diff --git a/index.html b/index.html
index efedf42..5fa28b2 100644
--- a/index.html
+++ b/index.html
@@ -209,12 +209,16 @@ <h2 id="class-3">Class 3</h2>
 <h2 id="class-4">Class 4</h2>
 <ul>
 <li><p><a href="three.html">Using a custom GLSL shader in Three.js</a></p>
+<ul>
+<li><a href="https://codepen.io/grrrwaaa/pen/zYQxpyG?editors=0010">In class script</a></li>
+</ul>
 </li>
 <li><p><a href="nodejs.html">Node.js introduction</a></p>
 <ul>
 <li>Creating a server that can serve HTML pages</li>
 <li>Adding websockets for live updates</li>
 <li>Update a three.js scene with multiple live users</li>
+<li>The code from today: <a href="https://github.com/worldmaking/2024-datt4520-digm5520">https://github.com/worldmaking/2024-datt4520-digm5520</a> </li>
 </ul>
 </li>
 <li><p>Project discussion</p>
diff --git a/index.md b/index.md
index cd21a17..ea62a4b 100644
--- a/index.md
+++ b/index.md
@@ -114,11 +114,13 @@ Instructor: [Graham Wakefield](https://ampd.yorku.ca/profile/graham-wakefield/)
 ## Class 4
 
 - [Using a custom GLSL shader in Three.js](three.html)
+  - [In class script](https://codepen.io/grrrwaaa/pen/zYQxpyG?editors=0010)
 
 - [Node.js introduction](nodejs.html)
   - Creating a server that can serve HTML pages
   - Adding websockets for live updates
   - Update a three.js scene with multiple live users
+  - The code from today: https://github.com/worldmaking/2024-datt4520-digm5520 
 
 - Project discussion