diff --git a/server.ts b/server.ts
index 270db7e..92815e4 100644
--- a/server.ts
+++ b/server.ts
@@ -533,23 +533,37 @@ app.get('/api/tasks/list', async (c) => {
     }
 
     const baseFields = 'id,user,title,startDate,dueDate,priority,completed,content,size,status,owner,assigned_to,user_name,Username,expand.user.id,expand.user.email,expand.user.name,expand.user.username';
-    const fetchAllTasks = async () => {
+    const fetchTasksByRelationIds = async (userIds: string[]) => {
+      const ids = Array.from(new Set(userIds.map((id) => String(id || '').trim()).filter(Boolean)));
+      if (!ids.length) return [];
+      const relationFilter = ids.map((id) => `user = "${id.replace(/"/g, '\\"')}"`).join(' || ');
       return taskPb.collection(PB_TASKS_COLLECTION).getFullList({
+        filter: relationFilter,
         sort: '-startDate,-created',
         expand: 'user',
         fields: baseFields,
       });
     };
 
-    const matchTaskByName = (task: any, name: string): boolean => {
-      const target = String(name || '').trim().toLowerCase();
-      if (!target) return false;
-      const taskUserDisplay = String(task?.expand?.user?.name || task?.expand?.user?.username || task?.expand?.user?.email || '').trim().toLowerCase();
-      const taskUserRaw = String(task?.user || '').trim().toLowerCase();
-      const owner = String(task?.owner || '').trim().toLowerCase();
-      const assignedTo = String(task?.assigned_to || '').trim().toLowerCase();
-      const userName = String(task?.user_name || task?.Username || '').trim().toLowerCase();
-      return [taskUserDisplay, taskUserRaw, owner, assignedTo, userName].some((v) => v && v === target);
+    const resolveUserIdsByName = async (name: string): Promise<string[]> => {
+      const target = String(name || '').trim();
+      if (!target) return [];
+
+      const escaped = target.replace(/"/g, '\\"');
+      const matched = await taskPb.collection(PB_AUTH_COLLECTION).getFullList({
+        filter: `name = "${escaped}"`,
+        fields: 'id,name,email,username',
+      });
+
+      if (matched.length) {
+        return matched.map((user: any) => String(user.id || '').trim()).filter(Boolean);
+      }
+
+      if (meId && target === meName) {
+        return [meId];
+      }
+
+      return [];
     };
 
     let records: any[] = [];
@@ -557,14 +571,26 @@ app.get('/api/tasks/list', async (c) => {
     let effectiveUserId = requestedUserId || meId;
     let effectiveUserName = targetUserName;
     try {
-      const all = await fetchAllTasks();
       if (targetUserName) {
-        records = all.filter((task: any) => matchTaskByName(task, targetUserName));
+        const targetUserIds = await resolveUserIdsByName(targetUserName);
+        if (!targetUserIds.length) {
+          warning = `No Users record matched name "${targetUserName}".`;
+          records = [];
+        } else {
+          records = await fetchTasksByRelationIds(targetUserIds);
+          if (!records.length) {
+            warning = `No accessible Tasgird tasks matched Users.name "${targetUserName}".`;
+          }
+          effectiveUserId = targetUserIds[0] || effectiveUserId;
+        }
       } else if (requestedUserId || meId) {
         const fallbackId = String(requestedUserId || meId).trim();
-        records = all.filter((task: any) => String(task?.user || '').trim() === fallbackId);
+        records = await fetchTasksByRelationIds([fallbackId]);
+        if (!records.length) {
+          warning = 'No accessible Tasgird tasks matched the current user relation.';
+        }
       } else {
-        records = all;
+        records = [];
       }
     } catch (listErr) {
       const message = (listErr as Error)?.message || String(listErr);
@@ -577,12 +603,6 @@ app.get('/api/tasks/list', async (c) => {
       }, 500);
     }
 
-    if (!records.length) {
-      warning = targetUserName
-        ? `No accessible Tasgird tasks matched user name "${targetUserName}".`
-        : 'No accessible Tasgird tasks matched the current user.';
-    }
-
     return c.json({
       success: true,
       userId: effectiveUserId,
@@ -594,7 +614,7 @@ app.get('/api/tasks/list', async (c) => {
         user: task.user || task.expand?.user?.id || null,
         userDisplay: task.expand?.user
           ? (task.expand.user.name || task.expand.user.username || task.expand.user.email || task.expand.user.id)
-          : null,
+          : (task.user_name || task.Username || task.owner || task.assigned_to || task.user || null),
         title: task.title ?? '',
         startDate: task.startDate ?? null,
         dueDate: task.dueDate ?? null,