diff --git a/src/modb_database.h b/src/modb_database.h
index 0680940..5bf536a 100644
--- a/src/modb_database.h
+++ b/src/modb_database.h
@@ -2,7 +2,7 @@
 #define H__MODB_DATABASE__
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
 
 
 // Connection reference
diff --git a/src/modb_database_p.h b/src/modb_database_p.h
index d9dc199..1e3b957 100644
--- a/src/modb_database_p.h
+++ b/src/modb_database_p.h
@@ -5,7 +5,7 @@
 #include <stddef.h>
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
 
 
 int connectionUseMODB(stored_conn *sconn, modb_ref *modb, int override);
diff --git a/src/modb_groups.h b/src/modb_groups.h
index 859a616..d9fb5b8 100644
--- a/src/modb_groups.h
+++ b/src/modb_groups.h
@@ -2,7 +2,8 @@
 #define H__MODB_GROUPS__
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
+
 
 // Group object
 struct group_t {
diff --git a/src/modb_metadata.c b/src/modb_metadata.c
index b8e352d..630af78 100644
--- a/src/modb_metadata.c
+++ b/src/modb_metadata.c
@@ -3,11 +3,14 @@
 #include <stdio.h>
 
 #include "modb_metadata.h"
+#include "modb_objects.h"
+#include "modb_metadata_ext.h"
 #include "modb_users.h"
 #include "modb_groups.h"
 #include "modb_p.h"
 
 
+// ##### PRIVATE
 int tableRowsToMetadataList(column_data **col_data, size_t n_cols,
                             struct metadata_t ***metadata_list, size_t *n_metadatas)
 {
@@ -141,6 +144,83 @@ int doScalarMetadataListQuery(stored_conn *sconn, modb_ref *modb,
 
 
 
+// ##### PUBLIC
+struct metadata_t *allocMetadata(void)
+{
+  struct metadata_t *metadata;
+
+  metadata = malloc(sizeof(struct metadata_t));
+  if (metadata == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+  }
+  memset(metadata, 0, sizeof(struct metadata_t));
+
+  return metadata;
+}
+struct metadata_t **allocMetadataList(size_t n_metadatas)
+{
+  struct metadata_t **metadatas;
+
+  metadatas = (struct metadata_t **)malloc(sizeof(struct metadata_t *) * n_metadatas);
+  if (metadatas == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+    return 0;
+  }
+  memset(metadatas, 0, sizeof(struct metadata_t *) * n_metadatas);
+
+  return metadatas;
+}
+void freeMetadata(struct metadata_t **metadata_ptr)
+{
+  struct metadata_t *metadata = *metadata_ptr;
+
+  if (metadata->ext != 0) {
+    freeMetadataExt(&metadata->ext);
+  }
+
+  if (metadata->object != 0) {
+    freeObject(&metadata->object);
+  }
+
+  if (metadata->n_groups > 0) {
+    if (metadata->group_ids != 0) {
+      free(metadata->group_ids);
+      metadata->group_ids = 0;
+    }
+    if (metadata->groups != 0) {
+      freeGroups(&metadata->groups, metadata->n_groups);
+    }
+    metadata->n_groups = 0;
+  }
+
+  if (metadata->owner != 0) {
+    freeUser(&metadata->owner);
+  }
+
+  if (metadata->title != 0) {
+    free(metadata->title);
+    metadata->title = 0;
+  }
+
+  free(metadata);
+  *metadata_ptr = 0;
+}
+void freeMetadataList(struct metadata_t ***metadata_list_ptr, size_t n_metadatas)
+{
+  size_t idx;
+  struct metadata_t **metadatas_list= *metadata_list_ptr;
+
+  for (idx = 0; idx < n_metadatas; idx++) {
+    if (*(metadatas_list + idx) != 0) {
+      freeMetadata((metadatas_list + idx));
+    }
+  }
+
+  free(metadatas_list);
+  *metadata_list_ptr = 0;
+}
+
+
 int modbMetadataById(stored_conn *sconn, modb_ref *modb, unsigned int id,
                      struct metadata_t **metadata)
 {
diff --git a/src/modb_metadata.h b/src/modb_metadata.h
index 92a0d52..fea80ff 100644
--- a/src/modb_metadata.h
+++ b/src/modb_metadata.h
@@ -2,9 +2,41 @@
 #define H__MODB_METADATA__
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
 
