diff --git a/apps/web/src/components/ObjectTree.tsx b/apps/web/src/components/ObjectTree.tsx
new file mode 100644
index 0000000..257ccff
--- /dev/null
+++ b/apps/web/src/components/ObjectTree.tsx
@@ -0,0 +1,68 @@
+import type { ObjectTreeNode } from '@tts/extract';
+
+interface Props {
+  nodes: ObjectTreeNode[];
+  selectedGuid: string | null;
+  onSelect: (guid: string) => void;
+}
+
+export default function ObjectTree({ nodes, selectedGuid, onSelect }: Props) {
+  return (
+    <ul className="space-y-0.5">
+      {nodes.map((node) => (
+        <TreeNode
+          key={node.object.GUID}
+          node={node}
+          depth={0}
+          selectedGuid={selectedGuid}
+          onSelect={onSelect}
+        />
+      ))}
+    </ul>
+  );
+}
+
+function TreeNode({
+  node,
+  depth,
+  selectedGuid,
+  onSelect,
+}: {
+  node: ObjectTreeNode;
+  depth: number;
+  selectedGuid: string | null;
+  onSelect: (guid: string) => void;
+}) {
+  const selected = node.object.GUID === selectedGuid;
+  return (
+    <li>
+      <button
+        onClick={() => onSelect(node.object.GUID)}
+        style={{ paddingLeft: `${depth * 16 + 8}px` }}
+        className={`block w-full truncate rounded px-2 py-1 text-left text-sm ${
+          selected
+            ? 'bg-zinc-700 text-zinc-100'
+            : 'text-zinc-300 hover:bg-zinc-800 hover:text-zinc-100'
+        }`}
+      >
+        <span className="mr-1.5 rounded bg-zinc-800 px-1 py-0.5 text-xs uppercase text-zinc-500">
+          {node.object.Name}
+        </span>
+        <span className="truncate">{node.label}</span>
+      </button>
+      {node.children.length > 0 && (
+        <ul>
+          {node.children.map((child) => (
+            <TreeNode
+              key={child.object.GUID}
+              node={child}
+              depth={depth + 1}
+              selectedGuid={selectedGuid}
+              onSelect={onSelect}
+            />
+          ))}
+        </ul>
+      )}
+    </li>
+  );
+}
\ No newline at end of file
diff --git a/apps/web/src/components/viewers.tsx b/apps/web/src/components/viewers.tsx
new file mode 100644
index 0000000..428f36a
--- /dev/null
+++ b/apps/web/src/components/viewers.tsx
@@ -0,0 +1,46 @@
+import type { ReactNode } from 'react';
+import type { TTSObject } from '@tts/shared';
+
+/**
+ * A viewer renders a single selected object. Custom viewers can be registered
+ * per object class (`Name`) and will take precedence over the default viewer.
+ */
+export interface ObjectViewer {
+  /** The object class this viewer handles, e.g. `Card`, `Bag`. */
+  name: string;
+  component: (props: { object: TTSObject }) => ReactNode;
+}
+
+const registry = new Map<string, ObjectViewer['component']>();
+
+/** Register a viewer for a specific object class. */
+export function registerViewer(name: string, component: ObjectViewer['component']) {
+  registry.set(name, component);
+}
+
+/** Resolve the viewer for an object, falling back to the default viewer. */
+export function resolveViewer(object: TTSObject): ObjectViewer['component'] {
+  return registry.get(object.Name) ?? DefaultViewer;
+}
+
+/** The default viewer: a plain inspection of the object's fields. */
+export function DefaultViewer({ object }: { object: TTSObject }) {
+  return (
+    <dl className="grid grid-cols-1 gap-2 text-sm sm:grid-cols-2">
+      {Object.entries(object).map(([key, value]) => (
+        <div key={key} className="rounded-lg border border-zinc-800 bg-zinc-900 p-3">
+          <dt className="font-mono text-xs uppercase text-zinc-500">{key}</dt>
+          <dd className="mt-1 break-words text-zinc-200">
+            {typeof value === 'string' || typeof value === 'number' ? (
+              value
+            ) : (
+              <pre className="whitespace-pre-wrap font-mono text-xs">
+                {JSON.stringify(value, null, 2)}
+              </pre>
+            )}
+          </dd>
+        </div>
+      ))}
+    </dl>
+  );
+}
\ No newline at end of file
diff --git a/apps/web/src/pages/ModPage.tsx b/apps/web/src/pages/ModPage.tsx
index 9e74fd5..5a76309 100644
--- a/apps/web/src/pages/ModPage.tsx
+++ b/apps/web/src/pages/ModPage.tsx
@@ -1,32 +1,42 @@
-import { useEffect } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 import { useParams } from 'react-router-dom';
-import { collectRefs, flattenObjects } from '@tts/extract';
+import { buildTree, collectRefs } from '@tts/extract';
 import { useModStore } from '../stores/modStore';
 import { useSearchStore } from '../stores/searchStore';
 import { modFileUrl } from '../api';
+import ObjectTree from '../components/ObjectTree';
+import { resolveViewer } from '../components/viewers';
 
 export default function ModPage() {
   const { id } = useParams<{ id: string }>();
   const { mod, loading, error, load } = useModStore();
   const item = useSearchStore((s) => s.items.find((i) => i.id === id));
+  const [selectedGuid, setSelectedGuid] = useState<string | null>(null);
 
   useEffect(() => {
     if (id) load(id, item?.fileUrl);
   }, [id, item?.fileUrl, load]);
 
