diff --git a/.github/workflows/check-urls.yml b/.github/workflows/check-urls.yml
new file mode 100644
index 00000000..67d77310
--- /dev/null
+++ b/.github/workflows/check-urls.yml
@@ -0,0 +1,47 @@
+name: Check URLs
+
+on:
+  pull_request:
+    branches: [main]
+  schedule:
+    #        ┌───────────── minute (0 - 59)
+    #        │  ┌───────────── hour (0 - 23)
+    #        │  │ ┌───────────── day of the month (1 - 31)
+    #        │  │ │ ┌───────────── month (1 - 12 or JAN-DEC)
+    #        │  │ │ │ ┌───────────── day of the week (0 - 6 or SUN-SAT)
+    #        │  │ │ │ │
+    #        │  │ │ │ │
+    #        │  │ │ │ │
+    #        *  * * * *
+    - cron: '30 1 * * 0'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: urls-checker-code
+      uses: urlstechie/urlchecker-action@master
+      with:
+        subfolder: onnx_array_api
+        file_types: .md,.py,.rst,.ipynb
+        print_all: false
+        timeout: 2
+        retry_count# : 2
+        # exclude_urls: https://dumps.wikimedia.org/other/pageviews/%Y/%Y-%m/pageviews-%Y%m%d-%H0000.gz,https://dumps.wikimedia.org/frwiki/latest/latest-all-titles-in-ns0.gz
+        exclude_patterns: https://dumps.wikimedia.org/
+        # force_pass : true
+
+    - name: urls-checker-docs
+      uses: urlstechie/urlchecker-action@master
+      with:
+        subfolder: _doc
+        file_types: .md,.py,.rst,.ipynb
+        print_all: false
+        timeout: 2
+        retry_count# : 2
+        exclude_urls: https://hal.archives-ouvertes.fr/hal-00990252/document
+        exclude_patterns: https://www.data.gouv.fr/fr/datasets/r/e3d83ab3-dc52-4c99-abaf-8a38050cc68c,https://dev.azure.com/
+        # force_pass : true
diff --git a/_doc/LICENSE.txt b/_doc/LICENSE.txt
new file mode 100644
index 00000000..fa034ef7
--- /dev/null
+++ b/_doc/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2023, Xavier Dupré
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
\ No newline at end of file
diff --git a/_doc/api/ortops.rst b/_doc/api/ortops.rst
index b4ea9007..fdec4a5d 100644
--- a/_doc/api/ortops.rst
+++ b/_doc/api/ortops.rst
@@ -4,7 +4,7 @@ ortops
 ======
 
 .. toctree::
-    :maxdepth:
+    :maxdepth: 2
 
     ortops_tutorial
     ortops_optim
diff --git a/_doc/tutorial/index.rst b/_doc/tutorial/index.rst
index c15766f3..50db0c30 100644
--- a/_doc/tutorial/index.rst
+++ b/_doc/tutorial/index.rst
@@ -17,4 +17,4 @@ Introduction
     usefulcmd
     install_cuda_wsl
     build
-    example
+    examples