--- a
+++ b/docs/conf.py
@@ -0,0 +1,135 @@
+# Copyright (c) OpenMMLab. All rights reserved.
+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import os
+import subprocess
+import sys
+
+import pytorch_sphinx_theme
+
+sys.path.insert(0, os.path.abspath('..'))
+
+# -- Project information -----------------------------------------------------
+
+project = 'MMAction2'
+copyright = '2020, OpenMMLab'
+author = 'MMAction2 Authors'
+version_file = '../mmaction/version.py'
+
+
+def get_version():
+    with open(version_file, 'r') as f:
+        exec(compile(f.read(), version_file, 'exec'))
+    return locals()['__version__']
+
+
+# The full version, including alpha/beta/rc tags
+release = get_version()
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.autodoc', 'sphinx.ext.napoleon', 'sphinx.ext.viewcode',
+    'sphinx_markdown_tables', 'sphinx_copybutton', 'myst_parser'
+]
+
+# numpy and torch are required
+autodoc_mock_imports = ['mmaction.version', 'PIL']
+
+copybutton_prompt_text = r'>>> |\.\.\. '
+copybutton_prompt_is_regexp = True
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+
+# -- Options for HTML output -------------------------------------------------
+source_suffix = {'.rst': 'restructuredtext', '.md': 'markdown'}
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'pytorch_sphinx_theme'
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+
+html_theme_path = [pytorch_sphinx_theme.get_html_theme_path()]
+html_theme_options = {
+    # 'logo_url': 'https://mmaction2.readthedocs.io/en/latest/',
+    'menu': [
+        {
+            'name':
+            'Tutorial',
+            'url':
+            'https://colab.research.google.com/github/'
+            'open-mmlab/mmaction2/blob/master/demo/mmaction2_tutorial.ipynb'
+        },
+        {
+            'name': 'GitHub',
+            'url': 'https://github.com/open-mmlab/mmaction2'
+        },
+        {
+            'name':
+            'Upstream',
+            'children': [
+                {
+                    'name': 'MMCV',
+                    'url': 'https://github.com/open-mmlab/mmcv',
+                    'description': 'Foundational library for computer vision'
+                },
+                {
+                    'name':
+                    'MMClassification',
+                    'url':
+                    'https://github.com/open-mmlab/mmclassification',
+                    'description':
+                    'Open source image classification toolbox based on PyTorch'
+                },
+                {
+                    'name': 'MMDetection',
+                    'url': 'https://github.com/open-mmlab/mmdetection',
+                    'description': 'Object detection toolbox and benchmark'
+                },
+            ]
+        },
+    ],
+    # Specify the language of shared menu
+    'menu_lang':
+    'en'
+}
+
+language = 'en'
+master_doc = 'index'
+
+html_static_path = ['_static']
+html_css_files = ['css/readthedocs.css']
+
+myst_enable_extensions = ['colon_fence']
+
+
+def builder_inited_handler(app):
+    subprocess.run(['./merge_docs.sh'])
+    subprocess.run(['./stat.py'])
+
+
+def setup(app):
+    app.connect('builder-inited', builder_inited_handler)