProxy
+   * @return int 1 if `key` is in dict, 0 if not, and -1 on error
+   */
+  static int JSObjectProxy_contains(JSObjectProxy *self, PyObject *key);
+
   /**
    * @brief Assign method (.mp_ass_subscript), assigns a key-value pair if value is non-NULL, or deletes a key-value pair if value is NULL
    *
@@ -84,15 +93,6 @@ public:
    */
   static int JSObjectProxy_assign(JSObjectProxy *self, PyObject *key, PyObject *value);
 
-  /**
-   * @brief Helper function for various JSObjectProxy methods, sets a key-value pair on a JSObject given a python string key and a JS::Value value
-   *
-   * @param jsObject - The underlying backing store JSObject for the JSObjectProxy
-   * @param key - The key to be assigned or deleted
-   * @param value - The JS::Value to be assigned
-   */
-  static void JSObjectProxy_set_helper(JS::HandleObject jsObject, PyObject *key, JS::HandleValue value);
-
   /**
    * @brief Comparison method (.tp_richcompare), returns appropriate boolean given a comparison operator and other pyobject
    *
@@ -111,6 +111,7 @@ public:
    * @param visited
    * @return bool - Whether the compared objects are equal or not
    */
+  // private
   static bool JSObjectProxy_richcompare_helper(JSObjectProxy *self, PyObject *other, std::unordered_map<PyObject *, PyObject *> &visited);
 
   /**
@@ -141,6 +142,10 @@ static PyMappingMethods JSObjectProxy_mapping_methods = {
   .mp_ass_subscript = (objobjargproc)JSObjectProxyMethodDefinitions::JSObjectProxy_assign
 };
 
+static PySequenceMethods JSObjectProxy_sequence_methods = {
+  .sq_contains = (objobjproc)JSObjectProxyMethodDefinitions::JSObjectProxy_contains
+};
+
 /**
  * @brief Struct for the JSObjectProxyType, used by all JSObjectProxy objects
  */
diff --git a/src/JSObjectProxy.cc b/src/JSObjectProxy.cc
index 00392ba7..f2bb30bf 100644
--- a/src/JSObjectProxy.cc
+++ b/src/JSObjectProxy.cc
@@ -82,7 +82,23 @@ PyObject *JSObjectProxyMethodDefinitions::JSObjectProxy_get(JSObjectProxy *self,
   JS::RootedValue *value = new JS::RootedValue(GLOBAL_CX);
   JS_GetPropertyById(GLOBAL_CX, self->jsObject, id, value);
   JS::RootedObject *global = new JS::RootedObject(GLOBAL_CX, JS::GetNonCCWObjectGlobal(self->jsObject));
-  return pyTypeFactory(GLOBAL_CX, global, value)->getPyObject();
+  PyType *pyType = pyTypeFactory(GLOBAL_CX, global, value);
+  delete value;
+  delete global;
+  return pyType->getPyObject();
+}
+
+int JSObjectProxyMethodDefinitions::JSObjectProxy_contains(JSObjectProxy *self, PyObject *key)
+{
+  JS::RootedId id(GLOBAL_CX);
+  if (!keyToId(key, &id)) {
+    // TODO (Caleb Aikens): raise exception here
+    return -1; // key is not a str or int
+  }
+
+  JS::RootedValue value(GLOBAL_CX);
+  JS_GetPropertyById(GLOBAL_CX, self->jsObject, id, &value);
+  return value.isUndefined() ? 0 : 1;
 }
 
 int JSObjectProxyMethodDefinitions::JSObjectProxy_assign(JSObjectProxy *self, PyObject *key, PyObject *value)
@@ -104,15 +120,9 @@ int JSObjectProxyMethodDefinitions::JSObjectProxy_assign(JSObjectProxy *self, Py
   return 0;
 }
 
-void JSObjectProxyMethodDefinitions::JSObjectProxy_set_helper(JS::HandleObject jsObject, PyObject *key, JS::HandleValue value)
-{
-  JS::RootedId id(GLOBAL_CX);
-  keyToId(key, &id);
-  JS_SetPropertyById(GLOBAL_CX, jsObject, id, value);
-}
-
 PyObject *JSObjectProxyMethodDefinitions::JSObjectProxy_richcompare(JSObjectProxy *self, PyObject *other, int op)
 {
+
   if (op != Py_EQ && op != Py_NE) {
     Py_RETURN_NOTIMPLEMENTED;
   }
@@ -163,7 +173,8 @@ bool JSObjectProxyMethodDefinitions::JSObjectProxy_richcompare_helper(JSObjectPr
   }
 
   // iterate recursively through members of self and check for equality
-  for (size_t i = 0; i < props.length(); i++)
+  size_t length = props.length();
+  for (size_t i = 0; i < length; i++)
   {
     JS::HandleId id = props[i];
     JS::RootedValue *key = new JS::RootedValue(GLOBAL_CX);
diff --git a/src/modules/pythonmonkey/pythonmonkey.cc b/src/modules/pythonmonkey/pythonmonkey.cc
index af98ec1d..3b85ec2f 100644
--- a/src/modules/pythonmonkey/pythonmonkey.cc
+++ b/src/modules/pythonmonkey/pythonmonkey.cc
@@ -74,6 +74,7 @@ PyTypeObject JSObjectProxyType = {
   .tp_basicsize = sizeof(JSObjectProxy),
   .tp_dealloc = (destructor)JSObjectProxyMethodDefinitions::JSObjectProxy_dealloc,
   .tp_repr = (reprfunc)JSObjectProxyMethodDefinitions::JSObjectProxy_repr,
+  .tp_as_sequence = &JSObjectProxy_sequence_methods,
   .tp_as_mapping = &JSObjectProxy_mapping_methods,
   .tp_getattro = (getattrofunc)JSObjectProxyMethodDefinitions::JSObjectProxy_get,
   .tp_setattro = (setattrofunc)JSObjectProxyMethodDefinitions::JSObjectProxy_assign,
@@ -312,9 +313,9 @@ PyMethodDef PythonMonkeyMethods[] = {
 struct PyModuleDef pythonmonkey =
 {
   PyModuleDef_HEAD_INIT,
-  "pythonmonkey",                                   /* name of module */
-  "A module for python to JS interoperability",   /* module documentation, may be NULL */
-  -1,                                           /* size of per-interpreter state of the module, or -1 if the module keeps state in global variables. */
+  "pythonmonkey",                                         /* name of module */
+  "A module for Python to JavaScript interoperability",   /* module documentation, may be NULL */
+  -1,                                                     /* size of per-interpreter state of the module, or -1 if the module keeps state in global variables. */
   PythonMonkeyMethods
 };