+  const tree = useMemo(() => (mod ? buildTree(mod) : []), [mod]);
+  const refs = useMemo(() => (mod ? collectRefs(mod) : []), [mod]);
+
+  const selected = useMemo(
+    () => (mod ? findInTree(tree, selectedGuid) : undefined),
+    [tree, selectedGuid],
+  );
+
   if (loading) return <p className="text-sm text-zinc-400">Loading mod…</p>;
   if (error) return <p className="text-sm text-red-400">{error}</p>;
   if (!mod) return <p className="text-sm text-zinc-500">No mod loaded.</p>;
 
-  const objects = flattenObjects(mod);
-  const refs = collectRefs(mod);
+  const Viewer = selected ? resolveViewer(selected.object) : null;
 
   return (
     <div className="space-y-6">
       <div>
         <h1 className="text-2xl font-semibold">Mod {id}</h1>
         <p className="mt-1 text-sm text-zinc-400">
-          {mod.GameMode} · {mod.Date} · {objects.length} objects · {refs.length}{' '}
+          {mod.GameMode} · {mod.Date} · {tree.length} objects · {refs.length}{' '}
           asset refs
         </p>
         <a
@@ -37,42 +47,49 @@ export default function ModPage() {
         </a>
       </div>
 
-      <section>
-        <h2 className="mb-2 text-lg font-semibold">Asset references</h2>
-        {refs.length === 0 ? (
-          <p className="text-sm text-zinc-500">No external assets found.</p>
-        ) : (
-          <ul className="space-y-1">
-            {refs.map((ref) => (
-              <li key={ref.url} className="flex items-center gap-2 text-sm">
-                <span className="rounded bg-zinc-800 px-1.5 py-0.5 text-xs uppercase text-zinc-400">
-                  {ref.kind}
-                </span>
-                <a
-                  href={ref.url}
-                  target="_blank"
-                  rel="noreferrer"
-                  className="truncate text-zinc-300 hover:text-zinc-100"
-                >
-                  {ref.url}
-                </a>
-              </li>
-            ))}
-          </ul>
-        )}
-      </section>
+      <div className="grid grid-cols-1 gap-6 lg:grid-cols-[280px_1fr]">
+        <aside className="rounded-lg border border-zinc-800 bg-zinc-900 p-2">
+          <ObjectTree
+            nodes={tree}
+            selectedGuid={selectedGuid}
+            onSelect={setSelectedGuid}
+          />
+        </aside>
 
-      <section>
-        <h2 className="mb-2 text-lg font-semibold">Objects</h2>
-        <ul className="divide-y divide-zinc-800 rounded-lg border border-zinc-800">
-          {objects.map((o) => (
-            <li key={o.GUID} className="flex items-center justify-between px-3 py-2 text-sm">
-              <span className="font-medium">{o.Name}</span>
-              <span className="font-mono text-xs text-zinc-500">{o.GUID}</span>
-            </li>
-          ))}
-        </ul>
-      </section>
+        <section className="rounded-lg border border-zinc-800 bg-zinc-900 p-4">
+          {selected ? (
+            <>
+              <header className="mb-4">
+                <span className="rounded bg-zinc-800 px-1.5 py-0.5 text-xs uppercase text-zinc-400">
+                  {selected.object.Name}
+                </span>
+                <h2 className="mt-1 text-lg font-semibold">{selected.label}</h2>
+                <p className="font-mono text-xs text-zinc-500">
+                  {selected.object.GUID}
+                </p>
+              </header>
+              {Viewer && <Viewer object={selected.object} />}
+            </>
+          ) : (
+            <p className="text-sm text-zinc-500">
+              Select an object from the tree to inspect it.
+            </p>
+          )}
+        </section>
+      </div>
     </div>
   );
+}
+
+function findInTree(
+  nodes: ReturnType<typeof buildTree>,
+  guid: string | null,
+): ReturnType<typeof buildTree>[number] | undefined {
+  if (!guid) return undefined;
+  for (const node of nodes) {
+    if (node.object.GUID === guid) return node;
+    const found = findInTree(node.children, guid);
+    if (found) return found;
+  }
+  return undefined;
 }
\ No newline at end of file