diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 37ab699..688e380 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -11,8 +11,9 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  build:
+  build_jupyter-chat:
     runs-on: ubuntu-latest
+    name: Build jupyter_chat
 
     steps:
     - name: Checkout
@@ -24,48 +25,55 @@ jobs:
     - name: Install dependencies
       run: python -m pip install -U "jupyterlab>=4.0.0,<5"
 
-    - name: Lint the extension
+    - name: Lint the packages
       run: |
         set -eux
         jlpm
         jlpm run lint:check
 
+    - name: Build the core package
+      run: jlpm build:core
+
     - name: Test the packages
       run: |
         set -eux
         jlpm run test
 
-    - name: Build packages
-      run: jlpm build
+  build_extensions:
+    runs-on: ubuntu-latest
+    needs: build_jupyter-chat
+    strategy:
+      matrix:
+        extension: [collaborative, ws]
+    name: Build ${{ matrix.extension }} chat extension
 
-    - name: Package jupyterlab_ws_chat
-      working-directory: packages/jupyterlab-ws-chat
-      run: |
-        set -eux
-        pip install build
-        python -m build
-        pip uninstall -y "jupyterlab_ws_chat" jupyterlab
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
 
-    - name: Upload jupyterlab_ws_chat packages
-      uses: actions/upload-artifact@v3
-      with:
-        name: package-artifacts
-        path: packages/jupyterlab-ws-chat/dist/jupyterlab_ws_chat*
-        if-no-files-found: error
+    - name: Base Setup
+      uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
+
+    - name: Install dependencies
+      run: python -m pip install -U "jupyterlab>=4.0.0,<5"
+
+    - name: Build package
+      run:  |
+        jlpm install
+        jlpm build:${{ matrix.extension }}
 
-    - name: Package jupyterlab_collaborative_chat
-      working-directory: packages/jupyterlab-collaborative-chat
+    - name: Package extension
       run: |
         set -eux
-        pip install build
-        python -m build
-        pip uninstall -y "jupyterlab_collaborative_chat" jupyterlab
+        pip install build packages/jupyterlab-${{ matrix.extension }}-chat
+        python -m build packages/jupyterlab-${{ matrix.extension }}-chat
+        pip uninstall -y "jupyterlab_${{ matrix.extension }}_chat" jupyterlab
 
-    - name: Upload jupyterlab_collaborative_chat packages
+    - name: Upload package
       uses: actions/upload-artifact@v3
       with:
-        name: package-artifacts
-        path: packages/jupyterlab-collaborative-chat/dist/jupyterlab_collaborative_chat*
+        name: jupyterlab_${{ matrix.extension }}_chat-artifacts
+        path: packages/jupyterlab-${{ matrix.extension }}-chat/dist/jupyterlab_${{ matrix.extension }}_chat*
         if-no-files-found: error
 
   check_links:
diff --git a/README.md b/README.md
index 21d7bee..2e53176 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@
 
 [![Github Actions Status](https://github.com/jupyterlab-contrib/jupyter-chat/workflows/Build/badge.svg)](https://github.com/jupyterlab-contrib/jupyter-chat/actions/workflows/build.yml)
 
-A chat package for Jupyterlab extension, but also an extension for Jupyterab.
+This project is a monorepo containing the frontend components and extensions to build
+a chat in Jupyter.
 
 A lot of the components of this chat project come from
 [jupyter-ai](https://github.com/jupyterlab/jupyter-ai).
@@ -15,18 +16,29 @@ The typescript package is located in *packages/jupyter-chat* and builds an NPM
 package named `chat-jupyter`.
 
 This package provides a frontend library (using react), and is intended to be
-used by a jupyterlab extension.
+used by a jupyterlab extension to create a chat.
 
