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@@ -5,7 +5,7 @@ Tool that provides Python API to run Ansible programmatically.
 
 ### cotea allows:
 - **To control** Ansible execution by iterating over the Ansible plays and tasks
-- **To embed** Ansible into other systems
+- **To embed** Ansible into another system
 - **To debug** Ansible execution by getting the values of Ansible variables and by retrieving the results of the execution of Ansible tasks/plays
 
 ## Installation
diff --git a/docs/cotea_docs.md b/docs/cotea_docs.md
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@@ -1 +1,101 @@
-# cotea documentation
\ No newline at end of file
+# cotea documentation
+
+The [runner](https://github.com/ispras/cotea/blob/main/src/runner.py#L29) class is the main class in *cotea*. It wraps *ansible-playbook* command. With the use of *runner* class, user runs and controls Ansible programmatically, gets additional information about the execution.
+
+The second point of interaction is the [argument_maker](https://github.com/ispras/cotea/blob/main/src/arguments_maker.py#L1) class. With the use of it, user can pass any argument for Ansible launch just like he passed arguments for *ansible-playbook* in the command line.
+
+## argument_maker
+
+The constructor of this class does not accept arguments. The class has only one method:
+
+**add_arg(self, param_name, value=None)**
+- *param_name* is the name of argument in the same notation as the *ansible-playbook* command line arguments names. For example, "-i" or "--extra-vars".
+- *value* is the given arguments value if needed (optional). For instanse, "-v" doesn't have any value. 
+
+Usage examples:
+```python
+# object creation
+arg_maker = argument_maker()
+
+# without value
+arg_maker.add_arg("-vvv")
+
+# with value
+inventory_path = "/path/to/inventory"
+arg_maker.add_arg("-i", inventory_path)
+
+# --extra-vars example
+extra_vars = {"jupyter_install": True, "spark_version": 2.4}
+arg_maker.add_arg("--extra-vars", extra_vars)
+
+```
+
+After all of the needed actions, *argument_maker* object should be passed to runner class *init* method.
+
+
+## runner
+
+**\_\_init\_\_(pb_path, arg_maker=None, debug_lvl=None, log_f=None)**
+- *pb_path* - path of the playbook .yaml file
+- *arg_maker* - object of *argument_maker* class
+- *debug_lvl* - currently this option is not for user purposes. It is planned that in future this option will this option will give usefull information for *cotea* user
+- *log_f* - path to file to which all the *cotea* output will be redirected. cotea output means the standard Ansible output with the *cotea* additional messages. This option can be useful when one embeds Ansible into another system. The system's output will not contain Ansible output in this case.
+
+### controlling interfaces
+
+**has_next_play(): bool**
+Checks if there is unexecuted *plays* in current Ansible execution. Returns *true* if there is.
+
+**setup_play_for_run(): bool**
+Starts a bunch of actions that are needed to setup play for run. Returns, when play is ready to run (returns *true*). If there was an error and *play* is not ready to start, returns *false*.
+
+**has_next_task(): bool**
+Checks if there is unexecuted *tasks* in currently executing *play*. Returns *true* if there is.
+
+**run_next_task()**
+Runs the next *task* in the currently executing *play*. 
+
+**finish_ansible()**
+Starts a bunch of actions that are needed to finish the current Ansible execution. This method has to be called only when there are no unexecuted *plays* and *tasks* (has_next_play and has_next_task return *false*).
+
+These five interfaces are the main part of *cotea*. They let one control the execution of *ansible-playbook* launch. Every usage of cotea will contain them in the following order:
+```python
+# r = runner(...)
+
+while r.has_next_play():
+    setup_ok = r.setup_play_for_run()
+    
+	if setup_ok:
+		while r.has_next_task():
+			r.run_next_task()
+
+r.finish_ansible()
+```
+
+**skip_next_task()**
+Skips the next tasks of currently executing play.
+
+### debugging interfaces
+**get_variable(var_name): str**
+- *var_name* - the name of the requested variable
+
+Returns value of the Ansible variable with name *var_name*.
+
+**was_error(): bool**
+Returns *true* if Ansible execution ends with an error.
+
+**get_error_msg(): str**
+If Ansible execution ends with an error(*was_error* returns *true*), returns error message.
+
+**get_cur_play_name(): str**
+Returns the current play name.
+
+**get_next_task_name(): str**
+Returns the next task name.
+
+**get_last_results(): []ansible.executor.task_result**
+Return a list with results of the last executed task on every host of the currently executing play. Results are objects of the Ansible class [TaskResult](https://github.com/ansible/ansible/blob/devel/lib/ansible/executor/task_result.py#L25). 
+
+**get_results(): []ansible.executor.task_result**
+Returns a list of task results which were obtained during the entire execution (at the calling moment). Results are objects of the Ansible class [TaskResult](https://github.com/ansible/ansible/blob/devel/lib/ansible/executor/task_result.py#L25). 
+