diff --git a/lib/rb/ext/constants.h b/lib/rb/ext/constants.h
new file mode 100644
index 0000000..57df544
--- /dev/null
+++ b/lib/rb/ext/constants.h
@@ -0,0 +1,95 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+
+extern int TTYPE_STOP;
+extern int TTYPE_BOOL;
+extern int TTYPE_BYTE;
+extern int TTYPE_I16;
+extern int TTYPE_I32;
+extern int TTYPE_I64;
+extern int TTYPE_DOUBLE;
+extern int TTYPE_STRING;
+extern int TTYPE_MAP;
+extern int TTYPE_SET;
+extern int TTYPE_LIST;
+extern int TTYPE_STRUCT;
+
+extern ID validate_method_id;
+extern ID write_struct_begin_method_id;
+extern ID write_struct_end_method_id;
+extern ID write_field_begin_method_id;
+extern ID write_field_end_method_id;
+extern ID write_boolean_method_id;
+extern ID write_byte_method_id;
+extern ID write_i16_method_id;
+extern ID write_i32_method_id;
+extern ID write_i64_method_id;
+extern ID write_double_method_id;
+extern ID write_string_method_id;
+extern ID write_map_begin_method_id;
+extern ID write_map_end_method_id;
+extern ID write_list_begin_method_id;
+extern ID write_list_end_method_id;
+extern ID write_set_begin_method_id;
+extern ID write_set_end_method_id;
+extern ID size_method_id;
+extern ID read_bool_method_id;
+extern ID read_byte_method_id;
+extern ID read_i16_method_id;
+extern ID read_i32_method_id;
+extern ID read_i64_method_id;
+extern ID read_string_method_id;
+extern ID read_double_method_id;
+extern ID read_map_begin_method_id;
+extern ID read_map_end_method_id;
+extern ID read_list_begin_method_id;
+extern ID read_list_end_method_id;
+extern ID read_set_begin_method_id;
+extern ID read_set_end_method_id;
+extern ID read_struct_begin_method_id;
+extern ID read_struct_end_method_id;
+extern ID read_field_begin_method_id;
+extern ID read_field_end_method_id;
+extern ID keys_method_id;
+extern ID entries_method_id; 
+extern ID name_method_id; 
+extern ID sort_method_id;
+extern ID write_field_stop_method_id;
+extern ID skip_method_id;
+extern ID write_method_id;
+extern ID read_all_method_id;
+extern ID native_qmark_method_id;
+
+extern ID fields_const_id;
+extern ID transport_ivar_id;
+extern ID strict_read_ivar_id;
+extern ID strict_write_ivar_id;
+
+extern VALUE type_sym;
+extern VALUE name_sym;
+extern VALUE key_sym;
+extern VALUE value_sym;
+extern VALUE element_sym;
+extern VALUE class_sym;
+
+extern VALUE rb_cSet;
+extern VALUE thrift_module;
+extern VALUE thrift_types_module;
+extern VALUE class_thrift_protocol;
+extern VALUE protocol_exception_class;