diff --git a/vendor/fxnode/UPSTREAM.md b/vendor/fxnode/UPSTREAM.md
index ca8b17a..30091e5 100644
--- a/vendor/fxnode/UPSTREAM.md
+++ b/vendor/fxnode/UPSTREAM.md
@@ -1,8 +1,8 @@
 # fxnode upstream provenance
 
 - Source: https://github.com/Heaust-ops/fxnode
-- Commit: `4e96585e99742959660d4107b0078c27ff13e708`
-- Tree: `4fcafa60557bcbd760d7aa8d8898c0adbe0bb2c8`
+- Commit: `618c4e02265568d542350902217641d1bbf1ef40`
+- Tree: `03fd4246af80f2e4c855369c5dcf362157c6ef58`
 - Imported: 2026-07-29
 - License: MIT (see `LICENSE` and `NOTICE.md`)
 - Local patches: none
@@ -14,8 +14,8 @@ This directory is a committed source snapshot. Application adaptations belong ou
 
 ```sh
 git clone --filter=blob:none https://github.com/Heaust-ops/fxnode /tmp/fxnode
-git -C /tmp/fxnode fetch --depth=1 origin 4e96585e99742959660d4107b0078c27ff13e708
-git -C /tmp/fxnode checkout --detach 4e96585e99742959660d4107b0078c27ff13e708
+git -C /tmp/fxnode fetch --depth=1 origin 618c4e02265568d542350902217641d1bbf1ef40
+git -C /tmp/fxnode checkout --detach 618c4e02265568d542350902217641d1bbf1ef40
 rm -rf vendor/fxnode
 mkdir -p vendor/fxnode
 git -C /tmp/fxnode archive HEAD | tar -x -C vendor/fxnode
diff --git a/vendor/fxnode/src/layout/types.ts b/vendor/fxnode/src/layout/types.ts
index 4f1aed3..4988e87 100644
--- a/vendor/fxnode/src/layout/types.ts
+++ b/vendor/fxnode/src/layout/types.ts
@@ -204,3 +204,11 @@ export function layoutSocketsCompatible(from: LayoutSocket, to: LayoutSocket): b
     from.direction === "output" && to.direction === "input" && (to.wildcardInput || to.accepts.includes(from.dataType))
   );
 }
+
+export function layoutSocketAcceptsLink(from: LayoutSocket, to: LayoutSocket): boolean {
+  return (
+    from.nodeId !== to.nodeId &&
+    layoutSocketsCompatible(from, to) &&
+    (to.capacity === 1 || to.linkIds.length < to.capacity)
+  );
+}
diff --git a/vendor/fxnode/src/render/canvas-renderer.ts b/vendor/fxnode/src/render/canvas-renderer.ts
index 6028296..dce97a4 100644
--- a/vendor/fxnode/src/render/canvas-renderer.ts
+++ b/vendor/fxnode/src/render/canvas-renderer.ts
@@ -2,7 +2,7 @@ import { GEOMETRY as G } from "../layout/constants.js";
 import { worldToView } from "../layout/geometry.js";
 import type { LinkId, NodeId, ParameterValue, SocketId } from "../core/types.js";
 import {
-  layoutSocketsCompatible,
+  layoutSocketAcceptsLink,
   type LayoutControl,
   type LayoutSnapshot,
   type LayoutSocket,
@@ -755,11 +755,24 @@ export function renderCanvas(
       context.bezierCurveTo(a.x + dx, a.y, b.x - dx, b.y, b.x, b.y);
       context.stroke();
       for (const socket of snapshot.sockets.values()) {
-        if (layoutSocketsCompatible(from, socket)) {
-          const p = worldToView(socket.anchor, t);
+        if (layoutSocketAcceptsLink(from, socket)) {
+          const candidate = socket.id === interaction.linkDrag.candidate;
           context.beginPath();
-          context.arc(p.x, p.y, socket.id === interaction.linkDrag.candidate ? 10 : 8, 0, Math.PI * 2);
-          context.strokeStyle = socket.id === interaction.linkDrag.candidate ? theme.emphasis : socket.color;
+          if (socket.shape === "multi-input" && socket.bounds) {
+            const topLeft = worldToView({ x: socket.bounds.x, y: socket.bounds.y }, t),
+              padding = candidate ? 4 : 2;
+            context.roundRect(
+              topLeft.x - padding,
+              topLeft.y - padding,
+              socket.bounds.width * t.zoom + padding * 2,
+              socket.bounds.height * t.zoom + padding * 2,
+              G.socket * t.zoom + padding,
+            );
+          } else {
+            const p = worldToView(socket.anchor, t);
+            context.arc(p.x, p.y, candidate ? 10 : 8, 0, Math.PI * 2);
+          }
+          context.strokeStyle = candidate ? theme.emphasis : socket.color;
           context.stroke();
         }
       }
diff --git a/vendor/fxnode/src/worker/interaction.ts b/vendor/fxnode/src/worker/interaction.ts
index 4424d3d..c86f9bb 100644
--- a/vendor/fxnode/src/worker/interaction.ts
+++ b/vendor/fxnode/src/worker/interaction.ts
@@ -3,7 +3,7 @@ import type { Command } from "../commands/types.js";
 import { viewToWorld } from "../layout/geometry.js";
