diff --git a/src/api/toolchain_routes.py b/src/api/toolchain_routes.py
index 504e884..cb443ee 100644
--- a/src/api/toolchain_routes.py
+++ b/src/api/toolchain_routes.py
@@ -489,6 +489,13 @@ async def gitea_webhook(
         logger.warning("Failed to parse webhook payload")
         return Response(status_code=200, content="invalid payload")
 
+    # 2. 幂等检查（需要在 payload 解析后，以支持内容去重）
+    if x_gitea_event and x_gitea_delivery:
+        async with _idempotency_lock:
+            if _is_duplicate(x_gitea_event, x_gitea_delivery, payload):
+                logger.debug("Duplicate webhook: %s/%s", x_gitea_event, x_gitea_delivery)
+                return Response(status_code=200, content="duplicate")
+
     # 4. 查找 handler
     handler = _EVENT_HANDLERS.get(x_gitea_event or "")
     if not handler: