diff --git a/builder/builder-tools/generate_api_docs.py b/builder/builder-tools/generate_api_docs.py
index d7a4fc7..a3d622a 100644
--- a/builder/builder-tools/generate_api_docs.py
+++ b/builder/builder-tools/generate_api_docs.py
@@ -9,19 +9,21 @@ sys.path.insert(0, os.path.realpath(os.path.join(current_dir, os.pardir, os.pard
 
 class DocsGenerator:
     def __init__(self,
-                 links_raltive_path="",
                  module_header="# Module {}",
                  functions_header="## Module functions",
                  class_header="## Class {}",
-                 function_header="### {}"
+                 function_header="### {}",
+                 contents_table_header="# API documentation\n"
+                                       "> Please note, following documentation files were automatically generated from the source code\n"
+                                       "## Table of contents"
                  ):
-        self.links_path = links_raltive_path
         self.module_header = module_header
         self.functions_header = functions_header
         self.class_header = class_header
         self.function_header = function_header
+        self.contents_table_header = contents_table_header
 
-    def get_full_markdown(self, module, links_path):
+    def _get_full_markdown(self, module, links_path):
         output = [self.module_header.format(
             "[{}]({})".format(
                 module.__name__,
@@ -33,12 +35,12 @@ class DocsGenerator:
             output.append(module.__doc__)
 
         output.append(self.functions_header)
-        output.extend(self.get_functions(module, links_path))
-        output.extend(self.get_classes(module, links_path))
+        output.extend(self._get_functions(module, links_path))
+        output.extend(self._get_classes(module, links_path))
 
         return output
 
-    def get_classes(self, item, links_path):
+    def _get_classes(self, item, links_path):
         output = list()
         for cls_name, cls in pydoc.inspect.getmembers(item, pydoc.inspect.isclass):
             if cls_name.startswith("_") or cls_name == "__class__":
@@ -54,12 +56,12 @@ class DocsGenerator:
                 ))
             )
             output.append(pydoc.inspect.getdoc(cls) or '...')  # Get the docstring
-            output.extend(self.get_functions(cls, links_path))  # Get the functions
-            output.extend(self.get_classes(cls, links_path))  # Recurse into any subclasses
+            output.extend(self._get_functions(cls, links_path))  # Get the functions
+            output.extend(self._get_classes(cls, links_path))  # Recurse into any subclasses
             output.append('\n')
         return output
 
-    def get_functions(self, item, links_path):
+    def _get_functions(self, item, links_path):
         output = []
         for func_name, func in pydoc.inspect.getmembers(item, pydoc.inspect.isfunction):
             if func_name.startswith('_') and func_name != '__init__':
@@ -83,23 +85,48 @@ class DocsGenerator:
 
         return output
 
-    def generate_docs(self, module_import_path, output_path):
+    @staticmethod
+    def _write_lines(path, lines):
+        with open(path, 'w') as f:
+            for line in lines:
+                f.write(line.replace("\n", os.linesep) + '\n')
+
+    @staticmethod
+    def _get_relpath(path1: str, path2: str) -> str:
+        return os.path.sep.join(
+            os.path.relpath(path1, path2).split(os.path.sep)[1:]
+        )
+
+    def generate_doc(self, module_import_path: str, output_path: str) -> None:
         try:
             module = pydoc.safeimport(module_import_path)
 
             if module is None:
                 logging.error("Module not found")
-                return
+                raise FileExistsError("Module not found")
+
         except pydoc.ErrorDuringImport as e:
             logging.error(f"Error while trying to import {module_import_path}: {e}")
+            raise e
         else:
+            relpath = self._get_relpath(module.__file__, output_path)
+            docs = self._get_full_markdown(module, relpath.replace(os.path.sep, "/"))
+            self._write_lines(output_path, docs)
+
+    def generate_docs(self, modules: list, output_dir: str, contents_name="SUMMARY") -> None:
+        contents_table = [self.contents_table_header]
+        contents_path = os.path.realpath(os.path.join(output_dir, f"{contents_name}.md"))
+        for module in modules:
+            name = module[module.rfind('.') + 1::]
+            path = os.path.realpath(os.path.join(output_dir, f"{name}.md"))
+            self.generate_doc(module, path)
+
             relpath = os.path.sep.join(
-                os.path.relpath(module.__file__, output_path).split(os.path.sep)[1:]
+                os.path.relpath(path, contents_path).split(os.path.sep)[1:]
             )
-            docs = self.get_full_markdown(module, relpath.replace(os.path.sep, "/"))
-            with open(output_path, 'w') as f:
-                for line in docs:
-                    f.write(line.replace("\n", os.linesep) + '\n')
+            contents_table.append(f"* [{name}]({relpath})")
+
+        self._write_lines(contents_path, contents_table)
 
 
 if __name__ == '__main__':
@@ -108,7 +135,5 @@ if __name__ == '__main__':
         "drone.modules.client_core",
     ]
     gen = DocsGenerator()
-    for module in modules_list:
-        name = module[module.rfind('.') + 1::]
-        gen.generate_docs(module, os.path.realpath(
-            os.path.join(current_dir, os.pardir, os.pardir, "docs", "en", "api", f"{name}.md")))
+    doc_path = os.path.realpath(os.path.join(current_dir, os.pardir, os.pardir, "docs", "en", "api"))
+    gen.generate_docs(modules_list, doc_path)
diff --git a/docs/en/api/SUMMARY.md b/docs/en/api/SUMMARY.md
new file mode 100644
index 0000000..53d0479
--- /dev/null
+++ b/docs/en/api/SUMMARY.md
@@ -0,0 +1,5 @@
+# API documentation

+> Please note, following documentation files were automatically generated from the source code

+## Table of contents
+* [messaging](messaging.md)
+* [client_core](client_core.md)