diff --git a/index.html b/index.html
index 67c72b4..39fbb60 100644
--- a/index.html
+++ b/index.html
@@ -285,6 +285,8 @@
   /* runna card */
   .card-runna { border-top-color: #3DF58A; }
   .card-runna .badge-preview { color: #3DF58A; border-color: rgba(61,245,138,0.3); background: rgba(61,245,138,0.06); }
+  .card-assembly-differ { border-top-color: #FF4FD8; }
+  .card-assembly-differ .badge-stable { color: #FF4FD8; border-color: rgba(255,79,216,0.3); background: rgba(255,79,216,0.06); }
   .card-arrow {
     position: absolute;
     top: 20px;
@@ -618,6 +620,16 @@ <h1><span>Modern .NET</span> libraries<br/>and CLIs. <span>Great DX.</span></h1>
           </div>
         </a>
 
+        <a class="project-card card-assembly-differ" href="https://github.com/nullean/assembly-differ">
+          <span class="card-arrow">↗</span>
+          <div class="card-lockup"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 372 96" width="372" height="96" role="img" aria-label="assembly-differ"><style>.adpsh{animation:adpsw 4.6s ease-in-out infinite}@keyframes adpsw{0%,64%{transform:translateX(0)}92%,100%{transform:translateX(521px)}}.adpr{animation:adpl 4.2s cubic-bezier(.34,1.56,.64,1) infinite}@keyframes adpl{0%,18%{transform:translateY(0)}36%,72%{transform:translateY(-6px)}90%,100%{transform:translateY(0)}}@media (prefers-reduced-motion:reduce){[class^="adp"]{animation:none!important}}</style><defs><linearGradient id="adpf" x1="0" y1=".2" x2="1" y2=".8"><stop offset=".44" stop-color="#ffb547"/><stop offset=".56" stop-color="#ff4fd8"/></linearGradient><radialGradient id="adpg" cx=".18" cy=".12" r="1.2"><stop offset="0" stop-color="#1b2126"/><stop offset=".55" stop-color="#0d1013"/><stop offset="1" stop-color="#08090b"/></radialGradient><linearGradient id="adps" x1="0" y1="0" x2="1" y2="0"><stop offset=".35" stop-color="#fff" stop-opacity="0"/><stop offset=".5" stop-color="#fff" stop-opacity=".8"/><stop offset=".65" stop-color="#fff" stop-opacity="0"/></linearGradient><mask id="adpm"><rect width="372" height="96" fill="#fff"/><rect x="5" y="5" width="362" height="86" fill="#000"/></mask><linearGradient id="adpla" x1="0" y1="0" x2="0" y2="1"><stop offset="0" stop-color="#ffd890"/><stop offset=".55" stop-color="#ffb547"/><stop offset="1" stop-color="#f08a2c"/></linearGradient><linearGradient id="adpra" x1="0" y1="0" x2="0" y2="1"><stop offset="0" stop-color="#ff9cf0"/><stop offset=".55" stop-color="#ff4fd8"/><stop offset="1" stop-color="#c932c4"/></linearGradient></defs><rect width="372" height="96" rx="10" fill="url(#adpf)"/><g mask="url(#adpm)"><rect class="adpsh" x="-120" y="-20" width="120" height="136" fill="url(#adps)" transform="skewX(-18)"/></g><rect x="5" y="5" width="362" height="86" rx="5" fill="url(#adpg)"/><g transform="translate(14 16)"><path d="M32 4 L5 54 L37 60 Z" fill="url(#adpla)" stroke="url(#adpla)" stroke-linejoin="round" stroke-width="2.4"/><path d="M32 6 L7 53" stroke="#fff" stroke-opacity=".4" stroke-width="1.4" stroke-linecap="round"/><g class="adpr"><path d="M32 4 L37 60 L60 49 Z" fill="url(#adpra)" stroke="url(#adpra)" stroke-linejoin="round" stroke-width="2.4"/><path d="M32 4 L37 60 L60 49 Z" fill="#000" fill-opacity=".18"/><path d="M33 7 L58.5 48.5" stroke="#fff" stroke-opacity=".3" stroke-width="1.2" stroke-linecap="round"/></g></g><g font-family="JetBrains Mono, ui-monospace, SFMono-Regular, Menlo, monospace" font-weight="700"><text x="90" y="59" font-size="29" letter-spacing="-1" fill="#ffffff">assembly<tspan fill="#ffb547">-</tspan>differ</text></g></svg></div>
+          <p class="card-tagline">Public API diffs for .NET. Suggests the version bump, labels pull requests, and shows agents what a package update breaks in their code.</p>
+          <div class="card-meta">
+            <span class="card-nuget">nuget <code>assembly-differ</code> · <code>assembly-differ.skills</code></span>
+            <span class="badge badge-stable">stable</span>
+          </div>
+        </a>
+
       </div>
     </div>
   </section>
diff --git a/projects.yml b/projects.yml
index 3aee653..384b2be 100644
--- a/projects.yml
+++ b/projects.yml
@@ -39,6 +39,14 @@ projects:
     nuget: Runna
     status: preview
 
+  - id: assembly-differ
+    name: assembly-differ
+    tagline: Public API diffs for .NET. Suggests the version bump, labels pull requests, and shows agents what a package update breaks in their code.
+    url: https://github.com/nullean/assembly-differ
+    repo: nullean/assembly-differ
+    nuget: assembly-differ
+    status: stable
+
   # - id: formatter
   #   name: Kerf
   #   tagline: Syntax and semantic style enforcement for C#.