diff --git a/Documentation/dev-plugin-pg-styling.txt b/Documentation/dev-plugin-pg-styling.txt
deleted file mode 100644
index 618d984685..0000000000
--- a/Documentation/dev-plugin-pg-styling.txt
+++ /dev/null
@@ -1,61 +0,0 @@
-= Gerrit Code Review - PolyGerrit Plugin Styling
-
-CAUTION: Work in progress. Hard hat area. +
-This document will be populated with details along with implementation. +
-link:https://groups.google.com/d/topic/repo-discuss/vb8WJ4m0hK0/discussion[Join the discussion.]
-
-== Plugin styles
-
-Plugins may provide link:https://www.polymer-project.org/2.0/docs/devguide/style-shadow-dom#style-modules[Polymer style modules] for UI CSS-based customization.
-
-PolyGerrit UI implements number of styling endpoints, which apply CSS mixins link:https://tabatkins.github.io/specs/css-apply-rule/[using @apply] to its direct contents.
-
-NOTE: Only items (ie CSS properties and mixin targets) documented here are guaranteed to work in the long term, since they are covered by integration tests. +
-When there is a need to add new property or endpoint, please link:https://bugs.chromium.org/p/gerrit/issues/entry?template=PolyGerrit%20Issue[file a bug] stating your usecase to track and maintain for future releases.
-
-Plugin should be html-based and imported following PolyGerrit's link:dev-plugins-pg.html#loading[dev guide].
-
-Plugin should provide Style Module, for example:
-
-``` html
-  <dom-module id="some-style">
-    <style>
-      :root {
-        --css-mixin-name: {
-          property: value;
-        }
-      }
-    </style>
-  </dom-module>
-```
-
-Plugin should register style module with a styling endpoint using `Plugin.prototype.registerStyleModule(endpointName, styleModuleName)`, for example:
-
-``` js
-  Gerrit.install(function(plugin) {
-    plugin.registerStyleModule('some-endpoint', 'some-style');
-  });
-```
-
-== Available styling endpoints
-=== change-metadata
-Following custom css mixins are recognized:
-
-* `--change-metadata-assignee`
-+
-is applied to `gr-change-metadata section.assignee`
-* `--change-metadata-label-status`
-+
-is applied to `gr-change-metadata section.labelStatus`
-* `--change-metadata-strategy`
-+
-is applied to `gr-change-metadata section.strategy`
-* `--change-metadata-topic`
-+
-is applied to `gr-change-metadata section.topic`
-
-Following CSS properties have link:https://gerrit.googlesource.com/gerrit/+/master/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata-it_test.html[long-term support via integration test]:
-
-* `display`
-+
-can be set to `none` to hide a section.
diff --git a/Documentation/dev-plugins-pg.txt b/Documentation/pg-plugin-dev.txt
similarity index 66%
rename from Documentation/dev-plugins-pg.txt
rename to Documentation/pg-plugin-dev.txt
index e1bf39e22e..92c52f6b3f 100644
--- a/Documentation/dev-plugins-pg.txt
+++ b/Documentation/pg-plugin-dev.txt
@@ -1,10 +1,5 @@
 = Gerrit Code Review - PolyGerrit Plugin Development
 
-CAUTION: Work in progress. Hard hat area. +
-This document will be populated with details along with implementation. +
-link:https://groups.google.com/d/topic/repo-discuss/vb8WJ4m0hK0/discussion[Join
-the discussion.]
-
 [[loading]]
 == Plugin loading and initialization
 
@@ -33,8 +28,8 @@ Here's a sample `myplugin.html`:
 </dom-module>
 ```
 
-[[low-level-api]]
-== Low-level DOM API
+[[low-level-api-concepts]]
+== Low-level DOM API concepts
 
 Basically, the DOM is the API surface. Low-level API provides methods for
 decorating, replacing, and styling DOM elements exposed through a set of
@@ -126,3 +121,119 @@ Note: TODO: Insert link to the full styling API.
   </style>
 </dom-module>
 ```
+
+[[high-level-api-concepts]]
+== High-level DOM API concepts
+
+High leve API is based on low-level DOM API and is essentially a standartized
+way for doing common tasks. It's less flexible, but will be a bit more stable.
+
+Common way to access high-leve API is through `plugin` instance passed into
+setup callback parameter of `Gerrit.install()`, also sometimes referred as
+`self`.
+
+[[low-level-api]]
+== Low-level DOM API
+
+Low-level DOM API methods are the base of all UI customization.
+
+=== attributeHelper
+`plugin.attributeHelper(element)`
+
+Note: TODO
+
+=== eventHelper
+`plugin.eventHelper(element)`
+
+Note: TODO
+
+=== hook
+`plugin.hook(endpointName, opt_options)`
+
+Note: TODO
+
+=== registerCustomComponent
+`plugin.registerCustomComponent(endpointName, opt_moduleName, opt_options)`
+
+Note: TODO
+
+=== registerStyleModule
+`plugin.registerStyleModule(endpointName, moduleName)`
+
+Note: TODO
+
+[[high-level-api]]
+== High-level API
+
+Plugin instance provides access to number of more specific APIs and methods
+to be used by plugin authors.
