.. _index-cr-connect-workflow:

===================
CR Connect Workflow
===================

CR Connect Workflow is the backend for CR Connect.

It has an **API** that takes requests from the front end,
and returns JSON responses.

There are SQLAlchemy database **models** for data persistence. We use a Postgres database.

It has **services** that offload most of the work for the API. These services can make calls to other services,
to SpiffWorkflow--our workflow engine, or to external data sources.

There are **scripts** which can be called from workflows. These scripts can call services or run standard Python.
They are a primary way of extending workflow capabilities.

.. image:: /_static/03/cr_connect_workflow.png

We will take a simple example of calling an external data source,
and use it to learn about the different parts of the CR Connect Workflow code base.


.. toctree::
   :maxdepth: 3

   01_scripts/00_index.rst
   02_services/00_index.rst
   03_api/00_index.rst
   04_errors/00_index.rst
   05_tests/00_index.rst
   06_models/00_index.rst