-### Jupyterab extension
+### Jupyterlab extensions
 
-The Jupyterlab extension is located in *packages/jupyterlab-ws-chat*.
+#### Chat extension based on shared document: *packages/jupyterlab-collaborative-chat*
 
-It is composed of a Python package named `jupyterlab_ws_chat`
-for the server side and a NPM package named `jupyterlab-ws-chat`.
+This extension is an implementation of the `chat-jupyter` package, relying on
+shared document (see [jupyter_ydoc](https://github.com/jupyter-server/jupyter_ydoc)).
+
+It is composed of:
+
+- a Python package named `jupyterlab_collaborative_chat`, which register
+  the `YChat` shared document in jupyter_ydoc
+- a NPM package named `jupyterlab-collaborative-chat`.
+
+#### Chat extension based on websocket: *packages/jupyterlab-ws-chat*
 
 This extension is an implementation of the `chat-jupyter` package, relying on
 websocket for the communication between server and front end.
 
+It is composed of a Python package named `jupyterlab_ws_chat`
+for the server side and a NPM package named `jupyterlab-ws-chat`.
+
 ## Contributing
 
 See the contributing part of each package for details.
diff --git a/package.json b/package.json
index 467827b..765dd8a 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
         "build": "lerna run build --stream",
         "build:core": "lerna run build --stream --scope \"chat-jupyter\"",
         "build:collaborative": "lerna run build --scope=jupyterlab-collaborative-chat --include-filtered-dependencies",
-        "build:websocket": "lerna run build --scope=jupyterlab-ws-chat --include-filtered-dependencies",
+        "build:ws": "lerna run build --scope=jupyterlab-ws-chat --include-filtered-dependencies",
         "build:prod": "lerna run build:prod --stream",
         "clean": "lerna run clean",
         "clean:all": "lerna run clean:all",
diff --git a/packages/jupyterlab-collaborative-chat/README.md b/packages/jupyterlab-collaborative-chat/README.md
index 0d97d5a..81f5de2 100644
--- a/packages/jupyterlab-collaborative-chat/README.md
+++ b/packages/jupyterlab-collaborative-chat/README.md
@@ -7,6 +7,11 @@ This extension is composed of a Python package named `jupyterlab_collaborative_c
 for the server extension and a NPM package named `jupyterlab-collaborative-chat`
 for the frontend extension.
 
+This extension registers a `YChat` shared document, and associate the document to a
+chat widget in the front end.
+
+![screenshot](screenshot.gif 'collaborative chat extension')
+
 ## Requirements
 
 - JupyterLab >= 4.0.0
diff --git a/packages/jupyterlab-collaborative-chat/screenshot.gif b/packages/jupyterlab-collaborative-chat/screenshot.gif
new file mode 100644
index 0000000..182e476
Binary files /dev/null and b/packages/jupyterlab-collaborative-chat/screenshot.gif differ
diff --git a/packages/jupyterlab-ws-chat/README.md b/packages/jupyterlab-ws-chat/README.md
index a2adf6e..5bbb63c 100644
--- a/packages/jupyterlab-ws-chat/README.md
+++ b/packages/jupyterlab-ws-chat/README.md
@@ -7,7 +7,7 @@ A chat extension for Jupyterlab
 This package is composed of a Python package named `jupyterlab_ws_chat`
 for the server side and a NPM package named `jupyterlab-ws-chat`
 
-![screenshot](screenshot.png 'chat extension')
+![screenshot](screenshot.png 'WS chat extension')
 
 ## Requirements
 
diff --git a/scripts/install.sh b/scripts/install.sh
index d77333d..ffd0949 100755
--- a/scripts/install.sh
+++ b/scripts/install.sh
@@ -2,14 +2,21 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 
+EXTENSION=$1
 
 # install core packages
 pip install jupyterlab~=4.0
 jlpm install
-jlpm build
 
-# install the collaborative chat extension
-pip install -e packages/jupyterlab-collaborative-chat[test]
+if [ -z "${EXTENSION}" ]; then
+  jlpm build
+  # install the collaborative chat extension
+  pip install -e packages/jupyterlab-collaborative-chat[test]
 
-# install websocket chat extension
-pip install -e packages/jupyterlab-ws-chat[test]
+  # install websocket chat extension
+  pip install -e packages/jupyterlab-ws-chat[test]
+else
+  PACKAGE="jupyterlab-${EXTENSION}-chat"
+  jlpm build:${EXTENSION}
+  pip install -e packages/${PACKAGE}[test]
+fi