From cd04625b13bc1b5505a390a3e3e551b5af8cbcd4 Mon Sep 17 00:00:00 2001
From: 7w1 <noreply@sl.sable.moe>
Date: Fri, 15 May 2026 20:49:16 -0500
Subject: [PATCH] support stable mutual rooms endpoint

---
 .changeset/stable-mutual-rooms-endpoint.md    |  5 ++
 src/app/components/user-profile/UserChips.tsx |  9 ++-
 src/app/hooks/useMutualRooms.ts               | 58 +++++++++++++++++--
 3 files changed, 64 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/stable-mutual-rooms-endpoint.md

diff --git a/.changeset/stable-mutual-rooms-endpoint.md b/.changeset/stable-mutual-rooms-endpoint.md
new file mode 100644
index 000000000..4c19da8db
--- /dev/null
+++ b/.changeset/stable-mutual-rooms-endpoint.md
@@ -0,0 +1,5 @@
+---
+default: patch
+---
+
+Add support for stable mutual rooms endpoint.
diff --git a/src/app/components/user-profile/UserChips.tsx b/src/app/components/user-profile/UserChips.tsx
index 168a973e5..2adeb5fbe 100644
--- a/src/app/components/user-profile/UserChips.tsx
+++ b/src/app/components/user-profile/UserChips.tsx
@@ -30,7 +30,11 @@ import { copyToClipboard } from '$utils/dom';
 import { getExploreServerPath } from '$pages/pathUtils';
 import { AsyncStatus, useAsyncCallback } from '$hooks/useAsyncCallback';
 import { factoryRoomIdByAtoZ } from '$utils/sort';
-import { useMutualRooms, useMutualRoomsSupport } from '$hooks/useMutualRooms';
+import {
+  useMutualRooms,
+  useMutualRoomsSupport,
+  useUnstableMutualRoomsSupport,
+} from '$hooks/useMutualRooms';
 import { useRoomNavigate } from '$hooks/useRoomNavigate';
 import { useDirectRooms } from '$pages/client/direct/useDirectRooms';
 import { useMediaAuthentication } from '$hooks/useMediaAuthentication';
@@ -352,6 +356,7 @@ export function MutualRoomsChip({
   const menuItemBg = chipFillColor ?? cardColor;
   const mx = useMatrixClient();
   const mutualRoomSupported = useMutualRoomsSupport();
+  const mutualRoomUnstable = useUnstableMutualRoomsSupport();
   const mutualRoomsState = useMutualRooms(userId);
   const { navigateRoom, navigateSpace } = useRoomNavigate();
   const closeUserRoomProfile = useCloseUserRoomProfile();
@@ -398,7 +403,7 @@ export function MutualRoomsChip({
 
   if (
     userId === mx.getSafeUserId() ||
-    !mutualRoomSupported ||
+    (!mutualRoomSupported && !mutualRoomUnstable) ||
     mutualRoomsState.status === AsyncStatus.Error
   ) {
     return null;
diff --git a/src/app/hooks/useMutualRooms.ts b/src/app/hooks/useMutualRooms.ts
index fe464ba57..7d95d7b2a 100644
--- a/src/app/hooks/useMutualRooms.ts
+++ b/src/app/hooks/useMutualRooms.ts
@@ -1,10 +1,12 @@
 import { useCallback } from 'react';
+import type { MatrixClient } from '$types/matrix-sdk';
+import { Method } from '$types/matrix-sdk';
 import { useMatrixClient } from './useMatrixClient';
 import type { AsyncState } from './useAsyncCallback';
 import { useAsyncCallbackValue } from './useAsyncCallback';
 import { useSpecVersions } from './useSpecVersions';
 
-export const useMutualRoomsSupport = (): boolean => {
+export const useUnstableMutualRoomsSupport = (): boolean => {
   const { unstable_features: unstableFeatures } = useSpecVersions();
 
   const supported =
@@ -15,16 +17,60 @@ export const useMutualRoomsSupport = (): boolean => {
   return !!supported;
 };
 
+export const useMutualRoomsSupport = (): boolean => {
+  const { unstable_features: unstableFeatures, versions } = useSpecVersions();
+
+  const supported =
+    versions.includes('v1.19') ||
+    !!unstableFeatures?.['uk.half-shot.msc2666.query_mutual_rooms.stable'];
+
+  return supported;
+};
+
+type MutualRoomsOK = {
+  joined: string[];
+  next_batch?: string;
+  count: number;
+};
+
+const fetchAllMutualRooms = async (mx: MatrixClient, userId: string): Promise<string[]> => {
+  const mutualRooms: Set<string> = new Set();
+
+  const collectFrom = async (nextBatch?: string): Promise<void> => {
+    const result = await mx.http.authedRequest<MutualRoomsOK>(
+      Method.Get,
+      '/mutual_rooms',
+      {
+        user_id: userId,
+        from: nextBatch,
+      },
+      undefined,
+      {
+        prefix: '/_matrix/client/v1',
+      }
+    );
+    result.joined.forEach((r) => mutualRooms.add(r));
+    if (typeof result.next_batch === 'string') {
+      await collectFrom(result.next_batch);
+    }
+  };
+
+  await collectFrom();
+  return Array.from(mutualRooms);
+};
+
 export const useMutualRooms = (userId: string): AsyncState<string[]> => {
   const mx = useMatrixClient();
 
-  const supported = useMutualRoomsSupport();
+  const unstableSupport = useUnstableMutualRoomsSupport();
+  const support = useMutualRoomsSupport();
 
   const [mutualRoomsState] = useAsyncCallbackValue(
-    useCallback(
-      () => (supported ? mx._unstable_getSharedRooms(userId) : Promise.resolve([])),
-      [mx, userId, supported]
-    )
+    useCallback(() => {
+      if (support) return fetchAllMutualRooms(mx, userId);
+      if (unstableSupport) return mx._unstable_getSharedRooms(userId);
+      return Promise.resolve([]);
+    }, [mx, userId, unstableSupport, support])
   );
 
   return mutualRoomsState;