diff --git a/tools/router-gate-decide.mjs b/tools/router-gate-decide.mjs
new file mode 100644
index 00000000..c7dce650
--- /dev/null
+++ b/tools/router-gate-decide.mjs
@@ -0,0 +1,12 @@
+/**
+ * Compare router recommendation (e.g. "#19", "superpowers:writing-plans", "writing-plans")
+ * with a registry node (id/slug/name). Returns true if any match.
+ */
+export function nodeMatches(recommendation, node) {
+  if (!recommendation || !node) return false;
+  return (
+    recommendation === node.id ||
+    recommendation === node.slug ||
+    recommendation === node.name
+  );
+}
diff --git a/tools/router-gate-decide.test.mjs b/tools/router-gate-decide.test.mjs
new file mode 100644
index 00000000..3f725b78
--- /dev/null
+++ b/tools/router-gate-decide.test.mjs
@@ -0,0 +1,28 @@
+import { describe, it, expect } from 'vitest';
+import { nodeMatches } from './router-gate-decide.mjs';
+
+describe('nodeMatches', () => {
+  it('matches #NN to node.id', () => {
+    expect(nodeMatches('#19', { name: 'writing-plans', id: '#19', slug: 'superpowers:writing-plans' })).toBe(true);
+  });
+
+  it('matches superpowers:X to canonical slug', () => {
+    expect(nodeMatches('superpowers:writing-plans', { name: 'writing-plans', id: '#19', slug: 'superpowers:writing-plans' })).toBe(true);
+  });
+
+  it('matches by name', () => {
+    expect(nodeMatches('writing-plans', { name: 'writing-plans', id: '#19', slug: 'superpowers:writing-plans' })).toBe(true);
+  });
+
+  it('rejects mismatch', () => {
+    expect(nodeMatches('#20', { name: 'writing-plans', id: '#19', slug: 'superpowers:writing-plans' })).toBe(false);
+  });
+
+  it('handles null recommendation', () => {
+    expect(nodeMatches(null, { name: 'writing-plans', id: '#19', slug: 'superpowers:writing-plans' })).toBe(false);
+  });
+
+  it('handles null node', () => {
+    expect(nodeMatches('#19', null)).toBe(false);
+  });
+});