-// MODB MetadataList
+
+// Metadata object
+struct metadata_t {
+  unsigned int id;
+
+  char *type;
+  size_t type_len;
+
+  char *title;
+  size_t title_len;
+
+  unsigned int owner_id;
+  struct user_t *owner;
+
+  int64_t created_on;
+  int64_t updated_on;
+  int64_t deleted_on;
+
+  unsigned int *group_ids;
+  struct group_t **groups;
+  size_t n_groups;
+
+  struct object_t *object;
+  struct metadata_ext_t *ext;
+};
+
+struct metadata_t *allocMetadata(void);
+struct metadata_t **allocMetadataList(size_t n_metadatas);
+void freeMetadata(struct metadata_t **metadata);
+void freeMetadataList(struct metadata_t ***metadata_list_ptr, size_t n_metadatas);
+
+
+// MODB Metadata
 int modbMetadataById(stored_conn *sconn, modb_ref *modb, unsigned int id,
                      struct metadata_t **metadata);
 // MetadataList by owner
diff --git a/src/modb_metadata_ext.c b/src/modb_metadata_ext.c
new file mode 100644
index 0000000..e79c738
--- /dev/null
+++ b/src/modb_metadata_ext.c
@@ -0,0 +1,54 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include "modb_metadata_ext.h"
+
+
+struct metadata_ext_t *allocMetadataExt(void)
+{
+  struct metadata_ext_t *metadata_ext;
+
+  metadata_ext = malloc(sizeof(struct metadata_ext_t));
+  if (metadata_ext == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+  }
+  memset(metadata_ext, 0, sizeof(struct metadata_ext_t));
+
+  return metadata_ext;
+}
+struct metadata_ext_t **allocMetadataExts(size_t n_metadata_exts)
+{
+  struct metadata_ext_t **metadata_exts;
+
+  metadata_exts = (struct metadata_ext_t **)malloc(sizeof(struct metadata_ext_t *) * n_metadata_exts);
+  if (metadata_exts == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+    return 0;
+  }
+  memset(metadata_exts, 0, sizeof(struct metadata_ext_t *) * n_metadata_exts);
+
+  return metadata_exts;
+}
+void freeMetadataExt(struct metadata_ext_t **metadata_ext_ptr)
+{
+  struct metadata_ext_t *metadata_ext = *metadata_ext_ptr;
+
+  free(metadata_ext);
+  *metadata_ext_ptr = 0;
+}
+void freeMetadataExts(struct metadata_ext_t ***metadata_exts_ptr, size_t n_metadata_exts)
+{
+  size_t idx;
+  struct metadata_ext_t **metadata_exts = *metadata_exts_ptr;
+
+  for (idx = 0; idx < n_metadata_exts; idx++) {
+    if (*(metadata_exts + idx) != 0) {
+      freeMetadataExt(metadata_exts + idx);
+    }
+  }
+
+  free(metadata_exts);
+  *metadata_exts_ptr = 0;
+}
diff --git a/src/modb_metadata_ext.h b/src/modb_metadata_ext.h
new file mode 100644
index 0000000..5176e4c
--- /dev/null
+++ b/src/modb_metadata_ext.h
@@ -0,0 +1,48 @@
+#ifndef H__MODB_METADATA_EXT__
+#define H__MODB_METADATA_EXT__
+
+#include "modb_ref.h"
+
+
+// MetadataExtended object
+struct metadata_ext_t {
+  unsigned int id;
+
+// TODO: dynamic extended metadata definition
+//  struct metadata_ext_value_t **meta_ext;
+//  size_t n_meta_ext;
+};
+
+//struct metadata_ext_value_t {
+//  char *key;
+//  enum e_column_type_t type;
+//  union {
+//    void *vptr;_ptr
+
+//    int8_t int8;
+//    uint8_t uint8;
+
+//    int16_t int16;
+//    uint16_t uint16;
+
+//    int32_t int32;
+//    uint32_t uint32;
+
+//    int64_t int64;
+//    uint64_t uint64;
+
+//    float flt;
+//    double dbl;
+
+//    char *ptr_str;
+//  } value;
+//  size_t value_len;
+//};
+
+struct metadata_ext_t *allocMetadataExt(void);
+struct metadata_ext_t **allocMetadataExts(size_t n_metadata_exts);
+void freeMetadataExt(struct metadata_ext_t **metadata_ext);
+void freeMetadataExts(struct metadata_ext_t ***metadata_exts_ptr, size_t n_metadata_exts);
+
+
+#endif // H__MODB_METADATA_EXT__
diff --git a/src/modb_objects.c b/src/modb_objects.c
index 5d7b2df..a9c2038 100644
--- a/src/modb_objects.c
+++ b/src/modb_objects.c
@@ -6,6 +6,7 @@
 #include "modb_p.h"
 
