diff --git a/shared/src/collab/collab.schema.ts b/shared/src/collab/collab.schema.ts
index be2a083bf..7d9a2a497 100644
--- a/shared/src/collab/collab.schema.ts
+++ b/shared/src/collab/collab.schema.ts
@@ -48,14 +48,11 @@ export const collabPollVoteRequestSchema = z.object({
 });
 export type CollabPollVoteRequest = z.infer<typeof collabPollVoteRequestSchema>;
 
-const httpUrl = z.string().trim().min(1).refine((value) => {
-  try {
-    const parsed = new URL(value);
-    return parsed.protocol === 'http:' || parsed.protocol === 'https:';
-  } catch {
-    return false;
-  }
-}, 'A valid http(s) URL is required');
+// `z.url()` rather than `new URL(...)`: this package compiles against lib
+// ES2022 only, deliberately, so it stays free of both DOM and Node globals and
+// `URL` is not one of the names it has. The protocol check stays, because
+// z.url() alone would accept mailto: and javascript:.
+const httpUrl = z.url().refine((value) => /^https?:\/\//i.test(value.trim()), 'A valid http(s) URL is required');
 
 export const collabLinkCreateRequestSchema = z.object({
   title: z.string().trim().min(1),
diff --git a/shared/src/realtime/events.schema.spec.ts b/shared/src/realtime/events.schema.spec.ts
index 27884ece2..826c5373b 100644
--- a/shared/src/realtime/events.schema.spec.ts
+++ b/shared/src/realtime/events.schema.spec.ts
@@ -73,6 +73,9 @@ const FIXTURES: Record<TrekWsEventName, Record<string, unknown>> = {
   'collab:note:created': { note: { id: 3 } },
   'collab:note:updated': { note: { id: 3 } },
   'collab:note:deleted': { noteId: 3 },
+  'collab:link:created': { link: { id: 4, title: 'Ferry', url: 'https://example.com' } },
+  'collab:link:updated': { link: { id: 4, title: 'Ferry', url: 'https://example.com' } },
+  'collab:link:deleted': { linkId: 4 },
   'collab:poll:created': { poll: { id: 2 } },
   'collab:poll:voted': { poll: { id: 2 } },
   'collab:poll:closed': { poll: { id: 2 } },
@@ -135,11 +138,11 @@ const DRIFT_VARIANTS: Partial<Record<TrekWsEventName, Record<string, unknown>[]>
 };
 
 describe('@trek/shared realtime event registry', () => {
-  it('WSEVT-REG-001: pins the authoritative inventory counts (66 trip + 32 user = 98)', () => {
-    // 66th trip event: packing:bag-totals (#2191).
-    expect(TREK_WS_TRIP_EVENT_NAMES).toHaveLength(66);
+  it('WSEVT-REG-001: pins the authoritative inventory counts (69 trip + 32 user = 101)', () => {
+    // 67th to 69th trip event: the three collab:link:* a shared link emits.
+    expect(TREK_WS_TRIP_EVENT_NAMES).toHaveLength(69);
     expect(TREK_WS_USER_EVENT_NAMES).toHaveLength(32);
-    expect(TREK_WS_EVENT_NAMES).toHaveLength(98);
+    expect(TREK_WS_EVENT_NAMES).toHaveLength(101);
   });
 
   it('WSEVT-REG-002: every name is domain:action shaped and outside the reserved plugin: namespace', () => {