diff --git a/packages/web/src/hooks/useWebSocket.ts b/packages/web/src/hooks/useWebSocket.ts
index 24598a5a..8da872b5 100644
--- a/packages/web/src/hooks/useWebSocket.ts
+++ b/packages/web/src/hooks/useWebSocket.ts
@@ -1,6 +1,6 @@
 import React, { useEffect, useRef } from 'react';
 import { useAuthStore } from '../stores/authStore';
-import { useSpaceStore, getChannelOrigin, getMyUserIdForOrigin } from '../stores/spaceStore';
+import { useSpaceStore, getChannelOrigin, getMyUserIdForOrigin, setMyUserIdForOrigin } from '../stores/spaceStore';
 import { useChatStore } from '../stores/chatStore';
 import { useVoiceStore } from '../stores/voiceStore';
 import { useSocialStore } from '../stores/socialStore';
@@ -109,6 +109,11 @@ function handleEvent(origin: string, event: ServerEvent): void {
 
       populateFromReady(origin, event.spaces, event.folders, event.dmChannels);
 
+      // Cache authoritative identity for this origin (federation-safe)
+      if (!isHome) {
+        setMyUserIdForOrigin(origin, event.user.id);
+      }
+
       // Mark remote instance as connected in instanceStore
       if (!isHome) {
         import('../stores/instanceStore').then(({ useInstanceStore }) => {
diff --git a/packages/web/src/stores/spaceStore.ts b/packages/web/src/stores/spaceStore.ts
index 8af956be..97986178 100644
--- a/packages/web/src/stores/spaceStore.ts
+++ b/packages/web/src/stores/spaceStore.ts
@@ -592,6 +592,14 @@ export function setUserIdForOriginResolver(resolver: (origin: string) => string
   _getUserIdForOrigin = resolver;
 }
 
+// Direct identity cache populated from WS ready events.
+// Bypasses the instanceStore resolver for reliable federation support.
+const _myUserIdByOrigin = new Map<string, string>();
+
+export function setMyUserIdForOrigin(origin: string, userId: string): void {
+  _myUserIdByOrigin.set(origin, userId);
+}
+
 /**
  * Returns the local user's ID on a given instance origin.
  * '' or falsy = home instance (returns authStore user ID).
@@ -599,5 +607,9 @@ export function setUserIdForOriginResolver(resolver: (origin: string) => string
  */
 export function getMyUserIdForOrigin(origin: string): string | undefined {
   if (!origin) return useAuthStore.getState().user?.id;
+  // Direct cache (populated from WS ready) takes priority — always correct
+  const cached = _myUserIdByOrigin.get(origin);
+  if (cached) return cached;
+  // Fallback to instanceStore resolver (may have placeholder user during connection)
   return _getUserIdForOrigin?.(origin);
 }