 
+// ##### PRIVATE
 int tableRowsToObjects(column_data **col_data, size_t n_cols,
                        struct object_t ***objects, size_t *n_objects)
 {
@@ -124,6 +125,59 @@ int doScalarObjectsQuery(stored_conn *sconn, modb_ref *modb,
 }
 
 
+// ##### PUBLIC
+struct object_t *allocObject(void)
+{
+  struct object_t *object;
+
+  object = malloc(sizeof(struct object_t));
+  if (object == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+  }
+  memset(object, 0, sizeof(struct object_t));
+
+  return object;
+}
+struct object_t **allocObjects(size_t n_objects)
+{
+  struct object_t **objects;
+
+  objects = (struct object_t **)malloc(sizeof(struct object_t *) * n_objects);
+  if (objects == 0) {
+    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+    return 0;
+  }
+  memset(objects, 0, sizeof(struct object_t *) * n_objects);
+
+  return objects;
+}
+void freeObject(struct object_t **object_ptr)
+{
+  struct object_t *object = *object_ptr;
+
+  if (object->data != 0) {
+    free(object->data);
+    object->data = 0;
+  }
+
+  free(object);
+  *object_ptr = 0;
+}
+void freeObjects(struct object_t ***objects_ptr, size_t n_objects)
+{
+  size_t idx;
+  struct object_t **objects = *objects_ptr;
+
+  for (idx = 0; idx < n_objects; idx++) {
+    if (*(objects + idx) != 0) {
+      freeObject(objects + idx);
+    }
+  }
+
+  free(objects);
+  *objects_ptr = 0;
+}
+
 
 int modbObjectById(stored_conn *sconn, modb_ref *modb, unsigned int id,
                    struct object_t **object)
diff --git a/src/modb_objects.h b/src/modb_objects.h
index 9840e90..9f78d4b 100644
--- a/src/modb_objects.h
+++ b/src/modb_objects.h
@@ -2,9 +2,22 @@
 #define H__MODB_OBJECTS__
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
+
+
+// Object object
+struct object_t {
+  unsigned int id;
+
+  char *data;
+  size_t data_len;
+};
+
+struct object_t *allocObject(void);
+struct object_t **allocObjects(size_t n_objects);
+void freeObject(struct object_t **object);
+void freeObjects(struct object_t ***objects_ptr, size_t n_objects);
 
-// object from row
 
 // MODB Objects
 int modbObjectById(stored_conn *sconn, modb_ref *modb, unsigned int id,
diff --git a/src/modb_p.h b/src/modb_p.h
index dc436f0..13839f2 100644
--- a/src/modb_p.h
+++ b/src/modb_p.h
@@ -3,9 +3,9 @@
 
 #include <stddef.h>
 
-#include "modb_types.h"
 #include "database.h"
 #include "strext.h"
+#include "modb_ref.h"
 
