diff --git a/interfaces/inc/file.h b/interfaces/inc/file.h
new file mode 100644
index 0000000..4066961
--- /dev/null
+++ b/interfaces/inc/file.h
@@ -0,0 +1,39 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+#ifndef SYNC_H
+#define SYNC_H
+
+#ifdef __cplusplus
+#include <cstdbool>
+#else
+#include <stdbool.h>
+#endif
+
+#include "umock_c/umock_c_prod.h"
+#include "constbuffer.h"
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FILE_DATA_RESULT_VALUES \
+    FILE_DATA_FAILURE, \
+    FILE_DATA_INVALID, \
+    FILE_DATA_OK
+
+MU_DEFINE_ENUM(FILE_DATA_RESULT, FILE_DATA_RESULT_VALUES);
+
+typedef void *FILE_HANDLE;
+typedef void(*FILE_WRITE_CB)(void* userContext, bool isSuccess);
+typedef void(*FILE_READ_CB)(void* userContext, FILE_DATA_RESULT result, CONSTBUFFER_HANDLE content);
+
+MOCKABLE_FUNCTION_WITH_RETURNS(, FILE_HANDLE, file_open, const char*, fullFileName, int64_t, desire_file_size)(0, MU_FAILURE);
+MOCKABLE_FUNCTION(, void, file_close, FILE_HANDLE, handle);
+
+MOCKABLE_FUNCTION_WITH_RETURNS(, int, file_write_async, FILE_HANDLE, handle, CONSTBUFFER_HANDLE, source, int64_t, position, FILE_WRITE_CB, user_callback, void*, user_context)(0, MU_FAILURE);
+MOCKABLE_FUNCTION_WITH_RETURNS(, int, file_read_async, FILE_HANDLE, handle, uint32_t, size, int64_t, position, FILE_READ_CB, user_callback, void*, user_context)(0, MU_FAILURE);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
\ No newline at end of file