diff --git a/README.rst b/README.rst
index dbe378c..200fd98 100644
--- a/README.rst
+++ b/README.rst
@@ -62,3 +62,231 @@ The ``fuel2`` CLI commands groups are the following:
   resource values
 - ``config override``, ``config rm override`` - operations for resource values
   overrides
+
+API
+---
+
+For all operations authentication is required. Auth token should be passed in
+the X-Auth-Token HTTP header. Tuning Box installed as a Fuel Nailgun extension
+thus base API URL is placed at ``http://MASTER_NODE_IP:8000/api/v1/config``
+All operations URLs should be concatenated with the base API URL.
+
+Environments operations
+=======================
+
+URL: ``/environments``
+Operations:
+
+- (GET) list environments
+- (POST) create environment
+
+For environment creation POST:
+
+.. code-block:: python
+
+    {
+        'hierarchy_levels': [
+            # list of hierarchy levels
+        ],
+        'components': [
+            # list of components ids
+        ]
+    }
+
+
+Environment operations
+======================
+
+URL: ``/environments/<int:component_id>``
+Operations:
+
+- (GET) get environment
+- (PUT/PATCH) update environment
+- (DELETE) delete environment
+
+Components operations
+=====================
+
+URL: ``/components``
+Operations:
+
+- (GET) list components
+- (POST) create component
+
+For component creation POST:
+
+.. code-block:: python
+
+    {
+        'name': str,
+        'resource_definitions': [
+            {
+                'name': str, 'content': str
+            }
+        ]
+    }
+
+
+Component operations
+====================
+
+URL: ``/components/<int:component_id>``
+Operations:
+
+- (GET) get component
+- (PUT/PATCH) update component
+- (DELETE) delete component
+
+Hierarchy levels operations
+===========================
+
+URL: ``/environments/<int:environment_id>/hierarchy_levels``
+Operations:
+
+- (GET) list environment hierarchy levels
+
+Hierarchy levels modifications performed via environment
+modifications.
+
+Hierarchy level operations
+==========================
+
+URL: ``/environments/<int:component_id>/<string:level>``
+Operations:
+
+- (GET) get hierarchy level
+
+.. _`keys operations`:
+
+Keys operations
+===============
+
+For performing keys operation send PATCH request to the appropriate URL. As data use
+list of keys written in the order of access. For instance you have the following data:
+
+.. code-block:: python
+
+    {
+        'k0': {
+            'k1': 'val01',
+            'k2': 'val02,
+            'k3': [{'k4': 'val030'}]
+        }
+    }
+
+For access to the val02 key path will be: ['k0', 'k2']
+If you want to modify value add required value to the keys path. For instance, if you
+want change 'val02' to 'val02_new' key paths will be: ['k0', 'k2', 'val02_new']
+
+If you want to delete 'k4' key use key path ['k0', 'k3', 0, 'k4']
+
+Key operations work only in batch mode, so you should pass list of keys paths to the
+appropriate API handler::
+
+    [['k0', 'k1', 'val01_new'], ['k0', 'k2', 'val02_new']]
+
+For adding new key 'new_k' to the data you should send the following keys paths::
+
+    [['new_k', 'new_val']]
+
+Resource definitions operations
+===============================
+
+URL: ``/resource_definitions``
+Operations:
+
+- (GET) list resource definitions
+- (POST) create resource definition
+
+For resource definition creation POST:
+
+.. code-block:: python
+
+    {
+        'name': str,
+        'component_id': int,
+        'content': str
+    }
+
+
+Resource definition operations
+==============================
+
+URL: ``/resource_definitions/<int:resource_definition_id>``
+Operations:
+
+- (GET) get resource definition
+- (PUT/PATCH) update resource definition
+- (DELETE) delete resource definition
+
+Resource definition keys operations
+===================================
+
+Operations with keys modifies resource definition content only.
+These operations supports nested keys. For details see: `keys operations`_.
+
+URL: ``/resource_definitions/<int:resource_definition_id>/keys/<keys_operation:operation>``
+Handled keys operations:
+
+- get resource value key
+- update resource definition key
+- delete resource definition key
+
+Resource values operations
+==========================
+
+URL: ``/environments/<int:environment_id>/<levels:levels>resources/<id_or_name:resource_id_or_name>/values``
+Operations:
+
+- (GET) get resource value
+- (PUT) create/update resource value
+
+For resource value creation set PUT HTTP request with data as workload.
+This data will be stored to the resource values bound to the appropriate
+level value.
+
+For merging data from all levels specify 'effective' parameter for GET
+HTTP request.
+
+For tracing the level from which data is got specify 'show_lookup'
+parameter for the GET HTTP request. Lookup has sense only if you are
+fetching the effective values.
+
+Resource values keys operations
+===============================
+
+Operations with keys modifies resource values only.
+These operations supports nested keys. For details see: `keys operations`_.
+
+URL: ``/environments/<int:environment_id>/<levels:levels>resources/<id_or_name:resource_id_or_name>/values/keys/<keys_operation:operation>``
+Handled keys operations:
+
+- get resource values key
+- update resource values key
+- delete resource values key
+
+Resource overrides operations
+=============================
+
+URL: ``/environments/<int:environment_id>/<levels:levels>resources/<id_or_name:resource_id_or_name>/overrides``
+Operations:
+
+- (GET) get resource overrides
+- (PUT) create/update resource overrides
+
+For resource value creation set PUT HTTP request with data as workload.
+This data will be stored to the resource override bound to the appropriate
+level value.
+
+Resource values keys operations
+===============================
+
+Operations with keys modifies resource overrides only.
+These operations supports nested keys. For details see: `keys operations`_.
+
+URL: ``/environments/<int:environment_id>/<levels:levels>resources/<id_or_name:resource_id_or_name>/overrides/keys/<keys_operation:operation>``
+Handled keys operations:
+
+- get resource value key
+- update resource value key
+- delete resource value key