 
 #define SYS_TABLE "_sys"
diff --git a/src/modb_ref.h b/src/modb_ref.h
new file mode 100644
index 0000000..1e9f0ac
--- /dev/null
+++ b/src/modb_ref.h
@@ -0,0 +1,12 @@
+#ifndef H__MODB_REF__
+#define H__MODB_REF__
+
+#include <stddef.h>
+
+struct modb_ref_t {
+  const char *name;
+  size_t name_len;
+};
+typedef struct modb_ref_t modb_ref;
+
+#endif // H__MODB_REF__
diff --git a/src/modb_types.c b/src/modb_types.c
deleted file mode 100644
index 36d2fe6..0000000
--- a/src/modb_types.c
+++ /dev/null
@@ -1,184 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-
-#include "modb_types.h"
-#include "modb_groups.h"
-#include "modb_users.h"
-#include "strext.h"
-
-
-struct metadata_t *allocMetadata(void)
-{
-  struct metadata_t *metadata;
-
-  metadata = malloc(sizeof(struct metadata_t));
-  if (metadata == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-  }
-  memset(metadata, 0, sizeof(struct metadata_t));
-
-  return metadata;
-}
-struct metadata_t **allocMetadataList(size_t n_metadatas)
-{
-  struct metadata_t **metadatas;
-
-  metadatas = (struct metadata_t **)malloc(sizeof(struct metadata_t *) * n_metadatas);
-  if (metadatas == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-    return 0;
-  }
-  memset(metadatas, 0, sizeof(struct metadata_t *) * n_metadatas);
-
-  return metadatas;
-}
-void freeMetadata(struct metadata_t **metadata_ptr)
-{
-  struct metadata_t *metadata = *metadata_ptr;
-
-  if (metadata->ext != 0) {
-    freeMetadataExt(&metadata->ext);
-  }
-
-  if (metadata->object != 0) {
-    freeObject(&metadata->object);
-  }
-
-  if (metadata->n_groups > 0) {
-    if (metadata->group_ids != 0) {
-      free(metadata->group_ids);
-      metadata->group_ids = 0;
-    }
-    if (metadata->groups != 0) {
-      freeGroups(&metadata->groups, metadata->n_groups);
-    }
-    metadata->n_groups = 0;
-  }
-
-  if (metadata->owner != 0) {
-    freeUser(&metadata->owner);
-  }
-
-  if (metadata->title != 0) {
-    free(metadata->title);
-    metadata->title = 0;
-  }
-
-  free(metadata);
-  *metadata_ptr = 0;
-}
-void freeMetadataList(struct metadata_t ***metadata_list_ptr, size_t n_metadatas)
-{
-  size_t idx;
-  struct metadata_t **metadatas_list= *metadata_list_ptr;
-
-  for (idx = 0; idx < n_metadatas; idx++) {
-    if (*(metadatas_list + idx) != 0) {
-      freeMetadata((metadatas_list + idx));
-    }
-  }
-
-  free(metadatas_list);
-  *metadata_list_ptr = 0;
-}
-
-struct object_t *allocObject(void)
-{
-  struct object_t *object;
-
-  object = malloc(sizeof(struct object_t));
-  if (object == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-  }
-  memset(object, 0, sizeof(struct object_t));
-
-  return object;
-}
-struct object_t **allocObjects(size_t n_objects)
-{
-  struct object_t **objects;
-
-  objects = (struct object_t **)malloc(sizeof(struct object_t *) * n_objects);
-  if (objects == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-    return 0;
-  }
-  memset(objects, 0, sizeof(struct object_t *) * n_objects);
-
-  return objects;
-}
-void freeObject(struct object_t **object_ptr)
-{
-  struct object_t *object = *object_ptr;
-
-  if (object->data != 0) {
-    free(object->data);
-    object->data = 0;
-  }
-
-  free(object);
-  *object_ptr = 0;
-}
-void freeObjects(struct object_t ***objects_ptr, size_t n_objects)
-{
-  size_t idx;
-  struct object_t **objects = *objects_ptr;
-
-  for (idx = 0; idx < n_objects; idx++) {
-    if (*(objects + idx) != 0) {
-      freeObject(objects + idx);
-    }
-  }
-
-  free(objects);
-  *objects_ptr = 0;
-}
-
-struct metadata_ext_t *allocMetadataExt(void)
-{
-  struct metadata_ext_t *metadata_ext;
