diff --git a/ai-service-admin/src/api/mid-platform.ts b/ai-service-admin/src/api/mid-platform.ts
index c9a87b5..9ec7f80 100644
--- a/ai-service-admin/src/api/mid-platform.ts
+++ b/ai-service-admin/src/api/mid-platform.ts
@@ -146,6 +146,20 @@ export interface SharedSessionInfo {
   history: DialogueMessage[]
 }
 
+export interface CreatePublicShareTokenRequest {
+  tenant_id?: string
+  api_key?: string
+  session_id: string
+  user_id?: string
+  expires_in_minutes?: number
+}
+
+export interface CreatePublicShareTokenResponse {
+  share_token: string
+  share_url: string
+  expires_at: string
+}
+
 export function createShare(sessionId: string, data: CreateShareRequest = {}): Promise<ShareResponse> {
   return request({
     url: `/mid/sessions/${sessionId}/share`,
@@ -154,6 +168,14 @@ export function createShare(sessionId: string, data: CreateShareRequest = {}): P
   })
 }
 
+export function createPublicShareToken(data: CreatePublicShareTokenRequest): Promise<CreatePublicShareTokenResponse> {
+  return request({
+    url: '/openapi/v1/share/token',
+    method: 'post',
+    data
+  })
+}
+
 export function getSharedSession(shareToken: string): Promise<SharedSessionInfo> {
   return request({
     url: `/mid/share/${shareToken}`,
diff --git a/ai-service/app/api/mid/share.py b/ai-service/app/api/mid/share.py
index 3e1f329..26221c6 100644
--- a/ai-service/app/api/mid/share.py
+++ b/ai-service/app/api/mid/share.py
@@ -33,8 +33,15 @@ settings = get_settings()
 
 
 def _utcnow() -> datetime:
-    """Get current UTC time with timezone info."""
-    return datetime.now(timezone.utc)
+    """Get current UTC time without timezone info (for DB compatibility)."""
+    return datetime.utcnow()
+
+
+def _normalize_datetime(dt: datetime) -> datetime:
+    """Normalize datetime to offset-naive UTC for comparison."""
+    if dt.tzinfo is not None:
+        return dt.replace(tzinfo=None)
+    return dt
 
 
 def _generate_share_url(share_token: str) -> str:
@@ -136,7 +143,7 @@ async def get_shared_session(
     if not shared.is_active:
         raise HTTPException(status_code=410, detail="Share is inactive")
     
-    if shared.expires_at < _utcnow():
+    if _normalize_datetime(shared.expires_at) < _utcnow():
         raise HTTPException(status_code=410, detail="Share has expired")
     
     if shared.current_users >= shared.max_concurrent_users:
@@ -216,7 +223,7 @@ async def list_shares(
             title=s.title,
             description=s.description,
             expires_at=s.expires_at.isoformat(),
-            is_active=s.is_active and s.expires_at > now,
+            is_active=s.is_active and _normalize_datetime(s.expires_at) > now,
             max_concurrent_users=s.max_concurrent_users,
             current_users=s.current_users,
             created_at=s.created_at.isoformat(),
@@ -303,7 +310,7 @@ async def join_shared_session(
     if not shared.is_active:
         raise HTTPException(status_code=410, detail="Share is inactive")
     
-    if shared.expires_at < _utcnow():
+    if _normalize_datetime(shared.expires_at) < _utcnow():
         raise HTTPException(status_code=410, detail="Share has expired")
     
     if shared.current_users >= shared.max_concurrent_users:
@@ -410,7 +417,7 @@ async def send_shared_message(
     if not shared.is_active:
         raise HTTPException(status_code=410, detail="Share is inactive")
     
-    if shared.expires_at < _utcnow():
+    if _normalize_datetime(shared.expires_at) < _utcnow():
         raise HTTPException(status_code=410, detail="Share has expired")
     
     user_message = ChatMessage(