 import { GEOMETRY as G } from "../layout/constants.js";
 import {
-  layoutSocketsCompatible,
+  layoutSocketAcceptsLink,
   type LayoutControl,
   type LayoutSnapshot,
   type Rect,
@@ -219,7 +219,7 @@ export const boxNodes = (layout: LayoutSnapshot, a: Vec2, b: Vec2): NodeId[] =>
 export const compatibleTargets = (layout: LayoutSnapshot, fromId: SocketId) => {
   const from = layout.sockets.get(fromId);
   if (!from || from.direction !== "output") return [];
-  return [...layout.sockets.values()].filter((to) => to.nodeId !== from.nodeId && layoutSocketsCompatible(from, to));
+  return [...layout.sockets.values()].filter((to) => layoutSocketAcceptsLink(from, to));
 };
 export function planLink(
   layout: LayoutSnapshot,
@@ -230,8 +230,9 @@ export function planLink(
   const from = layout.sockets.get(fromId),
     to = layout.sockets.get(toId);
   if (!from || !to || !compatibleTargets(layout, fromId).some((s) => s.id === toId)) return;
+  const replacing = to.capacity === 1 && to.linkIds.length > 0;
   const link: GraphLink = {
-    id: to.linkIds[0] ?? newId,
+    id: replacing ? to.linkIds[0]! : newId,
     fromNodeId: from.nodeId,
     fromSocketId: from.id,
     toNodeId: to.nodeId,
@@ -239,9 +240,7 @@ export function planLink(
     muted: false,
     extensions: {},
   };
-  return to.capacity === 1 && to.linkIds.length
-    ? { type: "link.replace", removeId: to.linkIds[0]!, link }
-    : { type: "link.add", link };
+  return replacing ? { type: "link.replace", removeId: to.linkIds[0]!, link } : { type: "link.add", link };
 }
 export const clampResize = (layout: LayoutSnapshot, id: NodeId, world: Vec2): Vec2 | undefined => {
   const n = layout.nodes.get(id);
diff --git a/vendor/fxnode/test/browser/examples.spec.ts b/vendor/fxnode/test/browser/examples.spec.ts
index 46a62ef..ceb3c51 100644
--- a/vendor/fxnode/test/browser/examples.spec.ts
+++ b/vendor/fxnode/test/browser/examples.spec.ts
@@ -161,6 +161,51 @@ test("logic nodes accept five links through one input and application evaluation
   expect(initial.incoming).toBe(5);
   expect(initial.labels).toContain("AND: false");
 
+  await page.evaluate(async () => {
+    const view = window.fxnodeStandalone.view!;
+    const modifiers = { alt: false, control: false, meta: false, shift: false };
+    view.feedInput({
+      kind: "pointer",
+      phase: "down",
+      pointerId: 41,
+      pointerType: "mouse",
+      position: { x: 353, y: 190 },
+      button: 0,
+      buttons: 1,
+      modifiers,
+    });
+    view.feedInput({
+      kind: "pointer",
+      phase: "move",
+      pointerId: 41,
+      pointerType: "mouse",
+      position: { x: 464, y: 468 },
+      button: 0,
+      buttons: 1,
+      modifiers,
+    });
+    await view.whenRendered();
+    view.feedInput({
+      kind: "pointer",
+      phase: "up",
+      pointerId: 41,
+      pointerType: "mouse",
+      position: { x: 464, y: 468 },
+      button: 0,
+      buttons: 0,
+      modifiers,
+    });
+  });
+  await expect
+    .poll(() =>
+      page.evaluate(() =>
+        window.fxnodeStandalone
+          .root!.getState()
+          .then((state) => state.links.filter((link) => link.toSocketId === "or:inputs").length),
+      ),
+    )
+    .toBe(4);
+
   await page.evaluate(async () => {
     const root = window.fxnodeStandalone.root!;
     const source = (await root.getState()).nodes.find((node) => node.id === "c")!;
diff --git a/vendor/fxnode/test/layout.test.ts b/vendor/fxnode/test/layout.test.ts
index 7ffec61..ab2f7c6 100644
--- a/vendor/fxnode/test/layout.test.ts
+++ b/vendor/fxnode/test/layout.test.ts
@@ -497,6 +497,14 @@ test("multi-input sockets use pill hit bounds and stable per-link anchors", () =
   for (const [id, anchor] of socket.linkAnchors) {
     assert.deepEqual(snapshot.links.get(id)!.points.at(-1), anchor);
   }
+  const next = planLink(
+    snapshot,
+    sources[0]!.sockets.find((candidate) => candidate.key === "mesh")!.id,
+    socket.id,
+    linkId("fresh-link"),
+  );
+  assert.equal(next?.type, "link.add");
+  if (next?.type === "link.add") assert.equal(next.link.id, linkId("fresh-link"));
   assert.deepEqual(hitTest(snapshot, worldToView({ x: socket.anchor.x, y: socket.bounds!.y - 2 }, transform)), {
     kind: "socket",
     id: socket.id,