diff --git a/modules/doc/actions.rst b/modules/doc/actions.rst
new file mode 100644
index 0000000000000000000000000000000000000000..ed8bf52c558e94c0e00914ac34129204ec41eb42
--- /dev/null
+++ b/modules/doc/actions.rst
@@ -0,0 +1,110 @@
+.. ost-actions:
+
+OST Actions
+================================================================================
+
+A pure command line interface of OST is provided by actions.
+You can execute ``ost -h`` for a list of possible actions and for every action,
+you can type ``ost <ACTION> -h`` to get a description on its usage.
+
+Here we list the most prominent actions with simple examples.
+
+.. ost-qs-score:
+
+Calculating QS-Score
+--------------------------------------------------------------------------------
+
+You can calculate quaternary structure score between two complexes
+from the command line with
+
+.. code-block:: console
+
+  $ ost qs-score [-h] [-v VERBOSITY] -m MODEL -r REFERENCE
+                 [-c CHAIN_MAPPING [CHAIN_MAPPING ...]] [-o OUTPUT]
+
+By default the verbosity is set to 3 which will result in the informations
+being shown in the console. The result can be (optionally) saved as JSON file
+which is the preferred way of parsing it as the log output might change in the
+future. The output file has following format:
+
+.. code-block:: python
+
+  {
+      "result": [
+          {
+              "status": <SUCCESS or FAILURE>,
+              "reference_name": <Reference name extracted from the file name>, 
+              "model_name": <Model name extracted from the file name>, 
+              "error": <ERROR message if any>, 
+              "best_score": <Best QS-score>, 
+              "lddt_score": <lDDT score>
+              "global_score": <Global QS-score>, 
+              "chain_mapping": <Mapping of chains eg. {"A": "B", "B": "A"}>, 
+          }
+      ]
+  }
+
+The "result" filed is a list as eg. in mmCIF file there can be many entities and
+the script will compare all combinations.
+
+Example usage:
+
+.. code-block:: console
+
+  $ curl https://www.cameo3d.org/static/data/modeling/2018.03.03/5X7J_B/bu_target_01.pdb > reference.pdb
+  $ curl https://www.cameo3d.org/static/data/modeling/2018.03.03/5X7J_B/servers/server11/oligo_model-1/superposed_oligo_model-1.pdb > model.pdb
+  $ ost qs-score -r reference.pdb -m model.pdb -o qs.json
+
+  Reading model from model.pdb
+  imported 2 chains, 396 residues, 3106 atoms; with 0 helices and 0 strands
+  Reading reference from reference.pdb
+  imported 3 chains, 408 residues, 3011 atoms; with 0 helices and 0 strands
+  #
+  Comparing model.pdb to reference.pdb
+  Chains removed from reference.pdb: _
+  Chains in reference.pdb: AB
+  Chains in model.pdb: AB
+  Chemically equivalent chain-groups in reference.pdb: [['B', 'A']]
+  Chemically equivalent chain-groups in model.pdb: [['A', 'B']]
+  Chemical chain-groups mapping: {('B', 'A'): ('A', 'B')}
+  Identifying Symmetry Groups...
+  Symmetry threshold 0.1 used for angles of reference.pdb
+  Symmetry threshold 0.1 used for axis of reference.pdb
+  Symmetry threshold 0.1 used for angles of model.pdb
+  Symmetry threshold 0.1 used for axis of model.pdb
+  Selecting Symmetry Groups...
+  Symmetry-groups used in reference.pdb: [('B',), ('A',)]
+  Symmetry-groups used in model.pdb: [('A',), ('B',)]
+  Closed Symmetry with strict parameters
+  Mapping found: {'A': 'B', 'B': 'A'}
+  QSscore reference.pdb, model.pdb: best: 0.90, global: 0.86
+  Computing lDDT score
+  Reference reference.pdb has: 2 chains
+  Model model.pdb has: 2 chains
+  Reference reference.pdb has: 384 residues
+  Model model.pdb has: 396 residues
+  lDDT score: 0.924
+
+This reads the model and reference file and calculates QS-score between them.
+In the example above the output file looks as follows:
+
+.. code-block:: python
+
+  {
+      "result": [
+          {
+              "status": "SUCCESS", 
+              "chain_mapping": {
+                  "A": "B", 
+                  "B": "A"
+              }, 
+              "global_score": 0.8649009937090414, 
+              "error": "", 
+              "reference_name": "reference.pdb", 
+              "best_score": 0.8979578363524581, 
+              "model_name": "model.pdb", 
+              "lddt_score": 0.924271821975708
+          }
+      ]
+  }
+
diff --git a/modules/index.rst b/modules/index.rst
index 2e8c37b274c8c40308f7aedb259fd51e1dd8888e..9ab3fdd1ddeaa810a0cfddeaa3c28083c3f22a9c 100644
--- a/modules/index.rst
+++ b/modules/index.rst
@@ -31,6 +31,7 @@ OpenStructure documentation
   table
   mol/alg/lddt
   mol/alg/molck
+  actions
 
 For Starters
 --------------------------------------------------------------------------------
@@ -106,6 +107,8 @@ Varia
 
 **Molck**: :doc:`Molecular Checker<mol/alg/molck>`
 
+**Actions**: :doc:`OST Actions<actions>`
+
 Extending OpenStructure
 --------------------------------------------------------------------------------