+
+=== changeReply
+`plugin.changeReply()`
+
+Note: TODO
+
+=== changeView
+`plugin.changeView()`
+
+Note: TODO
+
+=== delete
+`plugin.delete(url, opt_callback)`
+
+Note: TODO
+
+=== get
+`plugin.get(url, opt_callback)`
+
+Note: TODO
+
+=== getPluginName
+`plugin.getPluginName()`
+
+Note: TODO
+
+=== getServerInfo
+`plugin.getServerInfo()`
+
+Note: TODO
+
+=== on
+`plugin.on(eventName, callback)`
+
+Note: TODO
+
+=== popup
+`plugin.popup(moduleName)`
+
+Note: TODO
+
+=== post
+`plugin.post(url, payload, opt_callback)`
+
+Note: TODO
+
+[plugin-project]
+=== project
+`plugin.project()`
+
+.Params:
+- none
+
+.Returns:
+- Instance of link:pg-plugin-project-api.html[GrProjectApi].
+
+=== put
+`plugin.put(url, payload, opt_callback)`
+
+Note: TODO
+
+=== theme
+`plugin.theme()`
+
+Note: TODO
+
+=== url
+`plugin.url(opt_path)`
+
+Note: TODO
diff --git a/Documentation/pg-plugin-project-api.txt b/Documentation/pg-plugin-project-api.txt
new file mode 100644
index 0000000000..897430c8e7
--- /dev/null
+++ b/Documentation/pg-plugin-project-api.txt
@@ -0,0 +1,36 @@
+= Gerrit Code Review - Project admin customization API
+
+This API is provided by link:pg-plugin-dev.html#plugin-project[plugin.project()]
+and provides customization to admin page.
+
+== createCommand
+`projectApi.createCommand(title, checkVisibleCallback)`
+
+Create a project command in the admin panel.
+
+.Params
+- *title* String title.
+- *checkVisibleCallback* function to configure command visibility.
+
+.Returns
+- GrProjectApi for chainging.
+
+`checkVisibleCallback(projectName, projectConfig)`
+
+.Params
+- *projectName* String project name.
+- *projectConfig* Object REST API response for project config.
+
+.Returns
+- `false` to hide the command for the specific project.
+
+== onTap
+`projectApi.onTap(tapCalback)`
+
+Add a command tap callback.
+
+.Params
+- *tapCallback* function that's excuted on command tap.
+
+.Returns
+- Nothing
diff --git a/Documentation/pg-plugin-styling.txt b/Documentation/pg-plugin-styling.txt
new file mode 100644
index 0000000000..58b6d7a4ae
--- /dev/null
+++ b/Documentation/pg-plugin-styling.txt
@@ -0,0 +1,69 @@
+= Gerrit Code Review - PolyGerrit Plugin Styling
+
+== Plugin styles
+
+Plugins may provide
+link:https://www.polymer-project.org/2.0/docs/devguide/style-shadow-dom#style-modules[Polymer
+style modules] for UI CSS-based customization.
+
+PolyGerrit UI implements number of styling endpoints, which apply CSS mixins
+link:https://tabatkins.github.io/specs/css-apply-rule/[using @apply] to its
+direct contents.
+
+NOTE: Only items (ie CSS properties and mixin targets) documented here are
+guaranteed to work in the long term, since they are covered by integration
+tests. + When there is a need to add new property or endpoint, please
+link:https://bugs.chromium.org/p/gerrit/issues/entry?template=PolyGerrit%20Issue[file
+a bug] stating your usecase to track and maintain for future releases.
+
+Plugin should be html-based and imported following PolyGerrit's
+link:pg-plugin-dev.html#loading[dev guide].
+
+Plugin should provide Style Module, for example:
+
+``` html
+  <dom-module id="some-style">
+    <style>
+      :root {
+        --css-mixin-name: {
+          property: value;
+        }
+      }
+    </style>
+  </dom-module>
+```
+
+Plugin should register style module with a styling endpoint using
+`Plugin.prototype.registerStyleModule(endpointName, styleModuleName)`, for
+example:
+
+``` js
+  Gerrit.install(function(plugin) {
+    plugin.registerStyleModule('some-endpoint', 'some-style');
+  });
+```
+
+== Available styling endpoints
+=== change-metadata
+Following custom css mixins are recognized:
+
+* `--change-metadata-assignee`
++
+is applied to `gr-change-metadata section.assignee`
+* `--change-metadata-label-status`
++
+is applied to `gr-change-metadata section.labelStatus`
+* `--change-metadata-strategy`
++
+is applied to `gr-change-metadata section.strategy`
+* `--change-metadata-topic`
++
+is applied to `gr-change-metadata section.topic`
+
+Following CSS properties have
+link:https://gerrit.googlesource.com/gerrit/+/master/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata-it_test.html[long-term
+support via integration test]:
+
+* `display`
++
+can be set to `none` to hide a section.