6 files changed, 16 insertions, 2 deletions
diff --git a/synapse/handlers/admin.py b/synapse/handlers/admin.py
index 0e812a6d8b..2f0e5f3b0a 100644
--- a/synapse/handlers/admin.py
+++ b/synapse/handlers/admin.py
@@ -76,6 +76,7 @@ class AdminHandler:
             "consent_ts",
             "user_type",
             "is_guest",
+            "last_seen_ts",
         }
 
         if self._msc3866_enabled:
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index 625a47ec1a..91898a5c13 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -132,6 +132,7 @@ class UsersRestServletV2(RestServlet):
                 UserSortOrder.AVATAR_URL.value,
                 UserSortOrder.SHADOW_BANNED.value,
                 UserSortOrder.CREATION_TS.value,
+                UserSortOrder.LAST_SEEN_TS.value,
             ),
         )
 
diff --git a/synapse/storage/databases/main/__init__.py b/synapse/storage/databases/main/__init__.py
index a85633efcd..0836e247ef 100644
--- a/synapse/storage/databases/main/__init__.py
+++ b/synapse/storage/databases/main/__init__.py
@@ -277,6 +277,10 @@ class DataStore(
                 FROM users as u
                 LEFT JOIN profiles AS p ON u.name = p.full_user_id
                 LEFT JOIN erased_users AS eu ON u.name = eu.user_id
+                LEFT JOIN (
+                    SELECT user_id, MAX(last_seen) AS last_seen_ts
+                    FROM user_ips GROUP BY user_id
+                ) ls ON u.name = ls.user_id
                 {where_clause}
                 """
             sql = "SELECT COUNT(*) as total_users " + sql_base
@@ -286,7 +290,7 @@ class DataStore(
             sql = f"""
                 SELECT name, user_type, is_guest, admin, deactivated, shadow_banned,
                 displayname, avatar_url, creation_ts * 1000 as creation_ts, approved,
-                eu.user_id is not null as erased
+                eu.user_id is not null as erased, last_seen_ts
                 {sql_base}
                 ORDER BY {order_by_column} {order}, u.name ASC
                 LIMIT ? OFFSET ?
diff --git a/synapse/storage/databases/main/registration.py b/synapse/storage/databases/main/registration.py
index d3a01d526f..7e85b73e8e 100644
--- a/synapse/storage/databases/main/registration.py
+++ b/synapse/storage/databases/main/registration.py
@@ -206,8 +206,12 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
                     consent_server_notice_sent, appservice_id, creation_ts, user_type,
                     deactivated, COALESCE(shadow_banned, FALSE) AS shadow_banned,
                     COALESCE(approved, TRUE) AS approved,
-                    COALESCE(locked, FALSE) AS locked
+                    COALESCE(locked, FALSE) AS locked, last_seen_ts
                 FROM users
+                LEFT JOIN (
+                    SELECT user_id, MAX(last_seen) AS last_seen_ts
+                    FROM user_ips GROUP BY user_id
+                ) ls ON users.name = ls.user_id
                 WHERE name = ?
                 """,
                 (user_id,),
@@ -268,6 +272,7 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
             is_shadow_banned=bool(user_data["shadow_banned"]),
             user_id=UserID.from_string(user_data["name"]),
             user_type=user_data["user_type"],
+            last_seen_ts=user_data["last_seen_ts"],
         )
 
     async def is_trial_user(self, user_id: str) -> bool:
diff --git a/synapse/storage/databases/main/stats.py b/synapse/storage/databases/main/stats.py
index 6298f0984d..3a2966b9e4 100644
--- a/synapse/storage/databases/main/stats.py
+++ b/synapse/storage/databases/main/stats.py
@@ -107,6 +107,7 @@ class UserSortOrder(Enum):
     AVATAR_URL = "avatar_url"
     SHADOW_BANNED = "shadow_banned"
     CREATION_TS = "creation_ts"
+    LAST_SEEN_TS = "last_seen_ts"
 
 
 class StatsStore(StateDeltasStore):
diff --git a/synapse/types/__init__.py b/synapse/types/__init__.py
index e750417189..488714f60c 100644
--- a/synapse/types/__init__.py
+++ b/synapse/types/__init__.py
@@ -946,6 +946,7 @@ class UserInfo:
         is_guest:  True if the user is a guest user.
         is_shadow_banned:  True if the user has been shadow-banned.
         user_type:  User type (None for normal user, 'support' and 'bot' other options).
+        last_seen_ts:  Last activity timestamp of the user.
     """
 
     user_id: UserID
@@ -958,6 +959,7 @@ class UserInfo:
     is_deactivated: bool
     is_guest: bool
     is_shadow_banned: bool
+    last_seen_ts: Optional[int]
 
 
 class UserProfile(TypedDict):