-
-  metadata_ext = malloc(sizeof(struct metadata_ext_t));
-  if (metadata_ext == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-  }
-  memset(metadata_ext, 0, sizeof(struct metadata_ext_t));
-
-  return metadata_ext;
-}
-struct metadata_ext_t **allocMetadataExts(size_t n_metadata_exts)
-{
-  struct metadata_ext_t **metadata_exts;
-
-  metadata_exts = (struct metadata_ext_t **)malloc(sizeof(struct metadata_ext_t *) * n_metadata_exts);
-  if (metadata_exts == 0) {
-    fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
-    return 0;
-  }
-  memset(metadata_exts, 0, sizeof(struct metadata_ext_t *) * n_metadata_exts);
-
-  return metadata_exts;
-}
-void freeMetadataExt(struct metadata_ext_t **metadata_ext_ptr)
-{
-  struct metadata_ext_t *metadata_ext = *metadata_ext_ptr;
-
-  free(metadata_ext);
-  *metadata_ext_ptr = 0;
-}
-void freeMetadataExts(struct metadata_ext_t ***metadata_exts_ptr, size_t n_metadata_exts)
-{
-  size_t idx;
-  struct metadata_ext_t **metadata_exts = *metadata_exts_ptr;
-
-  for (idx = 0; idx < n_metadata_exts; idx++) {
-    if (*(metadata_exts + idx) != 0) {
-      freeMetadataExt(metadata_exts + idx);
-    }
-  }
-
-  free(metadata_exts);
-  *metadata_exts_ptr = 0;
-}
diff --git a/src/modb_types.h b/src/modb_types.h
deleted file mode 100644
index 01ab2a4..0000000
--- a/src/modb_types.h
+++ /dev/null
@@ -1,94 +0,0 @@
-#ifndef H__MODB_TYPES__
-#define H__MODB_TYPES__
-
-#include <stddef.h>
-#include <stdint.h>
-
-struct modb_ref_t {
-  const char *name;
-  size_t name_len;
-};
-typedef struct modb_ref_t modb_ref;
-
-struct metadata_t {
-  unsigned int id;
-
-  char *type;
-  size_t type_len;
-
-  char *title;
-  size_t title_len;
-
-  unsigned int owner_id;
-  struct user_t *owner;
-
-  int64_t created_on;
-  int64_t updated_on;
-  int64_t deleted_on;
-
-  unsigned int *group_ids;
-  struct group_t **groups;
-  size_t n_groups;
-
-  struct object_t *object;
-  struct metadata_ext_t *ext;
-};
-
-struct object_t {
-  unsigned int id;
-
-  char *data;
-  size_t data_len;
-};
-
-struct metadata_ext_t {
-  unsigned int id;
-
-// TODO: dynamic extended metadata definition
-//  struct metadata_ext_value_t **meta_ext;
-//  size_t n_meta_ext;
-};
-
-//struct metadata_ext_value_t {
-//  char *key;
-//  enum e_column_type_t type;
-//  union {
-//    void *vptr;_ptr
-
-//    int8_t int8;
-//    uint8_t uint8;
-
-//    int16_t int16;
-//    uint16_t uint16;
-
-//    int32_t int32;
-//    uint32_t uint32;
-
-//    int64_t int64;
-//    uint64_t uint64;
-
-//    float flt;
-//    double dbl;
-
-//    char *ptr_str;
-//  } value;
-//  size_t value_len;
-//};
-
-struct metadata_t *allocMetadata(void);
-struct metadata_t **allocMetadataList(size_t n_metadatas);
-void freeMetadata(struct metadata_t **metadata);
-void freeMetadataList(struct metadata_t ***metadata_list_ptr, size_t n_metadatas);
-
-struct object_t *allocObject(void);
-struct object_t **allocObjects(size_t n_objects);
-void freeObject(struct object_t **object);
-void freeObjects(struct object_t ***objects_ptr, size_t n_objects);
-
-struct metadata_ext_t *allocMetadataExt(void);
-struct metadata_ext_t **allocMetadataExts(size_t n_metadata_exts);
-void freeMetadataExt(struct metadata_ext_t **metadata_ext);
-void freeMetadataExts(struct metadata_ext_t ***metadata_exts_ptr, size_t n_metadata_exts);
-
-
-#endif // H__MODB_TYPES__
diff --git a/src/modb_users.h b/src/modb_users.h
index d67296a..4ab7bf1 100644
--- a/src/modb_users.h
+++ b/src/modb_users.h
@@ -2,7 +2,7 @@
 #define H__MODB_USERS__
 
 #include "database.h"
-#include "modb_types.h"
+#include "modb_ref.h"
 
 
 // User object