diff --git a/doc/source/conf.py b/doc/source/conf.py
index 9e0d2c7..f8ae368 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -25,7 +25,11 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = [ 'sphinxcontrib.blockdiag', 'sphinxcontrib.programoutput' ]
+extensions = [
+    'sphinx.ext.autodoc',
+    'sphinxcontrib.blockdiag',
+    'sphinxcontrib.programoutput'
+]
 #extensions = ['sphinx.ext.intersphinx']
 #intersphinx_mapping = {'python': ('http://docs.python.org/2.7', None)}
 
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 3c793da..8c12138 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -24,6 +24,7 @@
    launchers
    statsd
    client
+   internals
 
 Indices and tables
 ==================
diff --git a/doc/source/internals.rst b/doc/source/internals.rst
new file mode 100644
index 0000000..762eb6b
--- /dev/null
+++ b/doc/source/internals.rst
@@ -0,0 +1,87 @@
+Zuul Internals
+==============
+
+While most people should not need to understand the details of Zuul's internal
+data model, understanding the data model is essential for people writing
+code for Zuul, and might be interesting to advanced users. The model is
+defined in `zuul/model.py`_.
+
+.. _zuul/model.py: http://git.openstack.org/cgit/openstack-infra/zuul/tree/zuul/model.py
+
+Data Model
+----------
+
+It all starts with the :py:class:`~zuul.model.Pipeline`. A Pipeline is the
+basic organizational structure that everything else hangs off.
+
+.. autoclass:: zuul.model.Pipeline
+
+Pipelines have a configured
+:py:class:`Manager <zuul.manager.BasePipelineManager>` which controlls how
+the :py:class:`Change <zuul.model.Changeish>` objects are enqueued and
+processed.
+
+There are currently two,
+:py:class:`~zuul.manager.dependent.DependentPipelineManager` and
+:py:class:`~zuul.manager.independent.IndependentPipelineManager`
+
+.. autoclass:: zuul.manager.BasePipelineManager
+.. autoclass:: zuul.manager.dependent.DependentPipelineManager
+.. autoclass:: zuul.manager.independent.IndependentPipelineManager
+
+A :py:class:`~zuul.model.Pipeline` has one or more
+:py:class:`~zuul.model.ChangeQueue` objects.
+
+.. autoclass:: zuul.model.ChangeQueue
+
+A :py:class:`~zuul.model.Job` represents the definition of what to do. A
+:py:class:`~zuul.model.Build` represents a single run of a
+:py:class:`~zuul.model.Job`. A :py:class:`~zuul.model.JobTree` is used to
+encapsulate the dependencies between one or more :py:class:`~zuul.model.Job`
+objects.
+
+.. autoclass:: zuul.model.Job
+.. autoclass:: zuul.model.JobTree
+.. autoclass:: zuul.model.Build
+
+The :py:class:`~zuul.manager.base.PipelineManager` enqueues each
+:py:class:`Change <zuul.model.Changeish>` into the
+:py:class:`~zuul.model.ChangeQueue` in a :py:class:`~zuul.model.QueueItem`.
+
+.. autoclass:: zuul.model.QueueItem
+
+As the Changes are processed, each :py:class:`~zuul.model.Build` is put into
+a :py:class:`~zuul.model.BuildSet`
+
+.. autoclass:: zuul.model.BuildSet
+
+Changes
+~~~~~~~
+
+.. autoclass:: zuul.model.Changeish
+.. autoclass:: zuul.model.Change
+.. autoclass:: zuul.model.Ref
+
+Filters
+~~~~~~~
+
+.. autoclass:: zuul.model.ChangeishFilter
+.. autoclass:: zuul.model.EventFilter
+
+
+Tenants
+~~~~~~~
+
+An abide is a collection of tenants.
+
+.. autoclass:: zuul.model.UnparsedAbideConfig
+.. autoclass:: zuul.model.UnparsedTenantConfig
+
+Other Global Objects
+~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: zuul.model.Project
+.. autoclass:: zuul.model.Layout
+.. autoclass:: zuul.model.RepoFiles
+.. autoclass:: zuul.model.Worker
+.. autoclass:: zuul.model.TriggerEvent